Commit Graph

37230 Commits

Author SHA1 Message Date
Stanislav Fomichev
f0dce1d9b7 bpf: Use kvmalloc for map values in syscall
Use kvmalloc/kvfree for temporary value when manipulating a map via
syscall. kmalloc might not be sufficient for percpu maps where the value
is big (and further multiplied by hundreds of CPUs).

Can be reproduced with netcnt test on qemu with "-smp 255".

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210818235216.1159202-1-sdf@google.com
2021-08-20 00:09:38 +02:00
Linus Torvalds
f87d64319e Networking fixes for 5.14-rc7, including fixes from bpf, wireless and
mac80211 trees.
 
 Current release - regressions:
 
  - tipc: call tipc_wait_for_connect only when dlen is not 0
 
  - mac80211: fix locking in ieee80211_restart_work()
 
 Current release - new code bugs:
 
  - bpf: add rcu_read_lock in bpf_get_current_[ancestor_]cgroup_id()
 
  - ethernet: ice: fix perout start time rounding
 
  - wwan: iosm: prevent underflow in ipc_chnl_cfg_get()
 
 Previous releases - regressions:
 
  - bpf: clear zext_dst of dead insns
 
  - sch_cake: fix srchost/dsthost hashing mode
 
  - vrf: reset skb conntrack connection on VRF rcv
 
  - net/rds: dma_map_sg is entitled to merge entries
 
 Previous releases - always broken:
 
  - ethernet: bnxt: fix Tx path locking and races, add Rx path barriers
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes, including fixes from bpf, wireless and mac80211
  trees.

  Current release - regressions:

   - tipc: call tipc_wait_for_connect only when dlen is not 0

   - mac80211: fix locking in ieee80211_restart_work()

  Current release - new code bugs:

   - bpf: add rcu_read_lock in bpf_get_current_[ancestor_]cgroup_id()

   - ethernet: ice: fix perout start time rounding

   - wwan: iosm: prevent underflow in ipc_chnl_cfg_get()

  Previous releases - regressions:

   - bpf: clear zext_dst of dead insns

   - sch_cake: fix srchost/dsthost hashing mode

   - vrf: reset skb conntrack connection on VRF rcv

   - net/rds: dma_map_sg is entitled to merge entries

  Previous releases - always broken:

   - ethernet: bnxt: fix Tx path locking and races, add Rx path
     barriers"

* tag 'net-5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (42 commits)
  net: dpaa2-switch: disable the control interface on error path
  Revert "flow_offload: action should not be NULL when it is referenced"
  iavf: Fix ping is lost after untrusted VF had tried to change MAC
  i40e: Fix ATR queue selection
  r8152: fix the maximum number of PLA bp for RTL8153C
  r8152: fix writing USB_BP2_EN
  mptcp: full fully established support after ADD_ADDR
  mptcp: fix memory leak on address flush
  net/rds: dma_map_sg is entitled to merge entries
  net: mscc: ocelot: allow forwarding from bridge ports to the tag_8021q CPU port
  net: asix: fix uninit value bugs
  ovs: clear skb->tstamp in forwarding path
  net: mdio-mux: Handle -EPROBE_DEFER correctly
  net: mdio-mux: Don't ignore memory allocation errors
  net: mdio-mux: Delete unnecessary devm_kfree
  net: dsa: sja1105: fix use-after-free after calling of_find_compatible_node, or worse
  sch_cake: fix srchost/dsthost hashing mode
  ixgbe, xsk: clean up the resources in ixgbe_xsk_pool_enable error path
  net: qlcnic: add missed unlock in qlcnic_83xx_flash_read32
  mac80211: fix locking in ieee80211_restart_work()
  ...
2021-08-19 12:33:43 -07:00
Yonghong Song
594286b757 bpf: Fix NULL event->prog pointer access in bpf_overflow_handler
Andrii reported that libbpf CI hit the following oops when
running selftest send_signal:
  [ 1243.160719] BUG: kernel NULL pointer dereference, address: 0000000000000030
  [ 1243.161066] #PF: supervisor read access in kernel mode
  [ 1243.161066] #PF: error_code(0x0000) - not-present page
  [ 1243.161066] PGD 0 P4D 0
  [ 1243.161066] Oops: 0000 [#1] PREEMPT SMP NOPTI
  [ 1243.161066] CPU: 1 PID: 882 Comm: new_name Tainted: G           O      5.14.0-rc5 #1
  [ 1243.161066] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
  [ 1243.161066] RIP: 0010:bpf_overflow_handler+0x9a/0x1e0
  [ 1243.161066] Code: 5a 84 c0 0f 84 06 01 00 00 be 66 02 00 00 48 c7 c7 6d 96 07 82 48 8b ab 18 05 00 00 e8 df 55 eb ff 66 90 48 8d 75 48 48 89 e7 <ff> 55 30 41 89 c4 e8 fb c1 f0 ff 84 c0 0f 84 94 00 00 00 e8 6e 0f
  [ 1243.161066] RSP: 0018:ffffc900000c0d80 EFLAGS: 00000046
  [ 1243.161066] RAX: 0000000000000002 RBX: ffff8881002e0dd0 RCX: 00000000b4b47cf8
  [ 1243.161066] RDX: ffffffff811dcb06 RSI: 0000000000000048 RDI: ffffc900000c0d80
  [ 1243.161066] RBP: 0000000000000000 R08: 0000000000000000 R09: 1a9d56bb00000000
  [ 1243.161066] R10: 0000000000000001 R11: 0000000000080000 R12: 0000000000000000
  [ 1243.161066] R13: ffffc900000c0e00 R14: ffffc900001c3c68 R15: 0000000000000082
  [ 1243.161066] FS:  00007fc0be2d3380(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000
  [ 1243.161066] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 1243.161066] CR2: 0000000000000030 CR3: 0000000104f8e000 CR4: 00000000000006e0
  [ 1243.161066] Call Trace:
  [ 1243.161066]  <IRQ>
  [ 1243.161066]  __perf_event_overflow+0x4f/0xf0
  [ 1243.161066]  perf_swevent_hrtimer+0x116/0x130
  [ 1243.161066]  ? __lock_acquire+0x378/0x2730
  [ 1243.161066]  ? __lock_acquire+0x372/0x2730
  [ 1243.161066]  ? lock_is_held_type+0xd5/0x130
  [ 1243.161066]  ? find_held_lock+0x2b/0x80
  [ 1243.161066]  ? lock_is_held_type+0xd5/0x130
  [ 1243.161066]  ? perf_event_groups_first+0x80/0x80
  [ 1243.161066]  ? perf_event_groups_first+0x80/0x80
  [ 1243.161066]  __hrtimer_run_queues+0x1a3/0x460
  [ 1243.161066]  hrtimer_interrupt+0x110/0x220
  [ 1243.161066]  __sysvec_apic_timer_interrupt+0x8a/0x260
  [ 1243.161066]  sysvec_apic_timer_interrupt+0x89/0xc0
  [ 1243.161066]  </IRQ>
  [ 1243.161066]  asm_sysvec_apic_timer_interrupt+0x12/0x20
  [ 1243.161066] RIP: 0010:finish_task_switch+0xaf/0x250
  [ 1243.161066] Code: 31 f6 68 90 2a 09 81 49 8d 7c 24 18 e8 aa d6 03 00 4c 89 e7 e8 12 ff ff ff 4c 89 e7 e8 ca 9c 80 00 e8 35 af 0d 00 fb 4d 85 f6 <58> 74 1d 65 48 8b 04 25 c0 6d 01 00 4c 3b b0 a0 04 00 00 74 37 f0
  [ 1243.161066] RSP: 0018:ffffc900001c3d18 EFLAGS: 00000282
  [ 1243.161066] RAX: 000000000000031f RBX: ffff888104cf4980 RCX: 0000000000000000
  [ 1243.161066] RDX: 0000000000000000 RSI: ffffffff82095460 RDI: ffffffff820adc4e
  [ 1243.161066] RBP: ffffc900001c3d58 R08: 0000000000000001 R09: 0000000000000001
  [ 1243.161066] R10: 0000000000000001 R11: 0000000000080000 R12: ffff88813bd2bc80
  [ 1243.161066] R13: ffff8881002e8000 R14: ffff88810022ad80 R15: 0000000000000000
  [ 1243.161066]  ? finish_task_switch+0xab/0x250
  [ 1243.161066]  ? finish_task_switch+0x70/0x250
  [ 1243.161066]  __schedule+0x36b/0xbb0
  [ 1243.161066]  ? _raw_spin_unlock_irqrestore+0x2d/0x50
  [ 1243.161066]  ? lockdep_hardirqs_on+0x79/0x100
  [ 1243.161066]  schedule+0x43/0xe0
  [ 1243.161066]  pipe_read+0x30b/0x450
  [ 1243.161066]  ? wait_woken+0x80/0x80
  [ 1243.161066]  new_sync_read+0x164/0x170
  [ 1243.161066]  vfs_read+0x122/0x1b0
  [ 1243.161066]  ksys_read+0x93/0xd0
  [ 1243.161066]  do_syscall_64+0x35/0x80
  [ 1243.161066]  entry_SYSCALL_64_after_hwframe+0x44/0xae

The oops can also be reproduced with the following steps:
  ./vmtest.sh -s
  # at qemu shell
  cd /root/bpf && while true; do ./test_progs -t send_signal

Further analysis showed that the failure is introduced with
commit b89fbfbb85 ("bpf: Implement minimal BPF perf link").
With the above commit, the following scenario becomes possible:
    cpu1                        cpu2
                                hrtimer_interrupt -> bpf_overflow_handler
    (due to closing link_fd)
    bpf_perf_link_release ->
    perf_event_free_bpf_prog ->
    perf_event_free_bpf_handler ->
      WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler)
      event->prog = NULL
                                bpf_prog_run(event->prog, &ctx)

In the above case, the event->prog is NULL for bpf_prog_run, hence
causing oops.

To fix the issue, check whether event->prog is NULL or not. If it
is, do not call bpf_prog_run. This seems working as the above
reproducible step runs more than one hour and I didn't see any
failures.

Fixes: b89fbfbb85 ("bpf: Implement minimal BPF perf link")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210819155209.1927994-1-yhs@fb.com
2021-08-19 11:49:19 -07:00
Daniel Borkmann
f9dabe016b bpf: Undo off-by-one in interpreter tail call count limit
The BPF interpreter as well as x86-64 BPF JIT were both in line by allowing
up to 33 tail calls (however odd that number may be!). Recently, this was
changed for the interpreter to reduce it down to 32 with the assumption that
this should have been the actual limit "which is in line with the behavior of
the x86 JITs" according to b61a28cf11 ("bpf: Fix off-by-one in tail call
count limiting").

Paul recently reported:

  I'm a bit surprised by this because I had previously tested the tail call
  limit of several JIT compilers and found it to be 33 (i.e., allowing chains
  of up to 34 programs). I've just extended a test program I had to validate
  this again on the x86-64 JIT, and found a limit of 33 tail calls again [1].

  Also note we had previously changed the RISC-V and MIPS JITs to allow up to
  33 tail calls [2, 3], for consistency with other JITs and with the interpreter.
  We had decided to increase these two to 33 rather than decrease the other
  JITs to 32 for backward compatibility, though that probably doesn't matter
  much as I'd expect few people to actually use 33 tail calls.

  [1] ae78874829
  [2] 96bc4432f5 ("bpf, riscv: Limit to 33 tail calls")
  [3] e49e6f6db0 ("bpf, mips: Limit to 33 tail calls")

Therefore, revert b61a28cf11 to re-align interpreter to limit a maximum of
33 tail calls. While it is unlikely to hit the limit for the vast majority,
programs in the wild could one way or another depend on this, so lets rather
be a bit more conservative, and lets align the small remainder of JITs to 33.
If needed in future, this limit could be slightly increased, but not decreased.

Fixes: b61a28cf11 ("bpf: Fix off-by-one in tail call count limiting")
Reported-by: Paul Chaignon <paul@cilium.io>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/CAO5pjwTWrC0_dzTbTHFPSqDwA56aVH+4KFGVqdq8=ASs0MqZGQ@mail.gmail.com
2021-08-19 18:33:37 +02:00
Jakub Kicinski
316749009f Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2021-08-19

We've added 3 non-merge commits during the last 3 day(s) which contain
a total of 3 files changed, 29 insertions(+), 6 deletions(-).

The main changes are:

1) Fix to clear zext_dst for dead instructions which was causing invalid program
   rejections on JITs with bpf_jit_needs_zext such as s390x, from Ilya Leoshkevich.

2) Fix RCU splat in bpf_get_current_{ancestor_,}cgroup_id() helpers when they are
   invoked from sleepable programs, from Yonghong Song.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests, bpf: Test that dead ldx_w insns are accepted
  bpf: Clear zext_dst of dead insns
  bpf: Add rcu_read_lock in bpf_get_current_[ancestor_]cgroup_id() helpers
====================

Link: https://lore.kernel.org/r/20210819144904.20069-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-19 08:58:17 -07:00
Masami Hiramatsu
8e242060c6 tracing/probes: Reject events which have the same name of existing one
Since kprobe_events and uprobe_events only check whether the
other same-type probe event has the same name or not, if the
user gives the same name of the existing tracepoint event (or
the other type of probe events), it silently fails to create
the tracefs entry (but registered.) as below.

/sys/kernel/tracing # ls events/task/task_rename
enable   filter   format   hist     id       trigger
/sys/kernel/tracing # echo p:task/task_rename vfs_read >> kprobe_events
[  113.048508] Could not create tracefs 'task_rename' directory
/sys/kernel/tracing # cat kprobe_events
p:task/task_rename vfs_read

To fix this issue, check whether the existing events have the
same name or not in trace_probe_register_event_call(). If exists,
it rejects to register the new event.

Link: https://lkml.kernel.org/r/162936876189.187130.17558311387542061930.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 09:15:19 -04:00
Steven Rostedt (VMware)
8565a45d08 tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs
In preparation to allow event probes to use the process_fetch_insn()
callback in trace_probe_tmpl.h, change the data passed to it from a
pointer to pt_regs, as the event probe will not be using regs, and make it
a void pointer instead.

Update the process_fetch_insn() callers for kprobe and uprobe events to
have the regs defined in the function and just typecast the void pointer
parameter.

Link: https://lkml.kernel.org/r/20210819041842.291622924@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 09:09:03 -04:00
Steven Rostedt (VMware)
007517a019 tracing/probe: Change traceprobe_set_print_fmt() to take a type
Instead of a boolean "is_return" have traceprobe_set_print_fmt() take a
type (currently just PROBE_PRINT_NORMAL and PROBE_PRINT_RETURN). This will
simplify adding different types. For example, the development of the
event_probe, will need its own type as it prints an event, and not an IP.

Link: https://lkml.kernel.org/r/20210819041842.104626301@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 09:08:29 -04:00
Sebastian Andrzej Siewior
1daf08a066 livepatch: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: live-patching@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-08-19 12:00:24 +02:00
Christoph Hellwig
22f9feb499 dma-mapping: make the global coherent pool conditional
Only build the code to support the global coherent pool if support for
it is enabled.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-19 09:02:39 +02:00
Alexey Dobriyan
39f75da7bc isystem: trim/fixup stdarg.h and other headers
Delete/fixup few includes in anticipation of global -isystem compile
option removal.

Note: crypto/aegis128-neon-inner.c keeps <stddef.h> due to redefinition
of uintptr_t error (one definition comes from <stddef.h>, another from
<linux/types.h>).

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-08-19 09:02:55 +09:00
Steven Rostedt (VMware)
845cbf3e11 tracing/probes: Use struct_size() instead of defining custom macros
Remove SIZEOF_TRACE_KPROBE() and SIZEOF_TRACE_UPROBE() and use
struct_size() as that's what it is made for. No need to have custom
macros. Especially since struct_size() has some extra memory checks for
correctness.

Link: https://lkml.kernel.org/r/20210817035027.795000217@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18 18:13:52 -04:00
Steven Rostedt (VMware)
bc1b973455 tracing/probes: Allow for dot delimiter as well as slash for system names
Kprobe and uprobe events can add a "system" to the events that are created
via the kprobe_events and uprobe_events files respectively. If they do not
include a "system" in the name, then the default "kprobes" or "uprobes" is
used. The current notation to specify a system for one of these probe
events is to add a '/' delimiter in the name, where the content before the
'/' will be the system to use, and the content after will be the event
name.

 echo 'p:my_system/my_event' > kprobe_events

But this is inconsistent with the way histogram triggers separate their
system / event names. The histogram triggers use a '.' delimiter, which
can be confusing.

To allow this to be more consistent, as well as keep backward
compatibility, allow the kprobe and uprobe events to denote a system name
with either a '/' or a '.'.

That is:

  echo 'p:my_system/my_event' > kprobe_events

is equivalent to:

  echo 'p:my_system.my_event' > kprobe_events

Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035027.580493202@goodmis.org

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18 18:13:52 -04:00
Steven Rostedt (VMware)
fcd9db51df tracing/probe: Have traceprobe_parse_probe_arg() take a const arg
The two places that call traceprobe_parse_probe_arg() allocate a temporary
buffer to copy the argv[i] into, because argv[i] is constant and the
traceprobe_parse_probe_arg() will modify it to do the parsing. These two
places allocate this buffer and then free it right after calling this
function, leaving the onus of this allocation to the caller.

As there's about to be a third user of this function that will have to do
the same thing, instead of having the caller allocate the temporary
buffer, simply move that allocation into the traceprobe_parse_probe_arg()
itself, which will simplify the code of the callers.

Link: https://lkml.kernel.org/r/20210817035027.385422828@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18 18:13:52 -04:00
Steven Rostedt (VMware)
1d18538e6a tracing: Have dynamic events have a ref counter
As dynamic events are not created by modules, if something is attached to
one, calling "try_module_get()" on its "mod" field, is not going to keep
the dynamic event from going away.

Since dynamic events do not need the "mod" pointer of the event structure,
make a union out of it in order to save memory (there's one structure for
each of the thousand+ events in the kernel), and have any event with the
DYNAMIC flag set to use a ref counter instead.

Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035027.174869074@goodmis.org

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18 18:13:47 -04:00
Steven Rostedt (VMware)
8b0e6c744f tracing: Add DYNAMIC flag for dynamic events
To differentiate between static and dynamic events, add a new flag
DYNAMIC to the event flags that all dynamic events have set. This will
allow to differentiate when attaching to a dynamic event from a static
event.

Static events have a mod pointer that references the module they were
created in (or NULL for core kernel). This can be incremented when the
event has something attached to it. But there exists no such mechanism for
dynamic events. This is dangerous as the dynamic events may now disappear
without the "attachment" knowing that it no longer exists.

To enforce the dynamic flag, change dyn_event_add() to pass the event that
is being created such that it can set the DYNAMIC flag of the event. This
helps make sure that no location that creates a dynamic event misses
setting this flag.

Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035026.936958254@goodmis.org

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-18 18:10:32 -04:00
Linus Torvalds
a83955bdad cfi fix for v5.14-rc7
- Use rcu_read_{un}lock_sched_notrace to avoid recursion (Elliot Berman)
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Merge tag 'cfi-v5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull clang cfi fix from Kees Cook:

 - Use rcu_read_{un}lock_sched_notrace to avoid recursion (Elliot Berman)

* tag 'cfi-v5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  cfi: Use rcu_read_{un}lock_sched_notrace
2021-08-18 11:55:50 -07:00
Christoph Hellwig
39a2d3506b dma-mapping: add a dma_init_global_coherent helper
Add a new helper to initialize the global coherent pool.  This both
cleans up the existing initialization which indirects through the
reserved_mem_ops that are normally only used for struct device, and
also allows using the global pool for non-devicetree architectures.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18 16:24:11 +02:00
Christoph Hellwig
a6933571f3 dma-mapping: simplify dma_init_coherent_memory
Return the allocated dma_coherent_mem structure, set the
use_dma_pfn_offset and print the failure warning inside of
dma_init_coherent_memory instead of leaving that to the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18 16:24:10 +02:00
Christoph Hellwig
70d6aa0ecf dma-mapping: allow using the global coherent pool for !ARM
Switch an ifdef so that the global coherent pool is initialized for
any architecture that selects the DMA_GLOBAL_POOL symbol insted of
hardcoding ARM.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18 16:24:10 +02:00
Christoph Hellwig
faf4ef823a dma-direct: add support for dma_coherent_default_memory
Add an option to allocate uncached memory for dma_alloc_coherent from
the global dma_coherent_default_memory.  This will allow to move
arm-nommu (and eventually other platforms) to use generic code for
allocating uncached memory from a pre-populated pool.

