Commit Graph

3053 Commits

Author SHA1 Message Date
Steven Rostedt (Red Hat)
cb86e05390 tracing: Have preempt(irqs)off trace preempt disabled functions
Joel Fernandes reported that the function tracing of preempt disabled
sections was not being reported when running either the preemptirqsoff or
preemptoff tracers. This was due to the fact that the function tracer
callback for those tracers checked if irqs were disabled before tracing. But
this fails when we want to trace preempt off locations as well.

Joel explained that he wanted to see funcitons where interrupts are enabled
but preemption was disabled. The expected output he wanted:

   <...>-2265    1d.h1 3419us : preempt_count_sub <-irq_exit
   <...>-2265    1d..1 3419us : __do_softirq <-irq_exit
   <...>-2265    1d..1 3419us : msecs_to_jiffies <-__do_softirq
   <...>-2265    1d..1 3420us : irqtime_account_irq <-__do_softirq
   <...>-2265    1d..1 3420us : __local_bh_disable_ip <-__do_softirq
   <...>-2265    1..s1 3421us : run_timer_softirq <-__do_softirq
   <...>-2265    1..s1 3421us : hrtimer_run_pending <-run_timer_softirq
   <...>-2265    1..s1 3421us : _raw_spin_lock_irq <-run_timer_softirq
   <...>-2265    1d.s1 3422us : preempt_count_add <-_raw_spin_lock_irq
   <...>-2265    1d.s2 3422us : _raw_spin_unlock_irq <-run_timer_softirq
   <...>-2265    1..s2 3422us : preempt_count_sub <-_raw_spin_unlock_irq
   <...>-2265    1..s1 3423us : rcu_bh_qs <-__do_softirq
   <...>-2265    1d.s1 3423us : irqtime_account_irq <-__do_softirq
   <...>-2265    1d.s1 3423us : __local_bh_enable <-__do_softirq

There's a comment saying that the irq disabled check is because there's a
possible race that tracing_cpu may be set when the function is executed. But
I don't remember that race. For now, I added a check for preemption being
enabled too to not record the function, as there would be no race if that
was the case. I need to re-investigate this, as I'm now thinking that the
tracing_cpu will always be correct. But no harm in keeping the check for
now, except for the slight performance hit.

Link: http://lkml.kernel.org/r/1457770386-88717-1-git-send-email-agnel.joel@gmail.com

Fixes: 5e6d2b9cfa "tracing: Use one prologue for the preempt irqs off tracer function tracers"
Cc: stable@vget.kernel.org # 2.6.37+
Reported-by: Joel Fernandes <agnel.joel@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-18 12:47:38 -04:00
Chunyu Hu
c8ca003b2f tracing: Fix return while holding a lock in register_tracer()
commit d39cdd2036 ("tracing: Make tracer_flags use the right set_flag
callback")  introduces a potential mutex deadlock issue, as it forgets to
free the mutex when allocaing the tracer_flags gets fail.

The issue was found by Dan Carpenter through Smatch static code check tool.

Link: http://lkml.kernel.org/r/1457958941-30265-1-git-send-email-chuhu@redhat.com

Fixes: d39cdd2036 ("tracing: Make tracer_flags use the right set_flag callback")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-18 10:36:21 -04:00
Geliang Tang
6363c6b599 ftrace: Use kasprintf() in ftrace_profile_tracefs()
Use kasprintf() instead of kmalloc() and snprintf().

Link: http://lkml.kernel.org/r/135a7bc36e51fd9eaa57124dd2140285b771f738.1458050835.git.geliangtang@163.com

Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-18 10:31:34 -04:00
Jiri Olsa
7f50d06bb6 ftrace: Update dynamic ftrace calls only if necessary
Currently dynamic ftrace calls are updated any time
the ftrace_ops is un/registered. If we do  this update
only when it's needed, we save lot of time for perf
system wide ftrace function sampling/counting.

The reason is that for system wide sampling/counting,
perf creates event for each cpu in the system.

Each event then registers separate copy of ftrace_ops,
which ends up in FTRACE_UPDATE_CALLS updates. On servers
with many cpus that means serious stall (240 cpus server):

Counting:
  # time ./perf stat -e ftrace:function -a sleep 1

   Performance counter stats for 'system wide':

              370,663      ftrace:function

          1.401427505 seconds time elapsed

  real    3m51.743s
  user    0m0.023s
  sys     3m48.569s

Sampling:
  # time ./perf record -e ftrace:function -a sleep 1
  [ perf record: Woken up 0 times to write data ]
  Warning:
  Processed 141200 events and lost 5 chunks!

  [ perf record: Captured and wrote 10.703 MB perf.data (135950 samples) ]

  real    2m31.429s
  user    0m0.213s
  sys     2m29.494s

There's no reason to do the FTRACE_UPDATE_CALLS update
for each event in perf case, because all the ftrace_ops
always share the same filter, so the updated calls are
always the same.

It's required that only first ftrace_ops registration
does the FTRACE_UPDATE_CALLS update (also sometimes
the second if the first one used the trampoline), but
the rest can be only cheaply linked into the ftrace_ops
list.

Counting:
  # time ./perf stat -e ftrace:function -a sleep 1

   Performance counter stats for 'system wide':

             398,571      ftrace:function

         1.377503733 seconds time elapsed

  real    0m2.787s
  user    0m0.005s
  sys     0m1.883s

Sampling:
  # time ./perf record -e ftrace:function -a sleep 1
  [ perf record: Woken up 0 times to write data ]
  Warning:
  Processed 261730 events and lost 9 chunks!

