linux-toradex.git/kernel/trace/trace_events.c, branch v5.12-rc5 Linux kernel for Apalis and Colibri modules Merge tag 'trace-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 2021-02-22T22:07:15+00:00 Linus Torvalds torvalds@linux-foundation.org 2021-02-22T22:07:15+00:00 c9584234709aff90fbf38f71904a068ee9e8bce3 Pull tracing updates from Steven Rostedt: - Update to the way irqs and preemption is tracked via the trace event PC field - Fix handling of unregistering event failing due to allocate memory. This is only triggered by failure injection, as it is pretty much guaranteed to have less than a page allocation succeed. - Do not show the useless "filter" or "enable" files for the "ftrace" trace system, as they have no effect on doing anything. - Add a warning if kprobes are registered more than once. - Synthetic events now have their fields parsed by semicolons. Old formats without semicolons will still work, but new features will require them. - New option to allow trace events to show %p without hashing in trace file. The trace file can only be read by root, and reading the raw event buffer did not have any pointers hashed, so this does not expose anything new. - New directory in tools called tools/tracing, where a new tool that reads sequential latency reports from the ftrace latency tracers. - Other minor fixes and cleanups. * tag 'trace-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) kprobes: Fix to delay the kprobes jump optimization tracing/tools: Add the latency-collector to tools directory tracing: Make hash-ptr option default tracing: Add ptr-hash option to show the hashed pointer value tracing: Update the stage 3 of trace event macro comment tracing: Show real address for trace event arguments selftests/ftrace: Add '!event' synthetic event syntax check selftests/ftrace: Update synthetic event syntax errors tracing: Add a backward-compatibility check for synthetic event creation tracing: Update synth command errors tracing: Rework synthetic event command parsing tracing/dynevent: Delegate parsing to create function kprobes: Warn if the kprobe is reregistered ftrace: Remove unused ftrace_force_update() tracepoints: Code clean up tracepoints: Do not punish non static call users tracepoints: Remove unnecessary "data_args" macro parameter tracing: Do not create "enable" or "filter" files for ftrace event subsystem kernel: trace: preemptirq_delay_test: add cpu affinity tracepoint: Do not fail unregistering a probe due to memory failure ... 
Pull tracing updates from Steven Rostedt:

 - Update to the way irqs and preemption is tracked via the trace event
   PC field

 - Fix handling of unregistering event failing due to allocate memory.
   This is only triggered by failure injection, as it is pretty much
   guaranteed to have less than a page allocation succeed.

 - Do not show the useless "filter" or "enable" files for the "ftrace"
   trace system, as they have no effect on doing anything.

 - Add a warning if kprobes are registered more than once.

 - Synthetic events now have their fields parsed by semicolons. Old
   formats without semicolons will still work, but new features will
   require them.

 - New option to allow trace events to show %p without hashing in trace
   file. The trace file can only be read by root, and reading the raw
   event buffer did not have any pointers hashed, so this does not
   expose anything new.

 - New directory in tools called tools/tracing, where a new tool that
   reads sequential latency reports from the ftrace latency tracers.

 - Other minor fixes and cleanups.