Note that this is a different pool from the one that platforms that
can remap at runtime use for GFP_ATOMIC allocations for now, although
there might be opportunities to eventually end up with a common codebase
for the two use cases.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18 16:24:09 +02:00
Ingo Molnar
7f3b457977 Merge branch 'kcsan' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/debug
Pull KCSAN updates from Paul E. McKenney:

 - improve comments
 - introduce CONFIG_KCSAN_STRICT (which RCU uses)
 - optimize use of get_ctx() by kcsan_found_watchpoint()
 - rework atomic.h into permissive.h
 - add the ability to ignore writes that change only one bit of a given data-racy variable.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-08-18 08:35:23 +02:00
Colin Ian King
8cacfc85b6 bpf: Remove redundant initialization of variable allow
The variable allow is being initialized with a value that is never read, it
is being updated later on. The assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817170842.495440-1-colin.king@canonical.com
2021-08-17 14:09:12 -07:00
Linus Torvalds
614cb2751d tracing: Limit the shooting in the foot of tp_printk
The "tp_printk" option redirects the trace event output to printk at boot
 up. This is useful when a machine crashes before boot where the trace events
 can not be retrieved by the in kernel ring buffer. But it can be "dangerous"
 because trace events can be located in high frequency locations such as
 interrupts and the scheduler, where a printk can slow it down that it live
 locks the machine (because by the time the printk finishes, the next event
 is triggered). Thus tp_printk must be used with care.
 
 It was discovered that the filter logic to trace events does not apply to
 the tp_printk events. This can cause a surprise and live lock when the user
 expects it to be filtered to limit the amount of events printed to the
 console when in fact it still prints everything.
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Merge tag 'trace-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Limit the shooting in the foot of tp_printk

  The "tp_printk" option redirects the trace event output to printk at
  boot up. This is useful when a machine crashes before boot where the
  trace events can not be retrieved by the in kernel ring buffer. But it
  can be "dangerous" because trace events can be located in high
  frequency locations such as interrupts and the scheduler, where a
  printk can slow it down that it live locks the machine (because by the
  time the printk finishes, the next event is triggered). Thus tp_printk
  must be used with care.

  It was discovered that the filter logic to trace events does not apply
  to the tp_printk events. This can cause a surprise and live lock when
  the user expects it to be filtered to limit the amount of events
  printed to the console when in fact it still prints everything"

* tag 'trace-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Apply trace filters on all output channels
2021-08-17 09:47:18 -10:00
Sebastian Andrzej Siewior
99c37d1a63 tracing: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Link: https://lkml.kernel.org/r/20210803141621.780504-37-bigeasy@linutronix.de

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-17 15:47:14 -04:00
Lai Jiangshan
d812796eb3 workqueue: Assign a color to barrier work items
There was no strong reason to or not to flush barrier work items in
flush_workqueue().  And we have to make barrier work items not participate
in nr_active so we had been using WORK_NO_COLOR for them which also makes
them can't be flushed by flush_workqueue().

And the users of flush_workqueue() often do not intend to wait barrier work
items issued by flush_work().  That made the choice sound perfect.

But barrier work items have reference to internal structure (pool_workqueue)
and the worker thread[s] is/are still busy for the workqueue user when the
barrrier work items are not done.  So it is reasonable to make flush_workqueue()
also watch for flush_work() to make it more robust.

And a problem[1] reported by Li Zhe shows that we need such robustness.
The warning logs are listed below:

WARNING: CPU: 0 PID: 19336 at kernel/workqueue.c:4430 destroy_workqueue+0x11a/0x2f0
*****
destroy_workqueue: test_workqueue9 has the following busy pwq
  pwq 4: cpus=2 node=0 flags=0x0 nice=0 active=0/1 refcnt=2
      in-flight: 5658:wq_barrier_func
Showing busy workqueues and worker pools:
*****

It shows that even after drain_workqueue() returns, the barrier work item
is still in flight and the pwq (and a worker) is still busy on it.

The problem is caused by flush_workqueue() not watching flush_work():

Thread A				Worker
					/* normal work item with linked */
					process_scheduled_works()
destroy_workqueue()			  process_one_work()
  drain_workqueue()			    /* run normal work item */
				 /--	    pwq_dec_nr_in_flight()
    flush_workqueue()	    <---/
		/* the last normal work item is done */
  sanity_check				  process_one_work()
				       /--  raw_spin_unlock_irq(&pool->lock)
    raw_spin_lock_irq(&pool->lock)  <-/     /* maybe preempt */
    *WARNING*				    wq_barrier_func()
					    /* maybe preempt by cond_resched() */

Thread A can get the pool lock after the Worker unlocks the pool lock before
running wq_barrier_func().  And if there is any preemption happen around
wq_barrier_func(), destroy_workqueue()'s sanity check is more likely to
get the lock and catch it.  (Note: preemption is not necessary to cause the bug,
the unlocking is enough to possibly trigger the WARNING.)

A simple solution might be just executing all linked barrier work items
once without releasing pool lock after the head work item's
pwq_dec_nr_in_flight().  But this solution has two problems:

  1) the head work item might also be barrier work item when the user-queued
     work item is cancelled. For example:
	thread 1:		thread 2:
	queue_work(wq, &my_work)
	flush_work(&my_work)
				cancel_work_sync(&my_work);
	/* Neiter my_work nor the barrier work is scheduled. */
				destroy_workqueue(wq);
	/* This is an easier way to catch the WARNING. */

  2) there might be too much linked barrier work items and running them
     all once without releasing pool lock just causes trouble.

The only solution is to make flush_workqueue() aslo watch barrier work
items.  So we have to assign a color to these barrier work items which
is the color of the head (user-queued) work item.

Assigning a color doesn't cause any problem in ative management, because
the prvious patch made barrier work items not participate in nr_active
via WORK_STRUCT_INACTIVE rather than reliance on the (old) WORK_NO_COLOR.

[1]: https://lore.kernel.org/lkml/20210812083814.32453-1-lizhe.67@bytedance.com/
Reported-by: Li Zhe <lizhe.67@bytedance.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-17 07:49:10 -10:00
Lai Jiangshan
018f3a13dd workqueue: Mark barrier work with WORK_STRUCT_INACTIVE
Currently, WORK_NO_COLOR has two meanings:
	Not participate in flushing
	Not participate in nr_active

And only non-barrier work items are marked with WORK_STRUCT_INACTIVE
when they are in inactive_works list.  The barrier work items are not
marked INACTIVE even linked in inactive_works list since these tail
items are always moved together with the head work item.

These definitions are simple, clean and practical. (Except a small
blemish that only the first meaning of WORK_NO_COLOR is documented in
include/linux/workqueue.h while both meanings are in workqueue.c)

But dual-purpose WORK_NO_COLOR used for barrier work items has proven to
be problematical[1].  Only the second purpose is obligatory.  So we plan
to make barrier work items participate in flushing but keep them still
not participating in nr_active.

So the plan is to mark barrier work items inactive without using
WORK_NO_COLOR in this patch so that we can assign a flushing color to
them in next patch.

The reasonable way is to add or reuse a bit in work data of the work
item.  But adding a bit will double the size of pool_workqueue.

Currently, WORK_STRUCT_INACTIVE is only used in try_to_grab_pending()
for user-queued work items and try_to_grab_pending() can't work for
barrier work items.  So we extend WORK_STRUCT_INACTIVE to also mark
barrier work items no matter which list they are in because we don't
need to determind which list a barrier work item is in.

So the meaning of WORK_STRUCT_INACTIVE becomes just "the work items don't
participate in nr_active" (no matter whether it is a barrier work item or
a user-queued work item).  And WORK_STRUCT_INACTIVE for user-queued work
items means they are in inactive_works list.

This patch does it by setting WORK_STRUCT_INACTIVE for barrier work items
in insert_wq_barrier() and checking WORK_STRUCT_INACTIVE first in
pwq_dec_nr_in_flight().  And the meaning of WORK_NO_COLOR is reduced to
only "not participating in flushing".

There is no functionality change intended in this patch.  Because
WORK_NO_COLOR+WORK_STRUCT_INACTIVE represents the previous WORK_NO_COLOR
in meaning and try_to_grab_pending() doesn't use for barrier work items
and avoids being confused by this extended WORK_STRUCT_INACTIVE.

A bunch of comment for nr_active & WORK_STRUCT_INACTIVE is also added for
documenting how WORK_STRUCT_INACTIVE works in nr_active management.

[1]: https://lore.kernel.org/lkml/20210812083814.32453-1-lizhe.67@bytedance.com/
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-17 07:49:10 -10:00
Lai Jiangshan
d21cece0db workqueue: Change the code of calculating work_flags in insert_wq_barrier()
Add a local var @work_flags to calculate work_flags step by step, so that
we don't need to squeeze several flags in only the last line of code.

Parepare for next patch to add a bit to barrier work item's flag.  Not
squshing this to next patch makes it clear that what it will have changed.

No functional change intended.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-17 07:49:10 -10:00
Lai Jiangshan
c4560c2c88 workqueue: Change arguement of pwq_dec_nr_in_flight()
Make pwq_dec_nr_in_flight() use work_data rather just work_color.

Prepare for later patch to get WORK_STRUCT_INACTIVE bit from work_data
in pwq_dec_nr_in_flight().

No functional change intended.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-17 07:49:09 -10:00
Lai Jiangshan
f97a4a1a3f workqueue: Rename "delayed" (delayed by active management) to "inactive"
There are two kinds of "delayed" work items in workqueue subsystem.

One is for timer-delayed work items which are visible to workqueue users.
The other kind is for work items delayed by active management which can
not be directly visible to workqueue users.  We mixed the word "delayed"
for both kinds and caused somewhat ambiguity.

This patch renames the later one (delayed by active management) to
"inactive", because it is used for workqueue active management and
most of its related symbols are named with "active" or "activate".

All "delayed" and "DELAYED" are carefully checked and renamed one by
one to avoid accidentally changing the name of the other kind for
timer-delayed.

No functional change intended.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-17 07:49:09 -10:00
Thomas Gleixner
31552385f8 locking/spinlock/rt: Prepare for RT local_lock
Add the static and runtime initializer mechanics to support the RT variant
of local_lock, which requires the lock type in the lockdep map to be set
to LD_LOCK_PERCPU.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.967526724@linutronix.de
2021-08-17 19:06:13 +02:00
Steven Rostedt
992caf7f17 locking/rtmutex: Add adaptive spinwait mechanism
Going to sleep when locks are contended can be quite inefficient when the
contention time is short and the lock owner is running on a different CPU.

The MCS mechanism cannot be used because MCS is strictly FIFO ordered while
for rtmutex based locks the waiter ordering is priority based.

Provide a simple adaptive spinwait mechanism which currently restricts the
spinning to the top priority waiter.

[ tglx: Provide a contemporary changelog, extended it to all rtmutex based
  	locks and updated it to match the other spin on owner implementations ]

Originally-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.912050691@linutronix.de
2021-08-17 19:06:11 +02:00
Gregory Haskins
48eb3f4fcf locking/rtmutex: Implement equal priority lock stealing
The current logic only allows lock stealing to occur if the current task is
of higher priority than the pending owner.

Significant throughput improvements can be gained by allowing the lock
stealing to include tasks of equal priority when the contended lock is a
spin_lock or a rw_lock and the tasks are not in a RT scheduling task.

The assumption was that the system will make faster progress by allowing
the task already on the CPU to take the lock rather than waiting for the
system to wake up a different task.

This does add a degree of unfairness, but in reality no negative side
effects have been observed in the many years that this has been used in the
RT kernel.

[ tglx: Refactored and rewritten several times by Steve Rostedt, Sebastian
  	Siewior and myself ]

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.857240222@linutronix.de
2021-08-17 19:06:07 +02:00
Thomas Gleixner
51711e825a locking/rtmutex: Prevent lockdep false positive with PI futexes
On PREEMPT_RT the futex hashbucket spinlock becomes 'sleeping' and rtmutex
based. That causes a lockdep false positive because some of the futex
functions invoke spin_unlock(&hb->lock) with the wait_lock of the rtmutex
associated to the pi_futex held.  spin_unlock() in turn takes wait_lock of
the rtmutex on which the spinlock is based which makes lockdep notice a
lock recursion.

Give the futex/rtmutex wait_lock a separate key.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.750701219@linutronix.de
2021-08-17 19:06:02 +02:00
Thomas Gleixner
07d91ef510 futex: Prevent requeue_pi() lock nesting issue on RT
The requeue_pi() operation on RT kernels creates a problem versus the
task::pi_blocked_on state when a waiter is woken early (signal, timeout)
and that early wake up interleaves with the requeue_pi() operation.

When the requeue manages to block the waiter on the rtmutex which is
associated to the second futex, then a concurrent early wakeup of that
waiter faces the problem that it has to acquire the hash bucket spinlock,
which is not an issue on non-RT kernels, but on RT kernels spinlocks are
substituted by 'sleeping' spinlocks based on rtmutex. If the hash bucket
lock is contended then blocking on that spinlock would result in a
impossible situation: blocking on two locks at the same time (the hash
bucket lock and the rtmutex representing the PI futex).

It was considered to make the hash bucket locks raw_spinlocks, but
especially requeue operations with a large amount of waiters can introduce
significant latencies, so that's not an option for RT.

The RT tree carried a solution which (ab)used task::pi_blocked_on to store
the information about an ongoing requeue and an early wakeup which worked,
but required to add checks for these special states all over the place.

The distangling of an early wakeup of a waiter for a requeue_pi() operation
is already looking at quite some different states and the task::pi_blocked_on
magic just expanded that to a hard to understand 'state machine'.

This can be avoided by keeping track of the waiter/requeue state in the
futex_q object itself.

Add a requeue_state field to struct futex_q with the following possible
states:

	Q_REQUEUE_PI_NONE
	Q_REQUEUE_PI_IGNORE
	Q_REQUEUE_PI_IN_PROGRESS
	Q_REQUEUE_PI_WAIT
	Q_REQUEUE_PI_DONE
	Q_REQUEUE_PI_LOCKED

The waiter starts with state = NONE and the following state transitions are
valid:

On the waiter side:
  Q_REQUEUE_PI_NONE		-> Q_REQUEUE_PI_IGNORE
  Q_REQUEUE_PI_IN_PROGRESS	-> Q_REQUEUE_PI_WAIT

On the requeue side:
  Q_REQUEUE_PI_NONE		-> Q_REQUEUE_PI_INPROGRESS
  Q_REQUEUE_PI_IN_PROGRESS	-> Q_REQUEUE_PI_DONE/LOCKED
  Q_REQUEUE_PI_IN_PROGRESS	-> Q_REQUEUE_PI_NONE (requeue failed)
  Q_REQUEUE_PI_WAIT		-> Q_REQUEUE_PI_DONE/LOCKED
  Q_REQUEUE_PI_WAIT		-> Q_REQUEUE_PI_IGNORE (requeue failed)

The requeue side ignores a waiter with state Q_REQUEUE_PI_IGNORE as this
signals that the waiter is already on the way out. It also means that
the waiter is still on the 'wait' futex, i.e. uaddr1.

The waiter side signals early wakeup to the requeue side either through
setting state to Q_REQUEUE_PI_IGNORE or to Q_REQUEUE_PI_WAIT depending
on the current state. In case of Q_REQUEUE_PI_IGNORE it can immediately
proceed to take the hash bucket lock of uaddr1. If it set state to WAIT,
which means the wakeup is interleaving with a requeue in progress it has
to wait for the requeue side to change the state. Either to DONE/LOCKED
or to IGNORE. DONE/LOCKED means the waiter q is now on the uaddr2 futex
and either blocked (DONE) or has acquired it (LOCKED). IGNORE is set by
the requeue side when the requeue attempt failed via deadlock detection
and therefore the waiter's futex_q is still on the uaddr1 futex.

While this is not strictly required on !RT making this unconditional has
the benefit of common code and it also allows the waiter to avoid taking
the hash bucket lock on the way out in certain cases, which reduces
contention.

Add the required helpers required for the state transitions, invoke them at
the right places and restructure the futex_wait_requeue_pi() code to handle
the return from wait (early or not) based on the state machine values.

On !RT enabled kernels the waiter spin waits for the state going from
Q_REQUEUE_PI_WAIT to some other state, on RT enabled kernels this is
handled by rcuwait_wait_event() and the corresponding wake up on the
requeue side.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.693317658@linutronix.de
2021-08-17 19:05:59 +02:00
Thomas Gleixner
6231acbd08 futex: Simplify handle_early_requeue_pi_wakeup()
Move the futex key match out of handle_early_requeue_pi_wakeup() which
allows to simplify that function. The upcoming state machine for
requeue_pi() will make that go away.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.638938670@linutronix.de
2021-08-17 19:05:57 +02:00
Thomas Gleixner
d69cba5c71 futex: Reorder sanity checks in futex_requeue()
No point in allocating memory when the input parameters are bogus.
Validate all parameters before proceeding.

Suggested-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.581789253@linutronix.de
2021-08-17 19:05:54 +02:00
Thomas Gleixner
c18eaa3aca futex: Clarify comment in futex_requeue()
The comment about the restriction of the number of waiters to wake for the
REQUEUE_PI case is confusing at best. Rewrite it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.524990421@linutronix.de
2021-08-17 19:05:51 +02:00
Thomas Gleixner
64b7b715f7 futex: Restructure futex_requeue()
No point in taking two more 'requeue_pi' conditionals just to get to the
requeue. Same for the requeue_pi case just the other way round.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.468835790@linutronix.de
2021-08-17 19:05:49 +02:00
Thomas Gleixner
59c7ecf154 futex: Correct the number of requeued waiters for PI
The accounting is wrong when either the PI sanity check or the
requeue PI operation fails. Adjust it in the failure path.

Will be simplified in the next step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.416427548@linutronix.de
2021-08-17 19:05:46 +02:00
Thomas Gleixner
8e74633dce futex: Remove bogus condition for requeue PI
For requeue PI it's required to establish PI state for the PI futex to
which waiters are requeued. This either acquires the user space futex on
behalf of the top most waiter on the inner 'waitqueue' futex, or attaches to
the PI state of an existing waiter, or creates on attached to the owner of
the futex.

This code can retry in case of failure, but retry can never happen when the
pi state was successfully created. The condition to run this code is:

  (task_count - nr_wake) < nr_requeue

which is always true because:

   task_count = 0
   nr_wake = 1
   nr_requeue >= 0

Remove it completely.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.362730187@linutronix.de
2021-08-17 19:05:44 +02:00
Thomas Gleixner
f6f4ec00b5 futex: Clarify futex_requeue() PI handling
When requeuing to a PI futex, then the requeue code tries to trylock the PI
futex on behalf of the topmost waiter on the inner 'waitqueue' futex. If
that succeeds, then PI state has to be allocated in order to requeue further
waiters to the PI futex.

The comment and the code are confusing, as the PI state allocation uses
lookup_pi_state(), which either attaches to an existing waiter or to the
owner. As the PI futex was just acquired, there cannot be a waiter on the
PI futex because the hash bucket lock is held.