  [ perf record: Captured and wrote 19.907 MB perf.data (256293 samples) ]

  real    1m31.948s
  user    0m0.309s
  sys     1m32.051s

Link: http://lkml.kernel.org/r/1458138873-1553-6-git-send-email-jolsa@kernel.org

Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-18 10:30:34 -04:00
Jiri Olsa
84b6d3e614 ftrace: Make ftrace_hash_rec_enable return update bool
Change __ftrace_hash_rec_update to return true in case
we need to update dynamic ftrace call records. It return
false in case no update is needed.

Link: http://lkml.kernel.org/r/1458138873-1553-5-git-send-email-jolsa@kernel.org

Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-18 10:30:15 -04:00
Chunyu Hu
1cf8067b54 tracing: Fix typoes in code comment and printk in trace_nop.c
echo nop > /sys/kernel/debug/tracing/options/current_tracer
echo 1 > /sys/kernel/debug/tracing/options/test_nop_accept
echo 0 > /sys/kernel/debug/tracing/options/test_nop_accept
echo 1 > /sys/kernel/debug/tracing/options/test_nop_refuse

Before the fix, the dmesg is a bit ugly since a align issue.

[  191.973081] nop_test_accept flag set to 1: we accept. Now cat trace_options to see the result
[  195.156942] nop_test_refuse flag set to 1: we refuse.Now cat trace_options to see the result

After the fix, the dmesg will show aligned log for nop_test_refuse and nop_test_accept.

[ 2718.032413] nop_test_refuse flag set to 1: we refuse. Now cat trace_options to see the result
[ 2734.253360] nop_test_accept flag set to 1: we accept. Now cat trace_options to see the result

Link: http://lkml.kernel.org/r/1457444222-8654-2-git-send-email-chuhu@redhat.com

Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:23:57 -05:00
Steven Rostedt (Red Hat)
353206f5ca tracing: Use flags instead of bool in trigger structure
gcc isn't known for handling bool in structures. Instead of using bool, use
an integer mask and use bit flags instead.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:36 -05:00
Tom Zanussi
a88e1cfb1d tracing: Add an unreg_all() callback to trigger commands
Add a new unreg_all() callback that can be used to remove all
command-specific triggers from an event and arrange to have it called
whenever a trigger file is opened with O_TRUNC set.

Commands that don't want truncate semantics, or existing commands that
don't implement this function simply do nothing and their triggers
remain intact.

Link: http://lkml.kernel.org/r/2b7d62854d01f28c19185e1bbb8f826f385edfba.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:35 -05:00
Tom Zanussi
a5863dae84 tracing: Add needs_rec flag to event triggers
Add a new needs_rec flag for triggers that require unconditional
access to trace records in order to function.

Normally a trigger requires access to the contents of a trace record
only if it has a filter associated with it (since filters need the
contents of a record in order to make a filtering decision).  Some
types of triggers, such as 'hist' triggers, require access to trace
record contents independent of the presence of filters, so add a new
flag for those triggers.

Link: http://lkml.kernel.org/r/7be8fa38f9b90fdb6c47ca0f98d20a07b9fd512b.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:34 -05:00
Tom Zanussi
104f281044 tracing: Add a per-event-trigger 'paused' field
Add a simple per-trigger 'paused' flag, allowing individual triggers
to pause.  We could leave it to individual triggers that need this
functionality to do it themselves, but we also want to allow other
events to control pausing, so add it to the trigger data.

Link: http://lkml.kernel.org/r/fed37e4879684d7dcc57fe00ce0cbf170032b06d.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:33 -05:00
Tom Zanussi
dbfeaa7aba tracing: Add get_syscall_name()
Add a utility function to grab the syscall name from the syscall
metadata, given a syscall id.

Link: http://lkml.kernel.org/r/be26a8dfe3f15e16a837799f1c1e2b4d62742843.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:32 -05:00
Tom Zanussi
c4a5923055 tracing: Add event record param to trigger_ops.func()
Some triggers may need access to the trace event, so pass it in.  Also
fix up the existing trigger funcs and their callers.

Link: http://lkml.kernel.org/r/543e31e9fc445ef61077421ab219033401c39846.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:31 -05:00
Tom Zanussi
ab4bf00892 tracing: Make event trigger functions available
Make various event trigger utility functions available outside of
trace_events_trigger.c so that new triggers can be defined outside of
that file.

Link: http://lkml.kernel.org/r/4a40c1695dd43cac6cd475d72e13ffe30ba84bff.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:30 -05:00
Tom Zanussi
4ef56902fb tracing: Make ftrace_event_field checking functions available
Make is_string_field() and is_function_field() accessible outside of
trace_event_filters.c for other users of ftrace_event_fields.

Link: http://lkml.kernel.org/r/2d3f00d3311702e556e82eed7754bae6f017939f.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:29 -05:00
Chunyu Hu
d39cdd2036 tracing: Make tracer_flags use the right set_flag callback
When I was updating the ftrace_stress test of ltp. I encountered
a strange phenomemon, excute following steps:

echo nop > /sys/kernel/debug/tracing/current_tracer
echo 0 > /sys/kernel/debug/tracing/options/funcgraph-cpu
bash: echo: write error: Invalid argument

check dmesg:
[ 1024.903855] nop_test_refuse flag set to 0: we refuse.Now cat trace_options to see the result

The reason is that the trace option test will randomly setup trace
option under tracing/options no matter what the current_tracer is.
but the set_tracer_option is always using the set_flag callback
from the current_tracer. This patch adds a pointer to tracer_flags
and make it point to the tracer it belongs to. When the option is
setup, the set_flag of the right tracer will be used no matter
what the the current_tracer is.

And the old dummy_tracer_flags is used for all the tracers which
doesn't have a tracer_flags, having issue to use it to save the
pointer of a tracer. So remove it and use dynamic dummy tracer_flags
for tracers needing a dummy tracer_flags, as a result, there are no
tracers sharing tracer_flags, so remove the check code.

