4260 Commits

Author SHA1 Message Date
Linus Torvalds
dad1c12ed8 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:

 - Remove the unused per rq load array and all its infrastructure, by
   Dietmar Eggemann.

 - Add utilization clamping support by Patrick Bellasi. This is a
   refinement of the energy aware scheduling framework with support for
   boosting of interactive and capping of background workloads: to make
   sure critical GUI threads get maximum frequency ASAP, and to make
   sure background processing doesn't unnecessarily move to cpufreq
   governor to higher frequencies and less energy efficient CPU modes.

 - Add the bare minimum of tracepoints required for LISA EAS regression
   testing, by Qais Yousef - which allows automated testing of various
   power management features, including energy aware scheduling.

 - Restructure the former tsk_nr_cpus_allowed() facility that the -rt
   kernel used to modify the scheduler's CPU affinity logic such as
   migrate_disable() - introduce the task->cpus_ptr value instead of
   taking the address of &task->cpus_allowed directly - by Sebastian
   Andrzej Siewior.

 - Misc optimizations, fixes, cleanups and small enhancements - see the
   Git log for details.

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  sched/uclamp: Add uclamp support to energy_compute()
  sched/uclamp: Add uclamp_util_with()
  sched/cpufreq, sched/uclamp: Add clamps for FAIR and RT tasks
  sched/uclamp: Set default clamps for RT tasks
  sched/uclamp: Reset uclamp values on RESET_ON_FORK
  sched/uclamp: Extend sched_setattr() to support utilization clamping
  sched/core: Allow sched_setattr() to use the current policy
  sched/uclamp: Add system default clamps
  sched/uclamp: Enforce last task's UCLAMP_MAX
  sched/uclamp: Add bucket local max tracking
  sched/uclamp: Add CPU's clamp buckets refcounting
  sched/fair: Rename weighted_cpuload() to cpu_runnable_load()
  sched/debug: Export the newly added tracepoints
  sched/debug: Add sched_overutilized tracepoint
  sched/debug: Add new tracepoint to track PELT at se level
  sched/debug: Add new tracepoints to track PELT at rq level
  sched/debug: Add a new sched_trace_*() helper functions
  sched/autogroup: Make autogroup_path() always available
  sched/wait: Deduplicate code with do-while
  sched/topology: Remove unused 'sd' parameter from arch_scale_cpu_capacity()
  ...
2019-07-08 16:39:53 -07:00
Ingo Molnar
552a031ba1 Linux 5.2
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Merge tag 'v5.2' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-08 18:04:41 +02:00
Linus Torvalds
550d1f5bda This includes three fixes:
- Fixes a deadlock from a previous fix to keep module loading
    and function tracing text modifications from stepping on each other.
    (this has a few patches to help document the issue in comments)
 
  - Fix a crash when the snapshot buffer gets out of sync with the
    main ring buffer.
 
  - Fix a memory leak when reading the memory logs
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Merge tag 'trace-v5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "This includes three fixes:

   - Fix a deadlock from a previous fix to keep module loading and
     function tracing text modifications from stepping on each other
     (this has a few patches to help document the issue in comments)

   - Fix a crash when the snapshot buffer gets out of sync with the main
     ring buffer

   - Fix a memory leak when reading the memory logs"

* tag 'trace-v5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/x86: Anotate text_mutex split between ftrace_arch_code_modify_post_process() and ftrace_arch_code_modify_prepare()
  tracing/snapshot: Resize spare buffer if size changed
  tracing: Fix memory leak in tracing_err_log_open()
  ftrace/x86: Add a comment to why we take text_mutex in ftrace_arch_code_modify_prepare()
  ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()
2019-07-04 10:26:17 +09:00
Eiichi Tsukata
46cc0b4442 tracing/snapshot: Resize spare buffer if size changed
Current snapshot implementation swaps two ring_buffers even though their
sizes are different from each other, that can cause an inconsistency
between the contents of buffer_size_kb file and the current buffer size.

For example:

  # cat buffer_size_kb
  7 (expanded: 1408)
  # echo 1 > events/enable
  # grep bytes per_cpu/cpu0/stats
  bytes: 1441020
  # echo 1 > snapshot             // current:1408, spare:1408
  # echo 123 > buffer_size_kb     // current:123,  spare:1408
  # echo 1 > snapshot             // current:1408, spare:123
  # grep bytes per_cpu/cpu0/stats
  bytes: 1443700
  # cat buffer_size_kb
  123                             // != current:1408

And also, a similar per-cpu case hits the following WARNING:

Reproducer:

  # echo 1 > per_cpu/cpu0/snapshot
  # echo 123 > buffer_size_kb
  # echo 1 > per_cpu/cpu0/snapshot

WARNING:

  WARNING: CPU: 0 PID: 1946 at kernel/trace/trace.c:1607 update_max_tr_single.part.0+0x2b8/0x380
  Modules linked in:
  CPU: 0 PID: 1946 Comm: bash Not tainted 5.2.0-rc6 #20
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
  RIP: 0010:update_max_tr_single.part.0+0x2b8/0x380
  Code: ff e8 dc da f9 ff 0f 0b e9 88 fe ff ff e8 d0 da f9 ff 44 89 ee bf f5 ff ff ff e8 33 dc f9 ff 41 83 fd f5 74 96 e8 b8 da f9 ff <0f> 0b eb 8d e8 af da f9 ff 0f 0b e9 bf fd ff ff e8 a3 da f9 ff 48
  RSP: 0018:ffff888063e4fca0 EFLAGS: 00010093
  RAX: ffff888066214380 RBX: ffffffff99850fe0 RCX: ffffffff964298a8
  RDX: 0000000000000000 RSI: 00000000fffffff5 RDI: 0000000000000005
  RBP: 1ffff1100c7c9f96 R08: ffff888066214380 R09: ffffed100c7c9f9b
  R10: ffffed100c7c9f9a R11: 0000000000000003 R12: 0000000000000000
  R13: 00000000ffffffea R14: ffff888066214380 R15: ffffffff99851060
  FS:  00007f9f8173c700(0000) GS:ffff88806d000000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000714dc0 CR3: 0000000066fa6000 CR4: 00000000000006f0
  Call Trace:
   ? trace_array_printk_buf+0x140/0x140
   ? __mutex_lock_slowpath+0x10/0x10
   tracing_snapshot_write+0x4c8/0x7f0
   ? trace_printk_init_buffers+0x60/0x60
   ? selinux_file_permission+0x3b/0x540
   ? tracer_preempt_off+0x38/0x506
   ? trace_printk_init_buffers+0x60/0x60
   __vfs_write+0x81/0x100
   vfs_write+0x1e1/0x560
   ksys_write+0x126/0x250
   ? __ia32_sys_read+0xb0/0xb0
   ? do_syscall_64+0x1f/0x390
   do_syscall_64+0xc1/0x390
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

This patch adds resize_buffer_duplicate_size() to check if there is a
difference between current/spare buffer sizes and resize a spare buffer
if necessary.