Clarify the comment and use attach_to_pi_owner() directly. As the task on
which behalf the PI futex has been acquired is guaranteed to be alive and
not exiting, this call must succeed. Add a WARN_ON() in case that fails.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.305142462@linutronix.de
2021-08-17 19:05:41 +02:00
Thomas Gleixner
c363b7ed79 futex: Clean up stale comments
The futex key reference mechanism is long gone. Clean up the stale comments
which still mention it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.249178312@linutronix.de
2021-08-17 19:05:39 +02:00
Thomas Gleixner
dc7109aaa2 futex: Validate waiter correctly in futex_proxy_trylock_atomic()
The loop in futex_requeue() has a sanity check for the waiter, which is
missing in futex_proxy_trylock_atomic(). In theory the key2 check is
sufficient, but futexes are cursed so add it for completeness and paranoia
sake.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.193767519@linutronix.de
2021-08-17 19:05:36 +02:00
Thomas Gleixner
bb630f9f7a locking/rtmutex: Add mutex variant for RT
Add the necessary defines, helpers and API functions for replacing struct mutex on
a PREEMPT_RT enabled kernel with an rtmutex based variant.

No functional change when CONFIG_PREEMPT_RT=n

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.081517417@linutronix.de
2021-08-17 19:05:29 +02:00
Peter Zijlstra
f8635d509d locking/ww_mutex: Implement rtmutex based ww_mutex API functions
Add the actual ww_mutex API functions which replace the mutex based variant
on RT enabled kernels.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.024057938@linutronix.de
2021-08-17 19:05:26 +02:00
Peter Zijlstra
add461325e locking/rtmutex: Extend the rtmutex core to support ww_mutex
Add a ww acquire context pointer to the waiter and various functions and
add the ww_mutex related invocations to the proper spots in the locking
code, similar to the mutex based variant.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.966139174@linutronix.de
2021-08-17 19:05:23 +02:00
Peter Zijlstra
2408f7a378 locking/ww_mutex: Add rt_mutex based lock type and accessors
Provide the defines for RT mutex based ww_mutexes and fix up the debug logic
so it's either enabled by DEBUG_MUTEXES or DEBUG_RT_MUTEXES on RT kernels.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.908012566@linutronix.de
2021-08-17 19:05:11 +02:00
Peter Zijlstra
8850d77370 locking/ww_mutex: Add RT priority to W/W order
RT mutex based ww_mutexes cannot order based on timestamps. They have to
order based on priority. Add the necessary decision logic.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.847536630@linutronix.de
2021-08-17 19:05:08 +02:00
Peter Zijlstra
dc4564f5dc locking/ww_mutex: Implement rt_mutex accessors
Provide the type defines and the helper inlines for rtmutex based ww_mutexes.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.790760545@linutronix.de
2021-08-17 19:05:06 +02:00
Thomas Gleixner
653a5b0bd9 locking/ww_mutex: Abstract out internal lock accesses
Accessing the internal wait_lock of mutex and rtmutex is slightly
different. Provide helper functions for that.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.734635961@linutronix.de
2021-08-17 19:05:03 +02:00
Peter Zijlstra
bdb189148d locking/ww_mutex: Abstract out mutex types
Some ww_mutex helper functions use pointers for the underlying mutex and
mutex_waiter. The upcoming rtmutex based implementation needs to share
these functions. Add and use defines for the types and replace the direct
types in the affected functions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.678720245@linutronix.de
2021-08-17 19:05:00 +02:00
Peter Zijlstra
9934ccc75c locking/ww_mutex: Abstract out mutex accessors
Move the mutex related access from various ww_mutex functions into helper
functions so they can be substituted for rtmutex based ww_mutex later.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.622477030@linutronix.de
2021-08-17 19:04:57 +02:00
Peter Zijlstra
843dac28f9 locking/ww_mutex: Abstract out waiter enqueueing
The upcoming rtmutex based ww_mutex needs a different handling for
enqueueing a waiter. Split it out into a helper function.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.566318143@linutronix.de
2021-08-17 19:04:54 +02:00
Peter Zijlstra
23d599eb23 locking/ww_mutex: Abstract out the waiter iteration
Split out the waiter iteration functions so they can be substituted for a
rtmutex based ww_mutex later.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.509186185@linutronix.de
2021-08-17 19:04:52 +02:00
Peter Zijlstra
5297ccb2c5 locking/ww_mutex: Remove the __sched annotation from ww_mutex APIs
None of these functions will be on the stack when blocking in
schedule(), hence __sched is not needed.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.453235952@linutronix.de
2021-08-17 19:04:49 +02:00
Peter Zijlstra (Intel)
2674bd181f locking/ww_mutex: Split out the W/W implementation logic into kernel/locking/ww_mutex.h
Split the W/W mutex helper functions out into a separate header file, so
they can be shared with a rtmutex based variant later.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.396893399@linutronix.de
2021-08-17 19:04:46 +02:00
Peter Zijlstra (Intel)
aaa77de10b locking/ww_mutex: Split up ww_mutex_unlock()
Split the ww related part out into a helper function so it can be reused
for a rtmutex based ww_mutex implementation.

[ mingo: Fixed bisection failure. ]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.340166556@linutronix.de
2021-08-17 19:04:44 +02:00
Peter Zijlstra
c0afb0ffc0 locking/ww_mutex: Gather mutex_waiter initialization
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.281927514@linutronix.de
2021-08-17 19:04:41 +02:00
Peter Zijlstra
cf702eddcd locking/ww_mutex: Simplify lockdep annotations
No functional change.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.222921634@linutronix.de
2021-08-17 19:04:28 +02:00
Thomas Gleixner
ebf4c55c1d locking/mutex: Make mutex::wait_lock raw
The wait_lock of mutex is really a low level lock. Convert it to a
raw_spinlock like the wait_lock of rtmutex.

[ mingo: backmerged the test_lockup.c build fix by bigeasy. ]

Co-developed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.166863404@linutronix.de
2021-08-17 19:03:33 +02:00
Thomas Gleixner
43d2d52d70 locking/mutex: Move the 'struct mutex_waiter' definition from <linux/mutex.h> to the internal header
Move the mutex waiter declaration from the public <linux/mutex.h> header
to the internal kernel/locking/mutex.h header.

There is no reason to expose it outside of the core code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.054325923@linutronix.de
2021-08-17 18:24:31 +02:00
Thomas Gleixner
a321fb9038 locking/mutex: Consolidate core headers, remove kernel/locking/mutex-debug.h
Having two header files which contain just the non-debug and debug variants
is mostly waste of disc space and has no real value. Stick the debug
variants into the common mutex.h file as counterpart to the stubs for the
non-debug case.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.995350521@linutronix.de
2021-08-17 18:24:22 +02:00
Peter Zijlstra
715f7f9ece locking/rtmutex: Squash !RT tasks to DEFAULT_PRIO
Ensure all !RT tasks have the same prio such that they end up in FIFO
order and aren't split up according to nice level.

The reason why nice levels were taken into account so far is historical. In
the early days of the rtmutex code it was done to give the PI boosting and
deboosting a larger coverage.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.938676930@linutronix.de
2021-08-17 17:51:02 +02:00
Thomas Gleixner
8282947f67 locking/rwlock: Provide RT variant
Similar to rw_semaphores, on RT the rwlock substitution is not writer fair,
because it's not feasible to have a writer inherit its priority to
multiple readers. Readers blocked on a writer follow the normal rules of
priority inheritance. Like RT spinlocks, RT rwlocks are state preserving
across the slow lock operations (contended case).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.882793524@linutronix.de
2021-08-17 17:50:51 +02:00
Thomas Gleixner
0f383b6dc9 locking/spinlock: Provide RT variant
Provide the actual locking functions which make use of the general and
spinlock specific rtmutex code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.826621464@linutronix.de
2021-08-17 17:48:13 +02:00
Jia He
a2071573d6 sysctl: introduce new proc handler proc_dobool
This is to let bool variable could be correctly displayed in
big/little endian sysctl procfs. sizeof(bool) is arch dependent,
proc_dobool should work in all arches.

Suggested-by: Pan Xinhui <xinhui@linux.vnet.ibm.com>
Signed-off-by: Jia He <hejianet@gmail.com>
[thuth: rebased the patch to the current kernel version]
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-17 11:47:53 -04:00
Thomas Gleixner
1c143c4b65 locking/rtmutex: Provide the spin/rwlock core lock function
A simplified version of the rtmutex slowlock function, which neither handles
signals nor timeouts, and is careful about preserving the state of the
blocked task across the lock operation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.770228446@linutronix.de
2021-08-17 17:45:37 +02:00
Thomas Gleixner
e17ba59b7e locking/rtmutex: Guard regular sleeping locks specific functions
Guard the regular sleeping lock specific functionality, which is used for
rtmutex on non-RT enabled kernels and for mutex, rtmutex and semaphores on
RT enabled kernels so the code can be reused for the RT specific
implementation of spinlocks and rwlocks in a different compilation unit.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.311535693@linutronix.de
2021-08-17 17:23:27 +02:00
Thomas Gleixner
456cfbc65c locking/rtmutex: Prepare RT rt_mutex_wake_q for RT locks
Add an rtlock_task pointer to rt_mutex_wake_q, which allows to handle the RT
specific wakeup for spin/rwlock waiters. The pointer is just consuming 4/8
bytes on the stack so it is provided unconditionaly to avoid #ifdeffery all
over the place.

This cannot use a regular wake_q, because a task can have concurrent wakeups which
would make it miss either lock or the regular wakeups, depending on what gets
queued first, unless task struct gains a separate wake_q_node for this, which
would be overkill, because there can only be a single task which gets woken
up in the spin/rw_lock unlock path.

No functional change for non-RT enabled kernels.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.253614678@linutronix.de
2021-08-17 17:21:09 +02:00
Thomas Gleixner
7980aa397c locking/rtmutex: Use rt_mutex_wake_q_head
Prepare for the required state aware handling of waiter wakeups via wake_q
and switch the rtmutex code over to the rtmutex specific wrapper.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.197113263@linutronix.de
2021-08-17 17:20:14 +02:00
Thomas Gleixner
b576e640ce locking/rtmutex: Provide rt_wake_q_head and helpers
To handle the difference between wakeups for regular sleeping locks (mutex,
rtmutex, rw_semaphore) and the wakeups for 'sleeping' spin/rwlocks on
PREEMPT_RT enabled kernels correctly, it is required to provide a
wake_q_head construct which allows to keep them separate.

Provide a wrapper around wake_q_head and the required helpers, which will be
extended with the state handling later.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.139337655@linutronix.de
2021-08-17 17:18:15 +02:00
Thomas Gleixner
c014ef69b3 locking/rtmutex: Add wake_state to rt_mutex_waiter
Regular sleeping locks like mutexes, rtmutexes and rw_semaphores are always
entering and leaving a blocking section with task state == TASK_RUNNING.

On a non-RT kernel spinlocks and rwlocks never affect the task state, but
on RT kernels these locks are converted to rtmutex based 'sleeping' locks.

So in case of contention the task goes to block, which requires to carefully
preserve the task state, and restore it after acquiring the lock taking
regular wakeups for the task into account, which happened while the task was
blocked. This state preserving is achieved by having a separate task state
for blocking on a RT spin/rwlock and a saved_state field in task_struct
along with careful handling of these wakeup scenarios in try_to_wake_up().

To avoid conditionals in the rtmutex code, store the wake state which has
to be used for waking a lock waiter in rt_mutex_waiter which allows to
handle the regular and RT spin/rwlocks by handing it to wake_up_state().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.079800739@linutronix.de
2021-08-17 17:15:36 +02:00
Thomas Gleixner
42254105df locking/rwsem: Add rtmutex based R/W semaphore implementation
The RT specific R/W semaphore implementation used to restrict the number of
readers to one, because a writer cannot block on multiple readers and
inherit its priority or budget.

The single reader restricting was painful in various ways:

 - Performance bottleneck for multi-threaded applications in the page fault
   path (mmap sem)

 - Progress blocker for drivers which are carefully crafted to avoid the
   potential reader/writer deadlock in mainline.

The analysis of the writer code paths shows that properly written RT tasks
should not take them. Syscalls like mmap(), file access which take mmap sem
write locked have unbound latencies, which are completely unrelated to mmap
sem. Other R/W sem users like graphics drivers are not suitable for RT tasks
either.

So there is little risk to hurt RT tasks when the RT rwsem implementation is
done in the following way:

 - Allow concurrent readers

 - Make writers block until the last reader left the critical section. This
   blocking is not subject to priority/budget inheritance.

 - Readers blocked on a writer inherit their priority/budget in the normal
   way.

There is a drawback with this scheme: R/W semaphores become writer unfair
though the applications which have triggered writer starvation (mostly on
mmap_sem) in the past are not really the typical workloads running on a RT
system. So while it's unlikely to hit writer starvation, it's possible. If
there are unexpected workloads on RT systems triggering it, the problem
has to be revisited.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.016885947@linutronix.de
2021-08-17 17:12:47 +02:00
Thomas Gleixner
943f0edb75 locking/rt: Add base code for RT rw_semaphore and rwlock
On PREEMPT_RT, rw_semaphores and rwlocks are substituted with an rtmutex and
a reader count. The implementation is writer unfair, as it is not feasible
to do priority inheritance on multiple readers, but experience has shown
that real-time workloads are not the typical workloads which are sensitive
to writer starvation.

The inner workings of rw_semaphores and rwlocks on RT are almost identical
except for the task state and signal handling. rw_semaphores are not state
preserving over a contention, they are expected to enter and leave with state
== TASK_RUNNING. rwlocks have a mechanism to preserve the state of the task
at entry and restore it after unblocking taking potential non-lock related
wakeups into account. rw_semaphores can also be subject to signal handling
interrupting a blocked state, while rwlocks ignore signals.

To avoid code duplication, provide a shared implementation which takes the
small difference vs. state and signals into account. The code is included
into the relevant rw_semaphore/rwlock base code and compiled for each use
case separately.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.957920571@linutronix.de
2021-08-17 17:12:22 +02:00
Thomas Gleixner
ebbdc41e90 locking/rtmutex: Provide rt_mutex_slowlock_locked()
Split the inner workings of rt_mutex_slowlock() out into a separate
function, which can be reused by the upcoming RT lock substitutions,
e.g. for rw_semaphores.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.841971086@linutronix.de
2021-08-17 17:04:09 +02:00
Peter Zijlstra
830e6acc8a locking/rtmutex: Split out the inner parts of 'struct rtmutex'
RT builds substitutions for rwsem, mutex, spinlock and rwlock around
rtmutexes. Split the inner working out so each lock substitution can use
them with the appropriate lockdep annotations. This avoids having an extra
unused lockdep map in the wrapped rtmutex.

No functional change.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.784739994@linutronix.de
2021-08-17 17:04:01 +02:00
Thomas Gleixner
531ae4b06a locking/rtmutex: Split API from implementation
Prepare for reusing the inner functions of rtmutex for RT lock
substitutions: introduce kernel/locking/rtmutex_api.c and move
them there.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.726560996@linutronix.de
2021-08-17 17:03:07 +02:00
Thomas Gleixner
709e0b6286 locking/rtmutex: Switch to from cmpxchg_*() to try_cmpxchg_*()
Allows the compiler to generate better code depending on the architecture.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.668958502@linutronix.de
2021-08-17 17:01:47 +02:00
Sebastian Andrzej Siewior
785159301b locking/rtmutex: Convert macros to inlines
Inlines are type-safe...

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.610830960@linutronix.de
2021-08-17 17:00:48 +02:00
Thomas Gleixner
6991436c2b sched/core: Provide a scheduling point for RT locks
RT enabled kernels substitute spin/rwlocks with 'sleeping' variants based
on rtmutexes. Blocking on such a lock is similar to preemption versus:

 - I/O scheduling and worker handling, because these functions might block
   on another substituted lock, or come from a lock contention within these
   functions.

 - RCU considers this like a preemption, because the task might be in a read
   side critical section.

Add a separate scheduling point for this, and hand a new scheduling mode
argument to __schedule() which allows, along with separate mode masks, to
handle this gracefully from within the scheduler, without proliferating that
to other subsystems like RCU.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.372319055@linutronix.de
2021-08-17 16:57:17 +02:00
Thomas Gleixner
b4bfa3fcfe sched/core: Rework the __schedule() preempt argument
PREEMPT_RT needs to hand a special state into __schedule() when a task
blocks on a 'sleeping' spin/rwlock. This is required to handle
rcu_note_context_switch() correctly without having special casing in the
RCU code. From an RCU point of view the blocking on the sleeping spinlock
is equivalent to preemption, because the task might be in a read side
critical section.

schedule_debug() also has a check which would trigger with the !preempt
case, but that could be handled differently.

To avoid adding another argument and extra checks which cannot be optimized
out by the compiler, the following solution has been chosen:

 - Replace the boolean 'preempt' argument with an unsigned integer
   'sched_mode' argument and define constants to hand in:
   (0 == no preemption, 1 = preemption).

 - Add two masks to apply on that mode: one for the debug/rcu invocations,
   and one for the actual scheduling decision.

   For a non RT kernel these masks are UINT_MAX, i.e. all bits are set,
   which allows the compiler to optimize the AND operation out, because it is
   not masking out anything. IOW, it's not different from the boolean.

   RT enabled kernels will define these masks separately.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.315473019@linutronix.de
2021-08-17 16:53:43 +02:00
Thomas Gleixner
5f220be214 sched/wakeup: Prepare for RT sleeping spin/rwlocks
Waiting for spinlocks and rwlocks on non RT enabled kernels is task::state
preserving. Any wakeup which matches the state is valid.

RT enabled kernels substitutes them with 'sleeping' spinlocks. This creates
an issue vs. task::__state.

In order to block on the lock, the task has to overwrite task::__state and a
consecutive wakeup issued by the unlocker sets the state back to
TASK_RUNNING. As a consequence the task loses the state which was set
before the lock acquire and also any regular wakeup targeted at the task
while it is blocked on the lock.

To handle this gracefully, add a 'saved_state' member to task_struct which
is used in the following way:

 1) When a task blocks on a 'sleeping' spinlock, the current state is saved
    in task::saved_state before it is set to TASK_RTLOCK_WAIT.

 2) When the task unblocks and after acquiring the lock, it restores the saved
    state.

 3) When a regular wakeup happens for a task while it is blocked then the
    state change of that wakeup is redirected to operate on task::saved_state.

    This is also required when the task state is running because the task
    might have been woken up from the lock wait and has not yet restored
    the saved state.

To make it complete, provide the necessary helpers to save and restore the
saved state along with the necessary documentation how the RT lock blocking
is supposed to work.

For non-RT kernels there is no functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.258751046@linutronix.de
2021-08-17 16:49:02 +02:00
Thomas Gleixner
43295d73ad sched/wakeup: Split out the wakeup ->__state check
RT kernels have a slightly more complicated handling of wakeups due to
'sleeping' spin/rwlocks. If a task is blocked on such a lock then the
original state of the task is preserved over the blocking period, and
any regular (non lock related) wakeup has to be targeted at the
saved state to ensure that these wakeups are not lost.

Once the task acquires the lock it restores the task state from the saved state.

To avoid cluttering try_to_wake_up() with that logic, split the wakeup
state check out into an inline helper and use it at both places where
task::__state is checked against the state argument of try_to_wake_up().

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.088945085@linutronix.de
2021-08-17 16:40:54 +02:00
Thomas Gleixner
b41cda0376 locking/rtmutex: Set proper wait context for lockdep
RT mutexes belong to the LD_WAIT_SLEEP class. Make them so.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.031014562@linutronix.de
2021-08-17 16:38:50 +02:00
Ingo Molnar
c87866ede4 Linux 5.14-rc6
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Merge tag 'v5.14-rc6' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-08-17 16:16:29 +02:00
Andrii Nakryiko
7adfc6c9b3 bpf: Add bpf_get_attach_cookie() BPF helper to access bpf_cookie value
Add new BPF helper, bpf_get_attach_cookie(), which can be used by BPF programs
to get access to a user-provided bpf_cookie value, specified during BPF
program attachment (BPF link creation) time.

Naming is hard, though. With the concept being named "BPF cookie", I've
considered calling the helper:
  - bpf_get_cookie() -- seems too unspecific and easily mistaken with socket
    cookie;
  - bpf_get_bpf_cookie() -- too much tautology;
  - bpf_get_link_cookie() -- would be ok, but while we create a BPF link to
    attach BPF program to BPF hook, it's still an "attachment" and the
    bpf_cookie is associated with BPF program attachment to a hook, not a BPF
    link itself. Technically, we could support bpf_cookie with old-style
    cgroup programs.So I ultimately rejected it in favor of
    bpf_get_attach_cookie().

