36288 Commits

Author SHA1 Message Date
Florent Revest
7b15523a98 bpf: Add a bpf_snprintf helper
The implementation takes inspiration from the existing bpf_trace_printk
helper but there are a few differences:

To allow for a large number of format-specifiers, parameters are
provided in an array, like in bpf_seq_printf.

Because the output string takes two arguments and the array of
parameters also takes two arguments, the format string needs to fit in
one argument. Thankfully, ARG_PTR_TO_CONST_STR is guaranteed to point to
a zero-terminated read-only map so we don't need a format string length
arg.

Because the format-string is known at verification time, we also do
a first pass of format string validation in the verifier logic. This
makes debugging easier.

Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210419155243.1632274-4-revest@chromium.org
2021-04-19 15:27:36 -07:00
Florent Revest
fff13c4bb6 bpf: Add a ARG_PTR_TO_CONST_STR argument type
This type provides the guarantee that an argument is going to be a const
pointer to somewhere in a read-only map value. It also checks that this
pointer is followed by a zero character before the end of the map value.

Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210419155243.1632274-3-revest@chromium.org
2021-04-19 15:27:36 -07:00
Florent Revest
d9c9e4db18 bpf: Factorize bpf_trace_printk and bpf_seq_printf
Two helpers (trace_printk and seq_printf) have very similar
implementations of format string parsing and a third one is coming
(snprintf). To avoid code duplication and make the code easier to
maintain, this moves the operations associated with format string
parsing (validation and argument sanitization) into one generic
function.

The implementation of the two existing helpers already drifted quite a
bit so unifying them entailed a lot of changes:

- bpf_trace_printk always expected fmt[fmt_size] to be the terminating
  NULL character, this is no longer true, the first 0 is terminating.
- bpf_trace_printk now supports %% (which produces the percentage char).
- bpf_trace_printk now skips width formating fields.
- bpf_trace_printk now supports the X modifier (capital hexadecimal).
- bpf_trace_printk now supports %pK, %px, %pB, %pi4, %pI4, %pi6 and %pI6
- argument casting on 32 bit has been simplified into one macro and
  using an enum instead of obscure int increments.

- bpf_seq_printf now uses bpf_trace_copy_string instead of
  strncpy_from_kernel_nofault and handles the %pks %pus specifiers.
- bpf_seq_printf now prints longs correctly on 32 bit architectures.

- both were changed to use a global per-cpu tmp buffer instead of one
  stack buffer for trace_printk and 6 small buffers for seq_printf.
- to avoid per-cpu buffer usage conflict, these helpers disable
  preemption while the per-cpu buffer is in use.
- both helpers now support the %ps and %pS specifiers to print symbols.

The implementation is also moved from bpf_trace.c to helpers.c because
the upcoming bpf_snprintf helper will be made available to all BPF
programs and will need it.

Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210419155243.1632274-2-revest@chromium.org
2021-04-19 15:27:36 -07:00
Linus Torvalds
7af0814097 Revert "gcov: clang: fix clang-11+ build"
This reverts commit 04c53de57cb6435738961dace8b1b71d3ecd3c39.

Nathan Chancellor points out that it should not have been merged into
mainline by itself. It was a fix for "gcov: use kvmalloc()", which is
still in -mm/-next. Merging it alone has broken the build.

Link: https://github.com/ClangBuiltLinux/continuous-integration2/runs/2384465683?check_suite_focus=true
Reported-by: Nathan Chancellor <nathan@kernel.org>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-19 15:08:49 -07:00
Kan Liang
55bcf6ef31 perf: Extend PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE
Current Hardware events and Hardware cache events have special perf
types, PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE. The two types don't
pass the PMU type in the user interface. For a hybrid system, the perf
subsystem doesn't know which PMU the events belong to. The first capable
PMU will always be assigned to the events. The events never get a chance
to run on the other capable PMUs.

Extend the two types to become PMU aware types. The PMU type ID is
stored at attr.config[63:32].

