linux-stable.git/kernel/trace, branch v3.2.89 Linux kernel stable tree tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline() 2017-06-05T20:13:55+00:00 Amey Telawane ameyt@codeaurora.org 2017-05-03T10:11:14+00:00 e39e64193a8a611d11d4c62579a7246c1af70d1c commit e09e28671cda63e6308b31798b997639120e2a21 upstream. Strcpy is inherently not safe, and strlcpy() should be used instead. __trace_find_cmdline() uses strcpy() because the comms saved must have a terminating nul character, but it doesn't hurt to add the extra protection of using strlcpy() instead of strcpy(). Link: http://lkml.kernel.org/r/1493806274-13936-1-git-send-email-amit.pundir@linaro.org Signed-off-by: Amey Telawane <ameyt@codeaurora.org> [AmitP: Cherry-picked this commit from CodeAurora kernel/msm-3.10 https://source.codeaurora.org/quic/la/kernel/msm-3.10/commit/?id=2161ae9a70b12cf18ac8e5952a20161ffbccb477] Signed-off-by: Amit Pundir <amit.pundir@linaro.org> [ Updated change log and removed the "- 1" from len parameter ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit e09e28671cda63e6308b31798b997639120e2a21 upstream.

Strcpy is inherently not safe, and strlcpy() should be used instead.
__trace_find_cmdline() uses strcpy() because the comms saved must have a
terminating nul character, but it doesn't hurt to add the extra protection
of using strlcpy() instead of strcpy().

Link: http://lkml.kernel.org/r/1493806274-13936-1-git-send-email-amit.pundir@linaro.org

Signed-off-by: Amey Telawane <ameyt@codeaurora.org>
[AmitP: Cherry-picked this commit from CodeAurora kernel/msm-3.10
https://source.codeaurora.org/quic/la/kernel/msm-3.10/commit/?id=2161ae9a70b12cf18ac8e5952a20161ffbccb477]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
[ Updated change log and removed the "- 1" from len parameter ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tracing: Move mutex to protect against resetting of seq data 2016-11-20T01:01:42+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2016-09-24T02:57:13+00:00 e6711e36bb98f8538cadf8759a232cf49161fee6 commit 1245800c0f96eb6ebb368593e251d66c01e61022 upstream. The iter->seq can be reset outside the protection of the mutex. So can reading of user data. Move the mutex up to the beginning of the function. Fixes: d7350c3f45694 ("tracing/core: make the read callbacks reentrants") Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 1245800c0f96eb6ebb368593e251d66c01e61022 upstream.

The iter->seq can be reset outside the protection of the mutex. So can
reading of user data. Move the mutex up to the beginning of the function.

Fixes: d7350c3f45694 ("tracing/core: make the read callbacks reentrants")
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tracing: Fix crash from reading trace_pipe with sendfile 2016-04-30T22:05:20+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2016-03-18T19:46:48+00:00 1719bf67d6c52a9bc84ddf24a3e85d5f69fe3f90 commit a29054d9478d0435ab01b7544da4f674ab13f533 upstream. If tracing contains data and the trace_pipe file is read with sendfile(), then it can trigger a NULL pointer dereference and various BUG_ON within the VM code. There's a patch to fix this in the splice_to_pipe() code, but it's also a good idea to not let that happen from trace_pipe either. Link: http://lkml.kernel.org/r/1457641146-9068-1-git-send-email-rabin@rab.in Reported-by: Rabin Vincent <rabin.vincent@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit a29054d9478d0435ab01b7544da4f674ab13f533 upstream.

If tracing contains data and the trace_pipe file is read with sendfile(),
then it can trigger a NULL pointer dereference and various BUG_ON within the
VM code.

There's a patch to fix this in the splice_to_pipe() code, but it's also a
good idea to not let that happen from trace_pipe either.

Link: http://lkml.kernel.org/r/1457641146-9068-1-git-send-email-rabin@rab.in

Reported-by: Rabin Vincent <rabin.vincent@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tracing: Have preempt(irqs)off trace preempt disabled functions 2016-04-30T22:05:20+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2016-03-18T16:27:43+00:00 9e1128ecd9cab0f5af43cb4f8a6ff9091aaf15b8 commit cb86e05390debcc084cfdb0a71ed4c5dbbec517d upstream. 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: 5e6d2b9cfa3a "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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit cb86e05390debcc084cfdb0a71ed4c5dbbec517d upstream.

