summaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
authorAlexander Z Lam <azl@google.com>2013-07-01 19:37:54 -0700
committerSteven Rostedt <rostedt@goodmis.org>2013-07-01 23:30:08 -0400
commita82274151af2b075163e3c42c828529dee311487 (patch)
tree0923f9f765266925e9c800a461917ea312d3cc16 /kernel
parent2d71619c59fac95a5415a326162fa046161b938c (diff)
downloadop-kernel-dev-a82274151af2b075163e3c42c828529dee311487.zip
op-kernel-dev-a82274151af2b075163e3c42c828529dee311487.tar.gz
tracing: Protect ftrace_trace_arrays list in trace_events.c
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 Cc: Vaibhav Nagarnaik <vnagarnaik@google.com> Cc: David Sharp <dhsharp@google.com> Cc: Alexander Z Lam <lambchop468@gmail.com> Cc: stable@vger.kernel.org # 3.10 Signed-off-by: Alexander Z Lam <azl@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace.c2
-rw-r--r--kernel/trace/trace.h2
-rw-r--r--kernel/trace/trace_events.c11
3 files changed, 13 insertions, 2 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e04e711..e36da7f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -266,7 +266,7 @@ 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 a88939e..2c3cba59 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 5892470..35c6f23 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1008,6 +1008,7 @@ 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) {
@@ -1023,6 +1024,7 @@ 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;
@@ -1617,6 +1619,7 @@ 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);
@@ -1624,11 +1627,13 @@ 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)
{
@@ -1640,11 +1645,13 @@ 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) \
@@ -1788,6 +1795,7 @@ 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:
@@ -1798,6 +1806,7 @@ static int trace_module_notify(struct notifier_block *self,
break;
}
mutex_unlock(&event_mutex);
+ mutex_unlock(&trace_types_lock);
return 0;
}
OpenPOWER on IntegriCloud