Add a new PMU capability, PERF_PMU_CAP_EXTENDED_HW_TYPE, to indicate a
PMU which supports the extended PERF_TYPE_HARDWARE and
PERF_TYPE_HW_CACHE.

The PMU type is only required when searching a specific PMU. The PMU
specific codes will only be interested in the 'real' config value, which
is stored in the low 32 bit of the event->attr.config. Update the
event->attr.config in the generic code, so the PMU specific codes don't
need to calculate it separately.

If a user specifies a PMU type, but the PMU doesn't support the extended
type, error out.

If an event cannot be initialized in a PMU specified by a user, error
out immediately. Perf should not try to open it on other PMUs.

The new PMU capability is only set for the X86 hybrid PMUs for now.
Other architectures, e.g., ARM, may need it as well. The support on ARM
may be implemented later separately.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1618237865-33448-22-git-send-email-kan.liang@linux.intel.com
2021-04-19 20:03:29 +02:00
Zhouyi Zhou
0c89d87d1d preempt/dynamic: Fix typo in macro conditional statement
Commit 40607ee97e4e ("preempt/dynamic: Provide irqentry_exit_cond_resched()
static call") tried to provide irqentry_exit_cond_resched() static call
in irqentry_exit, but has a typo in macro conditional statement.

Fixes: 40607ee97e4e ("preempt/dynamic: Provide irqentry_exit_cond_resched() static call")
Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210410073523.5493-1-zhouzhouyi@gmail.com
2021-04-19 20:02:57 +02:00
Jakub Kicinski
8203c7ce4e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
 - keep the ZC code, drop the code related to reinit
net/bridge/netfilter/ebtables.c
 - fix build after move to net_generic

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-17 11:08:07 -07:00
Linus Torvalds
88a5af9439 Networking fixes for 5.12-rc8, including fixes from netfilter,
and bpf. BPF verifier changes stand out, otherwise things have
 slowed down.
 
 Current release - regressions:
 
  - gro: ensure frag0 meets IP header alignment
 
  - Revert "net: stmmac: re-init rx buffers when mac resume back"
 
  - ethernet: macb: fix the restore of cmp registers
 
 Previous releases - regressions:
 
  - ixgbe: Fix NULL pointer dereference in ethtool loopback test
 
  - ixgbe: fix unbalanced device enable/disable in suspend/resume
 
  - phy: marvell: fix detection of PHY on Topaz switches
 
  - make tcp_allowed_congestion_control readonly in non-init netns
 
  - xen-netback: Check for hotplug-status existence before watching
 
 Previous releases - always broken:
 
  - bpf: mitigate a speculative oob read of up to map value size by
         tightening the masking window
 
  - sctp: fix race condition in sctp_destroy_sock
 
  - sit, ip6_tunnel: Unregister catch-all devices
 
  - netfilter: nftables: clone set element expression template
 
  - netfilter: flowtable: fix NAT IPv6 offload mangling
 
  - net: geneve: check skb is large enough for IPv4/IPv6 header
 
  - netlink: don't call ->netlink_bind with table lock held
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.12-rc8, including fixes from netfilter, and
  bpf. BPF verifier changes stand out, otherwise things have slowed
  down.

  Current release - regressions:

   - gro: ensure frag0 meets IP header alignment

   - Revert "net: stmmac: re-init rx buffers when mac resume back"

   - ethernet: macb: fix the restore of cmp registers

  Previous releases - regressions:

   - ixgbe: Fix NULL pointer dereference in ethtool loopback test

   - ixgbe: fix unbalanced device enable/disable in suspend/resume

   - phy: marvell: fix detection of PHY on Topaz switches

   - make tcp_allowed_congestion_control readonly in non-init netns

   - xen-netback: Check for hotplug-status existence before watching

  Previous releases - always broken:

   - bpf: mitigate a speculative oob read of up to map value size by
     tightening the masking window

