diff options
author | Mark Brown <broonie@linaro.org> | 2014-03-14 12:32:15 +0000 |
---|---|---|
committer | Mark Brown <broonie@linaro.org> | 2014-03-14 12:32:15 +0000 |
commit | f58d5ed0c4c47aa8dbcc4f7a58e4c52752ce6511 (patch) | |
tree | fb4b04d21b4d8654b0e7a615f2b3bc445b48d08c /kernel/trace/trace_kprobe.c | |
parent | 8bb495e3f02401ee6f76d1b1d77f3ac9f079e376 (diff) | |
parent | eb192460ccd50e73475b6092a8953ef7945921c8 (diff) |
Merge branch 'linux-linaro-lsk-v3.10/be/32/core-20140413' of git://git.linaro.org/people/victor.kamensky/linux-linaro-tracking-be into lsk-v3.10-bev3.10/topic/old-arm64-bev3.10/topic/be
Diffstat (limited to 'kernel/trace/trace_kprobe.c')
-rw-r--r-- | kernel/trace/trace_kprobe.c | 42 |
1 files changed, 32 insertions, 10 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 9f46e98ba8f2..64abc8ca928b 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -90,7 +90,7 @@ 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); @@ -281,6 +281,8 @@ trace_probe_file_index(struct trace_probe *tp, struct ftrace_event_file *file) static int disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) { + struct ftrace_event_file **old = NULL; + int wait = 0; int ret = 0; mutex_lock(&probe_enable_lock); @@ -314,10 +316,7 @@ disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) } rcu_assign_pointer(tp->files, new); - - /* Make sure the probe is done with old files */ - synchronize_sched(); - kfree(old); + wait = 1; } else tp->flags &= ~TP_FLAG_PROFILE; @@ -326,11 +325,25 @@ 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_unlock: mutex_unlock(&probe_enable_lock); + 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(old); /* Ignored if link == NULL */ + } + return ret; } @@ -398,9 +411,12 @@ 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; } @@ -679,7 +695,9 @@ 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); } @@ -1312,11 +1330,15 @@ 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 */ |