Link: http://lkml.kernel.org/r/20190625012910.13109-1-devel@etsukata.com

Cc: stable@vger.kernel.org
Fixes: ad909e21bbe69 ("tracing: Add internal tracing_snapshot() functions")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-28 14:58:52 -04:00
Takeshi Misawa
d122ed6288 tracing: Fix memory leak in tracing_err_log_open()
When tracing_err_log_open() calls seq_open(), allocated memory is not freed.

kmemleak report:

unreferenced object 0xffff92c0781d1100 (size 128):
  comm "tail", pid 15116, jiffies 4295163855 (age 22.704s)
  hex dump (first 32 bytes):
    00 f0 08 e5 c0 92 ff ff 00 10 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000000d0687d5>] kmem_cache_alloc+0x11f/0x1e0
    [<000000003e3039a8>] seq_open+0x2f/0x90
    [<000000008dd36b7d>] tracing_err_log_open+0x67/0x140
    [<000000005a431ae2>] do_dentry_open+0x1df/0x3a0
    [<00000000a2910603>] vfs_open+0x2f/0x40
    [<0000000038b0a383>] path_openat+0x2e8/0x1690
    [<00000000fe025bda>] do_filp_open+0x9b/0x110
    [<00000000483a5091>] do_sys_open+0x1ba/0x260
    [<00000000c558b5fd>] __x64_sys_openat+0x20/0x30
    [<000000006881ec07>] do_syscall_64+0x5a/0x130
    [<00000000571c2e94>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix this by calling seq_release() in tracing_err_log_fops.release().

Link: http://lkml.kernel.org/r/20190628105640.GA1863@DESKTOP

Fixes: 8a062902be725 ("tracing: Add tracing error log")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Takeshi Misawa <jeliantsurux@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-28 14:57:23 -04:00
Petr Mladek
d5b844a2cf ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()
The commit 9f255b632bf12c4dd7 ("module: Fix livepatch/ftrace module text
permissions race") causes a possible deadlock between register_kprobe()
and ftrace_run_update_code() when ftrace is using stop_machine().

The existing dependency chain (in reverse order) is:

-> #1 (text_mutex){+.+.}:
       validate_chain.isra.21+0xb32/0xd70
       __lock_acquire+0x4b8/0x928
       lock_acquire+0x102/0x230
       __mutex_lock+0x88/0x908
       mutex_lock_nested+0x32/0x40
       register_kprobe+0x254/0x658
       init_kprobes+0x11a/0x168
       do_one_initcall+0x70/0x318
       kernel_init_freeable+0x456/0x508
       kernel_init+0x22/0x150
       ret_from_fork+0x30/0x34
       kernel_thread_starter+0x0/0xc

-> #0 (cpu_hotplug_lock.rw_sem){++++}:
       check_prev_add+0x90c/0xde0
       validate_chain.isra.21+0xb32/0xd70
       __lock_acquire+0x4b8/0x928
       lock_acquire+0x102/0x230
       cpus_read_lock+0x62/0xd0
       stop_machine+0x2e/0x60
       arch_ftrace_update_code+0x2e/0x40
       ftrace_run_update_code+0x40/0xa0
       ftrace_startup+0xb2/0x168
       register_ftrace_function+0x64/0x88
       klp_patch_object+0x1a2/0x290
       klp_enable_patch+0x554/0x980
       do_one_initcall+0x70/0x318
       do_init_module+0x6e/0x250
       load_module+0x1782/0x1990
       __s390x_sys_finit_module+0xaa/0xf0
       system_call+0xd8/0x2d0

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(text_mutex);
                               lock(cpu_hotplug_lock.rw_sem);
                               lock(text_mutex);
  lock(cpu_hotplug_lock.rw_sem);

It is similar problem that has been solved by the commit 2d1e38f56622b9b
("kprobes: Cure hotplug lock ordering issues"). Many locks are involved.
To be on the safe side, text_mutex must become a low level lock taken
after cpu_hotplug_lock.rw_sem.

This can't be achieved easily with the current ftrace design.
For example, arm calls set_all_modules_text_rw() already in
ftrace_arch_code_modify_prepare(), see arch/arm/kernel/ftrace.c.
This functions is called:

  + outside stop_machine() from ftrace_run_update_code()
  + without stop_machine() from ftrace_module_enable()

Fortunately, the problematic fix is needed only on x86_64. It is
the only architecture that calls set_all_modules_text_rw()
in ftrace path and supports livepatching at the same time.

Therefore it is enough to move text_mutex handling from the generic
kernel/trace/ftrace.c into arch/x86/kernel/ftrace.c:

   ftrace_arch_code_modify_prepare()
   ftrace_arch_code_modify_post_process()

This patch basically reverts the ftrace part of the problematic
commit 9f255b632bf12c4dd7 ("module: Fix livepatch/ftrace module
text permissions race"). And provides x86_64 specific-fix.

Some refactoring of the ftrace code will be needed when livepatching
is implemented for arm or nds32. These architectures call
set_all_modules_text_rw() and use stop_machine() at the same time.

Link: http://lkml.kernel.org/r/20190627081334.12793-1-pmladek@suse.com

Fixes: 9f255b632bf12c4dd7 ("module: Fix livepatch/ftrace module text permissions race")
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
[
  As reviewed by Miroslav Benes <mbenes@suse.cz>, removed return value of
  ftrace_run_update_code() as it is a void function.
]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-28 14:20:25 -04:00
Yonghong Song
9db1ff0a41 bpf: fix compiler warning with CONFIG_MODULES=n
With CONFIG_MODULES=n, the following compiler warning occurs:
  /data/users/yhs/work/net-next/kernel/trace/bpf_trace.c:605:13: warning:
      ‘do_bpf_send_signal’ defined but not used [-Wunused-function]
  static void do_bpf_send_signal(struct irq_work *entry)

The __init function send_signal_irq_work_init(), which calls
do_bpf_send_signal(), is defined under CONFIG_MODULES. Hence,
when CONFIG_MODULES=n, nobody calls static function do_bpf_send_signal(),
hence the warning.

The init function send_signal_irq_work_init() should work without
CONFIG_MODULES. Moving it out of CONFIG_MODULES
code section fixed the compiler warning, and also make bpf_send_signal()
helper work without CONFIG_MODULES.

Fixes: 8b401f9ed244 ("bpf: implement bpf_send_signal() helper")
Reported-By: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-26 14:44:07 +02:00
Ingo Molnar
b9271f0c65 Linux 5.2-rc6
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Merge tag 'v5.2-rc6' into perf/core, to refresh branch

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-24 19:25:52 +02:00
Ingo Molnar
d2abae71eb Linux 5.2-rc6
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Merge tag 'v5.2-rc6' into sched/core, to refresh the branch

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-24 19:19:53 +02:00
David S. Miller
13091aa305 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Honestly all the conflicts were simple overlapping changes,
nothing really interesting to report.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-17 20:20:36 -07:00
Linus Torvalds
da0f382029 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "Lots of bug fixes here:

   1) Out of bounds access in __bpf_skc_lookup, from Lorenz Bauer.

   2) Fix rate reporting in cfg80211_calculate_bitrate_he(), from John
      Crispin.

   3) Use after free in psock backlog workqueue, from John Fastabend.

   4) Fix source port matching in fdb peer flow rule of mlx5, from Raed
      Salem.

   5) Use atomic_inc_not_zero() in fl6_sock_lookup(), from Eric Dumazet.

   6) Network header needs to be set for packet redirect in nfp, from
      John Hurley.

   7) Fix udp zerocopy refcnt, from Willem de Bruijn.

   8) Don't assume linear buffers in vxlan and geneve error handlers,
      from Stefano Brivio.

   9) Fix TOS matching in mlxsw, from Jiri Pirko.

  10) More SCTP cookie memory leak fixes, from Neil Horman.

  11) Fix VLAN filtering in rtl8366, from Linus Walluij.

  12) Various TCP SACK payload size and fragmentation memory limit fixes
      from Eric Dumazet.

  13) Use after free in pneigh_get_next(), also from Eric Dumazet.