Currently all perf_event-backed BPF program types support
bpf_get_attach_cookie() helper. Follow-up patches will add support for
fentry/fexit programs as well.

While at it, mark bpf_tracing_func_proto() as static to make it obvious that
it's only used from within the kernel/trace/bpf_trace.c.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210815070609.987780-7-andrii@kernel.org
2021-08-17 00:45:07 +02:00
Andrii Nakryiko
82e6b1eee6 bpf: Allow to specify user-provided bpf_cookie for BPF perf links
Add ability for users to specify custom u64 value (bpf_cookie) when creating
BPF link for perf_event-backed BPF programs (kprobe/uprobe, perf_event,
tracepoints).

This is useful for cases when the same BPF program is used for attaching and
processing invocation of different tracepoints/kprobes/uprobes in a generic
fashion, but such that each invocation is distinguished from each other (e.g.,
BPF program can look up additional information associated with a specific
kernel function without having to rely on function IP lookups). This enables
new use cases to be implemented simply and efficiently that previously were
possible only through code generation (and thus multiple instances of almost
identical BPF program) or compilation at runtime (BCC-style) on target hosts
(even more expensive resource-wise). For uprobes it is not even possible in
some cases to know function IP before hand (e.g., when attaching to shared
library without PID filtering, in which case base load address is not known
for a library).

This is done by storing u64 bpf_cookie in struct bpf_prog_array_item,
corresponding to each attached and run BPF program. Given cgroup BPF programs
already use two 8-byte pointers for their needs and cgroup BPF programs don't
have (yet?) support for bpf_cookie, reuse that space through union of
cgroup_storage and new bpf_cookie field.

Make it available to kprobe/tracepoint BPF programs through bpf_trace_run_ctx.
This is set by BPF_PROG_RUN_ARRAY, used by kprobe/uprobe/tracepoint BPF
program execution code, which luckily is now also split from
BPF_PROG_RUN_ARRAY_CG. This run context will be utilized by a new BPF helper
giving access to this user-provided cookie value from inside a BPF program.
Generic perf_event BPF programs will access this value from perf_event itself
through passed in BPF program context.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/bpf/20210815070609.987780-6-andrii@kernel.org
2021-08-17 00:45:07 +02:00
Andrii Nakryiko
b89fbfbb85 bpf: Implement minimal BPF perf link
Introduce a new type of BPF link - BPF perf link. This brings perf_event-based
BPF program attachments (perf_event, tracepoints, kprobes, and uprobes) into
the common BPF link infrastructure, allowing to list all active perf_event
based attachments, auto-detaching BPF program from perf_event when link's FD
is closed, get generic BPF link fdinfo/get_info functionality.

BPF_LINK_CREATE command expects perf_event's FD as target_fd. No extra flags
are currently supported.

Force-detaching and atomic BPF program updates are not yet implemented, but
with perf_event-based BPF links we now have common framework for this without
the need to extend ioctl()-based perf_event interface.

One interesting consideration is a new value for bpf_attach_type, which
BPF_LINK_CREATE command expects. Generally, it's either 1-to-1 mapping from
bpf_attach_type to bpf_prog_type, or many-to-1 mapping from a subset of
bpf_attach_types to one bpf_prog_type (e.g., see BPF_PROG_TYPE_SK_SKB or
BPF_PROG_TYPE_CGROUP_SOCK). In this case, though, we have three different
program types (KPROBE, TRACEPOINT, PERF_EVENT) using the same perf_event-based
mechanism, so it's many bpf_prog_types to one bpf_attach_type. I chose to
define a single BPF_PERF_EVENT attach type for all of them and adjust
link_create()'s logic for checking correspondence between attach type and
program type.

The alternative would be to define three new attach types (e.g., BPF_KPROBE,
BPF_TRACEPOINT, and BPF_PERF_EVENT), but that seemed like unnecessary overkill
and BPF_KPROBE will cause naming conflicts with BPF_KPROBE() macro, defined by
libbpf. I chose to not do this to avoid unnecessary proliferation of
bpf_attach_type enum values and not have to deal with naming conflicts.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/bpf/20210815070609.987780-5-andrii@kernel.org
2021-08-17 00:45:07 +02:00
Andrii Nakryiko
652c1b17b8 bpf: Refactor perf_event_set_bpf_prog() to use struct bpf_prog input
Make internal perf_event_set_bpf_prog() use struct bpf_prog pointer as an
input argument, which makes it easier to re-use for other internal uses
(coming up for BPF link in the next patch). BPF program FD is not as
convenient and in some cases it's not available. So switch to struct bpf_prog,
move out refcounting outside and let caller do bpf_prog_put() in case of an
error. This follows the approach of most of the other BPF internal functions.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210815070609.987780-4-andrii@kernel.org
2021-08-17 00:45:07 +02:00
Andrii Nakryiko
7d08c2c911 bpf: Refactor BPF_PROG_RUN_ARRAY family of macros into functions
Similar to BPF_PROG_RUN, turn BPF_PROG_RUN_ARRAY macros into proper functions
with all the same readability and maintainability benefits. Making them into
functions required shuffling around bpf_set_run_ctx/bpf_reset_run_ctx
functions. Also, explicitly specifying the type of the BPF prog run callback
required adjusting __bpf_prog_run_save_cb() to accept const void *, casted
internally to const struct sk_buff.

Further, split out a cgroup-specific BPF_PROG_RUN_ARRAY_CG and
BPF_PROG_RUN_ARRAY_CG_FLAGS from the more generic BPF_PROG_RUN_ARRAY due to
the differences in bpf_run_ctx used for those two different use cases.

I think BPF_PROG_RUN_ARRAY_CG would benefit from further refactoring to accept
struct cgroup and enum bpf_attach_type instead of bpf_prog_array, fetching
cgrp->bpf.effective[type] and RCU-dereferencing it internally. But that
required including include/linux/cgroup-defs.h, which I wasn't sure is ok with
everyone.

The remaining generic BPF_PROG_RUN_ARRAY function will be extended to
pass-through user-provided context value in the next patch.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210815070609.987780-3-andrii@kernel.org
2021-08-17 00:45:07 +02:00
Andrii Nakryiko
fb7dd8bca0 bpf: Refactor BPF_PROG_RUN into a function
Turn BPF_PROG_RUN into a proper always inlined function. No functional and
performance changes are intended, but it makes it much easier to understand
what's going on with how BPF programs are actually get executed. It's more
obvious what types and callbacks are expected. Also extra () around input
parameters can be dropped, as well as `__` variable prefixes intended to avoid
naming collisions, which makes the code simpler to read and write.

This refactoring also highlighted one extra issue. BPF_PROG_RUN is both
a macro and an enum value (BPF_PROG_RUN == BPF_PROG_TEST_RUN). Turning
BPF_PROG_RUN into a function causes naming conflict compilation error. So
rename BPF_PROG_RUN into lower-case bpf_prog_run(), similar to
bpf_prog_run_xdp(), bpf_prog_run_pin_on_cpu(), etc. All existing callers of
BPF_PROG_RUN, the macro, are switched to bpf_prog_run() explicitly.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210815070609.987780-2-andrii@kernel.org
2021-08-17 00:45:07 +02:00
Valentin Schneider
15538a2057 notifier: Remove atomic_notifier_call_chain_robust()
This now has no more users, remove it.

Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-08-16 18:55:32 +02:00
Valentin Schneider
b2f6662ac0 PM: cpu: Make notifier chain use a raw_spinlock_t
Invoking atomic_notifier_chain_notify() requires acquiring a spinlock_t,
which can block under CONFIG_PREEMPT_RT. Notifications for members of the
cpu_pm notification chain will be issued by the idle task, which can never
block.

Making *all* atomic_notifiers use a raw_spinlock is too big of a hammer, as
only notifications issued by the idle task are problematic.

Special-case cpu_pm_notifier_chain by kludging a raw_notifier and
raw_spinlock_t together, matching the atomic_notifier behavior with a
raw_spinlock_t.

Fixes: 70d9329857 ("notifier: Fix broken error handling pattern")
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-08-16 18:55:32 +02:00
Randy Dunlap
dbcfa7156f PM: sleep: unmark 'state' functions as kernel-doc
Fix kernel-doc warnings in kernel/power/main.c by unmarking the
comment block as kernel-doc notation. This eliminates the following
kernel-doc warnings:

kernel/power/main.c:593: warning: expecting prototype for state(). Prototype was for state_show() instead
kernel/power/main.c:593: warning: Function parameter or member 'kobj' not described in 'state_show'
kernel/power/main.c:593: warning: Function parameter or member 'attr' not described in 'state_show'
kernel/power/main.c:593: warning: Function parameter or member 'buf' not described in 'state_show'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-08-16 18:49:39 +02:00
Linus Torvalds
b88bcc7d54 Fixes and clean ups to tracing:
- Fix header alignment when PREEMPT_RT is enabled for osnoise tracer
 
 - Inject "stop" event to see where osnoise stopped the trace
 
 - Define DYNAMIC_FTRACE_WITH_ARGS as some code had an #ifdef for it
 
 - Fix erroneous message for bootconfig cmdline parameter
 
 - Fix crash caused by not found variable in histograms
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Merge tag 'trace-v5.14-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Fixes and clean ups to tracing:

   - Fix header alignment when PREEMPT_RT is enabled for osnoise tracer

   - Inject "stop" event to see where osnoise stopped the trace

   - Define DYNAMIC_FTRACE_WITH_ARGS as some code had an #ifdef for it

   - Fix erroneous message for bootconfig cmdline parameter

   - Fix crash caused by not found variable in histograms"

* tag 'trace-v5.14-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing / histogram: Fix NULL pointer dereference on strcmp() on NULL event name
  init: Suppress wrong warning for bootconfig cmdline parameter
  tracing: define needed config DYNAMIC_FTRACE_WITH_ARGS
  trace/osnoise: Print a stop tracing message
  trace/timerlat: Add a header with PREEMPT_RT additional fields
  trace/osnoise: Add a header with PREEMPT_RT additional fields
2021-08-16 06:31:06 -10:00
zhaoxiao
bd74095389 tracepoint: Fix kerneldoc comments
Fix function name in tracepoint.c kernel-doc comment
to remove a warning found by clang_w1.

kernel/tracepoint.c:589: warning: expecting prototype for register_tracepoint_notifier(). Prototype was for register_tracepoint_module_notifier() instead
kernel/tracepoint.c:613: warning: expecting prototype for unregister_tracepoint_notifier(). Prototype was for unregister_tracepoint_module_notifier() instead

Link: https://lkml.kernel.org/r/20210816052430.16539-1-zhaoxiao@uniontech.com

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: zhaoxiao <zhaoxiao@uniontech.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:39:51 -04:00
Masami Hiramatsu
64dc7f6958 tracing/boot: Show correct histogram error command
Since trigger_process_regex() modifies given trigger actions
while parsing, the error message couldn't show what command
was passed to the trigger_process_regex() when it returns
an error.

To fix that, show the backed up trigger action command
instead of parsed buffer.

Link: https://lkml.kernel.org/r/162856126413.203126.9465564928450701424.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Masami Hiramatsu
17abd7c36c tracing/boot: Support multiple histograms for each event
Add multiple histograms support for each event. This allows
user to set multiple histograms to an event.

ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist[.N] {
...
}

The 'N' is a digit started string and it can be omitted
for the default histogram.

For example, multiple hist triggers example in the
Documentation/trace/histogram.rst can be written as below;

ftrace.event.net.netif_receive_skb.hist {
	1 {
		keys = skbaddr.hex
		values = len
		filter = len < 0
	}
	2 {
		keys = skbaddr.hex
		values = len
		filter = len > 4096
	}
	3 {
		keys = skbaddr.hex
		values = len
		filter = len == 256
	}
	4 {
		keys = skbaddr.hex
		values = len
	}
	5 {
		keys = len
		values = common_preempt_count
	}
}

Link: https://lkml.kernel.org/r/162856125628.203126.15846930277378572120.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Masami Hiramatsu
8993665abc tracing/boot: Support multiple handlers for per-event histogram
Support multiple handlers for per-event histogram in boot-time tracing.
Since the histogram can register multiple same handler-actions with
different parameters, this expands the syntax to support such cases.

With this update, the 'onmax', 'onchange' and 'onmatch' handler subkeys
under per-event histogram option will take a number subkeys optionally
as below. (see [.N])

ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist {
     onmax|onchange[.N] { var = <VAR>; <ACTION> [= <PARAM>] }
     onmatch[.N] { event = <EVENT>; <ACTION> [= <PARAM>] }
}

The 'N' must be a digit (or digit started word).

Thus user can add several handler-actions to the histogram,
for example,

ftrace.event.SOMEGROUP.SOMEEVENT.hist {
   keys = SOME_ID; lat = common_timestamp.usecs-$ts0
   onmatch.1 {
	event = GROUP1.STARTEVENT1
	trace = latency_event, SOME_ID, $lat
   }
   onmatch.2 {
	event = GROUP2.STARTEVENT2
	trace = latency_event, SOME_ID, $lat
   }
}

Then, it can trace the elapsed time from GROUP1.STARTEVENT1 to
SOMEGROUP.SOMEEVENT, and from GROUP2.STARTEVENT2 to
SOMEGROUP.SOMEEVENT with SOME_ID key.

Link: https://lkml.kernel.org/r/162856124905.203126.14913731908137885922.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Masami Hiramatsu
e66ed86ca6 tracing/boot: Add per-event histogram action options
Add a hist-trigger action syntax support to boot-time tracing.
Currently, boot-time tracing supports per-event actions as option
strings. However, for the histogram action, it has a special syntax
and usually needs a long action definition.
To make it readable and fit to the bootconfig syntax, this introduces
a new options for histogram.

Here are the histogram action options for boot-time tracing.

ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist {
     keys = <KEY>[,...]
     values = <VAL>[,...]
     sort = <SORT-KEY>[,...]
     size = <ENTRIES>
     name = <HISTNAME>
     var { <VAR> = <EXPR> ... }
     pause|continue|clear
     onmax|onchange { var = <VAR>; <ACTION> [= <PARAM>] }
     onmatch { event = <EVENT>; <ACTION> [= <PARAM>] }
     filter = <FILTER>
}

Where <ACTION> is one of below;

     trace = <EVENT>, <ARG1>[, ...]
     save = <ARG1>[, ...]
     snapshot

Link: https://lkml.kernel.org/r/162856124106.203126.10501871028479029087.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:21 -04:00
Masahiro Yamada
de32951b29 tracing: Simplify the Kconfig dependency of FTRACE
The entire FTRACE block is surrounded by 'if TRACING_SUPPORT' ...
'endif'.

Using 'depends on' is a simpler way to guard FTRACE.

Link: https://lkml.kernel.org/r/20210731052233.4703-1-masahiroy@kernel.org

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00
Steven Rostedt (VMware)
ed2cf90735 tracing: Allow execnames to be passed as args for synthetic events
Allow common_pid.execname to be saved in a variable in one histogram to be
passed to another histogram that can pass it as a parameter to a synthetic
event.

 ># echo 'hist:keys=pid:__arg__1=common_timestamp.usecs:arg2=common_pid.execname' \
       > events/sched/sched_waking/trigger
 ># echo 'wakeup_lat s32 pid; u64 delta; char wake_comm[]' > synthetic_events
 ># echo 'hist:keys=next_pid:pid=next_pid,delta=common_timestamp.usecs-$__arg__1,exec=$arg2'\
':onmatch(sched.sched_waking).trace(wakeup_lat,$pid,$delta,$exec)' \
 > events/sched/sched_switch/trigger

The above is a wake up latency synthetic event setup that passes the execname
of the common_pid that woke the task to the scheduling of that task, which
triggers a synthetic event that passes the original execname as a
parameter to display it.

 ># echo 1 > events/synthetic/enable
 ># cat trace
    <idle>-0       [006] d..4   186.863801: wakeup_lat: pid=1306 delta=65 wake_comm=kworker/u16:3
    <idle>-0       [000] d..4   186.863858: wakeup_lat: pid=163 delta=27 wake_comm=<idle>
    <idle>-0       [001] d..4   186.863903: wakeup_lat: pid=1307 delta=36 wake_comm=kworker/u16:4
    <idle>-0       [000] d..4   186.863927: wakeup_lat: pid=163 delta=5 wake_comm=<idle>
    <idle>-0       [006] d..4   186.863957: wakeup_lat: pid=1306 delta=24 wake_comm=kworker/u16:3
      sshd-1306    [006] d..4   186.864051: wakeup_lat: pid=61 delta=62 wake_comm=<idle>
    <idle>-0       [000] d..4   186.965030: wakeup_lat: pid=609 delta=18 wake_comm=<idle>
    <idle>-0       [006] d..4   186.987582: wakeup_lat: pid=1306 delta=65 wake_comm=kworker/u16:3
    <idle>-0       [000] d..4   186.987639: wakeup_lat: pid=163 delta=27 wake_comm=<idle>

Link: https://lkml.kernel.org/r/20210722142837.458596338@goodmis.org

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00
Steven Rostedt (VMware)
3347d80baa tracing: Have histogram types be constant when possible
Instead of kstrdup("const", GFP_KERNEL), have the hist_field type simply
assign the constant hist_field->type = "const"; And when the value passed
to it is a variable, use "kstrdup_const(var, GFP_KERNEL);" which will just
copy the value if the variable is already a constant. This saves on having
to allocate when not needed.

All frees of the hist_field->type will need to use kfree_const().

Link: https://lkml.kernel.org/r/20210722142837.280718447@goodmis.org

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00
Steven Rostedt (VMware)
3703643519 tracing/histogram: Update the documentation for the buckets modifier
Update both the tracefs README file as well as the histogram.rst to
include an explanation of what the buckets modifier is and how to use it.
Include an example with the wakeup_latency example for both log2 and the
buckets modifiers as there was no existing log2 example.

Link: https://lkml.kernel.org/r/20210707213922.167218794@goodmis.org

Acked-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00
Steven Rostedt (VMware)
de9a48a360 tracing: Add linear buckets to histogram logic
There's been several times I wished the histogram logic had a "grouping"
feature for the buckets. Currently, each bucket has a size of one. That
is, if you trace the amount of requested allocations, each allocation is
its own bucket, even if you are interested in what allocates 100 bytes or
less, 100 to 200, 200 to 300, etc.

Also, without grouping, it fills up the allocated histogram buckets
quickly. If you are tracking latency, and don't care if something is 200
microseconds off, or 201 microseconds off, but want to track them by say
10 microseconds each. This can not currently be done.

There is a log2 but that grouping get's too big too fast for a lot of
cases.

Introduce a "buckets=SIZE" command to each field where it will record in a
rounded number. For example:

 ># echo 'hist:keys=bytes_req.buckets=100:sort=bytes_req' > events/kmem/kmalloc/trigger
 ># cat events/kmem/kmalloc/hist
 # event histogram
 #
 # trigger info:
 hist:keys=bytes_req.buckets=100:vals=hitcount:sort=bytes_req.buckets=100:size=2048
 [active]
 #

 { bytes_req: ~ 0-99 } hitcount:       3149
 { bytes_req: ~ 100-199 } hitcount:       1468
 { bytes_req: ~ 200-299 } hitcount:         39
 { bytes_req: ~ 300-399 } hitcount:        306
 { bytes_req: ~ 400-499 } hitcount:        364
 { bytes_req: ~ 500-599 } hitcount:         32
 { bytes_req: ~ 600-699 } hitcount:         69
 { bytes_req: ~ 700-799 } hitcount:         37
 { bytes_req: ~ 1200-1299 } hitcount:         16
 { bytes_req: ~ 1400-1499 } hitcount:         30
 { bytes_req: ~ 2000-2099 } hitcount:          6
 { bytes_req: ~ 4000-4099 } hitcount:       2168
 { bytes_req: ~ 5000-5099 } hitcount:          6

 Totals:
     Hits: 7690
     Entries: 13
     Dropped: 0

Link: https://lkml.kernel.org/r/20210707213921.980359719@goodmis.org

Acked-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00
Masami Hiramatsu
6fe7c745f2 tracing/boot: Fix a hist trigger dependency for boot time tracing
Fixes a build error when CONFIG_HIST_TRIGGERS=n with boot-time
tracing. Since the trigger_process_regex() is defined only
when CONFIG_HIST_TRIGGERS=y, if it is disabled, the 'actions'
event option also must be disabled.

