Here's two fixes:

1) Discovered by Fengguang Wu's tests. I changed the parameters to
    the function graph x86 prepare_ftrace_return call but forgot
    to update the call from entry_32 (i386 version). This patch corrects
    that.
 
 2) I was tracing some code and found that the sched_switch tracepoint
    was showing tasks in the INTERRUPTIBLE state as RUNNING. This was
    due to the updates to convert preempt_count into a per_cpu variable.
    The tracepoint logic was made to use the tasks saved_preempt_count
    which could hold a stale "PREEMPT_ACTIVE", instead of using the
    current preempt_count() call.
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Merge tag 'trace-fixes-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Here's two fixes:

  1) Discovered by Fengguang Wu's tests.  I changed the parameters to
     the function graph x86 prepare_ftrace_return call but forgot to
     update the call from entry_32 (i386 version).  This patch corrects
     that.

  2) I was tracing some code and found that the sched_switch tracepoint
     was showing tasks in the INTERRUPTIBLE state as RUNNING.  This was
     due to the updates to convert preempt_count into a per_cpu
     variable.  The tracepoint logic was made to use the tasks
     saved_preempt_count which could hold a stale "PREEMPT_ACTIVE",
     instead of using the current preempt_count() call"

* tag 'trace-fixes-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/sched: Check preempt_count() for current when reading task->state
  ftrace/x86: Update i386 call to prepare_ftrace_return()
This commit is contained in:
Linus Torvalds 2014-12-13 14:01:11 -08:00
commit 52bb452558

View File

@ -1191,10 +1191,10 @@ ENTRY(ftrace_graph_caller)
pushl %eax
pushl %ecx
pushl %edx
movl 0xc(%esp), %edx
lea 0x4(%ebp), %eax
movl 0xc(%esp), %eax
lea 0x4(%ebp), %edx
movl (%ebp), %ecx
subl $MCOUNT_INSN_SIZE, %edx
subl $MCOUNT_INSN_SIZE, %eax
call prepare_ftrace_return
popl %edx
popl %ecx