diff options
Diffstat (limited to 'kernel/trace')
-rw-r--r-- | kernel/trace/fprobe.c | 15 | ||||
-rw-r--r-- | kernel/trace/rethook.c | 13 | ||||
-rw-r--r-- | kernel/trace/trace_eprobe.c | 18 |
3 files changed, 36 insertions, 10 deletions
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index e4704ec26df7..b70de44e6d3d 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -102,12 +102,14 @@ static void fprobe_kprobe_handler(unsigned long ip, unsigned long parent_ip, if (unlikely(kprobe_running())) { fp->nmissed++; - return; + goto recursion_unlock; } kprobe_busy_begin(); __fprobe_handler(ip, parent_ip, ops, fregs); kprobe_busy_end(); + +recursion_unlock: ftrace_test_recursion_unlock(bit); } @@ -371,19 +373,16 @@ int unregister_fprobe(struct fprobe *fp) if (!fprobe_is_registered(fp)) return -EINVAL; - /* - * rethook_free() starts disabling the rethook, but the rethook handlers - * may be running on other processors at this point. To make sure that all - * current running handlers are finished, call unregister_ftrace_function() - * after this. - */ if (fp->rethook) - rethook_free(fp->rethook); + rethook_stop(fp->rethook); ret = unregister_ftrace_function(&fp->ops); if (ret < 0) return ret; + if (fp->rethook) + rethook_free(fp->rethook); + ftrace_free_filter(&fp->ops); return ret; diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c index f32ee484391a..5eb9b598f4e9 100644 --- a/kernel/trace/rethook.c +++ b/kernel/trace/rethook.c @@ -54,6 +54,19 @@ static void rethook_free_rcu(struct rcu_head *head) } /** + * rethook_stop() - Stop using a rethook. + * @rh: the struct rethook to stop. + * + * Stop using a rethook to prepare for freeing it. If you want to wait for + * all running rethook handler before calling rethook_free(), you need to + * call this first and wait RCU, and call rethook_free(). + */ +void rethook_stop(struct rethook *rh) +{ + WRITE_ONCE(rh->handler, NULL); +} + +/** * rethook_free() - Free struct rethook. * @rh: the struct rethook to be freed. * diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index cb0077ba2b49..a0a704ba27db 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -644,6 +644,7 @@ static int enable_trace_eprobe(struct trace_event_call *call, struct trace_eprobe *ep; bool enabled; int ret = 0; + int cnt = 0; tp = trace_probe_primary_from_call(call); if (WARN_ON_ONCE(!tp)) @@ -667,12 +668,25 @@ static int enable_trace_eprobe(struct trace_event_call *call, if (ret) break; enabled = true; + cnt++; } if (ret) { /* Failed to enable one of them. Roll back all */ - if (enabled) - disable_eprobe(ep, file->tr); + if (enabled) { + /* + * It's a bug if one failed for something other than memory + * not being available but another eprobe succeeded. + */ + WARN_ON_ONCE(ret != -ENOMEM); + + list_for_each_entry(pos, trace_probe_probe_list(tp), list) { + ep = container_of(pos, struct trace_eprobe, tp); + disable_eprobe(ep, file->tr); + if (!--cnt) + break; + } + } if (file) trace_probe_remove_file(tp, file); else |