Link: https://lkml.kernel.org/r/162856123376.203126.582144262622247352.stgit@devnote2

Fixes: 81a59555ff ("tracing/boot: Add per-event settings")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:37:20 -04:00
Pingfan Liu
6c34df6f35 tracing: Apply trace filters on all output channels
The event filters are not applied on all of the output, which results in
the flood of printk when using tp_printk. Unfolding
event_trigger_unlock_commit_regs() into trace_event_buffer_commit(), so
the filters can be applied on every output.

Link: https://lkml.kernel.org/r/20210814034538.8428-1-kernelfans@gmail.com

Cc: stable@vger.kernel.org
Fixes: 0daa230296 ("tracing: Add tp_printk cmdline to have tracepoints go to printk()")
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-16 11:01:52 -04:00
Sagi Grimberg
2a14c9ae15 params: lift param_set_uint_minmax to common code
It is a useful helper hence move it to common code so others can enjoy
it.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-16 14:42:22 +02:00
Linus Torvalds
c4f14eac22 A set of fixes for PCI/MSI and x86 interrupt startup:
- Mask all MSI-X entries when enabling MSI-X otherwise stale unmasked
    entries stay around e.g. when a crashkernel is booted.
 
  - Enforce masking of a MSI-X table entry when updating it, which mandatory
    according to speification
 
  - Ensure that writes to MSI[-X} tables are flushed.
 
  - Prevent invalid bits being set in the MSI mask register
 
  - Properly serialize modifications to the mask cache and the mask register
    for multi-MSI.
 
  - Cure the violation of the affinity setting rules on X86 during interrupt
    startup which can cause lost and stale interrupts. Move the initial
    affinity setting ahead of actualy enabling the interrupt.
 
  - Ensure that MSI interrupts are completely torn down before freeing them
    in the error handling case.
 
  - Prevent an array out of bounds access in the irq timings code.
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Merge tag 'irq-urgent-2021-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Thomas Gleixner:
 "A set of fixes for PCI/MSI and x86 interrupt startup:

   - Mask all MSI-X entries when enabling MSI-X otherwise stale unmasked
     entries stay around e.g. when a crashkernel is booted.

   - Enforce masking of a MSI-X table entry when updating it, which
     mandatory according to speification

   - Ensure that writes to MSI[-X} tables are flushed.

   - Prevent invalid bits being set in the MSI mask register

   - Properly serialize modifications to the mask cache and the mask
     register for multi-MSI.

   - Cure the violation of the affinity setting rules on X86 during
     interrupt startup which can cause lost and stale interrupts. Move
     the initial affinity setting ahead of actualy enabling the
     interrupt.

   - Ensure that MSI interrupts are completely torn down before freeing
     them in the error handling case.

   - Prevent an array out of bounds access in the irq timings code"

* tag 'irq-urgent-2021-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  driver core: Add missing kernel doc for device::msi_lock
  genirq/msi: Ensure deactivation on teardown
  genirq/timings: Prevent potential array overflow in __irq_timings_store()
  x86/msi: Force affinity setup before startup
  x86/ioapic: Force affinity setup before startup
  genirq: Provide IRQCHIP_AFFINITY_PRE_STARTUP
  PCI/MSI: Protect msi_desc::masked for multi-MSI
  PCI/MSI: Use msi_mask_irq() in pci_msi_shutdown()
  PCI/MSI: Correct misleading comments
  PCI/MSI: Do not set invalid bits in MSI mask
  PCI/MSI: Enforce MSI[X] entry updates to be visible
  PCI/MSI: Enforce that MSI-X table entry is masked for update
  PCI/MSI: Mask all unused MSI-X entries
  PCI/MSI: Enable and mask MSI-X early
2021-08-15 06:49:40 -10:00
Linus Torvalds
839da25385 - Fix a CONFIG symbol's spelling
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Merge tag 'locking_urgent_for_v5.14_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fix from Borislav Petkov:

 - Fix a CONFIG symbol's spelling

* tag 'locking_urgent_for_v5.14_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rtmutex: Use the correct rtmutex debugging config option
2021-08-15 06:46:04 -10:00
Kuniyuki Iwashima
3478cfcfcd bpf: Support "%c" in bpf_bprintf_prepare().
/proc/net/unix uses "%c" to print a single-byte character to escape '\0' in
the name of the abstract UNIX domain socket.  The following selftest uses
it, so this patch adds support for "%c".  Note that it does not support
wide character ("%lc" and "%llc") for simplicity.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210814015718.42704-3-kuniyu@amazon.co.jp
2021-08-15 00:13:33 -07:00
Christoph Hellwig
2a047e0662 dma-mapping: return an unsigned int from dma_map_sg{,_attrs}
These can only return 0 for failure or the number of entries, so turn
the return value into an unsigned int.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
2021-08-14 09:18:36 +02:00
Stanislav Fomichev
f1248dee95 bpf: Allow bpf_get_netns_cookie in BPF_PROG_TYPE_CGROUP_SOCKOPT
This is similar to existing BPF_PROG_TYPE_CGROUP_SOCK
and BPF_PROG_TYPE_CGROUP_SOCK_ADDR.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210813230530.333779-2-sdf@google.com
2021-08-13 17:50:40 -07:00
Ilya Leoshkevich
45c709f8c7 bpf: Clear zext_dst of dead insns
"access skb fields ok" verifier test fails on s390 with the "verifier
bug. zext_dst is set, but no reg is defined" message. The first insns
of the test prog are ...

   0:	61 01 00 00 00 00 00 00 	ldxw %r0,[%r1+0]
   8:	35 00 00 01 00 00 00 00 	jge %r0,0,1
  10:	61 01 00 08 00 00 00 00 	ldxw %r0,[%r1+8]

... and the 3rd one is dead (this does not look intentional to me, but
this is a separate topic).

sanitize_dead_code() converts dead insns into "ja -1", but keeps
zext_dst. When opt_subreg_zext_lo32_rnd_hi32() tries to parse such
an insn, it sees this discrepancy and bails. This problem can be seen
only with JITs whose bpf_jit_needs_zext() returns true.

Fix by clearning dead insns' zext_dst.

The commits that contributed to this problem are:

1. 5aa5bd14c5 ("bpf: add initial suite for selftests"), which
   introduced the test with the dead code.
2. 5327ed3d44 ("bpf: verifier: mark verified-insn with
   sub-register zext flag"), which introduced the zext_dst flag.
3. 83a2881903 ("bpf: Account for BPF_FETCH in
   insn_has_def32()"), which introduced the sanity check.
4. 9183671af6 ("bpf: Fix leakage under speculation on
   mispredicted branches"), which bisect points to.

It's best to fix this on stable branches that contain the second one,
since that's the point where the inconsistency was introduced.

Fixes: 5327ed3d44 ("bpf: verifier: mark verified-insn with sub-register zext flag")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210812151811.184086-2-iii@linux.ibm.com
2021-08-13 17:43:43 +02:00
Jakub Kicinski
f4083a752a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
  9e26680733 ("bnxt_en: Update firmware call to retrieve TX PTP timestamp")
  9e518f2580 ("bnxt_en: 1PPS functions to configure TSIO pins")
  099fdeda65 ("bnxt_en: Event handler for PPS events")

kernel/bpf/helpers.c
include/linux/bpf-cgroup.h
  a2baf4e8bb ("bpf: Fix potentially incorrect results with bpf_get_local_storage()")
  c7603cfa04 ("bpf: Add ambient BPF runtime context stored in current")

drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
  5957cc557d ("net/mlx5: Set all field of mlx5_irq before inserting it to the xarray")
  2d0b41a376 ("net/mlx5: Refcount mlx5_irq with integer")

MAINTAINERS
  7b637cd52f ("MAINTAINERS: fix Microchip CAN BUS Analyzer Tool entry typo")
  7d901a1e87 ("net: phy: add Maxlinear GPY115/21x/24x driver")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-13 06:41:22 -07:00
Thomas Gleixner
04c2721d35 genirq: Fix kernel doc indentation
Fixes: 61377ec144 ("genirq: Clarify documentation for request_threaded_irq()")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2021-08-13 12:45:13 +02:00
Linus Torvalds
f8e6dfc64f Networking fixes for 5.14-rc6, including fixes from netfilter, bpf,
can and ieee802154.
 
 Current release - regressions:
 
  - r8169: fix ASPM-related link-up regressions
 
  - bridge: fix flags interpretation for extern learn fdb entries
 
  - phy: micrel: fix link detection on ksz87xx switch
 
  - Revert "tipc: Return the correct errno code"
 
  - ptp: fix possible memory leak caused by invalid cast
 
 Current release - new code bugs:
 
  - bpf: add missing bpf_read_[un]lock_trace() for syscall program
 
  - bpf: fix potentially incorrect results with bpf_get_local_storage()
 
  - page_pool: mask the page->signature before the checking, avoid
       dma mapping leaks
 
  - netfilter: nfnetlink_hook: 5 fixes to information in netlink dumps
 
  - bnxt_en: fix firmware interface issues with PTP
 
  - mlx5: Bridge, fix ageing time
 
 Previous releases - regressions:
 
  - linkwatch: fix failure to restore device state across suspend/resume
 
  - bareudp: fix invalid read beyond skb's linear data
 
 Previous releases - always broken:
 
  - bpf: fix integer overflow involving bucket_size
 
  - ppp: fix issues when desired interface name is specified via netlink
 
  - wwan: mhi_wwan_ctrl: fix possible deadlock
 
  - dsa: microchip: ksz8795: fix number of VLAN related bugs
 
  - dsa: drivers: fix broken backpressure in .port_fdb_dump
 
  - dsa: qca: ar9331: make proper initial port defaults
 
 Misc:
 
  - bpf: add lockdown check for probe_write_user helper
 
  - netfilter: conntrack: remove offload_pickup sysctl before 5.14 is out
 
  - netfilter: conntrack: collect all entries in one cycle,
 	      heuristically slow down garbage collection scans
 	      on idle systems to prevent frequent wake ups
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes, including fixes from netfilter, bpf, can and
  ieee802154.

  The size of this is pretty normal, but we got more fixes for 5.14
  changes this week than last week. Nothing major but the trend is the
  opposite of what we like. We'll see how the next week goes..

  Current release - regressions:

   - r8169: fix ASPM-related link-up regressions

   - bridge: fix flags interpretation for extern learn fdb entries

   - phy: micrel: fix link detection on ksz87xx switch

   - Revert "tipc: Return the correct errno code"

   - ptp: fix possible memory leak caused by invalid cast

  Current release - new code bugs:

   - bpf: add missing bpf_read_[un]lock_trace() for syscall program

   - bpf: fix potentially incorrect results with bpf_get_local_storage()

   - page_pool: mask the page->signature before the checking, avoid dma
     mapping leaks

   - netfilter: nfnetlink_hook: 5 fixes to information in netlink dumps

   - bnxt_en: fix firmware interface issues with PTP

   - mlx5: Bridge, fix ageing time

  Previous releases - regressions:

   - linkwatch: fix failure to restore device state across
     suspend/resume

   - bareudp: fix invalid read beyond skb's linear data

  Previous releases - always broken:

   - bpf: fix integer overflow involving bucket_size

   - ppp: fix issues when desired interface name is specified via
     netlink

   - wwan: mhi_wwan_ctrl: fix possible deadlock

   - dsa: microchip: ksz8795: fix number of VLAN related bugs

   - dsa: drivers: fix broken backpressure in .port_fdb_dump

   - dsa: qca: ar9331: make proper initial port defaults

  Misc:

   - bpf: add lockdown check for probe_write_user helper

   - netfilter: conntrack: remove offload_pickup sysctl before 5.14 is
     out

   - netfilter: conntrack: collect all entries in one cycle,
     heuristically slow down garbage collection scans on idle systems to
     prevent frequent wake ups"

* tag 'net-5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (87 commits)
  vsock/virtio: avoid potential deadlock when vsock device remove
  wwan: core: Avoid returning NULL from wwan_create_dev()
  net: dsa: sja1105: unregister the MDIO buses during teardown
  Revert "tipc: Return the correct errno code"
  net: mscc: Fix non-GPL export of regmap APIs
  net: igmp: increase size of mr_ifc_count
  MAINTAINERS: switch to my OMP email for Renesas Ethernet drivers
  tcp_bbr: fix u32 wrap bug in round logic if bbr_init() called after 2B packets
  net: pcs: xpcs: fix error handling on failed to allocate memory
  net: linkwatch: fix failure to restore device state across suspend/resume
  net: bridge: fix memleak in br_add_if()
  net: switchdev: zero-initialize struct switchdev_notifier_fdb_info emitted by drivers towards the bridge
  net: bridge: fix flags interpretation for extern learn fdb entries
  net: dsa: sja1105: fix broken backpressure in .port_fdb_dump
  net: dsa: lantiq: fix broken backpressure in .port_fdb_dump
  net: dsa: lan9303: fix broken backpressure in .port_fdb_dump
  net: dsa: hellcreek: fix broken backpressure in .port_fdb_dump
  bpf, core: Fix kernel-doc notation
  net: igmp: fix data-race in igmp_ifc_timer_expire()
  net: Fix memory leak in ieee802154_raw_deliver
  ...
2021-08-12 16:24:03 -10:00
Waiman Long
ee9707e859 cgroup/cpuset: Enable memory migration for cpuset v2
When a user changes cpuset.cpus, each task in a v2 cpuset will be moved
to one of the new cpus if it is not there already. For memory, however,
they won't be migrated to the new nodes when cpuset.mems changes. This is
an inconsistency in behavior.

In cpuset v1, there is a memory_migrate control file to enable such
behavior by setting the CS_MEMORY_MIGRATE flag. Make it the default
for cpuset v2 so that we have a consistent set of behavior for both
cpus and memory.

There is certainly a cost to make memory migration the default, but it
is a one time cost that shouldn't really matter as long as cpuset.mems
isn't changed frequenty.  Update the cgroup-v2.rst file to document the
new behavior and recommend against changing cpuset.mems frequently.

Since there won't be any concurrent access to the newly allocated cpuset
structure in cpuset_css_alloc(), we can use the cheaper non-atomic
__set_bit() instead of the more expensive atomic set_bit().

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-12 11:40:20 -10:00
Thomas Gleixner
f80e214895 hrtimer: Unbreak hrtimer_force_reprogram()
Since the recent consoliation of reprogramming functions,
hrtimer_force_reprogram() is affected by a check whether the new expiry
time is past the current expiry time.

This breaks the NOHZ logic as that relies on the fact that the tick hrtimer
is moved into the future. That means cpu_base->expires_next becomes stale
and subsequent reprogramming attempts fail as well until the situation is
cleaned up by an hrtimer interrupts.

For some yet unknown reason this leads to a complete stall, so for now
partially revert the offending commit to a known working state. The root
cause for the stall is still investigated and will be fixed in a subsequent
commit.

Fixes: b14bca97c9 ("hrtimer: Consolidate reprogramming code")
Reported-by: Mike Galbraith <efault@gmx.de>
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mike Galbraith <efault@gmx.de>
Link: https://lore.kernel.org/r/8735recskh.ffs@tglx
2021-08-12 22:34:40 +02:00
Thomas Gleixner
9482fd71db hrtimer: Use raw_cpu_ptr() in clock_was_set()
clock_was_set() can be invoked from preemptible context. Use raw_cpu_ptr()
to check whether high resolution mode is active or not. It does not matter
whether the task migrates after acquiring the pointer.

Fixes: e71a4153b7 ("hrtimer: Force clock_was_set() handling for the HIGHRES=n, NOHZ=y case")
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/875ywacsmb.ffs@tglx
2021-08-12 22:34:40 +02:00
Steven Rostedt (VMware)
5acce0bff2 tracing / histogram: Fix NULL pointer dereference on strcmp() on NULL event name
The following commands:

 # echo 'read_max u64 size;' > synthetic_events
 # echo 'hist:keys=common_pid:count=count:onmax($count).trace(read_max,count)' > events/syscalls/sys_enter_read/trigger

Causes:

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP
 CPU: 4 PID: 1763 Comm: bash Not tainted 5.14.0-rc2-test+ #155
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01
v03.03 07/14/2016
 RIP: 0010:strcmp+0xc/0x20
 Code: 75 f7 31 c0 0f b6 0c 06 88 0c 02 48 83 c0 01 84 c9 75 f1 4c 89 c0
c3 0f 1f 80 00 00 00 00 31 c0 eb 08 48 83 c0 01 84 d2 74 0f <0f> b6 14 07
3a 14 06 74 ef 19 c0 83 c8 01 c3 31 c0 c3 66 90 48 89
 RSP: 0018:ffffb5fdc0963ca8 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffffffffb3a4e040 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff9714c0d0b640 RDI: 0000000000000000
 RBP: 0000000000000000 R08: 00000022986b7cde R09: ffffffffb3a4dff8
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9714c50603c8
 R13: 0000000000000000 R14: ffff97143fdf9e48 R15: ffff9714c01a2210
 FS:  00007f1fa6785740(0000) GS:ffff9714da400000(0000)
knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000002d863004 CR4: 00000000001706e0
 Call Trace:
  __find_event_file+0x4e/0x80
  action_create+0x6b7/0xeb0
  ? kstrdup+0x44/0x60
  event_hist_trigger_func+0x1a07/0x2130
  trigger_process_regex+0xbd/0x110
  event_trigger_write+0x71/0xd0
  vfs_write+0xe9/0x310
  ksys_write+0x68/0xe0
  do_syscall_64+0x3b/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7f1fa6879e87

The problem was the "trace(read_max,count)" where the "count" should be
"$count" as "onmax()" only handles variables (although it really should be
able to figure out that "count" is a field of sys_enter_read). But there's
a path that does not find the variable and ends up passing a NULL for the
event, which ends up getting passed to "strcmp()".

Add a check for NULL to return and error on the command with:

 # cat error_log
  hist:syscalls:sys_enter_read: error: Couldn't create or find variable
  Command: hist:keys=common_pid:count=count:onmax($count).trace(read_max,count)
                                ^
Link: https://lkml.kernel.org/r/20210808003011.4037f8d0@oasis.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 50450603ec tracing: Add 'onmax' hist trigger action support
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-12 13:35:57 -04:00
Lukas Bulwahn
12f9951d3f tracing: define needed config DYNAMIC_FTRACE_WITH_ARGS
Commit 2860cd8a23 ("livepatch: Use the default ftrace_ops instead of
REGS when ARGS is available") intends to enable config LIVEPATCH when
ftrace with ARGS is available. However, the chain of configs to enable
LIVEPATCH is incomplete, as HAVE_DYNAMIC_FTRACE_WITH_ARGS is available,
but the definition of DYNAMIC_FTRACE_WITH_ARGS, combining DYNAMIC_FTRACE
and HAVE_DYNAMIC_FTRACE_WITH_ARGS, needed to enable LIVEPATCH, is missing
in the commit.

Fortunately, ./scripts/checkkconfigsymbols.py detects this and warns:

DYNAMIC_FTRACE_WITH_ARGS
Referencing files: kernel/livepatch/Kconfig

So, define the config DYNAMIC_FTRACE_WITH_ARGS analogously to the already
existing similar configs, DYNAMIC_FTRACE_WITH_REGS and
DYNAMIC_FTRACE_WITH_DIRECT_CALLS, in ./kernel/trace/Kconfig to connect the
chain of configs.

Link: https://lore.kernel.org/kernel-janitors/CAKXUXMwT2zS9fgyQHKUUiqo8ynZBdx2UEUu1WnV_q0OCmknqhw@mail.gmail.com/
Link: https://lkml.kernel.org/r/20210806195027.16808-1-lukas.bulwahn@gmail.com

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: stable@vger.kernel.org
Fixes: 2860cd8a23 ("livepatch: Use the default ftrace_ops instead of REGS when ARGS is available")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-12 13:35:57 -04:00
Daniel Bristot de Oliveira
0e05ba498d trace/osnoise: Print a stop tracing message
When using osnoise/timerlat with stop tracing, sometimes it is
not clear in which CPU the stop condition was hit, mainly
when using some extra events.