   - sctp: fix race condition in sctp_destroy_sock

   - sit, ip6_tunnel: Unregister catch-all devices

   - netfilter: nftables: clone set element expression template

   - netfilter: flowtable: fix NAT IPv6 offload mangling

   - net: geneve: check skb is large enough for IPv4/IPv6 header

   - netlink: don't call ->netlink_bind with table lock held"

* tag 'net-5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (52 commits)
  netlink: don't call ->netlink_bind with table lock held
  MAINTAINERS: update my email
  bpf: Update selftests to reflect new error states
  bpf: Tighten speculative pointer arithmetic mask
  bpf: Move sanitize_val_alu out of op switch
  bpf: Refactor and streamline bounds check into helper
  bpf: Improve verifier error messages for users
  bpf: Rework ptr_limit into alu_limit and add common error path
  bpf: Ensure off_reg has no mixed signed bounds for all types
  bpf: Move off_reg into sanitize_ptr_alu
  bpf: Use correct permission flag for mixed signed bounds arithmetic
  ch_ktls: do not send snd_una update to TCB in middle
  ch_ktls: tcb close causes tls connection failure
  ch_ktls: fix device connection close
  ch_ktls: Fix kernel panic
  i40e: fix the panic when running bpf in xdpdrv mode
  net/mlx5e: fix ingress_ifindex check in mlx5e_flower_parse_meta
  net/mlx5e: Fix setting of RS FEC mode
  net/mlx5: Fix setting of devlink traps in switchdev mode
  Revert "net: stmmac: re-init rx buffers when mac resume back"
  ...
2021-04-17 09:57:15 -07:00
Chen Jun
2d036dfa5f posix-timers: Preserve return value in clock_adjtime32()
The return value on success (>= 0) is overwritten by the return value of
put_old_timex32(). That works correct in the fault case, but is wrong for
the success case where put_old_timex32() returns 0.

Just check the return value of put_old_timex32() and return -EFAULT in case
it is not zero.

[ tglx: Massage changelog ]

Fixes: 3a4d44b61625 ("ntp: Move adjtimex related compat syscalls to native counterparts")
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Cochran <richardcochran@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210414030449.90692-1-chenjun102@huawei.com
2021-04-17 14:55:06 +02:00
Ali Saidi
84a24bf8c5 locking/qrwlock: Fix ordering in queued_write_lock_slowpath()
While this code is executed with the wait_lock held, a reader can
acquire the lock without holding wait_lock.  The writer side loops
checking the value with the atomic_cond_read_acquire(), but only truly
acquires the lock when the compare-and-exchange is completed
successfully which isn’t ordered. This exposes the window between the
acquire and the cmpxchg to an A-B-A problem which allows reads
following the lock acquisition to observe values speculatively before
the write lock is truly acquired.

We've seen a problem in epoll where the reader does a xchg while
holding the read lock, but the writer can see a value change out from
under it.

  Writer                                | Reader
  --------------------------------------------------------------------------------
  ep_scan_ready_list()                  |
  |- write_lock_irq()                   |
      |- queued_write_lock_slowpath()   |
	|- atomic_cond_read_acquire()   |
				        | read_lock_irqsave(&ep->lock, flags);
     --> (observes value before unlock) |  chain_epi_lockless()
     |                                  |    epi->next = xchg(&ep->ovflist, epi);
     |                                  | read_unlock_irqrestore(&ep->lock, flags);
     |                                  |
     |     atomic_cmpxchg_relaxed()     |
     |-- READ_ONCE(ep->ovflist);        |

A core can order the read of the ovflist ahead of the
atomic_cmpxchg_relaxed(). Switching the cmpxchg to use acquire
semantics addresses this issue at which point the atomic_cond_read can
be switched to use relaxed semantics.