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: 5e6d2b9cfa3a "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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ring-buffer: Update read stamp with first real commit on page 2015-12-30T02:25:58+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2015-11-23T15:35:36+00:00 1af93d99281a44405e7fcf130c061201405c577c commit b81f472a208d3e2b4392faa6d17037a89442f4ce upstream. Do not update the read stamp after swapping out the reader page from the write buffer. If the reader page is swapped out of the buffer before an event is written to it, then the read_stamp may get an out of date timestamp, as the page timestamp is updated on the first commit to that page. rb_get_reader_page() only returns a page if it has an event on it, otherwise it will return NULL. At that point, check if the page being returned has events and has not been read yet. Then at that point update the read_stamp to match the time stamp of the reader page. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit b81f472a208d3e2b4392faa6d17037a89442f4ce upstream.

Do not update the read stamp after swapping out the reader page from the
write buffer. If the reader page is swapped out of the buffer before an
event is written to it, then the read_stamp may get an out of date
timestamp, as the page timestamp is updated on the first commit to that
page.

rb_get_reader_page() only returns a page if it has an event on it, otherwise
it will return NULL. At that point, check if the page being returned has
events and has not been read yet. Then at that point update the read_stamp
to match the time stamp of the reader page.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tracing/filter: Do not allow infix to exceed end of string 2015-08-12T14:33:17+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2015-06-25T22:10:09+00:00 7cc2315e7b9c148ee549d4cfbf68735a578b64db commit 6b88f44e161b9ee2a803e5b2b1fbcf4e20e8b980 upstream. While debugging a WARN_ON() for filtering, I found that it is possible for the filter string to be referenced after its end. With the filter: # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter The filter_parse() function can call infix_get_op() which calls infix_advance() that updates the infix filter pointers for the cnt and tail without checking if the filter is already at the end, which will put the cnt to zero and the tail beyond the end. The loop then calls infix_next() that has ps->infix.cnt--; return ps->infix.string[ps->infix.tail++]; The cnt will now be below zero, and the tail that is returned is already passed the end of the filter string. So far the allocation of the filter string usually has some buffer that is zeroed out, but if the filter string is of the exact size of the allocated buffer there's no guarantee that the charater after the nul terminating character will be zero. Luckily, only root can write to the filter. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 6b88f44e161b9ee2a803e5b2b1fbcf4e20e8b980 upstream.

While debugging a WARN_ON() for filtering, I found that it is possible
for the filter string to be referenced after its end. With the filter:

 # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter

The filter_parse() function can call infix_get_op() which calls
infix_advance() that updates the infix filter pointers for the cnt
and tail without checking if the filter is already at the end, which
will put the cnt to zero and the tail beyond the end. The loop then calls
infix_next() that has

	ps->infix.cnt--;
	return ps->infix.string[ps->infix.tail++];

The cnt will now be below zero, and the tail that is returned is
already passed the end of the filter string. So far the allocation
of the filter string usually has some buffer that is zeroed out, but
if the filter string is of the exact size of the allocated buffer
there's no guarantee that the charater after the nul terminating
character will be zero.

Luckily, only root can write to the filter.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tracing/filter: Do not WARN on operand count going below zero 2015-08-12T14:33:17+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2015-06-25T22:02:29+00:00 b43dd35952747f563d0dec7aefb7570260f10353 commit b4875bbe7e68f139bd3383828ae8e994a0df6d28 upstream. When testing the fix for the trace filter, I could not come up with a scenario where the operand count goes below zero, so I added a WARN_ON_ONCE(cnt < 0) to the logic. But there is legitimate case that it can happen (although the filter would be wrong). # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter That is, a single operation without any operands will hit the path where the WARN_ON_ONCE() can trigger. Although this is harmless, and the filter is reported as a error. But instead of spitting out a warning to the kernel dmesg, just fail nicely and report it via the proper channels. Link: http://lkml.kernel.org/r/558C6082.90608@oracle.com Reported-by: Vince Weaver <vincent.weaver@maine.edu> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit b4875bbe7e68f139bd3383828ae8e994a0df6d28 upstream.

When testing the fix for the trace filter, I could not come up with
a scenario where the operand count goes below zero, so I added a
WARN_ON_ONCE(cnt < 0) to the logic. But there is legitimate case
that it can happen (although the filter would be wrong).

 # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter

That is, a single operation without any operands will hit the path
where the WARN_ON_ONCE() can trigger. Although this is harmless,
and the filter is reported as a error. But instead of spitting out
a warning to the kernel dmesg, just fail nicely and report it via
the proper channels.