  14) LAPB control block leak fix from Jeremy Sowden"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (145 commits)
  lapb: fixed leak of control-blocks.
  tipc: purge deferredq list for each grp member in tipc_group_delete
  ax25: fix inconsistent lock state in ax25_destroy_timer
  neigh: fix use-after-free read in pneigh_get_next
  tcp: fix compile error if !CONFIG_SYSCTL
  hv_sock: Suppress bogus "may be used uninitialized" warnings
  be2net: Fix number of Rx queues used for flow hashing
  net: handle 802.1P vlan 0 packets properly
  tcp: enforce tcp_min_snd_mss in tcp_mtu_probing()
  tcp: add tcp_min_snd_mss sysctl
  tcp: tcp_fragment() should apply sane memory limits
  tcp: limit payload size of sacked skbs
  Revert "net: phylink: set the autoneg state in phylink_phy_change"
  bpf: fix nested bpf tracepoints with per-cpu data
  bpf: Fix out of bounds memory access in bpf_sk_storage
  vsock/virtio: set SOCK_DONE on peer shutdown
  net: dsa: rtl8366: Fix up VLAN filtering
  net: phylink: set the autoneg state in phylink_phy_change
  net: add high_order_alloc_disable sysctl/static key
  tcp: add tcp_tx_skb_cache sysctl
  ...
2019-06-17 15:55:34 -07:00
Ingo Molnar
23da766ab1 Linux 5.2-rc5
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Merge tag 'v5.2-rc5' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-17 12:12:27 +02:00
Matt Mullins
9594dc3c7e bpf: fix nested bpf tracepoints with per-cpu data
BPF_PROG_TYPE_RAW_TRACEPOINTs can be executed nested on the same CPU, as
they do not increment bpf_prog_active while executing.

This enables three levels of nesting, to support
  - a kprobe or raw tp or perf event,
  - another one of the above that irq context happens to call, and
  - another one in nmi context
(at most one of which may be a kprobe or perf event).

Fixes: 20b9d7ac4852 ("bpf: avoid excessive stack usage for perf_sample_data")
Signed-off-by: Matt Mullins <mmullins@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-06-15 16:33:35 -07:00
Linus Torvalds
6a71398c6a This includes the following fixes:
- Out of range read of stack trace output
  - Fix for NULL pointer dereference in trace_uprobe_create()
  - Fix to a livepatching / ftrace permission race in the module code
  - Fix for NULL pointer dereference in free_ftrace_func_mapper()
  - A couple of build warning clean ups
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Merge tag 'trace-v5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Out of range read of stack trace output

 - Fix for NULL pointer dereference in trace_uprobe_create()

 - Fix to a livepatching / ftrace permission race in the module code

 - Fix for NULL pointer dereference in free_ftrace_func_mapper()

 - A couple of build warning clean ups

* tag 'trace-v5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix NULL pointer dereference in free_ftrace_func_mapper()
  module: Fix livepatch/ftrace module text permissions race
  tracing/uprobe: Fix obsolete comment on trace_uprobe_create()
  tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create()
  tracing: Make two symbols static
  tracing: avoid build warning with HAVE_NOP_MCOUNT
  tracing: Fix out-of-range read in trace_stack_print()
2019-06-15 07:24:11 -10:00
Wei Li
04e03d9a61 ftrace: Fix NULL pointer dereference in free_ftrace_func_mapper()
The mapper may be NULL when called from register_ftrace_function_probe()
with probe->data == NULL.

This issue can be reproduced as follow (it may be covered by compiler
optimization sometime):

/ # cat /sys/kernel/debug/tracing/set_ftrace_filter
#### all functions enabled ####
/ # echo foo_bar:dump > /sys/kernel/debug/tracing/set_ftrace_filter
[  206.949100] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[  206.952402] Mem abort info:
[  206.952819]   ESR = 0x96000006
[  206.955326]   Exception class = DABT (current EL), IL = 32 bits
[  206.955844]   SET = 0, FnV = 0
[  206.956272]   EA = 0, S1PTW = 0
[  206.956652] Data abort info:
[  206.957320]   ISV = 0, ISS = 0x00000006
[  206.959271]   CM = 0, WnR = 0
[  206.959938] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000419f3a000
[  206.960483] [0000000000000000] pgd=0000000411a87003, pud=0000000411a83003, pmd=0000000000000000
[  206.964953] Internal error: Oops: 96000006 [#1] SMP
[  206.971122] Dumping ftrace buffer:
[  206.973677]    (ftrace buffer empty)
[  206.975258] Modules linked in:
[  206.976631] Process sh (pid: 281, stack limit = 0x(____ptrval____))
[  206.978449] CPU: 10 PID: 281 Comm: sh Not tainted 5.2.0-rc1+ #17
[  206.978955] Hardware name: linux,dummy-virt (DT)
[  206.979883] pstate: 60000005 (nZCv daif -PAN -UAO)
[  206.980499] pc : free_ftrace_func_mapper+0x2c/0x118
[  206.980874] lr : ftrace_count_free+0x68/0x80
[  206.982539] sp : ffff0000182f3ab0
[  206.983102] x29: ffff0000182f3ab0 x28: ffff8003d0ec1700
[  206.983632] x27: ffff000013054b40 x26: 0000000000000001
[  206.984000] x25: ffff00001385f000 x24: 0000000000000000
[  206.984394] x23: ffff000013453000 x22: ffff000013054000
[  206.984775] x21: 0000000000000000 x20: ffff00001385fe28
[  206.986575] x19: ffff000013872c30 x18: 0000000000000000
[  206.987111] x17: 0000000000000000 x16: 0000000000000000
[  206.987491] x15: ffffffffffffffb0 x14: 0000000000000000
[  206.987850] x13: 000000000017430e x12: 0000000000000580
[  206.988251] x11: 0000000000000000 x10: cccccccccccccccc
[  206.988740] x9 : 0000000000000000 x8 : ffff000013917550
[  206.990198] x7 : ffff000012fac2e8 x6 : ffff000012fac000
[  206.991008] x5 : ffff0000103da588 x4 : 0000000000000001
[  206.991395] x3 : 0000000000000001 x2 : ffff000013872a28
[  206.991771] x1 : 0000000000000000 x0 : 0000000000000000
[  206.992557] Call trace:
[  206.993101]  free_ftrace_func_mapper+0x2c/0x118
[  206.994827]  ftrace_count_free+0x68/0x80
[  206.995238]  release_probe+0xfc/0x1d0
[  206.995555]  register_ftrace_function_probe+0x4a8/0x868
[  206.995923]  ftrace_trace_probe_callback.isra.4+0xb8/0x180
[  206.996330]  ftrace_dump_callback+0x50/0x70
[  206.996663]  ftrace_regex_write.isra.29+0x290/0x3a8
[  206.997157]  ftrace_filter_write+0x44/0x60
[  206.998971]  __vfs_write+0x64/0xf0
[  206.999285]  vfs_write+0x14c/0x2f0
[  206.999591]  ksys_write+0xbc/0x1b0
[  206.999888]  __arm64_sys_write+0x3c/0x58
[  207.000246]  el0_svc_common.constprop.0+0x408/0x5f0
[  207.000607]  el0_svc_handler+0x144/0x1c8
[  207.000916]  el0_svc+0x8/0xc
[  207.003699] Code: aa0003f8 a9025bf5 aa0103f5 f946ea80 (f9400303)
[  207.008388] ---[ end trace 7b6d11b5f542bdf1 ]---
[  207.010126] Kernel panic - not syncing: Fatal exception
[  207.011322] SMP: stopping secondary CPUs
[  207.013956] Dumping ftrace buffer:
[  207.014595]    (ftrace buffer empty)
[  207.015632] Kernel Offset: disabled
[  207.017187] CPU features: 0x002,20006008
[  207.017985] Memory Limit: none
[  207.019825] ---[ end Kernel panic - not syncing: Fatal exception ]---