Print a message informing in which CPU the trace stopped, like
in the example below:

          <idle>-0       [006] d.h.  2932.676616: #1672599 context    irq timer_latency     34689 ns
          <idle>-0       [006] dNh.  2932.676618: irq_noise: local_timer:236 start 2932.676615639 duration 2391 ns
          <idle>-0       [006] dNh.  2932.676620: irq_noise: virtio0-output.0:47 start 2932.676620180 duration 86 ns
          <idle>-0       [003] d.h.  2932.676621: #1673374 context    irq timer_latency      1200 ns
          <idle>-0       [006] d...  2932.676623: thread_noise: swapper/6:0 start 2932.676615964 duration 4339 ns
          <idle>-0       [003] dNh.  2932.676623: irq_noise: local_timer:236 start 2932.676620597 duration 1881 ns
          <idle>-0       [006] d...  2932.676623: sched_switch: prev_comm=swapper/6 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=timerlat/6 next_pid=852 next_prio=4
      timerlat/6-852     [006] ....  2932.676623: #1672599 context thread timer_latency     41931 ns
          <idle>-0       [003] d...  2932.676623: thread_noise: swapper/3:0 start 2932.676620854 duration 880 ns
          <idle>-0       [003] d...  2932.676624: sched_switch: prev_comm=swapper/3 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=timerlat/3 next_pid=849 next_prio=4
      timerlat/6-852     [006] ....  2932.676624: timerlat_main: stop tracing hit on cpu 6
      timerlat/3-849     [003] ....  2932.676624: #1673374 context thread timer_latency      4310 ns

Link: https://lkml.kernel.org/r/b30a0d7542adba019185f44ee648e60e14923b11.1626598844.git.bristot@kernel.org

Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-12 13:35:56 -04:00
Daniel Bristot de Oliveira
e1c4ad4a7f trace/timerlat: Add a header with PREEMPT_RT additional fields
Some extra flags are printed to the trace header when using the
PREEMPT_RT config. The extra flags are: need-resched-lazy,
preempt-lazy-depth, and migrate-disable.

Without printing these fields, the timerlat specific fields are
shifted by three positions, for example:

 # tracer: timerlat
 #
 #                                _-----=> irqs-off
 #                               / _----=> need-resched
 #                              | / _---=> hardirq/softirq
 #                              || / _--=> preempt-depth
 #                              || /
 #                              ||||             ACTIVATION
 #           TASK-PID      CPU# ||||   TIMESTAMP    ID            CONTEXT                LATENCY
 #              | |         |   ||||      |         |                  |                       |
           <idle>-0       [000] d..h...  3279.798871: #1     context    irq timer_latency       830 ns
            <...>-807     [000] .......  3279.798881: #1     context thread timer_latency     11301 ns

Add a new header for timerlat with the missing fields, to be used
when the PREEMPT_RT is enabled.

Link: https://lkml.kernel.org/r/babb83529a3211bd0805be0b8c21608230202c55.1626598844.git.bristot@kernel.org

Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-12 13:35:56 -04:00
Daniel Bristot de Oliveira
d03721a6e7 trace/osnoise: Add a header with PREEMPT_RT additional fields
Some extra flags are printed to the trace header when using the
PREEMPT_RT config. The extra flags are: need-resched-lazy,
preempt-lazy-depth, and migrate-disable.

Without printing these fields, the osnoise specific fields are
shifted by three positions, for example:

 # tracer: osnoise
 #
 #                                _-----=> irqs-off
 #                               / _----=> need-resched
 #                              | / _---=> hardirq/softirq
 #                              || / _--=> preempt-depth                            MAX
 #                              || /                                             SINGLE      Interference counters:
 #                              ||||               RUNTIME      NOISE  %% OF CPU  NOISE    +-----------------------------+
 #           TASK-PID      CPU# ||||   TIMESTAMP    IN US       IN US  AVAILABLE  IN US     HW    NMI    IRQ   SIRQ THREAD
 #              | |         |   ||||      |           |             |    |            |      |      |      |      |      |
            <...>-741     [000] .......  1105.690909: 1000000        234  99.97660      36     21      0   1001     22      3
            <...>-742     [001] .......  1105.691923: 1000000        281  99.97190     197      7      0   1012     35     14
            <...>-743     [002] .......  1105.691958: 1000000       1324  99.86760     118     11      0   1016    155    143
            <...>-744     [003] .......  1105.691998: 1000000        109  99.98910      21      4      0   1004     33      7
            <...>-745     [004] .......  1105.692015: 1000000       2023  99.79770      97     37      0   1023     52     18

Add a new header for osnoise with the missing fields, to be used
when the PREEMPT_RT is enabled.

Link: https://lkml.kernel.org/r/1f03289d2a51fde5a58c2e7def063dc630820ad1.1626598844.git.bristot@kernel.org

Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-12 13:35:56 -04:00
Linus Torvalds
f8fbb47c6e Merge branch 'for-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ucounts fix from Eric Biederman:
 "This fixes the ucount sysctls on big endian architectures.

  The counts were expanded to be longs instead of ints, and the sysctl
  code was overlooked, so only the low 32bit were being processed. On
  litte endian just processing the low 32bits is fine, but on 64bit big
  endian processing just the low 32bits results in the high order bits
  instead of the low order bits being processed and nothing works
  proper.

  This change took a little bit to mature as we have the SYSCTL_ZERO,
  and SYSCTL_INT_MAX macros that are only usable for sysctls operating
  on ints, but unfortunately are not obviously broken. Which resulted in
  the versions of this change working on big endian and not on little
  endian, because the int SYSCTL_ZERO when extended 64bit wound up being
  0x100000000. So we only allowed values greater than 0x100000000 and
  less than 0faff. Which unfortunately broken everything that tried to
  set the sysctls. (First reported with the windows subsystem for
  linux).

  I have tested this on x86_64 64bit after first reproducing the
  problems with the earlier version of this change, and then verifying
  the problems do not exist when we use appropriate long min and max
  values for extra1 and extra2"

* 'for-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ucounts: add missing data type changes
2021-08-12 07:20:16 -10:00
Ran Xiaokai
2863643fb8
set_user: add capability check when rlimit(RLIMIT_NPROC) exceeds
in copy_process(): non root users but with capability CAP_SYS_RESOURCE
or CAP_SYS_ADMIN will clean PF_NPROC_EXCEEDED flag even
rlimit(RLIMIT_NPROC) exceeds. Add the same capability check logic here.

Align the permission checks in copy_process() and set_user(). In
copy_process() CAP_SYS_RESOURCE or CAP_SYS_ADMIN capable users will be
able to circumvent and clear the PF_NPROC_EXCEEDED flag whereas they
aren't able to the same in set_user(). There's no obvious logic to this
and trying to unearth the reason in the thread didn't go anywhere.

The gist seems to be that this code wants to make sure that a program
can't successfully exec if it has gone through a set*id() transition
while exceeding its RLIMIT_NPROC.
A capable but non-INIT_USER caller getting PF_NPROC_EXCEEDED set during
a set*id() transition wouldn't be able to exec right away if they still
exceed their RLIMIT_NPROC at the time of exec. So their exec would fail
in fs/exec.c:

        if ((current->flags & PF_NPROC_EXCEEDED) &&
            is_ucounts_overlimit(current_ucounts(), UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC))) {
                retval = -EAGAIN;
                goto out_ret;
        }

However, if the caller were to fork() right after the set*id()
transition but before the exec while still exceeding their RLIMIT_NPROC
then they would get PF_NPROC_EXCEEDED cleared (while the child would
inherit it):

        retval = -EAGAIN;
        if (is_ucounts_overlimit(task_ucounts(p), UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC))) {
                if (p->real_cred->user != INIT_USER &&
                    !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN))
                        goto bad_fork_free;
        }
        current->flags &= ~PF_NPROC_EXCEEDED;

which means a subsequent exec by the capable caller would now succeed
even though they could still exceed their RLIMIT_NPROC limit. This seems
inconsistent. Allow a CAP_SYS_ADMIN or CAP_SYS_RESOURCE capable user to
avoid PF_NPROC_EXCEEDED as they already can in copy_process().

Cc: peterz@infradead.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, Ran Xiaokai <ran.xiaokai@zte.com.cn>, , ,

Link: https://lore.kernel.org/r/20210728072629.530435-1-ran.xiaokai@zte.com.cn
Cc: Neil Brown <neilb@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: James Morris <jamorris@linux.microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-08-12 14:54:25 +02:00
Sebastian Andrzej Siewior
80771c8228 padata: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-08-12 19:16:59 +08:00
Linus Torvalds
fd66ad69ef seccomp fixes for v5.14-rc6
- Fix typo in user notification documentation (Rodrigo Campos)
 
 - Fix userspace counter report when using TSYNC (Hsuan-Chi Kuo, Wiktor Garbacz)
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Merge tag 'seccomp-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull seccomp fixes from Kees Cook:

 - Fix typo in user notification documentation (Rodrigo Campos)

 - Fix userspace counter report when using TSYNC (Hsuan-Chi Kuo, Wiktor
   Garbacz)

* tag 'seccomp-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  seccomp: Fix setting loaded filter count during TSYNC
  Documentation: seccomp: Fix typo in user notification
2021-08-11 19:56:10 -10:00
Elliot Berman
14c4c8e415 cfi: Use rcu_read_{un}lock_sched_notrace
If rcu_read_lock_sched tracing is enabled, the tracing subsystem can
perform a jump which needs to be checked by CFI. For example, stm_ftrace
source is enabled as a module and hooks into enabled ftrace events. This
can cause an recursive loop where find_shadow_check_fn ->
rcu_read_lock_sched -> (call to stm_ftrace generates cfi slowpath) ->
find_shadow_check_fn -> rcu_read_lock_sched -> ...

To avoid the recursion, either the ftrace codes needs to be marked with
__no_cfi or CFI should not trace. Use the "_notrace" in CFI to avoid
tracing so that CFI can guard ftrace.

Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Cc: stable@vger.kernel.org
Fixes: cf68fffb66 ("add support for Clang CFI")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210811155914.19550-1-quic_eberman@quicinc.com
2021-08-11 13:11:12 -07:00
Hsuan-Chi Kuo
b4d8a58f8d seccomp: Fix setting loaded filter count during TSYNC
The desired behavior is to set the caller's filter count to thread's.
This value is reported via /proc, so this fixes the inaccurate count
exposed to userspace; it is not used for reference counting, etc.

Signed-off-by: Hsuan-Chi Kuo <hsuanchikuo@gmail.com>
Link: https://lore.kernel.org/r/20210304233708.420597-1-hsuanchikuo@gmail.com
Co-developed-by: Wiktor Garbacz <wiktorg@google.com>
Signed-off-by: Wiktor Garbacz <wiktorg@google.com>
Link: https://lore.kernel.org/lkml/20210810125158.329849-1-wiktorg@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Fixes: c818c03b66 ("seccomp: Report number of loaded filters in /proc/$pid/status")
2021-08-11 11:48:28 -07:00
Yonghong Song
2d3a1e3615 bpf: Add rcu_read_lock in bpf_get_current_[ancestor_]cgroup_id() helpers
Currently, if bpf_get_current_cgroup_id() or
bpf_get_current_ancestor_cgroup_id() helper is
called with sleepable programs e.g., sleepable
fentry/fmod_ret/fexit/lsm programs, a rcu warning
may appear. For example, if I added the following
hack to test_progs/test_lsm sleepable fentry program
test_sys_setdomainname:

  --- a/tools/testing/selftests/bpf/progs/lsm.c
  +++ b/tools/testing/selftests/bpf/progs/lsm.c
  @@ -168,6 +168,10 @@ int BPF_PROG(test_sys_setdomainname, struct pt_regs *regs)
          int buf = 0;
          long ret;

  +       __u64 cg_id = bpf_get_current_cgroup_id();
  +       if (cg_id == 1000)
  +               copy_test++;
  +
          ret = bpf_copy_from_user(&buf, sizeof(buf), ptr);
          if (len == -2 && ret == 0 && buf == 1234)
                  copy_test++;

I will hit the following rcu warning:

  include/linux/cgroup.h:481 suspicious rcu_dereference_check() usage!
  other info that might help us debug this:
    rcu_scheduler_active = 2, debug_locks = 1
    1 lock held by test_progs/260:
      #0: ffffffffa5173360 (rcu_read_lock_trace){....}-{0:0}, at: __bpf_prog_enter_sleepable+0x0/0xa0
    stack backtrace:
    CPU: 1 PID: 260 Comm: test_progs Tainted: G           O      5.14.0-rc2+ #176
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
    Call Trace:
      dump_stack_lvl+0x56/0x7b
      bpf_get_current_cgroup_id+0x9c/0xb1
      bpf_prog_a29888d1c6706e09_test_sys_setdomainname+0x3e/0x89c
      bpf_trampoline_6442469132_0+0x2d/0x1000
      __x64_sys_setdomainname+0x5/0x110
      do_syscall_64+0x3a/0x80
      entry_SYSCALL_64_after_hwframe+0x44/0xae

I can get similar warning using bpf_get_current_ancestor_cgroup_id() helper.
syzbot reported a similar issue in [1] for syscall program. Helper
bpf_get_current_cgroup_id() or bpf_get_current_ancestor_cgroup_id()
has the following callchain:
   task_dfl_cgroup
     task_css_set
       task_css_set_check
and we have
   #define task_css_set_check(task, __c)                                   \
           rcu_dereference_check((task)->cgroups,                          \
                   lockdep_is_held(&cgroup_mutex) ||                       \
                   lockdep_is_held(&css_set_lock) ||                       \
                   ((task)->flags & PF_EXITING) || (__c))
Since cgroup_mutex/css_set_lock is not held and the task
is not existing and rcu read_lock is not held, a warning
will be issued. Note that bpf sleepable program is protected by
rcu_read_lock_trace().

The above sleepable bpf programs are already protected
by migrate_disable(). Adding rcu_read_lock() in these
two helpers will silence the above warning.
I marked the patch fixing 95b861a793
("bpf: Allow bpf_get_current_ancestor_cgroup_id for tracing")
which added bpf_get_current_ancestor_cgroup_id() to tracing programs
in 5.14. I think backporting 5.14 is probably good enough as sleepable
progrems are not widely used.

This patch should fix [1] as well since syscall program is a sleepable
program protected with migrate_disable().

 [1] https://lore.kernel.org/bpf/0000000000006d5cab05c7d9bb87@google.com/

Fixes: 95b861a793 ("bpf: Allow bpf_get_current_ancestor_cgroup_id for tracing")
Reported-by: syzbot+7ee5c2c09c284495371f@syzkaller.appspotmail.com
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210810230537.2864668-1-yhs@fb.com
2021-08-11 11:45:43 -07:00
Waiman Long
e7cc9888dc cgroup/cpuset: Enable event notification when partition state changes
A valid cpuset partition can become invalid if all its CPUs are offlined
or somehow removed. This can happen through external events without
"cpuset.cpus.partition" being touched at all.

Users that rely on the property of a partition being present do not
currently have a simple way to get such an event notified other than
constant periodic polling which is both inefficient and cumbersome.

To make life easier for those users, event notification is now enabled
for "cpuset.cpus.partition" whenever its state changes.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-11 08:04:43 -10:00
Randy Dunlap
b4cc619608 cgroup: cgroup-v1: clean up kernel-doc notation
Fix kernel-doc warnings found in cgroup-v1.c:

kernel/cgroup/cgroup-v1.c:55: warning: No description found for return value of 'cgroup_attach_task_all'
kernel/cgroup/cgroup-v1.c:94: warning: expecting prototype for cgroup_trasnsfer_tasks(). Prototype was for cgroup_transfer_tasks() instead
cgroup-v1.c:96: warning: No description found for return value of 'cgroup_transfer_tasks'
kernel/cgroup/cgroup-v1.c:687: warning: No description found for return value of 'cgroupstats_build'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-11 07:57:43 -10:00
Randy Dunlap
49b3bd213a smp: Fix all kernel-doc warnings
Fix the following warnings:

kernel/smp.c:1189: warning: cannot understand function prototype: 'struct smp_call_on_cpu_struct '
kernel/smp.c:788: warning: No description found for return value of 'smp_call_function_single_async'
kernel/smp.c:990: warning: Function parameter or member 'wait' not described in 'smp_call_function_many'
kernel/smp.c:990: warning: Excess function parameter 'flags' description in 'smp_call_function_many'
kernel/smp.c:1198: warning: Function parameter or member 'work' not described in 'smp_call_on_cpu_struct'
kernel/smp.c:1198: warning: Function parameter or member 'done' not described in 'smp_call_on_cpu_struct'
kernel/smp.c:1198: warning: Function parameter or member 'func' not described in 'smp_call_on_cpu_struct'
kernel/smp.c:1198: warning: Function parameter or member 'data' not described in 'smp_call_on_cpu_struct'
kernel/smp.c:1198: warning: Function parameter or member 'ret' not described in 'smp_call_on_cpu_struct'
kernel/smp.c:1198: warning: Function parameter or member 'cpu' not described in 'smp_call_on_cpu_struct'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210810225051.3938-1-rdunlap@infradead.org
2021-08-11 14:47:16 +02:00
Randy Dunlap
3b35e7e6da genirq: Fix kernel-doc warnings in pm.c, msi.c and ipi.c
Fix all kernel-doc warnings in these 3 files and do some simple editing
(capitalize acronyms, capitalize Linux).

kernel/irq/pm.c:235: warning: expecting prototype for irq_pm_syscore_ops(). Prototype was for irq_pm_syscore_resume() instead
kernel/irq/msi.c:530: warning: expecting prototype for __msi_domain_free_irqs(). Prototype was for msi_domain_free_irqs() instead
kernel/irq/msi.c:31: warning: No description found for return value of 'alloc_msi_entry'
kernel/irq/msi.c:103: warning: No description found for return value of 'msi_domain_set_affinity'
kernel/irq/msi.c:288: warning: No description found for return value of 'msi_create_irq_domain'
kernel/irq/msi.c:499: warning: No description found for return value of 'msi_domain_alloc_irqs'
kernel/irq/msi.c:545: warning: No description found for return value of 'msi_get_domain_info'
kernel/irq/ipi.c:264: warning: expecting prototype for ipi_send_mask(). Prototype was for __ipi_send_mask() instead
kernel/irq/ipi.c:25: warning: No description found for return value of 'irq_reserve_ipi'
kernel/irq/ipi.c:116: warning: No description found for return value of 'irq_destroy_ipi'
kernel/irq/ipi.c:163: warning: No description found for return value of 'ipi_get_hwirq'
kernel/irq/ipi.c:222: warning: No description found for return value of '__ipi_send_single'
kernel/irq/ipi.c:308: warning: No description found for return value of 'ipi_send_single'
kernel/irq/ipi.c:329: warning: No description found for return value of 'ipi_send_mask'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210810234835.12547-1-rdunlap@infradead.org
2021-08-11 14:33:35 +02:00
Zhen Lei
290fdc4b7e genirq/timings: Fix error return code in irq_timings_test_irqs()
Return a negative error code from the error handling case instead of 0, as
done elsewhere in this function.

Fixes: f52da98d90 ("genirq/timings: Add selftest for irqs circular buffer")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210811093333.2376-1-thunder.leizhen@huawei.com
2021-08-11 14:33:35 +02:00
Baokun Li
92848731c4 genirq/matrix: Fix kernel doc warnings for irq_matrix_alloc_managed()
Describe the arguments correctly.

