linux-stable.git/kernel/trace, branch linux-3.6.y

ring-buffer: Fix race between integrity check and readers

2012-12-17T17:27:16+00:00

commit 9366c1ba13fbc41bdb57702e75ca4382f209c82f upstream.

The function rb_check_pages() was added to make sure the ring buffer's
pages were sane. This check is done when the ring buffer size is modified
as well as when the iterator is released (closing the "trace" file),
as that was considered a non fast path and a good place to do a sanity
check.

The problem is that the check does not have any locks around it.
If one process were to read the trace file, and another were to read
the raw binary file, the check could happen while the reader is reading
the file.

The issues with this is that the check requires to clear the HEAD page
before doing the full check and it restores it afterward. But readers
require the HEAD page to exist before it can read the buffer, otherwise
it gives a nasty warning and disables the buffer.

By adding the reader lock around the check, this keeps the race from
happening.

Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

ring-buffer: Fix NULL pointer if rb_set_head_page() fails

2012-12-17T17:27:15+00:00

commit 54f7be5b831254199522523ccab4c3d954bbf576 upstream.

The function rb_set_head_page() searches the list of ring buffer
pages for a the page that has the HEAD page flag set. If it does
not find it, it will do a WARN_ON(), disable the ring buffer and
return NULL, as this should never happen.

But if this bug happens to happen, not all callers of this function
can handle a NULL pointer being returned from it. That needs to be
fixed.

Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

ftrace: Clear bits properly in reset_iter_read()

2012-12-17T17:27:15+00:00

commit 70f77b3f7ec010ff9624c1f2e39a81babc9e2429 upstream.

There is a typo here where '&' is used instead of '|' and it turns the
statement into a noop.  The original code is equivalent to:

	iter->flags &= ~((1 << 2) & (1 << 4));

Link: http://lkml.kernel.org/r/20120609161027.GD6488@elgon.mountain

Signed-off-by: Dan Carpenter 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

ring-buffer: Check for uninitialized cpu buffer before resizing

2012-10-28T17:56:10+00:00

commit 8e49f418c9632790bf456634742d34d97120a784 upstream.

With a system where, num_present_cpus < num_possible_cpus, even if all
CPUs are online, non-present CPUs don't have per_cpu buffers allocated.
If per_cpu//buffer_size_kb is modified for such a CPU, it can cause
a panic due to NULL dereference in ring_buffer_resize().

To fix this, resize operation is allowed only if the per-cpu buffer has
been initialized.

Link: http://lkml.kernel.org/r/1349912427-6486-1-git-send-email-vnagarnaik@google.com

Signed-off-by: Vaibhav Nagarnaik 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

tracing/syscalls: Fix perf syscall tracing when syscall_nr == -1

2012-08-17T19:19:46+00:00

syscall_get_nr can return -1 in the case that the task is not executing
a system call.

This patch fixes perf_syscall_{enter,exit} to check that the syscall
number is valid before using it as an index into a bitmap.

Link: http://lkml.kernel.org/r/1345137254-7377-1-git-send-email-will.deacon@arm.com

Cc: Jason Baron 
Cc: Wade Farnsworth 
Cc: Frederic Weisbecker 
Signed-off-by: Will Deacon 
Signed-off-by: Steven Rostedt

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-08-03T17:57:20+00:00

Pull perf fixes from Ingo Molnar:
 "Fix merge window fallout and fix sleep profiling (this was always
  broken, so it's not a fix for the merge window - we can skip this one
  from the head of the tree)."

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/trace: Add ability to set a target task for events
  perf/x86: Fix USER/KERNEL tagging of samples properly
  perf/x86/intel/uncore: Make UNCORE_PMU_HRTIMER_INTERVAL 64-bit

perf/trace: Add ability to set a target task for events

2012-07-31T15:02:05+00:00

A few events are interesting not only for a current task.
For example, sched_stat_* events are interesting for a task
which wakes up. For this reason, it will be good if such
events will be delivered to a target task too.

Now a target task can be set by using __perf_task().

The original idea and a draft patch belongs to Peter Zijlstra.

I need these events for profiling sleep times. sched_switch is used for
getting callchains and sched_stat_* is used for getting time periods.
These events are combined in user space, then it can be analyzed by
perf tools.

Inspired-by: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: Paul Mackerras 
Cc: Arnaldo Carvalho de Melo 
Cc: Steven Rostedt 
Cc: Arun Sharma 
Signed-off-by: Andrew Vagin 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1342016098-213063-1-git-send-email-avagin@openvz.org
Signed-off-by: Ingo Molnar

Merge tag 'staging-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

2012-07-26T18:14:49+00:00

Pull staging tree patches from Greg Kroah-Hartman:
 "Here's the big staging tree merge for the 3.6-rc1 merge window.

  There are some patches in here outside of drivers/staging/, notibly
  the iio code (which is still stradeling the staging / not staging
  boundry), the pstore code, and the tracing code.  All of these have
  gotten acks from the various subsystem maintainers to be included in
  this tree.  The pstore and tracing patches are related, and are coming
  here as they replace one of the android staging drivers.

  Otherwise, the normal staging mess.  Lots of cleanups and a few new
  drivers (some iio drivers, and the large csr wireless driver
  abomination.)

  Signed-off-by: Greg Kroah-Hartman "

Fixed up trivial conflicts in drivers/staging/comedi/drivers/s626.h and
drivers/staging/gdm72xx/netlink_k.c

* tag 'staging-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1108 commits)
  staging: csr: delete a bunch of unused library functions
  staging: csr: remove csr_utf16.c
  staging: csr: remove csr_pmem.h
  staging: csr: remove CsrPmemAlloc
  staging: csr: remove CsrPmemFree()
  staging: csr: remove CsrMemAllocDma()
  staging: csr: remove CsrMemCalloc()
  staging: csr: remove CsrMemAlloc()
  staging: csr: remove CsrMemFree() and CsrMemFreeDma()
  staging: csr: remove csr_util.h
  staging: csr: remove CsrOffSetOf()
  stating: csr: remove unneeded #includes in csr_util.c
  staging: csr: make CsrUInt16ToHex static
  staging: csr: remove CsrMemCpy()
  staging: csr: remove CsrStrLen()
  staging: csr: remove CsrVsnprintf()
  staging: csr: remove CsrStrDup
  staging: csr: remove CsrStrChr()
  staging: csr: remove CsrStrNCmp
  staging: csr: remove CsrStrCmp
  ...

Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core

2012-07-18T09:18:00+00:00

Pull tracing fix from Steve Rostedt.

Signed-off-by: Ingo Molnar

Merge branch 'linus' into perf/core

2012-07-18T09:17:17+00:00

Pick up the latest ring-buffer fixes, before applying a new fix.

Signed-off-by: Ingo Molnar