Link: http://lkml.kernel.org/r/20190606031754.10798-1-liwei391@huawei.com

Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-14 17:40:21 -04:00
Josh Poimboeuf
9f255b632b module: Fix livepatch/ftrace module text permissions race
It's possible for livepatch and ftrace to be toggling a module's text
permissions at the same time, resulting in the following panic:

  BUG: unable to handle page fault for address: ffffffffc005b1d9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0003) - permissions violation
  PGD 3ea0c067 P4D 3ea0c067 PUD 3ea0e067 PMD 3cc13067 PTE 3b8a1061
  Oops: 0003 [#1] PREEMPT SMP PTI
  CPU: 1 PID: 453 Comm: insmod Tainted: G           O  K   5.2.0-rc1-a188339ca5 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-20181126_142135-anatol 04/01/2014
  RIP: 0010:apply_relocate_add+0xbe/0x14c
  Code: fa 0b 74 21 48 83 fa 18 74 38 48 83 fa 0a 75 40 eb 08 48 83 38 00 74 33 eb 53 83 38 00 75 4e 89 08 89 c8 eb 0a 83 38 00 75 43 <89> 08 48 63 c1 48 39 c8 74 2e eb 48 83 38 00 75 32 48 29 c1 89 08
  RSP: 0018:ffffb223c00dbb10 EFLAGS: 00010246
  RAX: ffffffffc005b1d9 RBX: 0000000000000000 RCX: ffffffff8b200060
  RDX: 000000000000000b RSI: 0000004b0000000b RDI: ffff96bdfcd33000
  RBP: ffffb223c00dbb38 R08: ffffffffc005d040 R09: ffffffffc005c1f0
  R10: ffff96bdfcd33c40 R11: ffff96bdfcd33b80 R12: 0000000000000018
  R13: ffffffffc005c1f0 R14: ffffffffc005e708 R15: ffffffff8b2fbc74
  FS:  00007f5f447beba8(0000) GS:ffff96bdff900000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffffffffc005b1d9 CR3: 000000003cedc002 CR4: 0000000000360ea0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   klp_init_object_loaded+0x10f/0x219
   ? preempt_latency_start+0x21/0x57
   klp_enable_patch+0x662/0x809
   ? virt_to_head_page+0x3a/0x3c
   ? kfree+0x8c/0x126
   patch_init+0x2ed/0x1000 [livepatch_test02]
   ? 0xffffffffc0060000
   do_one_initcall+0x9f/0x1c5
   ? kmem_cache_alloc_trace+0xc4/0xd4
   ? do_init_module+0x27/0x210
   do_init_module+0x5f/0x210
   load_module+0x1c41/0x2290
   ? fsnotify_path+0x3b/0x42
   ? strstarts+0x2b/0x2b
   ? kernel_read+0x58/0x65
   __do_sys_finit_module+0x9f/0xc3
   ? __do_sys_finit_module+0x9f/0xc3
   __x64_sys_finit_module+0x1a/0x1c
   do_syscall_64+0x52/0x61
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

The above panic occurs when loading two modules at the same time with
ftrace enabled, where at least one of the modules is a livepatch module:

CPU0					CPU1
klp_enable_patch()
  klp_init_object_loaded()
    module_disable_ro()
    					ftrace_module_enable()
					  ftrace_arch_code_modify_post_process()
				    	    set_all_modules_text_ro()
      klp_write_object_relocations()
        apply_relocate_add()
	  *patches read-only code* - BOOM

A similar race exists when toggling ftrace while loading a livepatch
module.

Fix it by ensuring that the livepatch and ftrace code patching
operations -- and their respective permissions changes -- are protected
by the text_mutex.

Link: http://lkml.kernel.org/r/ab43d56ab909469ac5d2520c5d944ad6d4abd476.1560474114.git.jpoimboe@redhat.com

Reported-by: Johannes Erdfelt <johannes@erdfelt.com>
Fixes: 444d13ff10fb ("modules: add ro_after_init support")
Acked-by: Jessica Yu <jeyu@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-14 17:01:50 -04:00
Eiichi Tsukata
a4158345ec tracing/uprobe: Fix obsolete comment on trace_uprobe_create()
Commit 0597c49c69d5 ("tracing/uprobes: Use dyn_event framework for
uprobe events") cleaned up the usage of trace_uprobe_create(), and the
function has been no longer used for removing uprobe/uretprobe.

Link: http://lkml.kernel.org/r/20190614074026.8045-2-devel@etsukata.com

Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-14 17:00:36 -04:00
Eiichi Tsukata
f01098c74b tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create()
Just like the case of commit 8b05a3a7503c ("tracing/kprobes: Fix NULL
pointer dereference in trace_kprobe_create()"), writing an incorrectly
formatted string to uprobe_events can trigger NULL pointer dereference.

Reporeducer:

  # echo r > /sys/kernel/debug/tracing/uprobe_events

dmesg:

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 8000000079d12067 P4D 8000000079d12067 PUD 7b7ab067 PMD 0
  Oops: 0000 [#1] PREEMPT SMP PTI
  CPU: 0 PID: 1903 Comm: bash Not tainted 5.2.0-rc3+ #15
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
  RIP: 0010:strchr+0x0/0x30
  Code: c0 eb 0d 84 c9 74 18 48 83 c0 01 48 39 d0 74 0f 0f b6 0c 07 3a 0c 06 74 ea 19 c0 83 c8 01 c3 31 c0 c3 0f 1f 84 00 00 00 00 00 <0f> b6 07 89 f2 40 38 f0 75 0e eb 13 0f b6 47 01 48 83 c
  RSP: 0018:ffffb55fc0403d10 EFLAGS: 00010293

  RAX: ffff993ffb793400 RBX: 0000000000000000 RCX: ffffffffa4852625
  RDX: 0000000000000000 RSI: 000000000000002f RDI: 0000000000000000
  RBP: ffffb55fc0403dd0 R08: ffff993ffb793400 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
  R13: ffff993ff9cc1668 R14: 0000000000000001 R15: 0000000000000000
  FS:  00007f30c5147700(0000) GS:ffff993ffda00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 000000007b628000 CR4: 00000000000006f0
  Call Trace:
   trace_uprobe_create+0xe6/0xb10
   ? __kmalloc_track_caller+0xe6/0x1c0
   ? __kmalloc+0xf0/0x1d0
   ? trace_uprobe_create+0xb10/0xb10
   create_or_delete_trace_uprobe+0x35/0x90
   ? trace_uprobe_create+0xb10/0xb10
   trace_run_command+0x9c/0xb0
   trace_parse_run_command+0xf9/0x1eb
   ? probes_open+0x80/0x80
   __vfs_write+0x43/0x90
   vfs_write+0x14a/0x2a0
   ksys_write+0xa2/0x170
   do_syscall_64+0x7f/0x200
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Link: http://lkml.kernel.org/r/20190614074026.8045-1-devel@etsukata.com

Cc: stable@vger.kernel.org
Fixes: 0597c49c69d5 ("tracing/uprobes: Use dyn_event framework for uprobe events")
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-14 16:51:14 -04:00
YueHaibing
ff585c5b9a tracing: Make two symbols static
Fix sparse warnings:

kernel/trace/trace.c:6927:24: warning:
 symbol 'get_tracing_log_err' was not declared. Should it be static?
kernel/trace/trace.c:8196:15: warning:
 symbol 'trace_instance_dir' was not declared. Should it be static?