And save the current tracer to trace_option_dentry seems not good as
it may waste mem space when mount the debug/trace fs more than one time.

Link: http://lkml.kernel.org/r/1457444222-8654-1-git-send-email-chuhu@redhat.com

Signed-off-by: Chunyu Hu <chuhu@redhat.com>
[ Fixed up function tracer options to work with the change ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:08 -05:00
Linus Torvalds
78baab7aa8 A feature was added in 4.3 that allowed users to filter trace points on
a tasks "comm" field. But this prevented filtering on a comm field that
 is within a trace event (like sched_migrate_task).
 
 When trying to filter on when a program migrated, this change prevented
 the filtering of the sched_migrate_task.
 
 To fix this, the event fields are examined first, and then the extra fields
 like "comm" and "cpu" are examined. Also, instead of testing to assign
 the comm filter function based on the field's name, the generic comm field
 is given a new filter type (FILTER_COMM). When this field is used to filter
 the type is checked. The same is done for the cpu filter field.
 
 Two new special filter types are added: "COMM" and "CPU". This allows users
 to still filter the tasks comm for events that have "comm" as one of their
 fields, in cases that users would like to filter sched_migrate_task on the
 comm of the task that called the event, and not the comm of the task that
 is being migrated.
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Merge tag 'trace-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "A feature was added in 4.3 that allowed users to filter trace points
  on a tasks "comm" field.  But this prevented filtering on a comm field
  that is within a trace event (like sched_migrate_task).

  When trying to filter on when a program migrated, this change
  prevented the filtering of the sched_migrate_task.

  To fix this, the event fields are examined first, and then the extra
  fields like "comm" and "cpu" are examined.  Also, instead of testing
  to assign the comm filter function based on the field's name, the
  generic comm field is given a new filter type (FILTER_COMM).  When
  this field is used to filter the type is checked.  The same is done
  for the cpu filter field.

  Two new special filter types are added: "COMM" and "CPU".  This allows
  users to still filter the tasks comm for events that have "comm" as
  one of their fields, in cases that users would like to filter
  sched_migrate_task on the comm of the task that called the event, and
  not the comm of the task that is being migrated"

* tag 'trace-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Do not have 'comm' filter override event 'comm' field
2016-03-04 16:57:04 -08:00
Steven Rostedt (Red Hat)
e57cbaf0eb tracing: Do not have 'comm' filter override event 'comm' field
Commit 9f61668073 "tracing: Allow triggers to filter for CPU ids and
process names" added a 'comm' filter that will filter events based on the
current tasks struct 'comm'. But this now hides the ability to filter events
that have a 'comm' field too. For example, sched_migrate_task trace event.
That has a 'comm' field of the task to be migrated.

 echo 'comm == "bash"' > events/sched_migrate_task/filter

will now filter all sched_migrate_task events for tasks named "bash" that
migrates other tasks (in interrupt context), instead of seeing when "bash"
itself gets migrated.

This fix requires a couple of changes.

1) Change the look up order for filter predicates to look at the events
   fields before looking at the generic filters.

2) Instead of basing the filter function off of the "comm" name, have the
   generic "comm" filter have its own filter_type (FILTER_COMM). Test
   against the type instead of the name to assign the filter function.

3) Add a new "COMM" filter that works just like "comm" but will filter based
   on the current task, even if the trace event contains a "comm" field.

Do the same for "cpu" field, adding a FILTER_CPU and a filter "CPU".

Cc: stable@vger.kernel.org # v4.3+
Fixes: 9f61668073 "tracing: Allow triggers to filter for CPU ids and process names"
Reported-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 09:57:10 -05:00
Linus Torvalds
5bb9871eb8 Another small bug reported to me by Chunyu Hu.
When perf added a "reg" function to the function tracing event (not a
 tracepoint), it caused that event to be displayed as a tracepoint and
 could cause errors in tracepoint handling. That was solved by adding a
 flag to ignore ftrace non-tracepoint events. But that flag was missed
 when displaying events in available_events, which should only contain
 tracepoint events.
 
 This broke a documented way to enable all events with:
 
   cat available_events > set_event
 
 As the function non-tracepoint event would cause that to error out.
 The commit here fixes that by having the available_events file not list
 events that have the ignore flag set.
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Merge tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Another small bug reported to me by Chunyu Hu.

  When perf added a "reg" function to the function tracing event (not a
  tracepoint), it caused that event to be displayed as a tracepoint and
  could cause errors in tracepoint handling.  That was solved by adding
  a flag to ignore ftrace non-tracepoint events.  But that flag was
  missed when displaying events in available_events, which should only
  contain tracepoint events.

  This broke a documented way to enable all events with:

      cat available_events > set_event

  As the function non-tracepoint event would cause that to error out.
  The commit here fixes that by having the available_events file not
  list events that have the ignore flag set"

* tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix showing function event in available_events
2016-02-25 20:12:09 -08:00
Steven Rostedt (Red Hat)
d045437a16 tracing: Fix showing function event in available_events
The ftrace:function event is only displayed for parsing the function tracer
data. It is not used to enable function tracing, and does not include an
"enable" file in its event directory.

Originally, this event was kept separate from other events because it did
not have a ->reg parameter. But perf added a "reg" parameter for its use
which caused issues, because it made the event available to functions where
it was not compatible for.

Commit 9b63776fa3 "tracing: Do not enable function event with enable"
added a TRACE_EVENT_FL_IGNORE_ENABLE flag that prevented the function event
from being enabled by normal trace events. But this commit missed keeping
the function event from being displayed by the "available_events" directory,
which is used to show what events can be enabled by set_event.