* tag 'trace-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  kprobes: Fix to delay the kprobes jump optimization
  tracing/tools: Add the latency-collector to tools directory
  tracing: Make hash-ptr option default
  tracing: Add ptr-hash option to show the hashed pointer value
  tracing: Update the stage 3 of trace event macro comment
  tracing: Show real address for trace event arguments
  selftests/ftrace: Add '!event' synthetic event syntax check
  selftests/ftrace: Update synthetic event syntax errors
  tracing: Add a backward-compatibility check for synthetic event creation
  tracing: Update synth command errors
  tracing: Rework synthetic event command parsing
  tracing/dynevent: Delegate parsing to create function
  kprobes: Warn if the kprobe is reregistered
  ftrace: Remove unused ftrace_force_update()
  tracepoints: Code clean up
  tracepoints: Do not punish non static call users
  tracepoints: Remove unnecessary "data_args" macro parameter
  tracing: Do not create "enable" or "filter" files for ftrace event subsystem
  kernel: trace: preemptirq_delay_test: add cpu affinity
  tracepoint: Do not fail unregistering a probe due to memory failure
  ...
tracing: Do not create "enable" or "filter" files for ftrace event subsystem 2021-02-05T23:04:39+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2021-02-05T23:04:39+00:00 2d396cb3b12641adcde91104a7c89994f2e876a6 The ftrace event subsystem is only created for showing the format files of events created by the ftrace tracers, and are not trace events. The ftrace subsystem currently has both the "enable" and "filter" files that in other subsystems are used to enable/disable all events within the subsystem or set a filter for all the subsystem events. As ftrace subsystem events do not use enable or filter operations, these files are useless in the ftrace subsystem. Remove them. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
The ftrace event subsystem is only created for showing the format files of
events created by the ftrace tracers, and are not trace events. The ftrace
subsystem currently has both the "enable" and "filter" files that in other
subsystems are used to enable/disable all events within the subsystem or set
a filter for all the subsystem events.

As ftrace subsystem events do not use enable or filter operations, these
files are useless in the ftrace subsystem. Remove them.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracing: Do not count ftrace events in top level enable output 2021-02-05T20:40:04+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2021-02-05T20:40:04+00:00 256cfdd6fdf70c6fcf0f7c8ddb0ebd73ce8f3bc9 The file /sys/kernel/tracing/events/enable is used to enable all events by echoing in "1", or disabling all events when echoing in "0". To know if all events are enabled, disabled, or some are enabled but not all of them, cating the file should show either "1" (all enabled), "0" (all disabled), or "X" (some enabled but not all of them). This works the same as the "enable" files in the individule system directories (like tracing/events/sched/enable). But when all events are enabled, the top level "enable" file shows "X". The reason is that its checking the "ftrace" events, which are special events that only exist for their format files. These include the format for the function tracer events, that are enabled when the function tracer is enabled, but not by the "enable" file. The check includes these events, which will always be disabled, and even though all true events are enabled, the top level "enable" file will show "X" instead of "1". To fix this, have the check test the event's flags to see if it has the "IGNORE_ENABLE" flag set, and if so, not test it. Cc: stable@vger.kernel.org Fixes: 553552ce1796c ("tracing: Combine event filter_active and enable into single flags field") Reported-by: "Yordan Karadzhov (VMware)" <y.karadz@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
The file /sys/kernel/tracing/events/enable is used to enable all events by
echoing in "1", or disabling all events when echoing in "0". To know if all
events are enabled, disabled, or some are enabled but not all of them,
cating the file should show either "1" (all enabled), "0" (all disabled), or
"X" (some enabled but not all of them). This works the same as the "enable"
files in the individule system directories (like tracing/events/sched/enable).

But when all events are enabled, the top level "enable" file shows "X". The
reason is that its checking the "ftrace" events, which are special events
that only exist for their format files. These include the format for the
function tracer events, that are enabled when the function tracer is
enabled, but not by the "enable" file. The check includes these events,
which will always be disabled, and even though all true events are enabled,
the top level "enable" file will show "X" instead of "1".

To fix this, have the check test the event's flags to see if it has the
"IGNORE_ENABLE" flag set, and if so, not test it.