Link: http://lkml.kernel.org/r/20190614153210.24424-1-yuehaibing@huawei.com

Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-14 16:49:26 -04:00
Vasily Gorbik
cbdaeaf050 tracing: avoid build warning with HAVE_NOP_MCOUNT
Selecting HAVE_NOP_MCOUNT enables -mnop-mcount (if gcc supports it)
and sets CC_USING_NOP_MCOUNT. Reuse __is_defined (which is suitable for
testing CC_USING_* defines) to avoid conditional compilation and fix
the following gcc 9 warning on s390:

kernel/trace/ftrace.c:2514:1: warning: ‘ftrace_code_disable’ defined
but not used [-Wunused-function]

Link: http://lkml.kernel.org/r/patch.git-1a82d13f33ac.your-ad-here.call-01559732716-ext-6629@work.hours

Fixes: 2f4df0017baed ("tracing: Add -mcount-nop option support")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-14 16:34:57 -04:00
Eiichi Tsukata
becf33f694 tracing: Fix out-of-range read in trace_stack_print()
Puts range check before dereferencing the pointer.

Reproducer:

  # echo stacktrace > trace_options
  # echo 1 > events/enable
  # cat trace > /dev/null

KASAN report:

  ==================================================================
  BUG: KASAN: use-after-free in trace_stack_print+0x26b/0x2c0
  Read of size 8 at addr ffff888069d20000 by task cat/1953

  CPU: 0 PID: 1953 Comm: cat Not tainted 5.2.0-rc3+ #5
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
  Call Trace:
   dump_stack+0x8a/0xce
   print_address_description+0x60/0x224
   ? trace_stack_print+0x26b/0x2c0
   ? trace_stack_print+0x26b/0x2c0
   __kasan_report.cold+0x1a/0x3e
   ? trace_stack_print+0x26b/0x2c0
   kasan_report+0xe/0x20
   trace_stack_print+0x26b/0x2c0
   print_trace_line+0x6ea/0x14d0
   ? tracing_buffers_read+0x700/0x700
   ? trace_find_next_entry_inc+0x158/0x1d0
   s_show+0xea/0x310
   seq_read+0xaa7/0x10e0
   ? seq_escape+0x230/0x230
   __vfs_read+0x7c/0x100
   vfs_read+0x16c/0x3a0
   ksys_read+0x121/0x240
   ? kernel_write+0x110/0x110
   ? perf_trace_sys_enter+0x8a0/0x8a0
   ? syscall_slow_exit_work+0xa9/0x410
   do_syscall_64+0xb7/0x390
   ? prepare_exit_to_usermode+0x165/0x200
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f867681f910
  Code: b6 fe ff ff 48 8d 3d 0f be 08 00 48 83 ec 08 e8 06 db 01 00 66 0f 1f 44 00 00 83 3d f9 2d 2c 00 00 75 10 b8 00 00 00 00 04
  RSP: 002b:00007ffdabf23488 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
  RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f867681f910
  RDX: 0000000000020000 RSI: 00007f8676cde000 RDI: 0000000000000003
  RBP: 00007f8676cde000 R08: ffffffffffffffff R09: 0000000000000000
  R10: 0000000000000871 R11: 0000000000000246 R12: 00007f8676cde000
  R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000000ec0

  Allocated by task 1214:
   save_stack+0x1b/0x80
   __kasan_kmalloc.constprop.0+0xc2/0xd0
   kmem_cache_alloc+0xaf/0x1a0
   getname_flags+0xd2/0x5b0
   do_sys_open+0x277/0x5a0
   do_syscall_64+0xb7/0x390
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

  Freed by task 1214:
   save_stack+0x1b/0x80
   __kasan_slab_free+0x12c/0x170
   kmem_cache_free+0x8a/0x1c0
   putname+0xe1/0x120
   do_sys_open+0x2c5/0x5a0
   do_syscall_64+0xb7/0x390
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

  The buggy address belongs to the object at ffff888069d20000
   which belongs to the cache names_cache of size 4096
  The buggy address is located 0 bytes inside of
   4096-byte region [ffff888069d20000, ffff888069d21000)
  The buggy address belongs to the page:
  page:ffffea0001a74800 refcount:1 mapcount:0 mapping:ffff88806ccd1380 index:0x0 compound_mapcount: 0
  flags: 0x100000000010200(slab|head)
  raw: 0100000000010200 dead000000000100 dead000000000200 ffff88806ccd1380
  raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
  page dumped because: kasan: bad access detected

  Memory state around the buggy address:
   ffff888069d1ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   ffff888069d1ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  >ffff888069d20000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                     ^
   ffff888069d20080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
   ffff888069d20100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ==================================================================

Link: http://lkml.kernel.org/r/20190610040016.5598-1-devel@etsukata.com

Fixes: 4285f2fcef80 ("tracing: Remove the ULONG_MAX stack trace hackery")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-14 16:28:42 -04:00
Greg Kroah-Hartman
3e6f176f30 blktrace: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-block@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-03 15:39:39 +02:00
Greg Kroah-Hartman
6a54cd872f trace: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-03 15:39:39 +02:00
Song Liu
9fd2e48b9a perf/core: Allow non-privileged uprobe for user processes
Currently, non-privileged user could only use uprobe with

    kernel.perf_event_paranoid = -1

However, setting perf_event_paranoid to -1 leaks other users' processes to
non-privileged uprobes.

To introduce proper permission control of uprobes, we are building the
following system:

  A daemon with CAP_SYS_ADMIN is in charge to create uprobes via tracefs;
  Users asks the daemon to create uprobes;
  Then user can attach uprobe only to processes owned by the user.

This patch allows non-privileged user to attach uprobe to processes owned
by the user.

The following example shows how to use uprobe with non-privileged user.
This is based on Brendan's blog post [1]

1. Create uprobe with root:

  sudo perf probe -x 'readline%return +0($retval):string'

2. Then non-root user can use the uprobe as:

  perf record -vvv -e probe_bash:readline__return -p <pid> sleep 20
  perf script

[1] http://www.brendangregg.com/blog/2015-06-28/linux-ftrace-uprobe.html

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@fb.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190507161545.788381-1-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-03 11:58:18 +02:00
Sebastian Andrzej Siewior
3bd3706251 sched/core: Provide a pointer to the valid CPU mask
In commit:

  4b53a3412d66 ("sched/core: Remove the tsk_nr_cpus_allowed() wrapper")

the tsk_nr_cpus_allowed() wrapper was removed. There was not
much difference in !RT but in RT we used this to implement
migrate_disable(). Within a migrate_disable() section the CPU mask is
restricted to single CPU while the "normal" CPU mask remains untouched.

As an alternative implementation Ingo suggested to use:

	struct task_struct {
		const cpumask_t		*cpus_ptr;
		cpumask_t		cpus_mask;
        };
with
	t->cpus_ptr = &t->cpus_mask;

In -RT we then can switch the cpus_ptr to:

	t->cpus_ptr = &cpumask_of(task_cpu(p));

in a migration disabled region. The rules are simple:

 - Code that 'uses' ->cpus_allowed would use the pointer.
 - Code that 'modifies' ->cpus_allowed would use the direct mask.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190423142636.14347-1-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-03 11:49:37 +02:00
David S. Miller
0462eaacee Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2019-05-31

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

Lots of exciting new features in the first PR of this developement cycle!
The main changes are:

1) misc verifier improvements, from Alexei.

2) bpftool can now convert btf to valid C, from Andrii.

3) verifier can insert explicit ZEXT insn when requested by 32-bit JITs.
   This feature greatly improves BPF speed on 32-bit architectures. From Jiong.

4) cgroups will now auto-detach bpf programs. This fixes issue of thousands
   bpf programs got stuck in dying cgroups. From Roman.

5) new bpf_send_signal() helper, from Yonghong.

6) cgroup inet skb programs can signal CN to the stack, from Lawrence.