Fixes: b519b56e378ee ("locking/qrwlock: Use atomic_cond_read_acquire() when spinning in qrwlock")
Signed-off-by: Ali Saidi <alisaidi@amazon.com>
[peterz: use try_cmpxchg()]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Tested-by: Steve Capper <steve.capper@arm.com>
2021-04-17 13:40:50 +02:00
Peter Zijlstra
9406415f46 sched/debug: Rename the sched_debug parameter to sched_verbose
CONFIG_SCHED_DEBUG is the build-time Kconfig knob, the boot param
sched_debug and the /debug/sched/debug_enabled knobs control the
sched_debug_enabled variable, but what they really do is make
SCHED_DEBUG more verbose, so rename the lot.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-04-17 13:22:44 +02:00
Johannes Berg
04c53de57c gcov: clang: fix clang-11+ build
With clang-11+, the code is broken due to my kvmalloc() conversion
(which predated the clang-11 support code) leaving one vmalloc() in
place.  Fix that.

Link: https://lkml.kernel.org/r/20210412214210.6e1ecca9cdc5.I24459763acf0591d5e6b31c7e3a59890d802f79c@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-16 16:10:37 -07:00
David S. Miller
b022654296 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2021-04-17

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

We've added 10 non-merge commits during the last 9 day(s) which contain
a total of 8 files changed, 175 insertions(+), 111 deletions(-).

The main changes are:

1) Fix a potential NULL pointer dereference in libbpf's xsk
   umem handling, from Ciara Loftus.

2) Mitigate a speculative oob read of up to map value size by
   tightening the masking window, from Daniel Borkmann.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-16 15:48:08 -07:00
Daniel Borkmann
7fedb63a83 bpf: Tighten speculative pointer arithmetic mask
This work tightens the offset mask we use for unprivileged pointer arithmetic
in order to mitigate a corner case reported by Piotr and Benedict where in
the speculative domain it is possible to advance, for example, the map value
pointer by up to value_size-1 out-of-bounds in order to leak kernel memory
via side-channel to user space.

Before this change, the computed ptr_limit for retrieve_ptr_limit() helper
represents largest valid distance when moving pointer to the right or left
which is then fed as aux->alu_limit to generate masking instructions against
the offset register. After the change, the derived aux->alu_limit represents
the largest potential value of the offset register which we mask against which
is just a narrower subset of the former limit.

For minimal complexity, we call sanitize_ptr_alu() from 2 observation points
in adjust_ptr_min_max_vals(), that is, before and after the simulated alu
operation. In the first step, we retieve the alu_state and alu_limit before
the operation as well as we branch-off a verifier path and push it to the
verification stack as we did before which checks the dst_reg under truncation,
in other words, when the speculative domain would attempt to move the pointer
out-of-bounds.

In the second step, we retrieve the new alu_limit and calculate the absolute
distance between both. Moreover, we commit the alu_state and final alu_limit
via update_alu_sanitation_state() to the env's instruction aux data, and bail
out from there if there is a mismatch due to coming from different verification
paths with different states.

Reported-by: Piotr Krysiuk <piotras@gmail.com>
Reported-by: Benedict Schlueter <benedict.schlueter@rub.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Benedict Schlueter <benedict.schlueter@rub.de>
2021-04-16 23:52:01 +02:00
Daniel Borkmann
f528819334 bpf: Move sanitize_val_alu out of op switch
Add a small sanitize_needed() helper function and move sanitize_val_alu()
out of the main opcode switch. In upcoming work, we'll move sanitize_ptr_alu()
as well out of its opcode switch so this helps to streamline both.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16 23:51:57 +02:00
Daniel Borkmann
073815b756 bpf: Refactor and streamline bounds check into helper
Move the bounds check in adjust_ptr_min_max_vals() into a small helper named
sanitize_check_bounds() in order to simplify the former a bit.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16 23:51:54 +02:00
Daniel Borkmann
a6aaece00a bpf: Improve verifier error messages for users
Consolidate all error handling and provide more user-friendly error messages
from sanitize_ptr_alu() and sanitize_val_alu().