Link: http://lkml.kernel.org/r/558C6082.90608@oracle.com

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tracing: Have filter check for balanced ops 2015-08-06T23:32:15+00:00 Steven Rostedt rostedt@goodmis.org 2015-06-15T21:50:25+00:00 9fa3f3e6f2a4f4797df5550a33ec5ac1088647e7 commit 2cf30dc180cea808077f003c5116388183e54f9e upstream. When the following filter is used it causes a warning to trigger: # cd /sys/kernel/debug/tracing # echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter -bash: echo: write error: Invalid argument # cat events/ext4/ext4_truncate_exit/filter ((dev==1)blocks==2) ^ parse_error: No error ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1223 at kernel/trace/trace_events_filter.c:1640 replace_preds+0x3c5/0x990() Modules linked in: bnep lockd grace bluetooth ... CPU: 3 PID: 1223 Comm: bash Tainted: G W 4.1.0-rc3-test+ #450 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 0000000000000668 ffff8800c106bc98 ffffffff816ed4f9 ffff88011ead0cf0 0000000000000000 ffff8800c106bcd8 ffffffff8107fb07 ffffffff8136b46c ffff8800c7d81d48 ffff8800d4c2bc00 ffff8800d4d4f920 00000000ffffffea Call Trace: [<ffffffff816ed4f9>] dump_stack+0x4c/0x6e [<ffffffff8107fb07>] warn_slowpath_common+0x97/0xe0 [<ffffffff8136b46c>] ? _kstrtoull+0x2c/0x80 [<ffffffff8107fb6a>] warn_slowpath_null+0x1a/0x20 [<ffffffff81159065>] replace_preds+0x3c5/0x990 [<ffffffff811596b2>] create_filter+0x82/0xb0 [<ffffffff81159944>] apply_event_filter+0xd4/0x180 [<ffffffff81152bbf>] event_filter_write+0x8f/0x120 [<ffffffff811db2a8>] __vfs_write+0x28/0xe0 [<ffffffff811dda43>] ? __sb_start_write+0x53/0xf0 [<ffffffff812e51e0>] ? security_file_permission+0x30/0xc0 [<ffffffff811dc408>] vfs_write+0xb8/0x1b0 [<ffffffff811dc72f>] SyS_write+0x4f/0xb0 [<ffffffff816f5217>] system_call_fastpath+0x12/0x6a ---[ end trace e11028bd95818dcd ]--- Worse yet, reading the error message (the filter again) it says that there was no error, when there clearly was. The issue is that the code that checks the input does not check for balanced ops. That is, having an op between a closed parenthesis and the next token. This would only cause a warning, and fail out before doing any real harm, but it should still not caues a warning, and the error reported should work: # cd /sys/kernel/debug/tracing # echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter -bash: echo: write error: Invalid argument # cat events/ext4/ext4_truncate_exit/filter ((dev==1)blocks==2) ^ parse_error: Meaningless filter expression And give no kernel warning. Link: http://lkml.kernel.org/r/20150615175025.7e809215@gandalf.local.home Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> [bwh: Backported to 3.2: drop the check for OP_NOT, which we don't have] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 2cf30dc180cea808077f003c5116388183e54f9e upstream.

When the following filter is used it causes a warning to trigger:

 # cd /sys/kernel/debug/tracing
 # echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter
-bash: echo: write error: Invalid argument
 # cat events/ext4/ext4_truncate_exit/filter
((dev==1)blocks==2)
^
parse_error: No error

 ------------[ cut here ]------------
 WARNING: CPU: 2 PID: 1223 at kernel/trace/trace_events_filter.c:1640 replace_preds+0x3c5/0x990()
 Modules linked in: bnep lockd grace bluetooth  ...
 CPU: 3 PID: 1223 Comm: bash Tainted: G        W       4.1.0-rc3-test+ #450
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
  0000000000000668 ffff8800c106bc98 ffffffff816ed4f9 ffff88011ead0cf0
  0000000000000000 ffff8800c106bcd8 ffffffff8107fb07 ffffffff8136b46c
  ffff8800c7d81d48 ffff8800d4c2bc00 ffff8800d4d4f920 00000000ffffffea
 Call Trace:
  [<ffffffff816ed4f9>] dump_stack+0x4c/0x6e
  [<ffffffff8107fb07>] warn_slowpath_common+0x97/0xe0
  [<ffffffff8136b46c>] ? _kstrtoull+0x2c/0x80
  [<ffffffff8107fb6a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff81159065>] replace_preds+0x3c5/0x990
  [<ffffffff811596b2>] create_filter+0x82/0xb0
  [<ffffffff81159944>] apply_event_filter+0xd4/0x180
  [<ffffffff81152bbf>] event_filter_write+0x8f/0x120
  [<ffffffff811db2a8>] __vfs_write+0x28/0xe0
  [<ffffffff811dda43>] ? __sb_start_write+0x53/0xf0
  [<ffffffff812e51e0>] ? security_file_permission+0x30/0xc0
  [<ffffffff811dc408>] vfs_write+0xb8/0x1b0
  [<ffffffff811dc72f>] SyS_write+0x4f/0xb0
  [<ffffffff816f5217>] system_call_fastpath+0x12/0x6a
 ---[ end trace e11028bd95818dcd ]---