7) miscellaneous cleanups, from many developers.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-31 21:21:18 -07:00
Linus Torvalds
9e82b4a91d This fixes a memory leak from the error path in the event filter logic.
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Merge tag 'trace-v5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "This fixes a memory leak from the error path in the event filter
  logic"

* tag 'trace-v5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Avoid memory leak in predicate_parse()
2019-05-29 11:26:40 -07:00
Stanislav Fomichev
e672db03ab bpf: tracing: properly use bpf_prog_array api
Now that we don't have __rcu markers on the bpf_prog_array helpers,
let's use proper rcu_dereference_protected to obtain array pointer
under mutex.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-29 15:17:35 +02:00
Tomas Bortoli
dfb4a6f219 tracing: Avoid memory leak in predicate_parse()
In case of errors, predicate_parse() goes to the out_free label
to free memory and to return an error code.

However, predicate_parse() does not free the predicates of the
temporary prog_stack array, thence leaking them.

Link: http://lkml.kernel.org/r/20190528154338.29976-1-tomasbortoli@gmail.com

Cc: stable@vger.kernel.org
Fixes: 80765597bc587 ("tracing: Rewrite filter logic to be simpler and faster")
Reported-by: syzbot+6b8e0fb820e570c59e19@syzkaller.appspotmail.com
Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
[ Added protection around freeing prog_stack[i].pred ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-28 16:27:58 -04:00
Steven Rostedt (VMware)
86b3de60a0 ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS
Commit c19fa94a8fed ("Add HAVE_64BIT_ALIGNED_ACCESS") added the config for
architectures that required 64bit aligned access for all 64bit words. As
the ftrace ring buffer stores data on 4 byte alignment, this config option
was used to force it to store data on 8 byte alignment to make sure the data
being stored and written directly into the ring buffer was 8 byte aligned as
it would cause issues trying to write an 8 byte word on a 4 not 8 byte
aligned memory location.

But with the removal of the metag architecture, which was the only
architecture to use this, there is no architecture supported by Linux that
requires 8 byte aligne access for all 8 byte words (4 byte alignment is good
enough). Removing this config can simplify the code a bit.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-28 09:36:19 -04:00
Yonghong Song
e1afb70252 bpf: check signal validity in nmi for bpf_send_signal() helper
Commit 8b401f9ed244 ("bpf: implement bpf_send_signal() helper")
introduced bpf_send_signal() helper. If the context is nmi,
the sending signal work needs to be deferred to irq_work.
If the signal is invalid, the error will appear in irq_work
and it won't be propagated to user.

This patch did an early check in the helper itself to notify
user invalid signal, as suggested by Daniel.

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-28 10:51:33 +02:00
Linus Torvalds
c5b440951a Make the GCC 9 warning for sub struct memset go away.
GCC 9 now warns about calling memset() on partial structures when it
 goes across multiple fields. This adds a helper for the place in
 tracing that does this type of clearing of a structure.
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Merge tag 'trace-v5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing warning fix from Steven Rostedt:
 "Make the GCC 9 warning for sub struct memset go away.

  GCC 9 now warns about calling memset() on partial structures when it
  goes across multiple fields. This adds a helper for the place in
  tracing that does this type of clearing of a structure"

* tag 'trace-v5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Silence GCC 9 array bounds warning
2019-05-26 13:49:40 -07:00
Cheng Jian
a124692b69 ftrace: Enable trampoline when rec count returns back to one
Custom trampolines can only be enabled if there is only a single ops
attached to it. If there's only a single callback registered to a function,
and the ops has a trampoline registered for it, then we can call the
trampoline directly. This is very useful for improving the performance of
ftrace and livepatch.

If more than one callback is registered to a function, the general
trampoline is used, and the custom trampoline is not restored back to the
direct call even if all the other callbacks were unregistered and we are
back to one callback for the function.

To fix this, set FTRACE_FL_TRAMP flag if rec count is decremented
to one, and the ops that left has a trampoline.

Testing After this patch :

insmod livepatch_unshare_files.ko
cat /sys/kernel/debug/tracing/enabled_functions

	unshare_files (1) R I	tramp: 0xffffffffc0000000(klp_ftrace_handler+0x0/0xa0) ->ftrace_ops_assist_func+0x0/0xf0

echo unshare_files > /sys/kernel/debug/tracing/set_ftrace_filter
echo function > /sys/kernel/debug/tracing/current_tracer
cat /sys/kernel/debug/tracing/enabled_functions

	unshare_files (2) R I ->ftrace_ops_list_func+0x0/0x150

echo nop > /sys/kernel/debug/tracing/current_tracer
cat /sys/kernel/debug/tracing/enabled_functions

	unshare_files (1) R I	tramp: 0xffffffffc0000000(klp_ftrace_handler+0x0/0xa0) ->ftrace_ops_assist_func+0x0/0xf0

Link: http://lkml.kernel.org/r/1556969979-111047-1-git-send-email-cj.chengjian@huawei.com

Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:43 -04:00
Steven Rostedt (VMware)
b6399cc789 tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline
When having kprobe trace event start up tests enabled and adding a
kprobe_event on the kernel command line, it produced the following:

 trace_kprobe: Testing kprobe tracing:
 WARNING: CPU: 5 PID: 1 at kernel/trace/trace_kprobe.c:1724 kprobe_trace_self_tests_init+0x32d/0x36b
 Modules linked in:
 CPU: 5 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc1-test+ #249
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 RIP: 0010:kprobe_trace_self_tests_init+0x32d/0x36b
 Code: b7 e8 4f 8d a2 fe 85 c0 74 10 0f 0b 48 c7 c7 c8 1b 0d b7 ff c3 e8 19 af 99 fe 48 c7 c7 40 93 27 b7 e8 7f 1a a5 fe 85 c0 74 10 <0f> 0b 48 c7 c7 f8 1b 0d b7 ff c3 e8 f9 ae
9 a0 fe 85
 RSP: 0018:ffffb36e40653e08 EFLAGS: 00010286
 RAX: 00000000fffffff0 RBX: 0000000000000000 RCX: ffffb36e40653d5c
 RDX: 0000000000000000 RSI: ffffffffb72776e0 RDI: 0000000000000246
 RBP: ffff98414fe58ff8 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffff98415d8aa940 R12: 0000000000000000
 R13: ffffffffb737c1b0 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff98415ea80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f959ce741b8 CR3: 000000011a210002 CR4: 00000000001606e0
 Call Trace:
  ? init_kprobe_trace+0x19e/0x19e
  ? do_early_param+0x8e/0x8e
  do_one_initcall+0x6f/0x2b4
  ? do_early_param+0x8e/0x8e
  kernel_init_freeable+0x21d/0x2c6
  ? rest_init+0x146/0x146
  kernel_init+0xa/0x10a
  ret_from_fork+0x3a/0x50
 ---[ end trace 488430c083a4c956 ]---

As with the trace events, if a trace event is set on the kernel command
line, the trace events start up tests are suspended. The kprobe start up
tests should do the same when a kprobe is enabled on the kernel command
line.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:43 -04:00
Steven Rostedt (VMware)
b3015fe41d tracing: Make a separate config for trace event self tests
The trace event self tests enable loop through *all* events, enables each
one, one at a time, runs some code to trigger various events (not
necessarily the same events), and checks if anything went wrong. The issue
is that trace events are usually the least likely start up test to cause a
problem, but they take the longest to run (because there are so many
events). When one of the other tests trigger a bug, the trace event start up
tests causes the bisect to take much longer, because it takes 10s of seconds
to get through the trace event tests.

By making them a separate config (even though they are enabled by default if
start up tests are set), it is possible to turn them off and still run the
other tracing start up tests much quicker.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:43 -04:00
Masami Hiramatsu
970988e19e tracing/kprobe: Add kprobe_event= boot parameter
Add kprobe_event= boot parameter to define kprobe events
at boot time.
The definition syntax is similar to tracefs/kprobe_events
interface, but use ',' and ';' instead of ' ' and '\n'
respectively. e.g.

  kprobe_event=p,vfs_read,$arg1,$arg2

This puts a probe on vfs_read with argument1 and 2, and
enable the new event.