One documented way to enable all events is to:

 cat available_events > set_event

But because the function event is displayed in the available_events, this
now causes an INVALID error:

 cat: write error: Invalid argument

Reported-by: Chunyu Hu <chuhu@redhat.com>
Fixes: 9b63776fa3 "tracing: Do not enable function event with enable"
Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-02-24 09:17:11 -05:00
Linus Torvalds
4de8ebeff8 Two more small fixes.
One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the
 stack made by the stack tracer. As the stack tracer scans the entire
 kernel stack, KASAN triggers seeing it as a "stack out of bounds" error.
 As the scan is looking at the contents of the stack from parent functions.
 The NOCHECK() tells KASAN that this is done on purpose, and is not some
 kind of stack overflow.
 
 The second fix is to the ftrace selftests, to retrieve the PID of executed
 commands from the shell with "$!" and not by parsing "jobs".
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Merge tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two more small fixes.

  One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the
  stack made by the stack tracer.  As the stack tracer scans the entire
  kernel stack, KASAN triggers seeing it as a "stack out of bounds"
  error.  As the scan is looking at the contents of the stack from
  parent functions.  The NOCHECK() tells KASAN that this is done on
  purpose, and is not some kind of stack overflow.

  The second fix is to the ftrace selftests, to retrieve the PID of
  executed commands from the shell with '$!' and not by parsing 'jobs'"

* tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing, kasan: Silence Kasan warning in check_stack of stack_tracer
  ftracetest: Fix instance test to use proper shell command for pids
2016-02-22 14:09:18 -08:00
Yang Shi
6e22c83664 tracing, kasan: Silence Kasan warning in check_stack of stack_tracer
When enabling stack trace via "echo 1 > /proc/sys/kernel/stack_tracer_enabled",
the below KASAN warning is triggered:

BUG: KASAN: stack-out-of-bounds in check_stack+0x344/0x848 at addr ffffffc0689ebab8
Read of size 8 by task ksoftirqd/4/29
page:ffffffbdc3a27ac0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x0()
page dumped because: kasan: bad access detected
CPU: 4 PID: 29 Comm: ksoftirqd/4 Not tainted 4.5.0-rc1 #129
Hardware name: Freescale Layerscape 2085a RDB Board (DT)
Call trace:
[<ffffffc000091300>] dump_backtrace+0x0/0x3a0
[<ffffffc0000916c4>] show_stack+0x24/0x30
[<ffffffc0009bbd78>] dump_stack+0xd8/0x168
[<ffffffc000420bb0>] kasan_report_error+0x6a0/0x920
[<ffffffc000421688>] kasan_report+0x70/0xb8
[<ffffffc00041f7f0>] __asan_load8+0x60/0x78
[<ffffffc0002e05c4>] check_stack+0x344/0x848
[<ffffffc0002e0c8c>] stack_trace_call+0x1c4/0x370
[<ffffffc0002af558>] ftrace_ops_no_ops+0x2c0/0x590
[<ffffffc00009f25c>] ftrace_graph_call+0x0/0x14
[<ffffffc0000881bc>] fpsimd_thread_switch+0x24/0x1e8
[<ffffffc000089864>] __switch_to+0x34/0x218
[<ffffffc0011e089c>] __schedule+0x3ac/0x15b8
[<ffffffc0011e1f6c>] schedule+0x5c/0x178
[<ffffffc0001632a8>] smpboot_thread_fn+0x350/0x960
[<ffffffc00015b518>] kthread+0x1d8/0x2b0
[<ffffffc0000874d0>] ret_from_fork+0x10/0x40
Memory state around the buggy address:
 ffffffc0689eb980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f4 f4 f4
 ffffffc0689eba00: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffc0689eba80: 00 00 f1 f1 f1 f1 00 f4 f4 f4 f3 f3 f3 f3 00 00
                                        ^
 ffffffc0689ebb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffc0689ebb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

The stacker tracer traverses the whole kernel stack when saving the max stack
trace. It may touch the stack red zones to cause the warning. So, just disable
the instrumentation to silence the warning.

Link: http://lkml.kernel.org/r/1455309960-18930-1-git-send-email-yang.shi@linaro.org

Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-02-19 12:36:44 -05:00
Linus Torvalds
705d43dbe1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching fixes from Jiri Kosina:

 - regression (from 4.4) fix for ordering issue, introduced by an
   earlier ftrace change, that broke live patching of modules.

   The fix replaces the ftrace module notifier by direct call in order
   to make the ordering guaranteed and well-defined.  The patch, from
   Jessica Yu, has been acked both by Steven and Rusty

 - error message fix from Miroslav Benes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  ftrace/module: remove ftrace module notifier
  livepatch: change the error message in asm/livepatch.h header files
2016-02-18 16:34:15 -08:00
Jessica Yu
7dcd182bec ftrace/module: remove ftrace module notifier
Remove the ftrace module notifier in favor of directly calling
ftrace_module_enable() and ftrace_release_mod() in the module loader.
Hard-coding the function calls directly in the module loader removes
dependence on the module notifier call chain and provides better
visibility and control over what gets called when, which is important
to kernel utilities such as livepatch.

This fixes a notifier ordering issue in which the ftrace module notifier
(and hence ftrace_module_enable()) for coming modules was being called
after klp_module_notify(), which caused livepatch modules to initialize
incorrectly. This patch removes dependence on the module notifier call
chain in favor of hard coding the corresponding function calls in the
module loader. This ensures that ftrace and livepatch code get called in
the correct order on patch module load and unload.

Fixes: 5156dca34a ("ftrace: Fix the race between ftrace and insmod")
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-02-17 22:14:06 +01:00
Linus Torvalds
ef582d095d A cleanup to the stack tracer broke stack tracing on s390.
Here's a simple fix to correct that issue.
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Merge tag 'trace-v4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "A cleanup to the stack tracer broke stack tracing on s390.  Here's a
  simple fix to correct that issue"

* tag 'trace-v4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/stacktrace: Show entire trace if passed in function not found
2016-02-03 09:31:34 -08:00
Linus Torvalds
29d14f0835 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "This is much bigger than typical fixes, but Peter found a category of
  races that spurred more fixes and more debugging enhancements.  Work
  started before the merge window, but got finished only now.