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16 23:51:48 +02:00
Daniel Borkmann
b658bbb844 bpf: Rework ptr_limit into alu_limit and add common error path
Small refactor with no semantic changes in order to consolidate the max
ptr_limit boundary check.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16 23:51:43 +02:00
Daniel Borkmann
24c109bb15 bpf: Ensure off_reg has no mixed signed bounds for all types
The mixed signed bounds check really belongs into retrieve_ptr_limit()
instead of outside of it in adjust_ptr_min_max_vals(). The reason is
that this check is not tied to PTR_TO_MAP_VALUE only, but to all pointer
types that we handle in retrieve_ptr_limit() and given errors from the latter
propagate back to adjust_ptr_min_max_vals() and lead to rejection of the
program, it's a better place to reside to avoid anything slipping through
for future types. The reason why we must reject such off_reg is that we
otherwise would not be able to derive a mask, see details in 9d7eceede769
("bpf: restrict unknown scalars of mixed signed bounds for unprivileged").

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16 23:51:39 +02:00
Daniel Borkmann
6f55b2f2a1 bpf: Move off_reg into sanitize_ptr_alu
Small refactor to drag off_reg into sanitize_ptr_alu(), so we later on can
use off_reg for generalizing some of the checks for all pointer types.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16 23:51:36 +02:00
Daniel Borkmann
9601148392 bpf: Use correct permission flag for mixed signed bounds arithmetic
We forbid adding unknown scalars with mixed signed bounds due to the
spectre v1 masking mitigation. Hence this also needs bypass_spec_v1
flag instead of allow_ptr_leaks.

Fixes: 2c78ee898d8f ("bpf: Implement CAP_BPF")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-04-16 23:51:21 +02:00
Chunguang Xu
ffeee417d9 cgroup: use tsk->in_iowait instead of delayacct_is_task_waiting_on_io()
If delayacct is disabled, then delayacct_is_task_waiting_on_io()
always returns false, which causes the statistical value to be
wrong. Perhaps tsk->in_iowait is better.

Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-04-16 16:49:37 -04:00
Jindong Yue
9c336c9935 tick/broadcast: Allow late registered device to enter oneshot mode
The broadcast device is switched to oneshot mode when the system switches
to oneshot mode. If a broadcast clock event device is registered after the
system switched to oneshot mode, it will stay in periodic mode forever.

Ensure that a late registered device which is selected as broadcast device
is initialized in oneshot mode when the system already uses oneshot mode.

[ tglx: Massage changelog ]

Signed-off-by: Jindong Yue <jindong.yue@nxp.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210331083318.21794-1-jindong.yue@nxp.com
2021-04-16 21:03:50 +02:00
Wang Wensheng
d7840aaadd tick: Use tick_check_replacement() instead of open coding it
The function tick_check_replacement() is the combination of
tick_check_percpu() and tick_check_preferred(), but tick_check_new_device()
has the same logic open coded.

Use the helper to simplify the code.

[ tglx: Massage changelog ]

Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210326022328.3266-1-wangwensheng4@huawei.com
2021-04-16 21:03:50 +02:00
Marc Kleine-Budde
07ff4aed01 time/timecounter: Mark 1st argument of timecounter_cyc2time() as const
The timecounter is not modified in this function. Mark it as const.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210303103544.994855-1-mkl@pengutronix.de
2021-04-16 21:03:50 +02:00
Peter Zijlstra
0c2de3f054 sched,fair: Alternative sched_slice()
The current sched_slice() seems to have issues; there's two possible
things that could be improved:

 - the 'nr_running' used for __sched_period() is daft when cgroups are
   considered. Using the RQ wide h_nr_running seems like a much more
   consistent number.

