Merge tag 'trace-fixes-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This includes a fix to a memory leak when adding filters to traces.
Also, Masami Hiramatsu fixed up some minor bugs that were discovered
by sparse."
* tag 'trace-fixes-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/kprobes: Make print_*probe_event static
tracing/kprobes: Fix a sparse warning for incorrect type in assignment
tracing/kprobes: Use rcu_dereference_raw for tp->files
tracing: Fix leaks of filter preds
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index a636117..e1b653f 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -750,7 +750,11 @@
static void __free_preds(struct event_filter *filter)
{
+ int i;
+
if (filter->preds) {
+ for (i = 0; i < filter->n_preds; i++)
+ kfree(filter->preds[i].ops);
kfree(filter->preds);
filter->preds = NULL;
}
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 636d45f..9f46e98 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -35,7 +35,7 @@
const char *symbol; /* symbol name */
struct ftrace_event_class class;
struct ftrace_event_call call;
- struct ftrace_event_file **files;
+ struct ftrace_event_file * __rcu *files;
ssize_t size; /* trace entry size */
unsigned int nr_args;
struct probe_arg args[];
@@ -185,9 +185,14 @@
static int trace_probe_nr_files(struct trace_probe *tp)
{
- struct ftrace_event_file **file = tp->files;
+ struct ftrace_event_file **file;
int ret = 0;
+ /*
+ * Since all tp->files updater is protected by probe_enable_lock,
+ * we don't need to lock an rcu_read_lock.
+ */
+ file = rcu_dereference_raw(tp->files);
if (file)
while (*(file++))
ret++;
@@ -209,9 +214,10 @@
mutex_lock(&probe_enable_lock);
if (file) {
- struct ftrace_event_file **new, **old = tp->files;
+ struct ftrace_event_file **new, **old;
int n = trace_probe_nr_files(tp);
+ old = rcu_dereference_raw(tp->files);
/* 1 is for new one and 1 is for stopper */
new = kzalloc((n + 2) * sizeof(struct ftrace_event_file *),
GFP_KERNEL);
@@ -251,11 +257,17 @@
static int
trace_probe_file_index(struct trace_probe *tp, struct ftrace_event_file *file)
{
+ struct ftrace_event_file **files;
int i;
- if (tp->files) {
- for (i = 0; tp->files[i]; i++)
- if (tp->files[i] == file)
+ /*
+ * Since all tp->files updater is protected by probe_enable_lock,
+ * we don't need to lock an rcu_read_lock.
+ */
+ files = rcu_dereference_raw(tp->files);
+ if (files) {
+ for (i = 0; files[i]; i++)
+ if (files[i] == file)
return i;
}
@@ -274,10 +286,11 @@
mutex_lock(&probe_enable_lock);
if (file) {
- struct ftrace_event_file **new, **old = tp->files;
+ struct ftrace_event_file **new, **old;
int n = trace_probe_nr_files(tp);
int i, j;
+ old = rcu_dereference_raw(tp->files);
if (n == 0 || trace_probe_file_index(tp, file) < 0) {
ret = -EINVAL;
goto out_unlock;
@@ -872,9 +885,16 @@
static __kprobes void
kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs)
{
- struct ftrace_event_file **file = tp->files;
+ /*
+ * Note: preempt is already disabled around the kprobe handler.
+ * However, we still need an smp_read_barrier_depends() corresponding
+ * to smp_wmb() in rcu_assign_pointer() to access the pointer.
+ */
+ struct ftrace_event_file **file = rcu_dereference_raw(tp->files);
- /* Note: preempt is already disabled around the kprobe handler */
+ if (unlikely(!file))
+ return;
+
while (*file) {
__kprobe_trace_func(tp, regs, *file);
file++;
@@ -925,9 +945,16 @@
kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
struct pt_regs *regs)
{
- struct ftrace_event_file **file = tp->files;
+ /*
+ * Note: preempt is already disabled around the kprobe handler.
+ * However, we still need an smp_read_barrier_depends() corresponding
+ * to smp_wmb() in rcu_assign_pointer() to access the pointer.
+ */
+ struct ftrace_event_file **file = rcu_dereference_raw(tp->files);
- /* Note: preempt is already disabled around the kprobe handler */
+ if (unlikely(!file))
+ return;
+
while (*file) {
__kretprobe_trace_func(tp, ri, regs, *file);
file++;
@@ -935,7 +962,7 @@
}
/* Event entry printers */
-enum print_line_t
+static enum print_line_t
print_kprobe_event(struct trace_iterator *iter, int flags,
struct trace_event *event)
{
@@ -971,7 +998,7 @@
return TRACE_TYPE_PARTIAL_LINE;
}
-enum print_line_t
+static enum print_line_t
print_kretprobe_event(struct trace_iterator *iter, int flags,
struct trace_event *event)
{