Cc: stable@vger.kernel.org
Fixes: 553552ce1796c ("tracing: Combine event filter_active and enable into single flags field")
Reported-by: "Yordan Karadzhov (VMware)" <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracing: Merge irqflags + preempt counter. 2021-02-02T22:02:06+00:00 Sebastian Andrzej Siewior bigeasy@linutronix.de 2021-01-25T19:45:08+00:00 36590c50b2d0729952511129916beeea30d31d81 The state of the interrupts (irqflags) and the preemption counter are both passed down to tracing_generic_entry_update(). Only one bit of irqflags is actually required: The on/off state. The complete 32bit of the preemption counter isn't needed. Just whether of the upper bits (softirq, hardirq and NMI) are set and the preemption depth is needed. The irqflags and the preemption counter could be evaluated early and the information stored in an integer `trace_ctx'. tracing_generic_entry_update() would use the upper bits as the TRACE_FLAG_* and the lower 8bit as the disabled-preemption depth (considering that one must be substracted from the counter in one special cases). The actual preemption value is not used except for the tracing record. The `irqflags' variable is mostly used only for the tracing record. An exception here is for instance wakeup_tracer_call() or probe_wakeup_sched_switch() which explicilty disable interrupts and use that `irqflags' to save (and restore) the IRQ state and to record the state. Struct trace_event_buffer has also the `pc' and flags' members which can be replaced with `trace_ctx' since their actual value is not used outside of trace recording. This will reduce tracing_generic_entry_update() to simply assign values to struct trace_entry. The evaluation of the TRACE_FLAG_* bits is moved to _tracing_gen_ctx_flags() which replaces preempt_count() and local_save_flags() invocations. As an example, ftrace_syscall_enter() may invoke: - trace_buffer_lock_reserve() -> … -> tracing_generic_entry_update() - event_trigger_unlock_commit() -> ftrace_trace_stack() -> … -> tracing_generic_entry_update() -> ftrace_trace_userstack() -> … -> tracing_generic_entry_update() In this case the TRACE_FLAG_* bits were evaluated three times. By using the `trace_ctx' they are evaluated once and assigned three times. A build with all tracers enabled on x86-64 with and without the patch: text data bss dec hex filename 21970669 17084168 7639260 46694097 2c87ed1 vmlinux.old 21970293 17084168 7639260 46693721 2c87d59 vmlinux.new text shrank by 379 bytes, data remained constant. Link: https://lkml.kernel.org/r/20210125194511.3924915-2-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
The state of the interrupts (irqflags) and the preemption counter are
both passed down to tracing_generic_entry_update(). Only one bit of
irqflags is actually required: The on/off state. The complete 32bit
of the preemption counter isn't needed. Just whether of the upper bits
(softirq, hardirq and NMI) are set and the preemption depth is needed.

The irqflags and the preemption counter could be evaluated early and the
information stored in an integer `trace_ctx'.
tracing_generic_entry_update() would use the upper bits as the
TRACE_FLAG_* and the lower 8bit as the disabled-preemption depth
(considering that one must be substracted from the counter in one
special cases).

The actual preemption value is not used except for the tracing record.
The `irqflags' variable is mostly used only for the tracing record. An
exception here is for instance wakeup_tracer_call() or
probe_wakeup_sched_switch() which explicilty disable interrupts and use
that `irqflags' to save (and restore) the IRQ state and to record the
state.

Struct trace_event_buffer has also the `pc' and flags' members which can
be replaced with `trace_ctx' since their actual value is not used
outside of trace recording.

This will reduce tracing_generic_entry_update() to simply assign values
to struct trace_entry. The evaluation of the TRACE_FLAG_* bits is moved
to _tracing_gen_ctx_flags() which replaces preempt_count() and
local_save_flags() invocations.

As an example, ftrace_syscall_enter() may invoke:
- trace_buffer_lock_reserve() -> … -> tracing_generic_entry_update()
- event_trigger_unlock_commit()
  -> ftrace_trace_stack() -> … -> tracing_generic_entry_update()
  -> ftrace_trace_userstack() -> … -> tracing_generic_entry_update()

In this case the TRACE_FLAG_* bits were evaluated three times. By using
the `trace_ctx' they are evaluated once and assigned three times.

A build with all tracers enabled on x86-64 with and without the patch:

    text     data      bss      dec      hex    filename
21970669 17084168  7639260 46694097  2c87ed1 vmlinux.old
21970293 17084168  7639260 46693721  2c87d59 vmlinux.new

text shrank by 379 bytes, data remained constant.

