Two updates.

- A memory fix with left over code from spliting out ftrace_ops
    and function graph tracer, where the function graph tracer could
    reset the trampoline pointer, leaving the old trampoline not to
    be freed (memory leak).
 
  - The update to Paul's patch that added the unnecessary READ_ONCE().
    This removes the unnecessary READ_ONCE() instead of having to rebase
    the branch to update the patch that added it.
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Merge tag 'trace-v4.14-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixlets from Steven Rostedt:
 "Two updates:

   - A memory fix with left over code from spliting out ftrace_ops and
     function graph tracer, where the function graph tracer could reset
     the trampoline pointer, leaving the old trampoline not to be freed
     (memory leak).

   - The update to Paul's patch that added the unnecessary READ_ONCE().
     This removes the unnecessary READ_ONCE() instead of having to
     rebase the branch to update the patch that added it"

* tag 'trace-v4.14-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  rcu: Remove extraneous READ_ONCE()s from rcu_irq_{enter,exit}()
  ftrace: Fix kmemleak in unregister_ftrace_graph
This commit is contained in:
Linus Torvalds 2017-10-04 08:34:01 -07:00
commit 013a8ee628
2 changed files with 2 additions and 16 deletions

View File

@ -884,7 +884,7 @@ void rcu_irq_exit(void)
rdtp = this_cpu_ptr(&rcu_dynticks);
/* Page faults can happen in NMI handlers, so check... */
if (READ_ONCE(rdtp->dynticks_nmi_nesting))
if (rdtp->dynticks_nmi_nesting)
return;
WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
@ -1022,7 +1022,7 @@ void rcu_irq_enter(void)
rdtp = this_cpu_ptr(&rcu_dynticks);
/* Page faults can happen in NMI handlers, so check... */
if (READ_ONCE(rdtp->dynticks_nmi_nesting))
if (rdtp->dynticks_nmi_nesting)
return;
oldval = rdtp->dynticks_nesting;

View File

@ -4954,9 +4954,6 @@ static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
static unsigned long save_global_trampoline;
static unsigned long save_global_flags;
static int __init set_graph_function(char *str)
{
strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
@ -6808,17 +6805,6 @@ void unregister_ftrace_graph(void)
unregister_pm_notifier(&ftrace_suspend_notifier);
unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
#ifdef CONFIG_DYNAMIC_FTRACE
/*
* Function graph does not allocate the trampoline, but
* other global_ops do. We need to reset the ALLOC_TRAMP flag
* if one was used.
*/
global_ops.trampoline = save_global_trampoline;
if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP)
global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP;
#endif
out:
mutex_unlock(&ftrace_lock);
}