Fixes the following W=1 kernel build warning(s):

kernel/irq/matrix.c:287: warning: Function parameter or
 member 'msk' not described in 'irq_matrix_alloc_managed'
kernel/irq/matrix.c:287: warning: Function parameter or
 member 'mapped_cpu' not described in 'irq_matrix_alloc_managed'
kernel/irq/matrix.c:287: warning: Excess function
 parameter 'cpu' description in 'irq_matrix_alloc_managed'

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210605063413.684085-1-libaokun1@huawei.com
2021-08-10 22:50:07 +02:00
Tanner Love
91cc470e79 genirq: Change force_irqthreads to a static key
With CONFIG_IRQ_FORCED_THREADING=y, testing the boolean force_irqthreads
could incur a cache line miss in invoke_softirq() and other places.

Replace the test with a static key to avoid the potential cache miss.

[ tglx: Dropped the IDE part, removed the export and updated blk-mq ]

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Tanner Love <tannerlove@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210602180338.3324213-1-tannerlove.kernel@gmail.com
2021-08-10 22:50:07 +02:00
Paul E. McKenney
b770efc460 Merge branches 'doc.2021.07.20c', 'fixes.2021.08.06a', 'nocb.2021.07.20c', 'nolibc.2021.07.20c', 'tasks.2021.07.20c', 'torture.2021.07.27a' and 'torturescript.2021.07.27a' into HEAD
doc.2021.07.20c: Documentation updates.
fixes.2021.08.06a: Miscellaneous fixes.
nocb.2021.07.20c: Callback-offloading (NOCB CPU) updates.
nolibc.2021.07.20c: Tiny userspace library updates.
tasks.2021.07.20c: Tasks RCU updates.
torture.2021.07.27a: In-kernel torture-test updates.
torturescript.2021.07.27a: Torture-test scripting updates.
2021-08-10 11:00:53 -07:00
Sebastian Andrzej Siewior
ed4fa2442e torture: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-08-10 10:48:07 -07:00
Sebastian Andrzej Siewior
d3dd95a885 rcu: Replace deprecated CPU-hotplug functions
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: rcu@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-08-10 10:47:32 -07:00
Dongli Zhang
ebca71a8c9 cpu/hotplug: Add debug printks for hotplug callback failures
CPU hotplug callbacks can fail and cause a rollback to the previous
state. These failures are silent and therefore hard to debug.

Add pr_debug() to the up and down paths which provide information about the
error code, the CPU and the failed state. The debug printks can be enabled
via kernel command line or sysfs.

[ tglx: Adopt to current mainline, massage printk and changelog ]

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Qais Yousef <qais.yousef@arm.com>
Link: https://lore.kernel.org/r/20210409055316.1709-1-dongli.zhang@oracle.com
2021-08-10 18:31:32 +02:00
YueHaibing
1782dc87b2 cpu/hotplug: Use DEVICE_ATTR_*() macro
Use DEVICE_ATTR_*() helper instead of plain DEVICE_ATTR,
which makes the code a bit shorter and easier to read.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210527141105.2312-1-yuehaibing@huawei.com
2021-08-10 18:11:12 +02:00
Randy Dunlap
11bc021d1f cpu/hotplug: Eliminate all kernel-doc warnings
kernel/cpu.c:57: warning: cannot understand function prototype: 'struct cpuhp_cpu_state '
kernel/cpu.c:115: warning: cannot understand function prototype: 'struct cpuhp_step '
kernel/cpu.c:146: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * cpuhp_invoke_callback _ Invoke the callbacks for a given state
kernel/cpu.c:75: warning: Function parameter or member 'fail' not described in 'cpuhp_cpu_state'
kernel/cpu.c:75: warning: Function parameter or member 'cpu' not described in 'cpuhp_cpu_state'
kernel/cpu.c:75: warning: Function parameter or member 'node' not described in 'cpuhp_cpu_state'
kernel/cpu.c:75: warning: Function parameter or member 'last' not described in 'cpuhp_cpu_state'
kernel/cpu.c:130: warning: Function parameter or member 'list' not described in 'cpuhp_step'
kernel/cpu.c:130: warning: Function parameter or member 'multi_instance' not described in 'cpuhp_step'
kernel/cpu.c:158: warning: No description found for return value of 'cpuhp_invoke_callback'
kernel/cpu.c:1188: warning: No description found for return value of 'cpu_device_down'
kernel/cpu.c:1400: warning: No description found for return value of 'cpu_device_up'
kernel/cpu.c:1425: warning: No description found for return value of 'bringup_hibernate_cpu'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210809223825.24512-1-rdunlap@infradead.org
2021-08-10 18:07:38 +02:00
Baokun Li
ed3cd1da67 cpu/hotplug: Fix kernel doc warnings for __cpuhp_setup_state_cpuslocked()
Fixes the following W=1 kernel build warning(s):

 kernel/cpu.c:1949: warning: Function parameter or member 
  'name' not described in '__cpuhp_setup_state_cpuslocked'

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210605063003.681049-1-libaokun1@huawei.com
2021-08-10 18:07:38 +02:00
Thomas Gleixner
1e7f7fbcd4 hrtimer: Avoid more SMP function calls in clock_was_set()
By unconditionally updating the offsets there are more indicators
whether the SMP function calls on clock_was_set() can be avoided:

  - When the offset update already happened on the remote CPU then the
    remote update attempt will yield the same seqeuence number and no
    IPI is required.

  - When the remote CPU is currently handling hrtimer_interrupt(). In
    that case the remote CPU will reevaluate the timer bases before
    reprogramming anyway, so nothing to do.

  - After updating it can be checked whether the first expiring timer in
    the affected clock bases moves before the first expiring (softirq)
    timer of the CPU. If that's not the case then sending the IPI is not
    required.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.887322464@linutronix.de
2021-08-10 17:57:23 +02:00
Marcelo Tosatti
81d741d346 hrtimer: Avoid unnecessary SMP function calls in clock_was_set()
Setting of clocks triggers an unconditional SMP function call on all online
CPUs to reprogram the clock event device.

However, only some clocks have their offsets updated and therefore
potentially require a reprogram. That's CLOCK_REALTIME and CLOCK_TAI and in
the case of resume (delayed sleep time injection) also CLOCK_BOOTTIME.

Instead of sending an IPI unconditionally, check each per CPU hrtimer base
whether it has active timers in the affected clock bases which are
indicated by the caller in the @bases argument of clock_was_set().

If that's not the case, skip the IPI and update the offsets remotely which
ensures that any subsequently armed timers on the affected clocks are
evaluated with the correct offsets.

[ tglx: Adopted to the new bases argument, removed the softirq_active
  	check, added comment, fixed up stale comment ]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.787536542@linutronix.de
2021-08-10 17:57:23 +02:00
Thomas Gleixner
17a1b8826b hrtimer: Add bases argument to clock_was_set()
clock_was_set() unconditionaly invokes retrigger_next_event() on all online
CPUs. This was necessary because that mechanism was also used for resume
from suspend to idle which is not longer the case.

The bases arguments allows the callers of clock_was_set() to hand in a mask
which tells clock_was_set() which of the hrtimer clock bases are affected
by the clock setting. This mask will be used in the next step to check
whether a CPU base has timers queued on a clock base affected by the event
and avoid the SMP function call if there are none.

Add a @bases argument, provide defines for the active bases masking and
fixup all callsites.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.691083465@linutronix.de
2021-08-10 17:57:23 +02:00
Thomas Gleixner
1b267793f4 time/timekeeping: Avoid invoking clock_was_set() twice
do_adjtimex() might end up scheduling a delayed clock_was_set() via
timekeeping_advance() and then invoke clock_was_set() directly which is
pointless.

Make timekeeping_advance() return whether an invocation of clock_was_set()
is required and handle it at the call sites which allows do_adjtimex() to
issue a single direct call if required.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.580966888@linutronix.de
2021-08-10 17:57:23 +02:00
Thomas Gleixner
a761a67f59 timekeeping: Distangle resume and clock-was-set events
Resuming timekeeping is a clock-was-set event and uses the clock-was-set
notification mechanism. This is in the way of making the clock-was-set
update for hrtimers selective so unnecessary IPIs are avoided when a CPU
base does not have timers queued which are affected by the clock setting.

Distangle it by invoking hrtimer_resume() on each unfreezing CPU and invoke
the new timerfd_resume() function from timekeeping_resume() which is the
only place where this is needed.

Rename hrtimer_resume() to hrtimer_resume_local() to reflect the change.

With this the clock_was_set*() functions are not longer required to IPI all
CPUs unconditionally and can get some smarts to avoid them.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.488853478@linutronix.de
2021-08-10 17:57:23 +02:00
Thomas Gleixner
e71a4153b7 hrtimer: Force clock_was_set() handling for the HIGHRES=n, NOHZ=y case
When CONFIG_HIGH_RES_TIMERS is disabled, but NOHZ is enabled then
clock_was_set() is not doing anything. With HIGHRES=n the kernel relies on
the periodic tick to update the clock offsets, but when NOHZ is enabled and
active then CPUs which are in a deep idle sleep do not have a periodic tick
which means the expiry of timers affected by clock_was_set() can be
arbitrarily delayed up to the point where the CPUs are brought out of idle
again.

Make the clock_was_set() logic unconditionaly available so that idle CPUs
are kicked out of idle to handle the update.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.288697903@linutronix.de
2021-08-10 17:57:22 +02:00
Thomas Gleixner
8c3b5e6ec0 hrtimer: Ensure timerfd notification for HIGHRES=n
If high resolution timers are disabled the timerfd notification about a
clock was set event is not happening for all cases which use
clock_was_set_delayed() because that's a NOP for HIGHRES=n, which is wrong.

Make clock_was_set_delayed() unconditially available to fix that.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.196661266@linutronix.de
2021-08-10 17:57:22 +02:00
Peter Zijlstra
b14bca97c9 hrtimer: Consolidate reprogramming code
This code is mostly duplicated. The redudant store in the force reprogram
case does no harm and the in hrtimer interrupt condition cannot be true for
the force reprogram invocations.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.054424875@linutronix.de
2021-08-10 17:57:22 +02:00
Thomas Gleixner
627ef5ae2d hrtimer: Avoid double reprogramming in __hrtimer_start_range_ns()
If __hrtimer_start_range_ns() is invoked with an already armed hrtimer then
the timer has to be canceled first and then added back. If the timer is the
first expiring timer then on removal the clockevent device is reprogrammed
to the next expiring timer to avoid that the pending expiry fires needlessly.

If the new expiry time ends up to be the first expiry again then the clock
event device has to reprogrammed again.

Avoid this by checking whether the timer is the first to expire and in that
case, keep the timer on the current CPU and delay the reprogramming up to
the point where the timer has been enqueued again.

Reported-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135157.873137732@linutronix.de
2021-08-10 17:57:22 +02:00
Frederic Weisbecker
ee375328f5 posix-cpu-timers: Recalc next expiration when timer_settime() ends up not queueing
There are several scenarios that can result in posix_cpu_timer_set()
not queueing the timer but still leaving the threadgroup cputime counter
running or keeping the tick dependency around for a random amount of time.

1) If timer_settime() is called with a 0 expiration on a timer that is
   already disabled, the process wide cputime counter will be started
   and won't ever get a chance to be stopped by stop_process_timer()
   since no timer is actually armed to be processed.

   The following snippet is enough to trigger the issue.

	void trigger_process_counter(void)
	{
		timer_t id;
		struct itimerspec val = { };

		timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
		timer_settime(id, TIMER_ABSTIME, &val, NULL);
		timer_delete(id);
	}

2) If timer_settime() is called with a 0 expiration on a timer that is
   already armed, the timer is dequeued but not really disarmed. So the
   process wide cputime counter and the tick dependency may still remain
   a while around.

   The following code snippet keeps this overhead around for one week after
   the timer deletion:

	void trigger_process_counter(void)
	{
		timer_t id;
		struct itimerspec val = { };

		val.it_value.tv_sec = 604800;
		timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
		timer_settime(id, 0, &val, NULL);
		timer_delete(id);
	}

3) If the timer was initially deactivated, this call to timer_settime()
   with an early expiration may have started the process wide cputime
   counter even though the timer hasn't been queued and armed because it
   has fired early and inline within posix_cpu_timer_set() itself. As a
   result the process wide cputime counter may never stop until a new
   timer is ever armed in the future.

   The following code snippet can reproduce this:

	void trigger_process_counter(void)
	{
		timer_t id;
		struct itimerspec val = { };

		signal(SIGALRM, SIG_IGN);
		timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
		val.it_value.tv_nsec = 1;
		timer_settime(id, TIMER_ABSTIME, &val, NULL);
	}

4) If the timer was initially armed with a former expiration value
   before this call to timer_settime() and the current call sets an
   early deadline that has already expired, the timer fires inline
   within posix_cpu_timer_set(). In this case it must have been dequeued
   before firing inline with its new expiration value, yet it hasn't
   been disarmed in this case. So the process wide cputime counter and
   the tick dependency may still be around for a while even after the
   timer fired.

   The following code snippet can reproduce this:

	void trigger_process_counter(void)
	{
		timer_t id;
		struct itimerspec val = { };

		signal(SIGALRM, SIG_IGN);
		timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
		val.it_value.tv_sec = 100;
		timer_settime(id, TIMER_ABSTIME, &val, NULL);
		val.it_value.tv_sec = 0;
		val.it_value.tv_nsec = 1;
		timer_settime(id, TIMER_ABSTIME, &val, NULL);
	}

Fix all these issues with triggering the related base next expiration
recalculation on the next tick. This also implies to re-evaluate the need
to keep around the process wide cputime counter and the tick dependency, in
a similar fashion to disarm_timer().

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210726125513.271824-7-frederic@kernel.org
2021-08-10 17:09:59 +02:00
Frederic Weisbecker
5c8f23e6b7 posix-cpu-timers: Consolidate timer base accessor
Remove the ad-hoc timer base accessors and provide a consolidated one.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210726125513.271824-6-frederic@kernel.org
2021-08-10 17:09:59 +02:00
Frederic Weisbecker
d9c1b2a108 posix-cpu-timers: Remove confusing return value override
The end of the function cannot be reached with an error in variable
ret. Unconfuse reviewers about that.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210726125513.271824-5-frederic@kernel.org
2021-08-10 17:09:59 +02:00
Frederic Weisbecker
406dd42bd1 posix-cpu-timers: Force next expiration recalc after itimer reset
When an itimer deactivates a previously armed expiration, it simply doesn't
do anything. As a result the process wide cputime counter keeps running and
the tick dependency stays set until it reaches the old ghost expiration
value.

This can be reproduced with the following snippet:

	void trigger_process_counter(void)
	{
		struct itimerval n = {};

		n.it_value.tv_sec = 100;
		setitimer(ITIMER_VIRTUAL, &n, NULL);
		n.it_value.tv_sec = 0;
		setitimer(ITIMER_VIRTUAL, &n, NULL);
	}

Fix this with resetting the relevant base expiration. This is similar to
disarming a timer.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210726125513.271824-4-frederic@kernel.org
2021-08-10 17:09:59 +02:00
Frederic Weisbecker
175cc3ab28 posix-cpu-timers: Force next_expiration recalc after timer deletion
A timer deletion only dequeues the timer but it doesn't shutdown
the related costly process wide cputimer counter and the tick dependency.

The following code snippet keeps this overhead around for one week after
the timer deletion:

	void trigger_process_counter(void)
	{
		timer_t id;
		struct itimerspec val = { };

		val.it_value.tv_sec = 604800;
		timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
		timer_settime(id, 0, &val, NULL);
		timer_delete(id);
	}

Make sure the next target's tick recalculates the nearest expiration and
clears the process wide counter and tick dependency if necessary.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210726125513.271824-3-frederic@kernel.org
2021-08-10 17:09:59 +02:00
Frederic Weisbecker
a5dec9f82a posix-cpu-timers: Assert task sighand is locked while starting cputime counter
Starting the process wide cputime counter needs to be done in the same
sighand locking sequence than actually arming the related timer otherwise
this races against concurrent timers setting/expiring in the same
threadgroup.

Detecting that the cputime counter is started without holding the sighand
lock is a first step toward debugging such situations.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210726125513.271824-2-frederic@kernel.org
2021-08-10 17:09:58 +02:00
Colin Ian King
1dae37c7e4 posix-timers: Remove redundant initialization of variable ret
The variable ret is being initialized with a value that is never read, it
is being updated later on. The assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210721120147.109570-1-colin.king@canonical.com
2021-08-10 17:02:11 +02:00
Jakub Kicinski
d1a4e0a957 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
bpf-next 2021-08-10

We've added 31 non-merge commits during the last 8 day(s) which contain
a total of 28 files changed, 3644 insertions(+), 519 deletions(-).

1) Native XDP support for bonding driver & related BPF selftests, from Jussi Maki.

2) Large batch of new BPF JIT tests for test_bpf.ko that came out as a result from
   32-bit MIPS JIT development, from Johan Almbladh.

3) Rewrite of netcnt BPF selftest and merge into test_progs, from Stanislav Fomichev.

4) Fix XDP bpf_prog_test_run infra after net to net-next merge, from Andrii Nakryiko.

5) Follow-up fix in unix_bpf_update_proto() to enforce socket type, from Cong Wang.

6) Fix bpf-iter-tcp4 selftest to print the correct dest IP, from Jose Blanquicet.

7) Various misc BPF XDP sample improvements, from Niklas Söderlund, Matthew Cover,
   and Muhammad Falak R Wani.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (31 commits)
  bpf, tests: Add tail call test suite
  bpf, tests: Add tests for BPF_CMPXCHG
  bpf, tests: Add tests for atomic operations
  bpf, tests: Add test for 32-bit context pointer argument passing
  bpf, tests: Add branch conversion JIT test
  bpf, tests: Add word-order tests for load/store of double words
  bpf, tests: Add tests for ALU operations implemented with function calls
  bpf, tests: Add more ALU64 BPF_MUL tests
  bpf, tests: Add more BPF_LSH/RSH/ARSH tests for ALU64
  bpf, tests: Add more ALU32 tests for BPF_LSH/RSH/ARSH
  bpf, tests: Add more tests of ALU32 and ALU64 bitwise operations
  bpf, tests: Fix typos in test case descriptions
  bpf, tests: Add BPF_MOV tests for zero and sign extension
  bpf, tests: Add BPF_JMP32 test cases
  samples, bpf: Add an explict comment to handle nested vlan tagging.
  selftests/bpf: Add tests for XDP bonding
  selftests/bpf: Fix xdp_tx.c prog section name
  net, core: Allow netdev_lower_get_next_private_rcu in bh context
  bpf, devmap: Exclude XDP broadcast to master device
  net, bonding: Add XDP support to the bonding driver
  ...
====================

Link: https://lore.kernel.org/r/20210810130038.16927-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-10 07:53:22 -07:00
Bixuan Cui
dbbc93576e genirq/msi: Ensure deactivation on teardown
msi_domain_alloc_irqs() invokes irq_domain_activate_irq(), but
msi_domain_free_irqs() does not enforce deactivation before tearing down
the interrupts.

This happens when PCI/MSI interrupts are set up and never used before being
torn down again, e.g. in error handling pathes. The only place which cleans
that up is the error handling path in msi_domain_alloc_irqs().

Move the cleanup from msi_domain_alloc_irqs() into msi_domain_free_irqs()
to cure that.

Fixes: f3b0946d62 ("genirq/msi: Make sure PCI MSIs are activated early")
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210518033117.78104-1-cuibixuan@huawei.com
2021-08-10 15:55:19 +02:00
Ben Dai
b9cc7d8a46 genirq/timings: Prevent potential array overflow in __irq_timings_store()
When the interrupt interval is greater than 2 ^ PREDICTION_BUFFER_SIZE *
PREDICTION_FACTOR us and less than 1s, the calculated index will be greater
than the length of irqs->ema_time[]. Check the calculated index before
using it to prevent array overflow.

Fixes: 23aa3b9a6b ("genirq/timings: Encapsulate storing function")
Signed-off-by: Ben Dai <ben.dai@unisoc.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210425150903.25456-1-ben.dai9703@gmail.com
2021-08-10 15:39:00 +02:00
Gustavo A. R. Silva
5a6c76b5de genirq/generic_chip: Use struct_size() in kzalloc()
Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows
that, in the worst scenario, could lead to heap overflows.