Link: https://lkml.kernel.org/r/20210125194511.3924915-2-bigeasy@linutronix.de

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Merge tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 2020-12-17T21:22:17+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-17T21:22:17+00:00 09c0796adf0c793462fda1d7c8c43324551405c7 Pull tracing updates from Steven Rostedt: "The major update to this release is that there's a new arch config option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. Currently, only x86_64 enables it. All the ftrace callbacks now take a struct ftrace_regs instead of a struct pt_regs. If the architecture has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will have enough information to read the arguments of the function being traced, as well as access to the stack pointer. This way, if a user (like live kernel patching) only cares about the arguments, then it can avoid using the heavier weight "regs" callback, that puts in enough information in the struct ftrace_regs to simulate a breakpoint exception (needed for kprobes). A new config option that audits the timestamps of the ftrace ring buffer at most every event recorded. Ftrace recursion protection has been cleaned up to move the protection to the callback itself (this saves on an extra function call for those callbacks). Perf now handles its own RCU protection and does not depend on ftrace to do it for it (saving on that extra function call). New debug option to add "recursed_functions" file to tracefs that lists all the places that triggered the recursion protection of the function tracer. This will show where things need to be fixed as recursion slows down the function tracer. The eval enum mapping updates done at boot up are now offloaded to a work queue, as it caused a noticeable pause on slow embedded boards. Various clean ups and last minute fixes" * tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) tracing: Offload eval map updates to a work queue Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS" ring-buffer: Add rb_check_bpage in __rb_allocate_pages ring-buffer: Fix two typos in comments tracing: Drop unneeded assignment in ring_buffer_resize() tracing: Disable ftrace selftests when any tracer is running seq_buf: Avoid type mismatch for seq_buf_init ring-buffer: Fix a typo in function description ring-buffer: Remove obsolete rb_event_is_commit() ring-buffer: Add test to validate the time stamp deltas ftrace/documentation: Fix RST C code blocks tracing: Clean up after filter logic rewriting tracing: Remove the useless value assignment in test_create_synth_event() livepatch: Use the default ftrace_ops instead of REGS when ARGS is available ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs MAINTAINERS: assign ./fs/tracefs to TRACING tracing: Fix some typos in comments ftrace: Remove unused varible 'ret' ring-buffer: Add recording of ring buffer recursion into recursed_functions ... 
Pull tracing updates from Steven Rostedt:
 "The major update to this release is that there's a new arch config
  option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS.

  Currently, only x86_64 enables it. All the ftrace callbacks now take a
  struct ftrace_regs instead of a struct pt_regs. If the architecture
  has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will
  have enough information to read the arguments of the function being
  traced, as well as access to the stack pointer.

  This way, if a user (like live kernel patching) only cares about the
  arguments, then it can avoid using the heavier weight "regs" callback,
  that puts in enough information in the struct ftrace_regs to simulate
  a breakpoint exception (needed for kprobes).

  A new config option that audits the timestamps of the ftrace ring
  buffer at most every event recorded.

  Ftrace recursion protection has been cleaned up to move the protection
  to the callback itself (this saves on an extra function call for those
  callbacks).

  Perf now handles its own RCU protection and does not depend on ftrace
  to do it for it (saving on that extra function call).

  New debug option to add "recursed_functions" file to tracefs that
  lists all the places that triggered the recursion protection of the
  function tracer. This will show where things need to be fixed as
  recursion slows down the function tracer.

  The eval enum mapping updates done at boot up are now offloaded to a
  work queue, as it caused a noticeable pause on slow embedded boards.

  Various clean ups and last minute fixes"

* tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  tracing: Offload eval map updates to a work queue
  Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"
  ring-buffer: Add rb_check_bpage in __rb_allocate_pages
  ring-buffer: Fix two typos in comments
  tracing: Drop unneeded assignment in ring_buffer_resize()
  tracing: Disable ftrace selftests when any tracer is running
  seq_buf: Avoid type mismatch for seq_buf_init
  ring-buffer: Fix a typo in function description
  ring-buffer: Remove obsolete rb_event_is_commit()
  ring-buffer: Add test to validate the time stamp deltas
  ftrace/documentation: Fix RST C code blocks
  tracing: Clean up after filter logic rewriting
  tracing: Remove the useless value assignment in test_create_synth_event()
  livepatch: Use the default ftrace_ops instead of REGS when ARGS is available
  ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default
  ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs
  MAINTAINERS: assign ./fs/tracefs to TRACING
  tracing: Fix some typos in comments
  ftrace: Remove unused varible 'ret'
  ring-buffer: Add recording of ring buffer recursion into recursed_functions
  ...
tracing: Disable ftrace selftests when any tracer is running 2020-12-14T17:05:03+00:00 Masami Hiramatsu mhiramat@kernel.org 2020-12-08T08:54:09+00:00 60efe21e5976d3d4170a8190ca76a271d6419754 Disable ftrace selftests when any tracer (kernel command line options like ftrace=, trace_events=, kprobe_events=, and boot-time tracing) starts running because selftest can disturb it. Currently ftrace= and trace_events= are checked, but kprobe_events has a different flag, and boot-time tracing didn't checked. This unifies the disabled flag and all of those boot-time tracing features sets the flag. This also fixes warnings on kprobe-event selftest (CONFIG_FTRACE_STARTUP_TEST=y and CONFIG_KPROBE_EVENTS=y) with boot-time tracing (ftrace.event.kprobes.EVENT.probes) like below; [ 59.803496] trace_kprobe: Testing kprobe tracing: [ 59.804258] ------------[ cut here ]------------ [ 59.805682] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:1987 kprobe_trace_self_tests_ib [ 59.806944] Modules linked in: [ 59.807335] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.10.0-rc7+ #172 [ 59.808029] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/204 [ 59.808999] RIP: 0010:kprobe_trace_self_tests_init+0x5f/0x42b [ 59.809696] Code: e8 03 00 00 48 c7 c7 30 8e 07 82 e8 6d 3c 46 ff 48 c7 c6 00 b2 1a 81 48 c7 c7 7 [ 59.812439] RSP: 0018:ffffc90000013e78 EFLAGS: 00010282 [ 59.813038] RAX: 00000000ffffffef RBX: 0000000000000000 RCX: 0000000000049443 [ 59.813780] RDX: 0000000000049403 RSI: 0000000000049403 RDI: 000000000002deb0 [ 59.814589] RBP: ffffc90000013e90 R08: 0000000000000001 R09: 0000000000000001 [ 59.815349] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000ffffffef [ 59.816138] R13: ffff888004613d80 R14: ffffffff82696940 R15: ffff888004429138 [ 59.816877] FS: 0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000 [ 59.817772] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 59.818395] CR2: 0000000001a8dd38 CR3: 0000000002222000 CR4: 00000000000006a0 [ 59.819144] Call Trace: [ 59.819469] ? init_kprobe_trace+0x6b/0x6b [ 59.819948] do_one_initcall+0x5f/0x300 [ 59.820392] ? rcu_read_lock_sched_held+0x4f/0x80 [ 59.820916] kernel_init_freeable+0x22a/0x271 [ 59.821416] ? rest_init+0x241/0x241 [ 59.821841] kernel_init+0xe/0x10f [ 59.822251] ret_from_fork+0x22/0x30 [ 59.822683] irq event stamp: 16403349 [ 59.823121] hardirqs last enabled at (16403359): [<ffffffff810db81e>] console_unlock+0x48e/0x580 [ 59.824074] hardirqs last disabled at (16403368): [<ffffffff810db786>] console_unlock+0x3f6/0x580 [ 59.825036] softirqs last enabled at (16403200): [<ffffffff81c0033a>] __do_softirq+0x33a/0x484 [ 59.825982] softirqs last disabled at (16403087): [<ffffffff81a00f02>] asm_call_irq_on_stack+0x10 [ 59.827034] ---[ end trace 200c544775cdfeb3 ]--- [ 59.827635] trace_kprobe: error on probing function entry. Link: https://lkml.kernel.org/r/160741764955.3448999.3347769358299456915.stgit@devnote2 Fixes: 4d655281eb1b ("tracing/boot Add kprobe event support") Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
Disable ftrace selftests when any tracer (kernel command line options
like ftrace=, trace_events=, kprobe_events=, and boot-time tracing)
starts running because selftest can disturb it.

Currently ftrace= and trace_events= are checked, but kprobe_events
has a different flag, and boot-time tracing didn't checked. This unifies
the disabled flag and all of those boot-time tracing features sets
the flag.

