diff options
| -rw-r--r-- | include/linux/rethook.h | 1 | ||||
| -rw-r--r-- | kernel/kprobes.c | 8 | ||||
| -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 |
5 files changed, 41 insertions, 14 deletions
diff --git a/include/linux/rethook.h b/include/linux/rethook.h index fdf26cd0e742..26b6f3c81a76 100644 --- a/include/linux/rethook.h +++ b/include/linux/rethook.h @@ -59,6 +59,7 @@ struct rethook_node { }; struct rethook *rethook_alloc(void *data, rethook_handler_t handler); +void rethook_stop(struct rethook *rh); void rethook_free(struct rethook *rh); void rethook_add_node(struct rethook *rh, struct rethook_node *node); struct rethook_node *rethook_try_get(struct rethook *rh); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ce13f1a35251..1fc6095d502d 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1072,7 +1072,7 @@ static int kprobe_ftrace_enabled; static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, int *cnt) { - int ret = 0; + int ret; lockdep_assert_held(&kprobe_mutex); @@ -1110,7 +1110,7 @@ static int arm_kprobe_ftrace(struct kprobe *p) static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, int *cnt) { - int ret = 0; + int ret; lockdep_assert_held(&kprobe_mutex); @@ -2007,9 +2007,9 @@ void __weak arch_kretprobe_fixup_return(struct pt_regs *regs, unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, void *frame_pointer) { - kprobe_opcode_t *correct_ret_addr = NULL; struct kretprobe_instance *ri = NULL; struct llist_node *first, *node = NULL; + kprobe_opcode_t *correct_ret_addr; struct kretprobe *rp; /* Find correct address and all nodes for this frame. */ @@ -2693,7 +2693,7 @@ void kprobe_free_init_mem(void) static int __init init_kprobes(void) { - int i, err = 0; + int i, err; /* FIXME allocate the probe table, currently defined statically */ /* initialize all list heads */ 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 |