 - (esp) cgroups can slice it real fine, which makes for easy
   over-scheduling, ensure min_gran is what the name says.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210412102001.611897312@infradead.org
2021-04-16 17:06:35 +02:00
Peter Zijlstra
d27e9ae2f2 sched: Move /proc/sched_debug to debugfs
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210412102001.548833671@infradead.org
2021-04-16 17:06:35 +02:00
Peter Zijlstra
3b87f136f8 sched,debug: Convert sysctl sched_domains to debugfs
Stop polluting sysctl, move to debugfs for SCHED_DEBUG stuff.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/YHgB/s4KCBQ1ifdm@hirez.programming.kicks-ass.net
2021-04-16 17:06:35 +02:00
Peter Zijlstra
1011dcce99 sched,preempt: Move preempt_dynamic to debug.c
Move the #ifdef SCHED_DEBUG bits to kernel/sched/debug.c in order to
collect all the debugfs bits.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210412102001.353833279@infradead.org
2021-04-16 17:06:34 +02:00
Peter Zijlstra
8a99b6833c sched: Move SCHED_DEBUG sysctl to debugfs
Stop polluting sysctl with undocumented knobs that really are debug
only, move them all to /debug/sched/ along with the existing
/debug/sched_* files that already exist.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210412102001.287610138@infradead.org
2021-04-16 17:06:34 +02:00
Peter Zijlstra
1d1c2509de sched: Remove sched_schedstats sysctl out from under SCHED_DEBUG
CONFIG_SCHEDSTATS does not depend on SCHED_DEBUG, it is inconsistent
to have the sysctl depend on it.

Suggested-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210412102001.161151631@infradead.org
2021-04-16 17:06:33 +02:00
Mel Gorman
b7cc6ec744 sched/numa: Allow runtime enabling/disabling of NUMA balance without SCHED_DEBUG
The ability to enable/disable NUMA balancing is not a debugging feature
and should not depend on CONFIG_SCHED_DEBUG.  For example, machines within
a HPC cluster may disable NUMA balancing temporarily for some jobs and
re-enable it for other jobs without needing to reboot.

This patch removes the dependency on CONFIG_SCHED_DEBUG for
kernel.numa_balancing sysctl. The other numa balancing related sysctls
are left as-is because if they need to be tuned then it is more likely
that NUMA balancing needs to be fixed instead.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210324133916.GQ15768@suse.de
2021-04-16 17:06:33 +02:00
Peter Zijlstra
b5c4477366 sched: Use cpu_dying() to fix balance_push vs hotplug-rollback
Use the new cpu_dying() state to simplify and fix the balance_push()
vs CPU hotplug rollback state.

Specifically, we currently rely on notifiers sched_cpu_dying() /
sched_cpu_activate() to terminate balance_push, however if the
cpu_down() fails when we're past sched_cpu_deactivate(), it should
terminate balance_push at that point and not wait until we hit
sched_cpu_activate().

Similarly, when cpu_up() fails and we're going back down, balance_push
should be active, where it currently is not.

So instead, make sure balance_push is enabled below SCHED_AP_ACTIVE
(when !cpu_active()), and gate it's utility with cpu_dying().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/YHgAYef83VQhKdC2@hirez.programming.kicks-ass.net
2021-04-16 17:06:32 +02:00
Peter Zijlstra
e40f74c535 cpumask: Introduce DYING mask
Introduce a cpumask that indicates (for each CPU) what direction the
CPU hotplug is currently going. Notably, it tracks rollbacks. Eg. when
an up fails and we do a roll-back down, it will accurately reflect the
direction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210310150109.151441252@infradead.org
2021-04-16 17:06:32 +02:00
Marco Elver
97ba62b278 perf: Add support for SIGTRAP on perf events
Adds bit perf_event_attr::sigtrap, which can be set to cause events to
send SIGTRAP (with si_code TRAP_PERF) to the task where the event
occurred. The primary motivation is to support synchronous signals on
perf events in the task where an event (such as breakpoints) triggered.

To distinguish perf events based on the event type, the type is set in
si_errno. For events that are associated with an address, si_addr is
copied from perf_sample_data.

The new field perf_event_attr::sig_data is copied to si_perf, which
allows user space to disambiguate which event (of the same type)
triggered the signal. For example, user space could encode the relevant
information it cares about in sig_data.

We note that the choice of an opaque u64 provides the simplest and most
flexible option. Alternatives where a reference to some user space data
is passed back suffer from the problem that modification of referenced
data (be it the event fd, or the perf_event_attr) can race with the
signal being delivered (of course, the same caveat applies if user space
decides to store a pointer in sig_data, but the ABI explicitly avoids
prescribing such a design).