This also fixes warnings on kprobe-event selftest
(CONFIG_FTRACE_STARTUP_TEST=y and CONFIG_KPROBE_EVENTS=y) with boot-time
tracing (ftrace.event.kprobes.EVENT.probes) like below;

[   59.803496] trace_kprobe: Testing kprobe tracing:
[   59.804258] ------------[ cut here ]------------
[   59.805682] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:1987 kprobe_trace_self_tests_ib
[   59.806944] Modules linked in:
[   59.807335] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.10.0-rc7+ #172
[   59.808029] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/204
[   59.808999] RIP: 0010:kprobe_trace_self_tests_init+0x5f/0x42b
[   59.809696] Code: e8 03 00 00 48 c7 c7 30 8e 07 82 e8 6d 3c 46 ff 48 c7 c6 00 b2 1a 81 48 c7 c7 7
[   59.812439] RSP: 0018:ffffc90000013e78 EFLAGS: 00010282
[   59.813038] RAX: 00000000ffffffef RBX: 0000000000000000 RCX: 0000000000049443
[   59.813780] RDX: 0000000000049403 RSI: 0000000000049403 RDI: 000000000002deb0
[   59.814589] RBP: ffffc90000013e90 R08: 0000000000000001 R09: 0000000000000001
[   59.815349] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000ffffffef
[   59.816138] R13: ffff888004613d80 R14: ffffffff82696940 R15: ffff888004429138
[   59.816877] FS:  0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000
[   59.817772] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   59.818395] CR2: 0000000001a8dd38 CR3: 0000000002222000 CR4: 00000000000006a0
[   59.819144] Call Trace:
[   59.819469]  ? init_kprobe_trace+0x6b/0x6b
[   59.819948]  do_one_initcall+0x5f/0x300
[   59.820392]  ? rcu_read_lock_sched_held+0x4f/0x80
[   59.820916]  kernel_init_freeable+0x22a/0x271
[   59.821416]  ? rest_init+0x241/0x241
[   59.821841]  kernel_init+0xe/0x10f
[   59.822251]  ret_from_fork+0x22/0x30
[   59.822683] irq event stamp: 16403349
[   59.823121] hardirqs last  enabled at (16403359): [<ffffffff810db81e>] console_unlock+0x48e/0x580
[   59.824074] hardirqs last disabled at (16403368): [<ffffffff810db786>] console_unlock+0x3f6/0x580
[   59.825036] softirqs last  enabled at (16403200): [<ffffffff81c0033a>] __do_softirq+0x33a/0x484
[   59.825982] softirqs last disabled at (16403087): [<ffffffff81a00f02>] asm_call_irq_on_stack+0x10
[   59.827034] ---[ end trace 200c544775cdfeb3 ]---
[   59.827635] trace_kprobe: error on probing function entry.

Link: https://lkml.kernel.org/r/160741764955.3448999.3347769358299456915.stgit@devnote2

Fixes: 4d655281eb1b ("tracing/boot Add kprobe event support")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracepoints: Migrate to use SYSCALL_WORK flag 2020-11-16T20:53:15+00:00 Gabriel Krisman Bertazi krisman@collabora.com 2020-11-16T17:42:01+00:00 524666cb5de7c38a1925e7401a6e59d68682dd8c On architectures using the generic syscall entry code the architecture independent syscall work is moved to flags in thread_info::syscall_work. This removes architecture dependencies and frees up TIF bits. Define SYSCALL_WORK_SYSCALL_TRACEPOINT, use it in the generic entry code and convert the code which uses the TIF specific helper functions to use the new *_syscall_work() helpers which either resolve to the new mode for users of the generic entry code or to the TIF based functions for the other architectures. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20201116174206.2639648-6-krisman@collabora.com 
On architectures using the generic syscall entry code the architecture
independent syscall work is moved to flags in thread_info::syscall_work.
This removes architecture dependencies and frees up TIF bits.