  Aside of that this contains the usual small fixes to perf and tools.
  Nothing particular exciting"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
  perf: Remove/simplify lockdep annotation
  perf: Synchronously clean up child events
  perf: Untangle 'owner' confusion
  perf: Add flags argument to perf_remove_from_context()
  perf: Clean up sync_child_event()
  perf: Robustify event->owner usage and SMP ordering
  perf: Fix STATE_EXIT usage
  perf: Update locking order
  perf: Remove __free_event()
  perf/bpf: Convert perf_event_array to use struct file
  perf: Fix NULL deref
  perf/x86: De-obfuscate code
  perf/x86: Fix uninitialized value usage
  perf: Fix race in perf_event_exit_task_context()
  perf: Fix orphan hole
  perf stat: Do not clean event's private stats
  perf hists: Fix HISTC_MEM_DCACHELINE width setting
  perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed
  perf tests: Remove wrong semicolon in while loop in CQM test
  perf: Synchronously free aux pages in case of allocation failure
  ...
2016-01-31 15:38:27 -08:00
Steven Rostedt
6ccd83714a tracing/stacktrace: Show entire trace if passed in function not found
When a max stack trace is discovered, the stack dump is saved. In order to
not record the overhead of the stack tracer, the ip of the traced function
is looked for within the dump. The trace is started from the location of
that function. But if for some reason the ip is not found, the entire stack
trace is then truncated. That's not very useful. Instead, print everything
if the ip of the traced function is not found within the trace.

This issue showed up on s390.

Link: http://lkml.kernel.org/r/20160129102241.1b3c9c04@gandalf.local.home

Fixes: 72ac426a5b ("tracing: Clean up stack tracing and fix fentry updates")
Cc: stable@vger.kernel.org # v4.3+
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-29 12:19:10 -05:00
Alexei Starovoitov
e03e7ee34f perf/bpf: Convert perf_event_array to use struct file
Robustify refcounting.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160126045947.GA40151@ast-mbp.thefacebook.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:25 +01:00
Linus Torvalds
26cd83670f This includes three minor fixes, mostly due to cut-and-paste issues.
The first is a cut and paste issue that changed the amount of stack
 to skip when tracing a stack dump from 0 to 6, which basically made
 the stack disappear for small stack traces.
 
 The second fix is just removing an unused field in a struct that is no
 longer used, and currently just wastes space.
 
 The third is another cut-and-paste fix that had a tracepoint recording
 the wrong field (it was recording the previous field a second time).
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Merge tag 'trace-v4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull minor tracing fixes from Steven Rostedt:
 "This includes three minor fixes, mostly due to cut-and-paste issues.

  The first is a cut and paste issue that changed the amount of stack to
  skip when tracing a stack dump from 0 to 6, which basically made the
  stack disappear for small stack traces.

  The second fix is just removing an unused field in a struct that is no
  longer used, and currently just wastes space.

  The third is another cut-and-paste fix that had a tracepoint recording
  the wrong field (it was recording the previous field a second time)"

* tag 'trace-v4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/dma-buf/fence: Fix timeline str value on fence_annotate_wait_on
  ftrace: Remove unused nr_trampolines var
  tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()
2016-01-28 17:00:50 -08:00
Steven Rostedt (Red Hat)
7717c6be69 tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()
While cleaning the stacktrace code I unintentially changed the skip depth of
trace_buffer_unlock_commit_regs() from 0 to 6. kprobes uses this function,
and with skipping 6 call backs, it can easily produce no stack.

Here's how I tested it:

 # echo 'p:ext4_sync_fs ext4_sync_fs ' > /sys/kernel/debug/tracing/kprobe_events
 # echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable
 # cat /sys/kernel/debug/trace
            sync-2394  [005]   502.457060: ext4_sync_fs: (ffffffff81317650)
            sync-2394  [005]   502.457063: kernel_stack:         <stack trace>
            sync-2394  [005]   502.457086: ext4_sync_fs: (ffffffff81317650)
            sync-2394  [005]   502.457087: kernel_stack:         <stack trace>
            sync-2394  [005]   502.457091: ext4_sync_fs: (ffffffff81317650)

After putting back the skip stack to zero, we have:

            sync-2270  [000]   748.052693: ext4_sync_fs: (ffffffff81317650)
            sync-2270  [000]   748.052695: kernel_stack:         <stack trace>
 => iterate_supers (ffffffff8126412e)
 => sys_sync (ffffffff8129c4b6)
 => entry_SYSCALL_64_fastpath (ffffffff8181f0b2)
            sync-2270  [000]   748.053017: ext4_sync_fs: (ffffffff81317650)
            sync-2270  [000]   748.053019: kernel_stack:         <stack trace>
 => iterate_supers (ffffffff8126412e)
 => sys_sync (ffffffff8129c4b6)
 => entry_SYSCALL_64_fastpath (ffffffff8181f0b2)
            sync-2270  [000]   748.053381: ext4_sync_fs: (ffffffff81317650)
            sync-2270  [000]   748.053383: kernel_stack:         <stack trace>
 => iterate_supers (ffffffff8126412e)
 => sys_sync (ffffffff8129c4b6)
 => entry_SYSCALL_64_fastpath (ffffffff8181f0b2)

Cc: stable@vger.kernel.org # v4.4+
Fixes: 73dddbb57b "tracing: Only create stacktrace option when STACKTRACE is configured"
Reported-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Tested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-14 09:28:19 -05:00
Linus Torvalds
c17488d066 Not much new with tracing for this release. Mostly just clean ups and
minor fixes.
 