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Link: https://lore.kernel.org/lkml/YBv3rAT566k+6zjg@hirez.programming.kicks-ass.net/
2021-04-16 16:32:41 +02:00
Marco Elver
fb6cc127e0 signal: Introduce TRAP_PERF si_code and si_perf to siginfo
Introduces the TRAP_PERF si_code, and associated siginfo_t field
si_perf. These will be used by the perf event subsystem to send signals
(if requested) to the task where an event occurred.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Acked-by: Arnd Bergmann <arnd@arndb.de> # asm-generic
Link: https://lkml.kernel.org/r/20210408103605.1676875-6-elver@google.com
2021-04-16 16:32:41 +02:00
Marco Elver
2e498d0a74 perf: Add support for event removal on exec
Adds bit perf_event_attr::remove_on_exec, to support removing an event
from a task on exec.

This option supports the case where an event is supposed to be
process-wide only, and should not propagate beyond exec, to limit
monitoring to the original process image only.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210408103605.1676875-5-elver@google.com
2021-04-16 16:32:41 +02:00
Marco Elver
2b26f0aa00 perf: Support only inheriting events if cloned with CLONE_THREAD
Adds bit perf_event_attr::inherit_thread, to restricting inheriting
events only if the child was cloned with CLONE_THREAD.

This option supports the case where an event is supposed to be
process-wide only (including subthreads), but should not propagate
beyond the current process's shared environment.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/YBvj6eJR%2FDY2TsEB@hirez.programming.kicks-ass.net/
2021-04-16 16:32:40 +02:00
Marco Elver
47f661eca0 perf: Apply PERF_EVENT_IOC_MODIFY_ATTRIBUTES to children
As with other ioctls (such as PERF_EVENT_IOC_{ENABLE,DISABLE}), fix up
handling of PERF_EVENT_IOC_MODIFY_ATTRIBUTES to also apply to children.

Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Link: https://lkml.kernel.org/r/20210408103605.1676875-3-elver@google.com
2021-04-16 16:32:40 +02:00
Peter Zijlstra
ef54c1a476 perf: Rework perf_event_exit_event()
Make perf_event_exit_event() more robust, such that we can use it from
other contexts. Specifically the up and coming remove_on_exec.

For this to work we need to address a few issues. Remove_on_exec will
not destroy the entire context, so we cannot rely on TASK_TOMBSTONE to
disable event_function_call() and we thus have to use
perf_remove_from_context().

When using perf_remove_from_context(), there's two races to consider.
The first is against close(), where we can have concurrent tear-down
of the event. The second is against child_list iteration, which should
not find a half baked event.

To address this, teach perf_remove_from_context() to special case
!ctx->is_active and about DETACH_CHILD.

[ elver@google.com: fix racing parent/child exit in sync_child_event(). ]
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210408103605.1676875-2-elver@google.com
2021-04-16 16:32:40 +02:00
Alexander Shishkin
d68e6799a5 perf: Cap allocation order at aux_watermark
Currently, we start allocating AUX pages half the size of the total
requested AUX buffer size, ignoring the attr.aux_watermark setting. This,
in turn, makes intel_pt driver disregard the watermark also, as it uses
page order for its SG (ToPA) configuration.

Now, this can be fixed in the intel_pt PMU driver, but seeing as it's the
only one currently making use of high order allocations, there is no
reason not to fix the allocator instead. This way, any other driver
wishing to add this support would not have to worry about this.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210414154955.49603-2-alexander.shishkin@linux.intel.com
2021-04-16 16:32:39 +02:00
Christoph Hellwig
42eb0d54c0 fs: split receive_fd_replace from __receive_fd
receive_fd_replace shares almost no code with the general case, so split
it out.  Also remove the "Bump the sock usage counts" comment from
both copies, as that is now what __receive_sock actually does.