Define SYSCALL_WORK_SYSCALL_TRACEPOINT, use it in the generic entry code
and convert the code which uses the TIF specific helper functions to use
the new *_syscall_work() helpers which either resolve to the new mode for
users of the generic entry code or to the TIF based functions for the other
architectures.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201116174206.2639648-6-krisman@collabora.com
ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs 2020-11-13T17:14:55+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2020-10-28T21:42:17+00:00 d19ad0775dcd64b49eecf4fa79c17959ebfbd26b In preparation to have arguments of a function passed to callbacks attached to functions as default, change the default callback prototype to receive a struct ftrace_regs as the forth parameter instead of a pt_regs. For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they will now need to get the pt_regs via a ftrace_get_regs() helper call. If this is called by a callback that their ftrace_ops did not have a FL_SAVE_REGS flag set, it that helper function will return NULL. This will allow the ftrace_regs to hold enough just to get the parameters and stack pointer, but without the worry that callbacks may have a pt_regs that is not completely filled. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
In preparation to have arguments of a function passed to callbacks attached
to functions as default, change the default callback prototype to receive a
struct ftrace_regs as the forth parameter instead of a pt_regs.

For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they
will now need to get the pt_regs via a ftrace_get_regs() helper call. If
this is called by a callback that their ftrace_ops did not have a
FL_SAVE_REGS flag set, it that helper function will return NULL.

This will allow the ftrace_regs to hold enough just to get the parameters
and stack pointer, but without the worry that callbacks may have a pt_regs
that is not completely filled.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracing: Fix some typos in comments 2020-11-11T01:39:40+00:00 Qiujun Huang hqjagain@gmail.com 2020-10-29T15:05:54+00:00 2b5894cc33e9dea189a7010c7ed57d414786d174 s/detetector/detector/ s/enfoced/enforced/ s/writen/written/ s/actualy/actually/ s/bascially/basically/ s/Regarldess/Regardless/ s/zeroes/zeros/ s/followd/followed/ s/incrememented/incremented/ s/separatelly/separately/ s/accesible/accessible/ s/sythetic/synthetic/ s/enabed/enabled/ s/heurisitc/heuristic/ s/assocated/associated/ s/otherwides/otherwise/ s/specfied/specified/ s/seaching/searching/ s/hierachry/hierarchy/ s/internel/internal/ s/Thise/This/ Link: https://lkml.kernel.org/r/20201029150554.3354-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
s/detetector/detector/
s/enfoced/enforced/
s/writen/written/
s/actualy/actually/
s/bascially/basically/
s/Regarldess/Regardless/
s/zeroes/zeros/
s/followd/followed/
s/incrememented/incremented/
s/separatelly/separately/
s/accesible/accessible/
s/sythetic/synthetic/
s/enabed/enabled/
s/heurisitc/heuristic/
s/assocated/associated/
s/otherwides/otherwise/
s/specfied/specified/
s/seaching/searching/
s/hierachry/hierarchy/
s/internel/internal/
s/Thise/This/

Link: https://lkml.kernel.org/r/20201029150554.3354-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
ftrace: Reverse what the RECURSION flag means in the ftrace_ops 2020-11-06T13:42:12+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2020-11-06T02:32:45+00:00 a25d036d939a30623ff73ecad9c8b9116b02e823 Now that all callbacks are recursion safe, reverse the meaning of the RECURSION flag and rename it from RECURSION_SAFE to simply RECURSION. Now only callbacks that request to have recursion protecting it will have the added trampoline to do so. Also remove the outdated comment about "PER_CPU" when determining to use the ftrace_ops_assist_func. Link: https://lkml.kernel.org/r/20201028115613.742454631@goodmis.org Link: https://lkml.kernel.org/r/20201106023547.904270143@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: linux-doc@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
Now that all callbacks are recursion safe, reverse the meaning of the
RECURSION flag and rename it from RECURSION_SAFE to simply RECURSION.
Now only callbacks that request to have recursion protecting it will
have the added trampoline to do so.

Also remove the outdated comment about "PER_CPU" when determining to
use the ftrace_ops_assist_func.

Link: https://lkml.kernel.org/r/20201028115613.742454631@goodmis.org
Link: https://lkml.kernel.org/r/20201106023547.904270143@goodmis.org

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh  Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>