diff options
| -rw-r--r-- | include/linux/fprobe.h | 5 | ||||
| -rw-r--r-- | kernel/trace/fprobe.c | 5 | ||||
| -rw-r--r-- | kernel/trace/trace_fprobe.c | 237 |
3 files changed, 126 insertions, 121 deletions
diff --git a/include/linux/fprobe.h b/include/linux/fprobe.h index 702099f08929..7964db96e41a 100644 --- a/include/linux/fprobe.h +++ b/include/linux/fprobe.h @@ -94,6 +94,7 @@ int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num); int register_fprobe_syms(struct fprobe *fp, const char **syms, int num); int unregister_fprobe(struct fprobe *fp); bool fprobe_is_registered(struct fprobe *fp); +int fprobe_count_ips_from_filter(const char *filter, const char *notfilter); #else static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter) { @@ -115,6 +116,10 @@ static inline bool fprobe_is_registered(struct fprobe *fp) { return false; } +static inline int fprobe_count_ips_from_filter(const char *filter, const char *notfilter) +{ + return -EOPNOTSUPP; +} #endif /** diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index ba7ff14f5339..b78fce0982c7 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -648,6 +648,11 @@ static int fprobe_init(struct fprobe *fp, unsigned long *addrs, int num) #define FPROBE_IPS_MAX INT_MAX +int fprobe_count_ips_from_filter(const char *filter, const char *notfilter) +{ + return get_ips_from_filter(filter, notfilter, NULL, NULL, FPROBE_IPS_MAX); +} + /** * register_fprobe() - Register fprobe to ftrace by pattern. * @fp: A fprobe data structure to be registered. diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c index 4a9ce7b0e084..79ffc1b2d519 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -600,98 +600,6 @@ static struct trace_fprobe *find_trace_fprobe(const char *event, return NULL; } -static inline int __enable_trace_fprobe(struct trace_fprobe *tf) -{ - if (trace_fprobe_is_registered(tf)) - enable_fprobe(&tf->fp); - - return 0; -} - -static void __disable_trace_fprobe(struct trace_probe *tp) -{ - struct trace_fprobe *tf; - - list_for_each_entry(tf, trace_probe_probe_list(tp), tp.list) { - if (!trace_fprobe_is_registered(tf)) - continue; - disable_fprobe(&tf->fp); - } -} - -/* - * Enable trace_probe - * if the file is NULL, enable "perf" handler, or enable "trace" handler. - */ -static int enable_trace_fprobe(struct trace_event_call *call, - struct trace_event_file *file) -{ - struct trace_probe *tp; - struct trace_fprobe *tf; - bool enabled; - int ret = 0; - - tp = trace_probe_primary_from_call(call); - if (WARN_ON_ONCE(!tp)) - return -ENODEV; - enabled = trace_probe_is_enabled(tp); - - /* This also changes "enabled" state */ - if (file) { - ret = trace_probe_add_file(tp, file); - if (ret) - return ret; - } else - trace_probe_set_flag(tp, TP_FLAG_PROFILE); - - if (!enabled) { - list_for_each_entry(tf, trace_probe_probe_list(tp), tp.list) { - /* TODO: check the fprobe is gone */ - __enable_trace_fprobe(tf); - } - } - - return 0; -} - -/* - * Disable trace_probe - * if the file is NULL, disable "perf" handler, or disable "trace" handler. - */ -static int disable_trace_fprobe(struct trace_event_call *call, - struct trace_event_file *file) -{ - struct trace_probe *tp; - - tp = trace_probe_primary_from_call(call); - if (WARN_ON_ONCE(!tp)) - return -ENODEV; - - if (file) { - if (!trace_probe_get_file_link(tp, file)) - return -ENOENT; - if (!trace_probe_has_single_file(tp)) - goto out; - trace_probe_clear_flag(tp, TP_FLAG_TRACE); - } else - trace_probe_clear_flag(tp, TP_FLAG_PROFILE); - - if (!trace_probe_is_enabled(tp)) - __disable_trace_fprobe(tp); - - out: - if (file) - /* - * Synchronization is done in below function. For perf event, - * file == NULL and perf_trace_event_unreg() calls - * tracepoint_synchronize_unregister() to ensure synchronize - * event. We don't need to care about it. - */ - trace_probe_remove_file(tp, file); - - return 0; -} - /* Event entry printers */ static enum print_line_t print_fentry_event(struct trace_iterator *iter, int flags, @@ -851,6 +759,29 @@ static int __regsiter_tracepoint_fprobe(struct trace_fprobe *tf) return register_fprobe_ips(&tf->fp, &ip, 1); } +/* Returns an error if the target function is not available, or 0 */ +static int trace_fprobe_verify_target(struct trace_fprobe *tf) +{ + int ret; + + if (trace_fprobe_is_tracepoint(tf)) { + + /* This tracepoint is not loaded yet */ + if (!tracepoint_user_is_registered(tf->tuser)) + return 0; + + /* We assume all stab function is tracable. */ + return tracepoint_user_ip(tf->tuser) ? 