This code was detected with the help of Coccinelle and, audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210513212729.GA214145@embeddedor
2021-08-10 15:35:20 +02:00
Cédric Le Goater
51be9e51a8 KVM: PPC: Book3S HV: XIVE: Fix mapping of passthrough interrupts
PCI MSI interrupt numbers are now mapped in a PCI-MSI domain but the
underlying calls handling the passthrough of the interrupt in the
guest need a number in the XIVE IRQ domain.

Use the IRQ data mapped in the XIVE IRQ domain and not the one in the
PCI-MSI domain.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210701132750.1475580-16-clg@kaod.org
2021-08-10 23:14:59 +10:00
Joel Savitz
61377ec144 genirq: Clarify documentation for request_threaded_irq()
Clarify wording and document commonly used IRQF_ONESHOT flag.

Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210731050740.444454-1-jsavitz@redhat.com
2021-08-10 15:06:04 +02:00
Sebastian Andrzej Siewior
844d87871b smpboot: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210803141621.780504-34-bigeasy@linutronix.de
2021-08-10 14:57:42 +02:00
Sebastian Andrzej Siewior
698429f9d0 clocksource: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210803141621.780504-35-bigeasy@linutronix.de
2021-08-10 14:53:58 +02:00
Sebastian Andrzej Siewior
746f5ea9c4 sched: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210803141621.780504-33-bigeasy@linutronix.de
2021-08-10 14:53:00 +02:00
Sebastian Andrzej Siewior
428e211641 genirq/affinity: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210803141621.780504-26-bigeasy@linutronix.de
2021-08-10 14:51:26 +02:00
Randy Dunlap
019d0454c6 bpf, core: Fix kernel-doc notation
Fix kernel-doc warnings in kernel/bpf/core.c (found by scripts/kernel-doc
and W=1 builds). That is, correct a function name in a comment and add
return descriptions for 2 functions.

Fixes these kernel-doc warnings:

  kernel/bpf/core.c:1372: warning: expecting prototype for __bpf_prog_run(). Prototype was for ___bpf_prog_run() instead
  kernel/bpf/core.c:1372: warning: No description found for return value of '___bpf_prog_run'
  kernel/bpf/core.c:1883: warning: No description found for return value of 'bpf_prog_select_runtime'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210809215229.7556-1-rdunlap@infradead.org
2021-08-10 13:09:28 +02:00
Matthew Bobrowski
490b9ba881 kernel/pid.c: implement additional checks upon pidfd_create() parameters
By adding the pidfd_create() declaration to linux/pid.h, we
effectively expose this function to the rest of the kernel. In order
to avoid any unintended behavior, or set false expectations upon this
function, ensure that constraints are forced upon each of the passed
parameters. This includes the checking of whether the passed struct
pid is a thread-group leader as pidfd creation is currently limited to
such pid types.

Link: https://lore.kernel.org/r/2e9b91c2d529d52a003b8b86c45f866153be9eb5.1628398044.git.repnop@google.com
Signed-off-by: Matthew Bobrowski <repnop@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-08-10 12:53:07 +02:00
Matthew Bobrowski
c576e0fcd6 kernel/pid.c: remove static qualifier from pidfd_create()
With the idea of returning pidfds from the fanotify API, we need to
expose a mechanism for creating pidfds. We drop the static qualifier
from pidfd_create() and add its declaration to linux/pid.h so that the
pidfd_create() helper can be called from other kernel subsystems
i.e. fanotify.

Link: https://lore.kernel.org/r/0c68653ec32f1b7143301f0231f7ed14062fd82b.1628398044.git.repnop@google.com
Signed-off-by: Matthew Bobrowski <repnop@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-08-10 12:53:04 +02:00
Thomas Gleixner
4b41ea606e Merge branch 'irq/urgent' into irq/core
to pick up fixes on which further changes depend on.
2021-08-10 11:01:42 +02:00
Thomas Gleixner
826da77129 genirq: Provide IRQCHIP_AFFINITY_PRE_STARTUP
X86 IO/APIC and MSI interrupts (when used without interrupts remapping)
require that the affinity setup on startup is done before the interrupt is
enabled for the first time as the non-remapped operation mode cannot safely
migrate enabled interrupts from arbitrary contexts. Provide a new irq chip
flag which allows affected hardware to request this.

This has to be opt-in because there have been reports in the past that some
interrupt chips cannot handle affinity setting before startup.

Fixes: 1840475676 ("genirq: Expose default irq affinity mask (take 3)")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210729222542.779791738@linutronix.de
2021-08-10 10:59:20 +02:00
Yonghong Song
a2baf4e8bb bpf: Fix potentially incorrect results with bpf_get_local_storage()
Commit b910eaaaa4 ("bpf: Fix NULL pointer dereference in bpf_get_local_storage()
helper") fixed a bug for bpf_get_local_storage() helper so different tasks
won't mess up with each other's percpu local storage.

The percpu data contains 8 slots so it can hold up to 8 contexts (same or
different tasks), for 8 different program runs, at the same time. This in
general is sufficient. But our internal testing showed the following warning
multiple times:

  [...]
  warning: WARNING: CPU: 13 PID: 41661 at include/linux/bpf-cgroup.h:193
     __cgroup_bpf_run_filter_sock_ops+0x13e/0x180
  RIP: 0010:__cgroup_bpf_run_filter_sock_ops+0x13e/0x180
  <IRQ>
   tcp_call_bpf.constprop.99+0x93/0xc0
   tcp_conn_request+0x41e/0xa50
   ? tcp_rcv_state_process+0x203/0xe00
   tcp_rcv_state_process+0x203/0xe00
   ? sk_filter_trim_cap+0xbc/0x210
   ? tcp_v6_inbound_md5_hash.constprop.41+0x44/0x160
   tcp_v6_do_rcv+0x181/0x3e0
   tcp_v6_rcv+0xc65/0xcb0
   ip6_protocol_deliver_rcu+0xbd/0x450
   ip6_input_finish+0x11/0x20
   ip6_input+0xb5/0xc0
   ip6_sublist_rcv_finish+0x37/0x50
   ip6_sublist_rcv+0x1dc/0x270
   ipv6_list_rcv+0x113/0x140
   __netif_receive_skb_list_core+0x1a0/0x210
   netif_receive_skb_list_internal+0x186/0x2a0
   gro_normal_list.part.170+0x19/0x40
   napi_complete_done+0x65/0x150
   mlx5e_napi_poll+0x1ae/0x680
   __napi_poll+0x25/0x120
   net_rx_action+0x11e/0x280
   __do_softirq+0xbb/0x271
   irq_exit_rcu+0x97/0xa0
   common_interrupt+0x7f/0xa0
   </IRQ>
   asm_common_interrupt+0x1e/0x40
  RIP: 0010:bpf_prog_1835a9241238291a_tw_egress+0x5/0xbac
   ? __cgroup_bpf_run_filter_skb+0x378/0x4e0
   ? do_softirq+0x34/0x70
   ? ip6_finish_output2+0x266/0x590
   ? ip6_finish_output+0x66/0xa0
   ? ip6_output+0x6c/0x130
   ? ip6_xmit+0x279/0x550
   ? ip6_dst_check+0x61/0xd0
  [...]

Using drgn [0] to dump the percpu buffer contents showed that on this CPU
slot 0 is still available, but slots 1-7 are occupied and those tasks in
slots 1-7 mostly don't exist any more. So we might have issues in
bpf_cgroup_storage_unset().

Further debugging confirmed that there is a bug in bpf_cgroup_storage_unset().
Currently, it tries to unset "current" slot with searching from the start.
So the following sequence is possible:

  1. A task is running and claims slot 0
  2. Running BPF program is done, and it checked slot 0 has the "task"
     and ready to reset it to NULL (not yet).
  3. An interrupt happens, another BPF program runs and it claims slot 1
     with the *same* task.
  4. The unset() in interrupt context releases slot 0 since it matches "task".
  5. Interrupt is done, the task in process context reset slot 0.

At the end, slot 1 is not reset and the same process can continue to occupy
slots 2-7 and finally, when the above step 1-5 is repeated again, step 3 BPF
program won't be able to claim an empty slot and a warning will be issued.

To fix the issue, for unset() function, we should traverse from the last slot
to the first. This way, the above issue can be avoided.

The same reverse traversal should also be done in bpf_get_local_storage() helper
itself. Otherwise, incorrect local storage may be returned to BPF program.

  [0] https://github.com/osandov/drgn

Fixes: b910eaaaa4 ("bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210810010413.1976277-1-yhs@fb.com
2021-08-10 10:27:16 +02:00
Daniel Borkmann
51e1bb9eea bpf: Add lockdown check for probe_write_user helper
Back then, commit 96ae522795 ("bpf: Add bpf_probe_write_user BPF helper
to be called in tracers") added the bpf_probe_write_user() helper in order
to allow to override user space memory. Its original goal was to have a
facility to "debug, divert, and manipulate execution of semi-cooperative
processes" under CAP_SYS_ADMIN. Write to kernel was explicitly disallowed
since it would otherwise tamper with its integrity.

One use case was shown in cf9b1199de ("samples/bpf: Add test/example of
using bpf_probe_write_user bpf helper") where the program DNATs traffic
at the time of connect(2) syscall, meaning, it rewrites the arguments to
a syscall while they're still in userspace, and before the syscall has a
chance to copy the argument into kernel space. These days we have better
mechanisms in BPF for achieving the same (e.g. for load-balancers), but
without having to write to userspace memory.

Of course the bpf_probe_write_user() helper can also be used to abuse
many other things for both good or bad purpose. Outside of BPF, there is
a similar mechanism for ptrace(2) such as PTRACE_PEEK{TEXT,DATA} and
PTRACE_POKE{TEXT,DATA}, but would likely require some more effort.
Commit 96ae522795 explicitly dedicated the helper for experimentation
purpose only. Thus, move the helper's availability behind a newly added
LOCKDOWN_BPF_WRITE_USER lockdown knob so that the helper is disabled under
the "integrity" mode. More fine-grained control can be implemented also
from LSM side with this change.

Fixes: 96ae522795 ("bpf: Add bpf_probe_write_user BPF helper to be called in tracers")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
2021-08-10 10:10:10 +02:00
Zhen Lei
07d25971b2 locking/rtmutex: Use the correct rtmutex debugging config option
It's CONFIG_DEBUG_RT_MUTEXES not CONFIG_DEBUG_RT_MUTEX.

Fixes: f7efc4799f ("locking/rtmutex: Inline chainwalk depth check")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210731123011.4555-1-thunder.leizhen@huawei.com
2021-08-10 08:21:52 +02:00
Linus Torvalds
9a73fa375d Merge branch 'for-5.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
 "One commit to fix a possible A-A deadlock around u64_stats_sync on
  32bit machines caused by updating it without disabling IRQ when it may
  be read from IRQ context"

* 'for-5.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: rstat: fix A-A deadlock on 32bit around u64_stats_sync
2021-08-09 16:47:36 -07:00
Sebastian Andrzej Siewior
c5c63b9a6a cgroup: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-09 12:53:35 -10:00
Waiman Long
6ba34d3c73 cgroup/cpuset: Fix violation of cpuset locking rule
The cpuset fields that manage partition root state do not strictly
follow the cpuset locking rule that update to cpuset has to be done
with both the callback_lock and cpuset_mutex held. This is now fixed
by making sure that the locking rule is upheld.

Fixes: 3881b86128 ("cpuset: Add an error state to cpuset.sched.partition")
Fixes: 4b842da276 ("cpuset: Make CPU hotplug work with partition")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-09 12:53:19 -10:00
Sebastian Andrzej Siewior
ffd8bea81f workqueue: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Cc: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-09 12:33:30 -10:00
Zhen Lei
e441b56fe4 workqueue: Replace deprecated ida_simple_*() with ida_alloc()/ida_free()
Replace ida_simple_get() with ida_alloc() and ida_simple_remove() with
ida_free(), the latter is more concise and intuitive.

In addition, if ida_alloc() fails, NULL is returned directly. This
eliminates unnecessary initialization of two local variables and an 'if'
judgment.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-09 12:32:38 -10:00
Cai Huoqing
67dc832537 workqueue: Fix typo in comments
Fix typo:
*assing  ==> assign
*alloced  ==> allocated
*Retun  ==> Return
*excute  ==> execute

v1->v2:
*reverse 'iff'
*update changelog

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-08-09 12:31:03 -10:00
Jussi Maki
aeea1b86f9 bpf, devmap: Exclude XDP broadcast to master device
If the ingress device is bond slave, do not broadcast back through it or
the bond master.

Signed-off-by: Jussi Maki <joamaki@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210731055738.16820-5-joamaki@gmail.com
2021-08-09 23:25:14 +02:00
Sven Schnelle
f153c22467 ucounts: add missing data type changes
commit f9c82a4ea8 ("Increase size of ucounts to atomic_long_t")
changed the data type of ucounts/ucounts_max to long, but missed to
adjust a few other places. This is noticeable on big endian platforms
from user space because the /proc/sys/user/max_*_names files all
contain 0.

v4 - Made the min and max constants long so the sysctl values
     are actually settable on little endian machines.
     -- EWB

Fixes: f9c82a4ea8 ("Increase size of ucounts to atomic_long_t")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Acked-by: Alexey Gladkov <legion@kernel.org>
v1: https://lkml.kernel.org/r/20210721115800.910778-1-svens@linux.ibm.com
v2: https://lkml.kernel.org/r/20210721125233.1041429-1-svens@linux.ibm.com
v3: https://lkml.kernel.org/r/20210730062854.3601635-1-svens@linux.ibm.com
Link: https://lkml.kernel.org/r/8735rijqlv.fsf_-_@disp2133
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2021-08-09 15:45:02 -05:00
Daniel Borkmann
71330842ff bpf: Add _kernel suffix to internal lockdown_bpf_read
Rename LOCKDOWN_BPF_READ into LOCKDOWN_BPF_READ_KERNEL so we have naming
more consistent with a LOCKDOWN_BPF_WRITE_USER option that we are adding.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
2021-08-09 21:50:41 +02:00
Logan Gunthorpe
d03c544192 dma-mapping: disallow .map_sg operations from returning zero on error
Now that all the .map_sg operations have been converted to returning
proper error codes, drop the code to handle a zero return value,
add a warning if a zero is returned.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-09 17:15:02 +02:00
Martin Oliveira
66ab63104f dma-mapping: return error code from dma_dummy_map_sg()
The .map_sg() op now expects an error code instead of zero on failure.

The only errno to return is -EINVAL in the case when DMA is not
supported.

Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-09 17:13:06 +02:00
Logan Gunthorpe
c81be74e7d dma-direct: return appropriate error code from dma_direct_map_sg()
Now that the map_sg() op expects error codes instead of return zero on
error, convert dma_direct_map_sg() to return an error code. Per the
documentation for dma_map_sgtable(), -EIO is returned due to an
DMA_MAPPING_ERROR with unknown cause.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-09 17:13:04 +02:00
Logan Gunthorpe
fffe3cc8c2 dma-mapping: allow map_sg() ops to return negative error codes
Allow dma_map_sgtable() to pass errors from the map_sg() ops. This
will be required for returning appropriate error codes when mapping
P2PDMA memory.

Introduce __dma_map_sg_attrs() which will return the raw error code
from the map_sg operation (whether it be negative or zero). Then add a
dma_map_sg_attrs() wrapper to convert any negative errors to zero to
satisfy the existing calling convention.

dma_map_sgtable() defines three error codes that .map_sg implementations
are allowed to return: -EINVAL, -ENOMEM and -EIO. The latter of which
is a generic return for cases that are passing DMA_MAPPING_ERROR
through.

dma_map_sgtable() will convert a zero error return for old map_sg() ops
into a -EIO return and return any negative errors as reported.

This allows map_sg implementations to start returning multiple
negative error codes. Legacy map_sg implementations can continue
to return zero until they are all converted.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-09 17:13:02 +02:00
Anthony Iliopoulos
173735c346 dma-debug: fix debugfs initialization order
Due to link order, dma_debug_init is called before debugfs has a chance
to initialize (via debugfs_init which also happens in the core initcall
stage), so the directories for dma-debug are never created.

Decouple dma_debug_fs_init from dma_debug_init and defer its init until
core_initcall_sync (after debugfs has been initialized) while letting
dma-debug initialization occur as soon as possible to catch any early
mappings, as suggested in [1].

[1] https://lore.kernel.org/linux-iommu/YIgGa6yF%2Fadg8OSN@kroah.com/

Fixes: 15b28bbcd5 ("dma-debug: move initialization to common code")
Signed-off-by: Anthony Iliopoulos <ailiop@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-09 17:06:11 +02:00
Kefeng Wang
1d7db834a0 dma-debug: use memory_intersects() directly
There is already a memory_intersects() helper in sections.h,
use memory_intersects() directly instead of private overlap().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-09 17:03:17 +02:00
Linus Torvalds
cceb634774 A single timer fix:
- Prevent a memory ordering issue in the timer expiry code which makes it
    possible to observe falsely that the callback has been executed already
    while that's not the case, which violates the guarantee of del_timer_sync().
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Merge tag 'timers-urgent-2021-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fix from Thomas Gleixner:
 "A single timer fix:

   - Prevent a memory ordering issue in the timer expiry code which
     makes it possible to observe falsely that the callback has been
     executed already while that's not the case, which violates the
     guarantee of del_timer_sync()"

* tag 'timers-urgent-2021-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers: Move clearing of base::timer_running under base:: Lock
2021-08-08 11:53:30 -07:00
Linus Torvalds
713f0f37e8 A single scheduler fix:
- Prevent a double enqueue caused by rt_effective_prio() being invoked
    twice in __sched_setscheduler().
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Merge tag 'sched-urgent-2021-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fix from Thomas Gleixner:
 "A single scheduler fix:

   - Prevent a double enqueue caused by rt_effective_prio() being
     invoked twice in __sched_setscheduler()"

* tag 'sched-urgent-2021-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/rt: Fix double enqueue caused by rt_effective_prio
2021-08-08 11:50:07 -07:00
Linus Torvalds
74eedeba45 A set of perf fixes:
- Correct the permission checks for perf event which send SIGTRAP to a
    different process and clean up that code to be more readable.
 
  - Prevent an out of bound MSR access in the x86 perf code which happened
    due to an incomplete limiting to the actually available hardware
    counters.
 
  - Prevent access to the AMD64_EVENTSEL_HOSTONLY bit when running inside a
    guest.
 
  - Handle small core counter re-enabling correctly by issuing an ACK right
    before reenabling it to prevent a stale PEBS record being kept around.
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Merge tag 'perf-urgent-2021-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Thomas Gleixner:
 "A set of perf fixes:

   - Correct the permission checks for perf event which send SIGTRAP to
     a different process and clean up that code to be more readable.

   - Prevent an out of bound MSR access in the x86 perf code which
     happened due to an incomplete limiting to the actually available
     hardware counters.

   - Prevent access to the AMD64_EVENTSEL_HOSTONLY bit when running
     inside a guest.

   - Handle small core counter re-enabling correctly by issuing an ACK
     right before reenabling it to prevent a stale PEBS record being
     kept around"

* tag 'perf-urgent-2021-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Apply mid ACK for small core
  perf/x86/amd: Don't touch the AMD64_EVENTSEL_HOSTONLY bit inside the guest
  perf/x86: Fix out of bound MSR access
  perf: Refactor permissions check into perf_check_permission()
  perf: Fix required permissions if sigtrap is requested
2021-08-08 11:46:13 -07:00
David S. Miller
84103209ba Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2021-08-07

The following pull-request contains BPF updates for your *net* tree.

We've added 4 non-merge commits during the last 9 day(s) which contain
a total of 4 files changed, 8 insertions(+), 7 deletions(-).

The main changes are:

1) Fix integer overflow in htab's lookup + delete batch op, from Tatsuhiko Yasumatsu.

2) Fix invalid fd 0 close in libbpf if BTF parsing failed, from Daniel Xu.

3) Fix libbpf feature probe for BPF_PROG_TYPE_CGROUP_SOCKOPT, from Robin Gögge.

4) Fix minor libbpf doc warning regarding code-block language, from Randy Dunlap.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-07 09:26:54 +01:00