Link: http://lkml.kernel.org/r/155851395498.15728.830529496248543583.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:43 -04:00
Masami Hiramatsu
539b75b2b9 tracing/kprobe: Cast user-space address correctly
Cast user-space address correctly to pass to probe_user_read().

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:43 -04:00
Matthias Kaehlcke
f08367b364 tracing: Use correct function name in trace_filter_add_remove_task() comment
The comment of trace_filter_add_remove_task() refers to the function as
'trace_pid_filter_add_remove_task', use the correct name.

Link: http://lkml.kernel.org/r/20190523192628.134406-1-mka@chromium.org

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:43 -04:00
Masami Hiramatsu
e65f7ae7f4 tracing/probe: Support user-space dereference
Support user-space dereference syntax for probe event arguments
to dereference the data-structure or array in user-space.

The syntax is just adding 'u' before an offset value.

 +|-u<OFFSET>(<FETCHARG>)

e.g. +u8(%ax), +u0(+0(%si))

For example, if you probe do_sched_setscheduler(pid, policy,
param) and record param->sched_priority, you can add new
probe as below;

 p do_sched_setscheduler priority=+u0($arg3)

Note that kprobe event provides this and it doesn't change the
dereference method automatically because we do not know whether
the given address is in userspace or kernel on some archs.

So as same as "ustring", this is an option for user, who has to
carefully choose the dereference method.

Link: http://lkml.kernel.org/r/155789872187.26965.4468456816590888687.stgit@devnote2

Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:42 -04:00
Masami Hiramatsu
88903c4643 tracing/probe: Add ustring type for user-space string
Add "ustring" type for fetching user-space string from kprobe event.
User can specify ustring type at uprobe event, and it is same as
"string" for uprobe.

Note that probe-event provides this option but it doesn't choose the
correct type automatically since we have not way to decide the address
is in user-space or not on some arch (and on some other arch, you can
fetch the string by "string" type). So user must carefully check the
target code (e.g. if you see __user on the target variable) and
use this new type.

Link: http://lkml.kernel.org/r/155789871009.26965.14167558859557329331.stgit@devnote2

Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:42 -04:00
Steven Rostedt (VMware)
7375dca164 ftrace: Make enable and update parameters bool when applicable
The code modification functions have "enable" and "update" variables that
are sometimes "int" but used as "bool". Remove the ambiguity and make them
"bool" when they are only used for true or false values.

Link: http://lkml.kernel.org/r/e1429923d9eda92a3cf5ee9e33c7eacce539781d.1558115654.git.naveen.n.rao@linux.vnet.ibm.com

Reported-by: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:42 -04:00
Miguel Ojeda
0c97bf863e tracing: Silence GCC 9 array bounds warning
Starting with GCC 9, -Warray-bounds detects cases when memset is called
starting on a member of a struct but the size to be cleared ends up
writing over further members.

Such a call happens in the trace code to clear, at once, all members
after and including `seq` on struct trace_iterator:

    In function 'memset',
        inlined from 'ftrace_dump' at kernel/trace/trace.c:8914:3:
    ./include/linux/string.h:344:9: warning: '__builtin_memset' offset
    [8505, 8560] from the object at 'iter' is out of the bounds of
    referenced subobject 'seq' with type 'struct trace_seq' at offset
    4368 [-Warray-bounds]
      344 |  return __builtin_memset(p, c, size);
          |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

In order to avoid GCC complaining about it, we compute the address
ourselves by adding the offsetof distance instead of referring
directly to the member.

Since there are two places doing this clear (trace.c and trace_kdb.c),
take the chance to move the workaround into a single place in
the internal header.

Link: http://lkml.kernel.org/r/20190523124535.GA12931@gmail.com

Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
[ Removed unnecessary parenthesis around "iter" ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:30 -04:00
Linus Torvalds
a2c48d98fc Tom Zanussi sent me some small fixes and cleanups to the histogram
code and I forgot to incorporate them.
 
 I also added a small clean up patch that was sent to me a while ago
 and I just noticed it.
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Merge tag 'trace-v5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Tom Zanussi sent me some small fixes and cleanups to the histogram
  code and I forgot to incorporate them.

  I also added a small clean up patch that was sent to me a while ago
  and I just noticed it"

* tag 'trace-v5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  kernel/trace/trace.h: Remove duplicate header of trace_seq.h
  tracing: Add a check_val() check before updating cond_snapshot() track_val
  tracing: Check keys for variable references in expressions too
  tracing: Prevent hist_field_var_ref() from accessing NULL tracing_map_elts
2019-05-25 10:08:14 -07:00
Yonghong Song
8b401f9ed2 bpf: implement bpf_send_signal() helper
This patch tries to solve the following specific use case.

Currently, bpf program can already collect stack traces
through kernel function get_perf_callchain()
when certain events happens (e.g., cache miss counter or
cpu clock counter overflows). But such stack traces are
not enough for jitted programs, e.g., hhvm (jited php).
To get real stack trace, jit engine internal data structures
need to be traversed in order to get the real user functions.

bpf program itself may not be the best place to traverse
the jit engine as the traversing logic could be complex and
it is not a stable interface either.

Instead, hhvm implements a signal handler,
e.g. for SIGALARM, and a set of program locations which
it can dump stack traces. When it receives a signal, it will
dump the stack in next such program location.

Such a mechanism can be implemented in the following way:
  . a perf ring buffer is created between bpf program
    and tracing app.
  . once a particular event happens, bpf program writes
    to the ring buffer and the tracing app gets notified.
  . the tracing app sends a signal SIGALARM to the hhvm.

But this method could have large delays and causing profiling
results skewed.

This patch implements bpf_send_signal() helper to send
a signal to hhvm in real time, resulting in intended stack traces.

Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-24 23:26:47 +02:00
Jagadeesh Pagadala
4eebe38a37 kernel/trace/trace.h: Remove duplicate header of trace_seq.h
Remove duplicate header which is included twice.

Link: http://lkml.kernel.org/r/1553725186-41442-1-git-send-email-jagdsh.linux@gmail.com

Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Jagadeesh Pagadala <jagdsh.linux@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-22 15:37:41 -04:00
Linus Torvalds
2c1212de6f SPDX update for 5.2-rc2, round 1
Here are series of patches that add SPDX tags to different kernel files,
 based on two different things:
   - SPDX entries are added to a bunch of files that we missed a year ago
     that do not have any license information at all.
 
     These were either missed because the tool saw the MODULE_LICENSE()
     tag, or some EXPORT_SYMBOL tags, and got confused and thought the
     file had a real license, or the files have been added since the last
     big sweep, or they were Makefile/Kconfig files, which we didn't
     touch last time.
 
   - Add GPL-2.0-only or GPL-2.0-or-later tags to files where our scan
     tools can determine the license text in the file itself.  Where this
     happens, the license text is removed, in order to cut down on the
     700+ different ways we have in the kernel today, in a quest to get
     rid of all of these.
 
 These patches have been out for review on the linux-spdx@vger mailing
 list, and while they were created by automatic tools, they were
 hand-verified by a bunch of different people, all whom names are on the
 patches are reviewers.
 
 The reason for these "large" patches is if we were to continue to
 progress at the current rate of change in the kernel, adding license
 tags to individual files in different subsystems, we would be finished
 in about 10 years at the earliest.
 
