diff options
| author | Alexander Z Lam <azl@google.com> | 2013-07-01 19:37:54 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-25 14:07:43 -0700 |
| commit | 9713f78568d0053621530fb9cf06756394b4403c (patch) | |
| tree | dba7b16aab7bc4d42bfc686b2f22171fe47cd4de | |
| parent | b7f15519edb2e3c3d7d07d6a0780a4386ef23085 (diff) | |
| download | lwn-9713f78568d0053621530fb9cf06756394b4403c.tar.gz lwn-9713f78568d0053621530fb9cf06756394b4403c.zip | |
tracing: Protect ftrace_trace_arrays list in trace_events.c
commit a82274151af2b075163e3c42c828529dee311487 upstream.
There are multiple places where the ftrace_trace_arrays list is accessed in
trace_events.c without the trace_types_lock held.
Link: http://lkml.kernel.org/r/1372732674-22726-1-git-send-email-azl@google.com
Signed-off-by: Alexander Z Lam <azl@google.com>
Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Cc: David Sharp <dhsharp@google.com>
Cc: Alexander Z Lam <lambchop468@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/trace/trace.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_events.c | 11 |
3 files changed, 13 insertions, 2 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b90c993462be..10d3f0871b48 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -240,7 +240,7 @@ static struct tracer *trace_types __read_mostly; /* * trace_types_lock is used to protect the trace_types list. */ -static DEFINE_MUTEX(trace_types_lock); +DEFINE_MUTEX(trace_types_lock); /* * serialize the access of the ring buffer diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 20572ed88c5c..7944b9294599 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -224,6 +224,8 @@ enum { extern struct list_head ftrace_trace_arrays; +extern struct mutex trace_types_lock; + /* * The global tracer (top) should be the first trace array added, * but we check the flag anyway. diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index bf56c1d07df3..f82d92dbd614 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1011,6 +1011,7 @@ static int subsystem_open(struct inode *inode, struct file *filp) int ret; /* Make sure the system still exists */ + mutex_lock(&trace_types_lock); mutex_lock(&event_mutex); list_for_each_entry(tr, &ftrace_trace_arrays, list) { list_for_each_entry(dir, &tr->systems, list) { @@ -1026,6 +1027,7 @@ static int subsystem_open(struct inode *inode, struct file *filp) } exit_loop: mutex_unlock(&event_mutex); + mutex_unlock(&trace_types_lock); if (!system) return -ENODEV; @@ -1620,6 +1622,7 @@ static void __add_event_to_tracers(struct ftrace_event_call *call, int trace_add_event_call(struct ftrace_event_call *call) { int ret; + mutex_lock(&trace_types_lock); mutex_lock(&event_mutex); ret = __register_event(call, NULL); @@ -1627,11 +1630,13 @@ int trace_add_event_call(struct ftrace_event_call *call) __add_event_to_tracers(call, NULL); mutex_unlock(&event_mutex); + mutex_unlock(&trace_types_lock); return ret; } /* - * Must be called under locking both of event_mutex and trace_event_sem. + * Must be called under locking of trace_types_lock, event_mutex and + * trace_event_sem. */ static void __trace_remove_event_call(struct ftrace_event_call *call) { @@ -1643,11 +1648,13 @@ static void __trace_remove_event_call(struct ftrace_event_call *call) /* Remove an event_call */ void trace_remove_event_call(struct ftrace_event_call *call) { + mutex_lock(&trace_types_lock); mutex_lock(&event_mutex); down_write(&trace_event_sem); __trace_remove_event_call(call); up_write(&trace_event_sem); mutex_unlock(&event_mutex); + mutex_unlock(&trace_types_lock); } #define for_each_event(event, start, end) \ @@ -1791,6 +1798,7 @@ static int trace_module_notify(struct notifier_block *self, { struct module *mod = data; + mutex_lock(&trace_types_lock); mutex_lock(&event_mutex); switch (val) { case MODULE_STATE_COMING: @@ -1801,6 +1809,7 @@ static int trace_module_notify(struct notifier_block *self, break; } mutex_unlock(&event_mutex); + mutex_unlock(&trace_types_lock); return 0; } |