diff options
| -rw-r--r-- | kernel/trace/trace_fprobe.c | 151 | ||||
| -rw-r--r-- | tools/testing/selftests/ftrace/test.d/dynevent/tprobe_syntax_errors.tc | 1 |
2 files changed, 101 insertions, 51 deletions
diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c index 8b1127e37da5..a079abd8955b 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -21,6 +21,7 @@ #define FPROBE_EVENT_SYSTEM "fprobes" #define TRACEPOINT_EVENT_SYSTEM "tracepoints" #define RETHOOK_MAXACTIVE_MAX 4096 +#define TRACEPOINT_STUB ERR_PTR(-ENOENT) static int trace_fprobe_create(const char *raw_command); static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev); @@ -674,6 +675,24 @@ static int unregister_fprobe_event(struct trace_fprobe *tf) return trace_probe_unregister_event_call(&tf->tp); } +static int __regsiter_tracepoint_fprobe(struct trace_fprobe *tf) +{ + struct tracepoint *tpoint = tf->tpoint; + unsigned long ip = (unsigned long)tpoint->probestub; + int ret; + + /* + * Here, we do 2 steps to enable fprobe on a tracepoint. + * At first, put __probestub_##TP function on the tracepoint + * and put a fprobe on the stub function. + */ + ret = tracepoint_probe_register_prio_may_exist(tpoint, + tpoint->probestub, NULL, 0); + if (ret < 0) + return ret; + return register_fprobe_ips(&tf->fp, &ip, 1); +} + /* Internal register function - just handle fprobe and flags */ static int __register_trace_fprobe(struct trace_fprobe *tf) { @@ -700,18 +719,12 @@ static int __register_trace_fprobe(struct trace_fprobe *tf) tf->fp.flags |= FPROBE_FL_DISABLED; if (trace_fprobe_is_tracepoint(tf)) { - struct tracepoint *tpoint = tf->tpoint; - unsigned long ip = (unsigned long)tpoint->probestub; - /* - * Here, we do 2 steps to enable fprobe on a tracepoint. - * At first, put __probestub_##TP function on the tracepoint - * and put a fprobe on the stub function. - */ - ret = tracepoint_probe_register_prio_may_exist(tpoint, - tpoint->probestub, NULL, 0); - if (ret < 0) - return ret; - return register_fprobe_ips(&tf->fp, &ip, 1); + + /* This tracepoint is not loaded yet */ + if (tf->tpoint == TRACEPOINT_STUB) + return 0; + + return __regsiter_tracepoint_fprobe(tf); } /* TODO: handle filter, nofilter or symbol list */ @@ -864,36 +877,6 @@ end: return ret; } -#ifdef CONFIG_MODULES -static int __tracepoint_probe_module_cb(struct notifier_block *self, - unsigned long val, void *data) -{ - struct tp_module *tp_mod = data; - struct trace_fprobe *tf; - struct dyn_event *pos; - - if (val != MODULE_STATE_GOING) - return NOTIFY_DONE; - - mutex_lock(&event_mutex); - for_each_trace_fprobe(tf, pos) { - if (tp_mod->mod == tf->mod) { - tracepoint_probe_unregister(tf->tpoint, - tf->tpoint->probestub, NULL); - tf->tpoint = NULL; - tf->mod = NULL; - } - } - mutex_unlock(&event_mutex); - - return NOTIFY_DONE; -} - -static struct notifier_block tracepoint_module_nb = { - .notifier_call = __tracepoint_probe_module_cb, -}; -#endif /* CONFIG_MODULES */ - struct __find_tracepoint_cb_data { const char *tp_name; struct tracepoint *tpoint; @@ -906,10 +889,12 @@ static void __find_tracepoint_module_cb(struct tracepoint *tp, struct module *mo if (!data->tpoint && !strcmp(data->tp_name, tp->name)) { data->tpoint = tp; - data->mod = mod; - if (!try_module_get(data->mod)) { - data->tpoint = NULL; - data->mod = NULL; + if (!data->mod) { + data->mod = mod; + if (!try_module_get(data->mod)) { + data->tpoint = NULL; + data->mod = NULL; + } } } } @@ -947,6 +932,67 @@ static struct tracepoint *find_tracepoint(const char *tp_name, return data.tpoint; } +#ifdef CONFIG_MODULES +static void reenable_trace_fprobe(struct trace_fprobe *tf) +{ + struct trace_probe *tp = &tf->tp; + + list_for_each_entry(tf, trace_probe_probe_list(tp), tp.list) { + __enable_trace_fprobe(tf); + } +} + +static struct tracepoint *find_tracepoint_in_module(struct module *mod, + const char *tp_name) +{ + struct __find_tracepoint_cb_data data = { + .tp_name = tp_name, + .mod = mod, + }; + + for_each_tracepoint_in_module(mod, __find_tracepoint_module_cb, &data); + return data.tpoint; +} + +static int __tracepoint_probe_module_cb(struct notifier_block *self, + unsigned long val, void *data) +{ + struct tp_module *tp_mod = data; + struct tracepoint *tpoint; + struct trace_fprobe *tf; + struct dyn_event *pos; + + if (val != MODULE_STATE_GOING && val != MODULE_STATE_COMING) + return NOTIFY_DONE; + + mutex_lock(&event_mutex); + for_each_trace_fprobe(tf, pos) { + if (val == MODULE_STATE_COMING && tf->tpoint == TRACEPOINT_STUB) { + tpoint = find_tracepoint_in_module(tp_mod->mod, tf->symbol); + if (tpoint) { + tf->tpoint = tpoint; + tf->mod = tp_mod->mod; + if (!WARN_ON_ONCE(__regsiter_tracepoint_fprobe(tf)) && + trace_probe_is_enabled(&tf->tp)) + reenable_trace_fprobe(tf); + } + } else if (val == MODULE_STATE_GOING && tp_mod->mod == tf->mod) { + tracepoint_probe_unregister(tf->tpoint, + tf->tpoint->probestub, NULL); + tf->tpoint = NULL; + tf->mod = NULL; + } + } + mutex_unlock(&event_mutex); + + return NOTIFY_DONE; +} + +static struct notifier_block tracepoint_module_nb = { + .notifier_call = __tracepoint_probe_module_cb, +}; +#endif /* CONFIG_MODULES */ + static int parse_symbol_and_return(int argc, const char *argv[], char **symbol, bool *is_return, bool is_tracepoint) @@ -1113,14 +1159,19 @@ static int __trace_fprobe_create(int argc, const char *argv[]) if (is_tracepoint) { ctx.flags |= TPARG_FL_TPOINT; tpoint = find_tracepoint(symbol, &tp_mod); - if (!tpoint) { + if (tpoint) { + ctx.funcname = kallsyms_lookup( + (unsigned long)tpoint->probestub, + NULL, NULL, NULL, sbuf); + } else if (IS_ENABLED(CONFIG_MODULES)) { + /* This *may* be loaded afterwards */ + tpoint = TRACEPOINT_STUB; + ctx.funcname = symbol; + } else { trace_probe_log_set_index(1); trace_probe_log_err(0, NO_TRACEPOINT); goto parse_error; } - ctx.funcname = kallsyms_lookup( - (unsigned long)tpoint->probestub, - NULL, NULL, NULL, sbuf); } else ctx.funcname = symbol; diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/tprobe_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/dynevent/tprobe_syntax_errors.tc index da117b8f1d12..ffe8ffef4027 100644 --- a/tools/testing/selftests/ftrace/test.d/dynevent/tprobe_syntax_errors.tc +++ b/tools/testing/selftests/ftrace/test.d/dynevent/tprobe_syntax_errors.tc @@ -9,7 +9,6 @@ check_error() { # command-with-error-pos-by-^ check_error 't^100 kfree' # BAD_MAXACT_TYPE -check_error 't ^non_exist_tracepoint' # NO_TRACEPOINT check_error 't:^/bar kfree' # NO_GROUP_NAME check_error 't:^12345678901234567890123456789012345678901234567890123456789012345/bar kfree' # GROUP_TOO_LONG |