[for-linus][PATCH 0/2] tracing: More fixes for 7.2

[Steven Rostedt]

tracing fixes for 7.2:

- Add mutex to protect parser in ftrace filtering

  The set_ftrace_filter file uses a parsing descriptor that is allocated at
  open and modified by writes. If multiple threads were to write to the
  descriptor at the same time, it can corrupt the parser.

  Add a mutex around the modifications of the parser descriptor.

- Fix possible corruption in perf syscall tracing

  The perf system call trace events can now read user space. To do so, the
  reads of user space enable preemption and disables it again. During this
  time that preemption is enabled, the task can migrate. The perf event list
  head is assigned via a per CPU pointer. It is done before the user space
  part is called. If the user space reading migrates the task to another
  CPU, then the head pointer is no longer valid.

  Re-assign the head pointer after the reading of user space to keep it
  using the correct data.

  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace/fixes

Head SHA1: 2c2b322acdcc78575b8d6afa64a085cf92e03c12


Steven Rostedt (1):
      tracing: perf: Fix stale head for perf syscall tracing

Tengda Wu (1):
      ftrace: Add global mutex to serialize trace_parser access

----
 kernel/trace/ftrace.c         | 13 +++++++++++++
 kernel/trace/trace_syscalls.c |  5 +++++
 2 files changed, 18 insertions(+)