 Here's what else is new:
 
  o  A new TRACE_EVENT_FN_COND macro, combining both _FN and _COND for
     those that want both.
 
  o  New selftest to test the instance create and delete
 
  o  Better debug output when ftrace fails
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Merge tag 'trace-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Not much new with tracing for this release.  Mostly just clean ups and
  minor fixes.

  Here's what else is new:

   - A new TRACE_EVENT_FN_COND macro, combining both _FN and _COND for
     those that want both.

   - New selftest to test the instance create and delete

   - Better debug output when ftrace fails"

* tag 'trace-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
  ftrace: Fix the race between ftrace and insmod
  ftrace: Add infrastructure for delayed enabling of module functions
  x86: ftrace: Fix the comments for ftrace_modify_code_direct()
  tracing: Fix comment to use tracing_on over tracing_enable
  metag: ftrace: Fix the comments for ftrace_modify_code
  sh: ftrace: Fix the comments for ftrace_modify_code()
  ia64: ftrace: Fix the comments for ftrace_modify_code()
  ftrace: Clean up ftrace_module_init() code
  ftrace: Join functions ftrace_module_init() and ftrace_init_module()
  tracing: Introduce TRACE_EVENT_FN_COND macro
  tracing: Use seq_buf_used() in seq_buf_to_user() instead of len
  bpf: Constify bpf_verifier_ops structure
  ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too
  ftrace: Remove use of control list and ops
  ftrace: Fix output of enabled_functions for showing tramp
  ftrace: Fix a typo in comment
  ftrace: Show all tramps registered to a record on ftrace_bug()
  ftrace: Add variable ftrace_expected for archs to show expected code
  ftrace: Add new type to distinguish what kind of ftrace_bug()
  tracing: Update cond flag when enabling or disabling a trigger
  ...
2016-01-12 20:04:15 -08:00
Linus Torvalds
33caf82acf Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "All kinds of stuff.  That probably should've been 5 or 6 separate
  branches, but by the time I'd realized how large and mixed that bag
  had become it had been too close to -final to play with rebasing.

  Some fs/namei.c cleanups there, memdup_user_nul() introduction and
  switching open-coded instances, burying long-dead code, whack-a-mole
  of various kinds, several new helpers for ->llseek(), assorted
  cleanups and fixes from various people, etc.

  One piece probably deserves special mention - Neil's
  lookup_one_len_unlocked().  Similar to lookup_one_len(), but gets
  called without ->i_mutex and tries to avoid ever taking it.  That, of
  course, means that it's not useful for any directory modifications,
  but things like getting inode attributes in nfds readdirplus are fine
  with that.  I really should've asked for moratorium on lookup-related
  changes this cycle, but since I hadn't done that early enough...  I
  *am* asking for that for the coming cycle, though - I'm going to try
  and get conversion of i_mutex to rwsem with ->lookup() done under lock
  taken shared.

  There will be a patch closer to the end of the window, along the lines
  of the one Linus had posted last May - mechanical conversion of
  ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
  inode_is_locked()/inode_lock_nested().  To quote Linus back then:

    -----
    |    This is an automated patch using
    |
    |        sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
    |        sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
    |        sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[     ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
    |        sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
    |        sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
    |
    |    with a very few manual fixups
    -----

  I'm going to send that once the ->i_mutex-affecting stuff in -next
  gets mostly merged (or when Linus says he's about to stop taking
  merges)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  nfsd: don't hold i_mutex over userspace upcalls
  fs:affs:Replace time_t with time64_t
  fs/9p: use fscache mutex rather than spinlock
  proc: add a reschedule point in proc_readfd_common()
  logfs: constify logfs_block_ops structures
  fcntl: allow to set O_DIRECT flag on pipe
  fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
  fs: xattr: Use kvfree()
  [s390] page_to_phys() always returns a multiple of PAGE_SIZE
  nbd: use ->compat_ioctl()
  fs: use block_device name vsprintf helper
  lib/vsprintf: add %*pg format specifier
  fs: use gendisk->disk_name where possible
  poll: plug an unused argument to do_poll
  amdkfd: don't open-code memdup_user()
  cdrom: don't open-code memdup_user()
  rsxx: don't open-code memdup_user()
  mtip32xx: don't open-code memdup_user()
  [um] mconsole: don't open-code memdup_user_nul()
  [um] hostaudio: don't open-code memdup_user()
  ...
2016-01-12 17:11:47 -08:00
Qiu Peiyang
5156dca34a ftrace: Fix the race between ftrace and insmod
We hit ftrace_bug report when booting Android on a 64bit ATOM SOC chip.
Basically, there is a race between insmod and ftrace_run_update_code.

After load_module=>ftrace_module_init, another thread jumps in to call
ftrace_run_update_code=>ftrace_arch_code_modify_prepare
                        =>set_all_modules_text_rw, to change all modules
as RW. Since the new module is at MODULE_STATE_UNFORMED, the text attribute
is not changed. Then, the 2nd thread goes ahead to change codes.
However, load_module continues to call complete_formation=>set_section_ro_nx,
then 2nd thread would fail when probing the module's TEXT.

The patch fixes it by using notifier to delay the enabling of ftrace
records to the time when module is at state MODULE_STATE_COMING.

Link: http://lkml.kernel.org/r/567CE628.3000609@intel.com

Signed-off-by: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-07 15:56:21 -05:00
Steven Rostedt (Red Hat)
b7ffffbb46 ftrace: Add infrastructure for delayed enabling of module functions
Qiu Peiyang pointed out that there's a race when enabling function tracing
and loading a module. In order to make the modifications of converting nops
in the prologue of functions into callbacks, the text needs to be converted
from read-only to read-write. When enabling function tracing, the text
permission is updated, the functions are modified, and then they are put
back.

