lkml.org 
[lkml]   [2013]   [Jul]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 9/9] tracing: Remove locking trace_types_lock from tracing_reset_all_online_cpus()
On 07/26/2013 03:03 PM, Steven Rostedt wrote:
> From: "Steven Rostedt (Red Hat)"<rostedt@goodmis.org>
>
> Commit a82274151af "tracing: Protect ftrace_trace_arrays list in trace_events.c"
> added taking the trace_types_lock mutex in trace_events.c as there were
> several locations that needed it for protection. Unfortunately, it also
> encapsulated a call to tracing_reset_all_online_cpus() which also takes
> the trace_types_lock, causing a deadlock.
>
> This happens when a module has tracepoints and has been traced. When the
> module is removed, the trace events module notifier will grab the
> trace_types_lock, do a bunch of clean ups, and also clears the buffer
> by calling tracing_reset_all_online_cpus. This doesn't happen often
> which explains why it wasn't caught right away.
>
> Commit a82274151af was marked for stable, which means this must be
> sent to stable too.
>
> Link:http://lkml.kernel.org/r/51EEC646.7070306@broadcom.com
>
> Reported-by: Arend van *Spril*<arend@broadcom.com>

Nasty dutch names, huh. If we ever meet on a summit you may try to
pronounce it :-) Way easier than Finnish.

Regards,
Arend

> Tested-by: Arend van *Spriel*<arend@broadcom.com>
> Cc: Alexander Z Lam<azl@google.com>
> Cc: Vaibhav Nagarnaik<vnagarnaik@google.com>
> Cc: David Sharp<dhsharp@google.com>
> Cc:stable@vger.kernel.org # 3.10
> Signed-off-by: Steven Rostedt<rostedt@goodmis.org>
> ---
> kernel/trace/trace.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)




\
 
 \ /
  Last update: 2013-07-26 19:01    [W:0.052 / U:0.372 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site