[AV: ... and make the only user of receive_fd_replace() choose between
it and receive_fd() according to what userland had passed to it in
flags]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-04-16 00:13:04 -04:00
Steven Rostedt (VMware)
e1db6338d6 ftrace: Reuse the output of the function tracer for func_repeats
The func_repeats event shows the output of the function tracer followed by
a count of the number of repeats the previous function had made, as well
as the timestamp of the last function that was repeated.

The printing of the function should be the same as is for the function it
is displaying. Reuse the code in trace_fn_trace() by making a helper
function print_fn_trace() and use it for trace_func_repeats_print().

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-04-15 16:34:26 -04:00
Yordan Karadzhov (VMware)
22db095d57 tracing: Add "func_no_repeats" option for function tracing
If the option is activated the function tracing record gets
consolidated in the cases when a single function is called number
of times consecutively. Instead of having an identical record for
each call of the function we will record only the first call
following by event showing the number of repeats.

Link: https://lkml.kernel.org/r/20210415181854.147448-7-y.karadz@gmail.com

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-04-15 14:50:02 -04:00
Yordan Karadzhov (VMware)
4994891ebb tracing: Unify the logic for function tracing options
Currently the logic for dealing with the options for function tracing
has two different implementations. One is used when we set the flags
(in "static int func_set_flag()") and another used when we initialize
the tracer (in "static int function_trace_init()"). Those two
implementations are meant to do essentially the same thing and they
are both not very convenient for adding new options. In this patch
we add a helper function that provides a single implementation of
the logic for dealing with the options and we make it such that new
options can be easily added.

Link: https://lkml.kernel.org/r/20210415181854.147448-6-y.karadz@gmail.com

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-04-15 14:50:02 -04:00
Yordan Karadzhov (VMware)
c658797f1a tracing: Add method for recording "func_repeats" events
This patch only provides the implementation of the method.
Later we will used it in a combination with a new option for
function tracing.

Link: https://lkml.kernel.org/r/20210415181854.147448-5-y.karadz@gmail.com

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-04-15 14:50:02 -04:00
Yordan Karadzhov (VMware)
20344c54d1 tracing: Add "last_func_repeats" to struct trace_array
The field is used to keep track of the consecutive (on the same CPU) calls
of a single function. This information is needed in order to consolidate
the function tracing record in the cases when a single function is called
number of times.

Link: https://lkml.kernel.org/r/20210415181854.147448-4-y.karadz@gmail.com

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-04-15 14:50:02 -04:00
Yordan Karadzhov (VMware)
f689e4f280 tracing: Define new ftrace event "func_repeats"
The event aims to consolidate the function tracing record in the cases
when a single function is called number of times consecutively.

	while (cond)
		do_func();

This may happen in various scenarios (busy waiting for example).
The new ftrace event can be used to show repeated function events with
a single event and save space on the ring buffer

Link: https://lkml.kernel.org/r/20210415181854.147448-3-y.karadz@gmail.com

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-04-15 14:50:01 -04:00
Yordan Karadzhov (VMware)
eaa7a89720 tracing: Define static void trace_print_time()
The part of the code that prints the time of the trace record in
"int trace_print_context()" gets extracted in a static function. This
is done as a preparation for a following patch, in which we will define
a new ftrace event called "func_repeats". The new static method,
defined here, will be used by this new event to print the time of the
last repeat of a function that is consecutively called number of times.

Link: https://lkml.kernel.org/r/20210415181854.147448-2-y.karadz@gmail.com

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-04-15 14:50:01 -04:00
Eric Dumazet
5e0ccd4a3b rseq: Optimise rseq_get_rseq_cs() and clear_rseq_cs()
Commit ec9c82e03a74 ("rseq: uapi: Declare rseq_cs field as union,
update includes") added regressions for our servers.

Using copy_from_user() and clear_user() for 64bit values
is suboptimal.

We can use faster put_user() and get_user() on 64bit arches.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lkml.kernel.org/r/20210413203352.71350-4-eric.dumazet@gmail.com
2021-04-14 18:04:09 +02:00