When loading a module, the updates to convert function calls to mcount is
done before the module text is set to read-only. But after it is done, the
module text is visible by the function tracer. Thus we have the following
race:

	CPU 0			CPU 1
	-----			-----
   start function tracing
   set text to read-write
			     load_module
			     add functions to ftrace
			     set module text read-only

   update all functions to callbacks
   modify module functions too
   < Can't it's read-only >

When this happens, ftrace detects the issue and disables itself till the
next reboot.

To fix this, a new DISABLED flag is added for ftrace records, which all
module functions get when they are added. Then later, after the module code
is all set, the records will have the DISABLED flag cleared, and they will
be enabled if any callback wants all functions to be traced.

Note, this doesn't add the delay to later. It simply changes the
ftrace_module_init() to do both the setting of DISABLED records, and then
immediately calls the enable code. This helps with testing this new code as
it has the same behavior as previously. Another change will come after this
to have the ftrace_module_enable() called after the text is set to
read-only.

Cc: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-07 15:40:01 -05:00
Qiu Peiyang
f36d1be293 tracing: Fix setting of start_index in find_next()
When we do cat /sys/kernel/debug/tracing/printk_formats, we hit kernel
panic at t_show.

general protection fault: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 2957 Comm: sh Tainted: G W  O 3.14.55-x86_64-01062-gd4acdc7 #2
RIP: 0010:[<ffffffff811375b2>]
 [<ffffffff811375b2>] t_show+0x22/0xe0
RSP: 0000:ffff88002b4ebe80  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004
RDX: 0000000000000004 RSI: ffffffff81fd26a6 RDI: ffff880032f9f7b1
RBP: ffff88002b4ebe98 R08: 0000000000001000 R09: 000000000000ffec
R10: 0000000000000000 R11: 000000000000000f R12: ffff880004d9b6c0
R13: 7365725f6d706400 R14: ffff880004d9b6c0 R15: ffffffff82020570
FS:  0000000000000000(0000) GS:ffff88003aa00000(0063) knlGS:00000000f776bc40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f6c02ff0 CR3: 000000002c2b3000 CR4: 00000000001007f0
Call Trace:
 [<ffffffff811dc076>] seq_read+0x2f6/0x3e0
 [<ffffffff811b749b>] vfs_read+0x9b/0x160
 [<ffffffff811b7f69>] SyS_read+0x49/0xb0
 [<ffffffff81a3a4b9>] ia32_do_call+0x13/0x13
 ---[ end trace 5bd9eb630614861e ]---
Kernel panic - not syncing: Fatal exception

When the first time find_next calls find_next_mod_format, it should
iterate the trace_bprintk_fmt_list to find the first print format of
the module. However in current code, start_index is smaller than *pos
at first, and code will not iterate the list. Latter container_of will
get the wrong address with former v, which will cause mod_fmt be a
meaningless object and so is the returned mod_fmt->fmt.

This patch will fix it by correcting the start_index. After fixed,
when the first time calls find_next_mod_format, start_index will be
equal to *pos, and code will iterate the trace_bprintk_fmt_list to
get the right module printk format, so is the returned mod_fmt->fmt.

Link: http://lkml.kernel.org/r/5684B900.9000309@intel.com

Cc: stable@vger.kernel.org # 3.12+
Fixes: 102c9323c3 "tracing: Add __tracepoint_string() to export string pointers"
Signed-off-by: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-04 15:22:47 -05:00
Al Viro
70f6cbb6f9 kernel/*: switch to memdup_user_nul()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-04 10:27:55 -05:00
Al Viro
16e5c1fc36 convert a bunch of open-coded instances of memdup_user_nul()
A _lot_ of ->write() instances were open-coding it; some are
converted to memdup_user_nul(), a lot more remain...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-04 10:26:58 -05:00
Chuyu Hu
05a724bd44 tracing: Fix comment to use tracing_on over tracing_enable
The file tracing_enable is obsolete and does not exist anymore. Replace
the comment that references it with the proper tracing_on file.

Link: http://lkml.kernel.org/r/1450787141-45544-1-git-send-email-chuhu@redhat.com

Signed-off-by: Chuyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:25 -05:00
Steven Rostedt (Red Hat)
97e9b4fca5 ftrace: Clean up ftrace_module_init() code
The start and end variables were only used when ftrace_module_init() was
split up into multiple functions. No need to keep them around after the
merger.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:23 -05:00
Abel Vesa
b6b71f66a1 ftrace: Join functions ftrace_module_init() and ftrace_init_module()
Simple cleanup. No need for two functions here.
The whole work can simply be done inside 'ftrace_module_init'.

Link: http://lkml.kernel.org/r/1449067197-5718-1-git-send-email-abelvesa@linux.com

Signed-off-by: Abel Vesa <abelvesa@linux.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:22 -05:00
Julia Lawall
27dff4e041 bpf: Constify bpf_verifier_ops structure
This bpf_verifier_ops structure is never modified, like the other
bpf_verifier_ops structures, so declare it as const.

Done with the help of Coccinelle.

Link: http://lkml.kernel.org/r/1449855359-13724-1-git-send-email-Julia.Lawall@lip6.fr

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:19 -05:00
Steven Rostedt (Red Hat)
c68c0fa293 ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too
Jiri Olsa noted that the change to replace the control_ops did not update
the trampoline for when running perf on a single CPU and with CONFIG_PREEMPT
disabled (where dynamic ops, like perf, can use trampolines directly). The
result was that perf function could be called when RCU is not watching as
well as not handle the ftrace_local_disable().

