diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2013-03-13 16:15:19 +0100 |
|---|---|---|
| committer | Steven Rostedt <rostedt@rostedt.homelinux.com> | 2013-03-13 22:57:44 +0100 |
| commit | 740466bc89ad8bd5afcc8de220f715f62b21e365 (patch) | |
| tree | e2226505f6f4d248adbd7fb448f40e949f899126 /kernel/trace | |
| parent | tracing: Fix race in snapshot swapping (diff) | |
| download | linux-740466bc89ad8bd5afcc8de220f715f62b21e365.tar.xz linux-740466bc89ad8bd5afcc8de220f715f62b21e365.zip | |
tracing: Fix free of probe entry by calling call_rcu_sched()
Because function tracing is very invasive, and can even trace
calls to rcu_read_lock(), RCU access in function tracing is done
with preempt_disable_notrace(). This requires a synchronize_sched()
for updates and not a synchronize_rcu().
Function probes (traceon, traceoff, etc) must be freed after
a synchronize_sched() after its entry has been removed from the
hash. But call_rcu() is used. Fix this by using call_rcu_sched().
Also fix the usage to use hlist_del_rcu() instead of hlist_del().
Cc: stable@vger.kernel.org
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/ftrace.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 98ca94a41819..e6effd0c40a9 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3108,8 +3108,8 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, continue; } - hlist_del(&entry->node); - call_rcu(&entry->rcu, ftrace_free_entry_rcu); + hlist_del_rcu(&entry->node); + call_rcu_sched(&entry->rcu, ftrace_free_entry_rcu); } } __disable_ftrace_function_probe(); |