Worse yet, reading the error message (the filter again) it says that
there was no error, when there clearly was. The issue is that the
code that checks the input does not check for balanced ops. That is,
having an op between a closed parenthesis and the next token.

This would only cause a warning, and fail out before doing any real
harm, but it should still not caues a warning, and the error reported
should work:

 # cd /sys/kernel/debug/tracing
 # echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter
-bash: echo: write error: Invalid argument
 # cat events/ext4/ext4_truncate_exit/filter
((dev==1)blocks==2)
^
parse_error: Meaningless filter expression

And give no kernel warning.

Link: http://lkml.kernel.org/r/20150615175025.7e809215@gandalf.local.home

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[bwh: Backported to 3.2: drop the check for OP_NOT, which we don't have]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ring-buffer-benchmark: Fix the wrong sched_priority of producer 2015-08-06T23:32:15+00:00 Wang Long long.wanglong@huawei.com 2015-06-10T08:12:37+00:00 67766970d59d88c721c31387a9d3df4e4fb9bb37 commit 108029323910c5dd1ef8fa2d10da1ce5fbce6e12 upstream. The producer should be used producer_fifo as its sched_priority, so correct it. Link: http://lkml.kernel.org/r/1433923957-67842-1-git-send-email-long.wanglong@huawei.com Signed-off-by: Wang Long <long.wanglong@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 108029323910c5dd1ef8fa2d10da1ce5fbce6e12 upstream.

The producer should be used producer_fifo as its sched_priority,
so correct it.

Link: http://lkml.kernel.org/r/1433923957-67842-1-git-send-email-long.wanglong@huawei.com

Signed-off-by: Wang Long <long.wanglong@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ftrace: Fix ftrace enable ordering of sysctl ftrace_enabled 2015-05-09T22:16:27+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2015-03-07T00:55:13+00:00 826ba3143f8ddc543c32f0f496543eea3720dcb9 commit 524a38682573b2e15ab6317ccfe50280441514be upstream. Some archs (specifically PowerPC), are sensitive with the ordering of the enabling of the calls to function tracing and setting of the function to use to be traced. That is, update_ftrace_function() sets what function the ftrace_caller trampoline should call. Some archs require this to be set before calling ftrace_run_update_code(). Another bug was discovered, that ftrace_startup_sysctl() called ftrace_run_update_code() directly. If the function the ftrace_caller trampoline changes, then it will not be updated. Instead a call to ftrace_startup_enable() should be called because it tests to see if the callback changed since the code was disabled, and will tell the arch to update appropriately. Most archs do not need this notification, but PowerPC does. The problem could be seen by the following commands: # echo 0 > /proc/sys/kernel/ftrace_enabled # echo function > /sys/kernel/debug/tracing/current_tracer # echo 1 > /proc/sys/kernel/ftrace_enabled # cat /sys/kernel/debug/tracing/trace The trace will show that function tracing was not active. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 524a38682573b2e15ab6317ccfe50280441514be upstream.

Some archs (specifically PowerPC), are sensitive with the ordering of
the enabling of the calls to function tracing and setting of the
function to use to be traced.

That is, update_ftrace_function() sets what function the ftrace_caller
trampoline should call. Some archs require this to be set before
calling ftrace_run_update_code().

Another bug was discovered, that ftrace_startup_sysctl() called
ftrace_run_update_code() directly. If the function the ftrace_caller
trampoline changes, then it will not be updated. Instead a call
to ftrace_startup_enable() should be called because it tests to see
if the callback changed since the code was disabled, and will
tell the arch to update appropriately. Most archs do not need this
notification, but PowerPC does.

The problem could be seen by the following commands:

 # echo 0 > /proc/sys/kernel/ftrace_enabled
 # echo function > /sys/kernel/debug/tracing/current_tracer
 # echo 1 > /proc/sys/kernel/ftrace_enabled
 # cat /sys/kernel/debug/tracing/trace

The trace will show that function tracing was not active.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>