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Diffstat (limited to 'kernel/trace/trace_kprobe.c')
-rw-r--r--kernel/trace/trace_kprobe.c50
1 files changed, 32 insertions, 18 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 7ed6976493c8..243f6834d026 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -95,7 +95,7 @@ static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
}
static int register_probe_event(struct trace_probe *tp);
-static void unregister_probe_event(struct trace_probe *tp);
+static int unregister_probe_event(struct trace_probe *tp);
static DEFINE_MUTEX(probe_lock);
static LIST_HEAD(probe_list);
@@ -243,11 +243,11 @@ find_event_file_link(struct trace_probe *tp, struct ftrace_event_file *file)
static int
disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
{
+ struct event_file_link *link = NULL;
+ int wait = 0;
int ret = 0;
if (file) {
- struct event_file_link *link;
-
link = find_event_file_link(tp, file);
if (!link) {
ret = -EINVAL;
@@ -255,10 +255,7 @@ disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
}
list_del_rcu(&link->list);
- /* synchronize with kprobe_trace_func/kretprobe_trace_func */
- synchronize_sched();
- kfree(link);
-
+ wait = 1;
if (!list_empty(&tp->files))
goto out;
@@ -271,8 +268,22 @@ disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
disable_kretprobe(&tp->rp);
else
disable_kprobe(&tp->rp.kp);
+ wait = 1;
}
out:
+ if (wait) {
+ /*
+ * Synchronize with kprobe_trace_func/kretprobe_trace_func
+ * to ensure disabled (all running handlers are finished).
+ * This is not only for kfree(), but also the caller,
+ * trace_remove_event_call() supposes it for releasing
+ * event_call related objects, which will be accessed in
+ * the kprobe_trace_func/kretprobe_trace_func.
+ */
+ synchronize_sched();
+ kfree(link); /* Ignored if link == NULL */
+ }
+
return ret;
}
@@ -340,9 +351,12 @@ static int unregister_trace_probe(struct trace_probe *tp)
if (trace_probe_is_enabled(tp))
return -EBUSY;
+ /* Will fail if probe is being used by ftrace or perf */
+ if (unregister_probe_event(tp))
+ return -EBUSY;
+
__unregister_trace_probe(tp);
list_del(&tp->list);
- unregister_probe_event(tp);
return 0;
}
@@ -621,7 +635,9 @@ static int release_all_trace_probes(void)
/* TODO: Use batch unregistration */
while (!list_empty(&probe_list)) {
tp = list_entry(probe_list.next, struct trace_probe, list);
- unregister_trace_probe(tp);
+ ret = unregister_trace_probe(tp);
+ if (ret)
+ goto end;
free_trace_probe(tp);
}
@@ -1087,9 +1103,6 @@ kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs)
__size = sizeof(*entry) + tp->size + dsize;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
- if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
- "profile buffer not large enough"))
- return;
entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
if (!entry)
@@ -1120,9 +1133,6 @@ kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri,
__size = sizeof(*entry) + tp->size + dsize;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
- if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
- "profile buffer not large enough"))
- return;
entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
if (!entry)
@@ -1242,11 +1252,15 @@ static int register_probe_event(struct trace_probe *tp)
return ret;
}
-static void unregister_probe_event(struct trace_probe *tp)
+static int unregister_probe_event(struct trace_probe *tp)
{
+ int ret;
+
/* tp->event is unregistered in trace_remove_event_call() */
- trace_remove_event_call(&tp->call);
- kfree(tp->call.print_fmt);
+ ret = trace_remove_event_call(&tp->call);
+ if (!ret)
+ kfree(tp->call.print_fmt);
+ return ret;
}
/* Make a debugfs interface for controlling probe points */