Modify the ftrace_ops_get_func() to also check the RCU and PER_CPU ops flags
and use the recursive function if they are set. The recursive function is
modified to check those flags and execute the appropriate checks if they are
set.

Link: http://lkml.kernel.org/r/20151201134213.GA14155@krava.brq.redhat.com

Reported-by: Jiri Olsa <jolsa@redhat.com>
Patch-fixed-up-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:19 -05:00
Steven Rostedt (Red Hat)
ba27f2bc73 ftrace: Remove use of control list and ops
Currently perf has its own list function within the ftrace infrastructure
that seems to be used only to allow for it to have per-cpu disabling as well
as a check to make sure that it's not called while RCU is not watching. It
uses something called the "control_ops" which is used to iterate over ops
under it with the control_list_func().

The problem is that this control_ops and control_list_func unnecessarily
complicates the code. By replacing FTRACE_OPS_FL_CONTROL with two new flags
(FTRACE_OPS_FL_RCU and FTRACE_OPS_FL_PER_CPU) we can remove all the code
that is special with the control ops and add the needed checks within the
generic ftrace_list_func().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:18 -05:00
Steven Rostedt (Red Hat)
030f4e1cb8 ftrace: Fix output of enabled_functions for showing tramp
When showing all tramps registered to a ftrace record in the file
enabled_functions, it exits the loop with ops == NULL. But then it is
suppose to show the function on the ops->trampoline and
add_trampoline_func() is called with the given ops. But because ops is now
NULL (to exit the loop), it always shows the static trampoline instead of
the one that is really registered to the record.

The call to add_trampoline_func() that shows the trampoline for the given
ops needs to be called at every iteration.

Fixes: 39daa7b9e8 "ftrace: Show all tramps registered to a record on ftrace_bug()"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:17 -05:00
Li Bin
b8ec330a63 ftrace: Fix a typo in comment
s/ARCH_SUPPORT_FTARCE_OPS/ARCH_SUPPORTS_FTRACE_OPS/

Link: http://lkml.kernel.org/r/1448879016-8659-1-git-send-email-huawei.libin@huawei.com

Signed-off-by: Li Bin <huawei.libin@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:26:51 -05:00
Linus Torvalds
51825c8a86 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "This tree includes four core perf fixes for misc bugs, three fixes to
  x86 PMU drivers, and two updates to old email addresses"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Do not send exit event twice
  perf/x86/intel: Fix INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA macro
  perf/x86/intel: Make L1D_PEND_MISS.FB_FULL not constrained on Haswell
  perf: Fix PERF_EVENT_IOC_PERIOD deadlock
  treewide: Remove old email address
  perf/x86: Fix LBR call stack save/restore
  perf: Update email address in MAINTAINERS
  perf/core: Robustify the perf_cgroup_from_task() RCU checks
  perf/core: Fix RCU problem with cgroup context switching code
2015-12-08 13:01:23 -08:00
Steven Rostedt (Red Hat)
0f72e37e42 tracing: Add sched_wakeup_new and sched_waking tracepoints for pid filter
The set_event_pid filter relies on attaching to the sched_switch and
sched_wakeup tracepoints to see if it should filter the tracing on schedule
tracepoints. By adding the callbacks to sched_wakeup, pids in the
set_event_pid file will trace the wakeups of those tasks with those pids.

But sched_wakeup_new and sched_waking were missed. These two should also be
traced. Luckily, these tracepoints share the same class as sched_wakeup
which means they can use the same pre and post callbacks as sched_wakeup
does.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-01 16:08:05 -05:00
Steven Rostedt (Red Hat)
39daa7b9e8 ftrace: Show all tramps registered to a record on ftrace_bug()
When an anomaly is detected in the function call modification code,
ftrace_bug() is called to disable function tracing as well as give any
information that may help debug the problem. Currently, only the first found
trampoline that is attached to the failed record is reported. Instead, show
all trampolines that are hooked to it.

Also, not only show the ops pointer but also report the function it calls.

While at it, add this info to the enabled_functions debug file too.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-25 16:04:59 -05:00
Steven Rostedt (Red Hat)
b05086c77a ftrace: Add variable ftrace_expected for archs to show expected code
When an anomaly is found while modifying function code, ftrace_bug() is
called which disables the function tracing infrastructure and reports
information about what failed. If the code that is to be replaced does not
match what is expected, then actual code is shown. Currently there is no
arch generic way to show what was expected.

Add a new variable pointer calld ftrace_expected that the arch code can set
to point to what it expected so that ftrace_bug() can report the actual text
as well as the text that was expected to be there.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-25 15:24:16 -05:00
Steven Rostedt (Red Hat)
02a392a043 ftrace: Add new type to distinguish what kind of ftrace_bug()
The ftrace function hook utility has several internal checks to make sure
that whatever it modifies is exactly what it expects to be modifying. This
is essential as modifying running code can be extremely dangerous to the
system.

When an anomaly is detected, ftrace_bug() is called which sends a splat to
the console and disables function tracing. There's some extra information
that is printed to help diagnose the issue.

One thing that is missing though is output of what ftrace was doing at the
time of the crash. Was it updating a call site or perhaps converting a call
site to a nop? A new global enum variable is created to state what ftrace
was doing at the time of the anomaly, and this is reported in ftrace_bug().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-25 15:24:15 -05:00
Tom Zanussi
4e4a4d7570 tracing: Update cond flag when enabling or disabling a trigger
When a trigger is enabled, the cond flag should be set beforehand,
otherwise a trigger that's expecting to process a trace record
(e.g. one with post_trigger set) could be invoked without one.

Likewise a trigger's cond flag should be reset after it's disabled,
not before.

Link: http://lkml.kernel.org/r/a420b52a67b1c2d3cab017914362d153255acb99.1448303214.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-25 15:24:14 -05:00