 There will be more series of these types of patches coming over the next
 few weeks as the tools and reviewers crunch through the more "odd"
 variants of how to say "GPLv2" that developers have come up with over
 the years, combined with other fun oddities (GPL + a BSD disclaimer?)
 that are being unearthed, with the goal for the whole kernel to be
 cleaned up.
 
 These diffstats are not small, 3840 files are touched, over 10k lines
 removed in just 24 patches.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull SPDX update from Greg KH:
 "Here is a series of patches that add SPDX tags to different kernel
  files, based on two different things:

   - SPDX entries are added to a bunch of files that we missed a year
     ago that do not have any license information at all.

     These were either missed because the tool saw the MODULE_LICENSE()
     tag, or some EXPORT_SYMBOL tags, and got confused and thought the
     file had a real license, or the files have been added since the
     last big sweep, or they were Makefile/Kconfig files, which we
     didn't touch last time.

   - Add GPL-2.0-only or GPL-2.0-or-later tags to files where our scan
     tools can determine the license text in the file itself. Where this
     happens, the license text is removed, in order to cut down on the
     700+ different ways we have in the kernel today, in a quest to get
     rid of all of these.

  These patches have been out for review on the linux-spdx@vger mailing
  list, and while they were created by automatic tools, they were
  hand-verified by a bunch of different people, all whom names are on
  the patches are reviewers.

  The reason for these "large" patches is if we were to continue to
  progress at the current rate of change in the kernel, adding license
  tags to individual files in different subsystems, we would be finished
  in about 10 years at the earliest.

  There will be more series of these types of patches coming over the
  next few weeks as the tools and reviewers crunch through the more
  "odd" variants of how to say "GPLv2" that developers have come up with
  over the years, combined with other fun oddities (GPL + a BSD
  disclaimer?) that are being unearthed, with the goal for the whole
  kernel to be cleaned up.

  These diffstats are not small, 3840 files are touched, over 10k lines
  removed in just 24 patches"

* tag 'spdx-5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (24 commits)
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 25
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 24
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 23
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 22
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 21
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 20
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 19
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 17
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 15
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 14
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 12
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 11
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 10
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 9
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 7
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 5
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 4
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 3
  ...
2019-05-21 12:33:38 -07:00
Tom Zanussi
9b2ca371b1 tracing: Add a check_val() check before updating cond_snapshot() track_val
Without this check a snapshot is taken whenever a bucket's max is hit,
rather than only when the global max is hit, as it should be.

Before:

  In this example, we do a first run of the workload (cyclictest),
  examine the output, note the max ('triggering value') (347), then do
  a second run and note the max again.

  In this case, the max in the second run (39) is below the max in the
  first run, but since we haven't cleared the histogram, the first max
  is still in the histogram and is higher than any other max, so it
  should still be the max for the snapshot.  It isn't however - the
  value should still be 347 after the second run.

  # echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
  # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmax($wakeup_lat).save(next_prio,next_comm,prev_pid,prev_prio,prev_comm):onmax($wakeup_lat).snapshot() if next_comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger

  # cyclictest -p 80 -n -s -t 2 -D 2

  # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist

  { next_pid:       2143 } hitcount:        199
    max:         44  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/4

  { next_pid:       2145 } hitcount:       1325
    max:         38  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/2

  { next_pid:       2144 } hitcount:       1982
    max:        347  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/6

  Snapshot taken (see tracing/snapshot).  Details:
      triggering value { onmax($wakeup_lat) }:        347
      triggered by event with key: { next_pid:       2144 }

  # cyclictest -p 80 -n -s -t 2 -D 2

  # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist

  { next_pid:       2143 } hitcount:        199
    max:         44  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/4

  { next_pid:       2148 } hitcount:        199
    max:         16  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/1

  { next_pid:       2145 } hitcount:       1325
    max:         38  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/2

  { next_pid:       2150 } hitcount:       1326
    max:         39  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/4

  { next_pid:       2144 } hitcount:       1982
    max:        347  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/6

  { next_pid:       2149 } hitcount:       1983
    max:        130  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/0

  Snapshot taken (see tracing/snapshot).  Details:
    triggering value { onmax($wakeup_lat) }:    39
    triggered by event with key: { next_pid:       2150 }

After:

  In this example, we do a first run of the workload (cyclictest),
  examine the output, note the max ('triggering value') (375), then do
  a second run and note the max again.

  In this case, the max in the second run is still 375, the highest in
  any bucket, as it should be.

  # cyclictest -p 80 -n -s -t 2 -D 2

  # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist

  { next_pid:       2072 } hitcount:        200
    max:         28  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/5

  { next_pid:       2074 } hitcount:       1323
    max:        375  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/2

  { next_pid:       2073 } hitcount:       1980
    max:        153  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/6

  Snapshot taken (see tracing/snapshot).  Details:
    triggering value { onmax($wakeup_lat) }:        375
    triggered by event with key: { next_pid:       2074 }

  # cyclictest -p 80 -n -s -t 2 -D 2

  # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist

  { next_pid:       2101 } hitcount:        199
    max:         49  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/6

  { next_pid:       2072 } hitcount:        200
    max:         28  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/5

  { next_pid:       2074 } hitcount:       1323
    max:        375  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/2

  { next_pid:       2103 } hitcount:       1325
    max:         74  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/4

  { next_pid:       2073 } hitcount:       1980
    max:        153  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/6

  { next_pid:       2102 } hitcount:       1981
    max:         84  next_prio:         19  next_comm: cyclictest
    prev_pid:         12  prev_prio:        120  prev_comm: kworker/0:1

  Snapshot taken (see tracing/snapshot).  Details:
    triggering value { onmax($wakeup_lat) }:        375
    triggered by event with key: { next_pid:       2074 }

Link: http://lkml.kernel.org/r/95958351329f129c07504b4d1769c47a97b70d65.1555597045.git.tom.zanussi@linux.intel.com

Cc: stable@vger.kernel.org
Fixes: a3785b7eca8fd ("tracing: Add hist trigger snapshot() action")
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-21 12:48:07 -04:00
Tom Zanussi
c8d94a1878 tracing: Check keys for variable references in expressions too
There's an existing check for variable references in keys, but it
doesn't go far enough.  It checks whether a key field is a variable
reference but doesn't check whether it's an expression containing
variable references, which can cause the same problems for callers.

Use the existing field_has_hist_vars() function rather than a direct
top-level flag check to catch all possible variable references.

Link: http://lkml.kernel.org/r/e8c3d3d53db5ca90ceea5a46e5413103a6902fc7.1555597045.git.tom.zanussi@linux.intel.com

Cc: stable@vger.kernel.org
Fixes: 067fe038e70f6 ("tracing: Add variable reference handling to hist triggers")
Reported-by: Vincent Bernat <vincent@bernat.ch>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-21 12:46:32 -04:00
Tom Zanussi
55267c88c0 tracing: Prevent hist_field_var_ref() from accessing NULL tracing_map_elts
hist_field_var_ref() is an implementation of hist_field_fn_t(), which
can be called with a null tracing_map_elt elt param when assembling a
key in event_hist_trigger().

In the case of hist_field_var_ref() this doesn't make sense, because a
variable can only be resolved by looking it up using an already
assembled key i.e. a variable can't be used to assemble a key since
the key is required in order to access the variable.

Upper layers should prevent the user from constructing a key using a
variable in the first place, but in case one slips through, it
shouldn't cause a NULL pointer dereference.  Also if one does slip
through, we want to know about it, so emit a one-time warning in that
case.

Link: http://lkml.kernel.org/r/64ec8dc15c14d305295b64cdfcc6b2b9dd14753f.1555597045.git.tom.zanussi@linux.intel.com

Reported-by: Vincent Bernat <vincent@bernat.ch>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-21 12:43:49 -04:00
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00