0 : -ENOENT; + } + + /* + * Note: since we don't lock the module, even if this succeeded, + * register_fprobe() later can fail. + */ + ret = fprobe_count_ips_from_filter(tf->symbol, NULL); + return (ret < 0) ? ret : 0; +} + /* Internal register function - just handle fprobe and flags */ static int __register_trace_fprobe(struct trace_fprobe *tf) { @@ -870,11 +801,7 @@ static int __register_trace_fprobe(struct trace_fprobe *tf) return ret; } - /* Set/clear disabled flag according to tp->flag */ - if (trace_probe_is_enabled(&tf->tp)) - tf->fp.flags &= ~FPROBE_FL_DISABLED; - else - tf->fp.flags |= FPROBE_FL_DISABLED; + tf->fp.flags &= ~FPROBE_FL_DISABLED; if (trace_fprobe_is_tracepoint(tf)) { @@ -895,10 +822,10 @@ static void __unregister_trace_fprobe(struct trace_fprobe *tf) if (trace_fprobe_is_registered(tf)) { unregister_fprobe(&tf->fp); memset(&tf->fp, 0, sizeof(tf->fp)); - if (trace_fprobe_is_tracepoint(tf)) { - tracepoint_user_put(tf->tuser); - tf->tuser = NULL; - } + } + if (trace_fprobe_is_tracepoint(tf)) { + tracepoint_user_put(tf->tuser); + tf->tuser = NULL; } } @@ -958,7 +885,7 @@ static bool trace_fprobe_has_same_fprobe(struct trace_fprobe *orig, return false; } -static int append_trace_fprobe(struct trace_fprobe *tf, struct trace_fprobe *to) +static int append_trace_fprobe_event(struct trace_fprobe *tf, struct trace_fprobe *to) { int ret; @@ -986,7 +913,7 @@ static int append_trace_fprobe(struct trace_fprobe *tf, struct trace_fprobe *to) if (ret) return ret; - ret = __register_trace_fprobe(tf); + ret = trace_fprobe_verify_target(tf); if (ret) trace_probe_unlink(&tf->tp); else @@ -995,8 +922,8 @@ static int append_trace_fprobe(struct trace_fprobe *tf, struct trace_fprobe *to) return ret; } -/* Register a trace_probe and probe_event */ -static int register_trace_fprobe(struct trace_fprobe *tf) +/* Register a trace_probe and probe_event, and check the fprobe is available. */ +static int register_trace_fprobe_event(struct trace_fprobe *tf) { struct trace_fprobe *old_tf; int ret; @@ -1006,7 +933,7 @@ static int register_trace_fprobe(struct trace_fprobe *tf) old_tf = find_trace_fprobe(trace_probe_name(&tf->tp), trace_probe_group_name(&tf->tp)); if (old_tf) - return append_trace_fprobe(tf, old_tf); + return append_trace_fprobe_event(tf, old_tf); /* Register new event */ ret = register_fprobe_event(tf); @@ -1019,8 +946,8 @@ static int register_trace_fprobe(struct trace_fprobe *tf) return ret; } - /* Register fprobe */ - ret = __register_trace_fprobe(tf); + /* Verify fprobe is sane. */ + ret = trace_fprobe_verify_target(tf); if (ret < 0) unregister_fprobe_event(tf); else @@ -1084,15 +1011,6 @@ static struct tracepoint *find_tracepoint(const char *tp_name, } #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); - } -} - /* * Find a tracepoint from specified module. In this case, this does not get the * module's refcount. The caller must ensure the module is not freed. @@ -1146,9 +1064,8 @@ static int __tracepoint_probe_module_cb(struct notifier_block *self, } /* Finally enable fprobe on this module. */ - if (!WARN_ON_ONCE(__regsiter_tracepoint_fprobe(tf)) && - trace_probe_is_enabled(&tf->tp)) - reenable_trace_fprobe(tf); + if (trace_probe_is_enabled(&tf->tp) && !trace_fprobe_is_registered(tf)) + WARN_ON_ONCE(__regsiter_tracepoint_fprobe(tf)); } else if (val == MODULE_STATE_GOING) { tuser = tf->tuser; /* Unregister all tracepoint_user in this module. */ @@ -1397,7 +1314,7 @@ static int trace_fprobe_create_internal(int argc, const char *argv[], if (ret < 0) return ret; - ret = register_trace_fprobe(tf); + ret = register_trace_fprobe_event(tf); if (ret) { trace_probe_log_set_index(1); if (ret == -EILSEQ) @@ -1467,6 +1384,84 @@ static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev) } /* + * Enable trace_probe + * if the file is NULL, enable "perf" handler, or enable "trace" handler. + */ +static int enable_trace_fprobe(struct trace_event_call *call, + struct trace_event_file *file) +{ + struct trace_probe *tp; + struct trace_fprobe *tf; + bool enabled; + int ret = 0; + + tp = trace_probe_primary_from_call(call); + if (WARN_ON_ONCE(!tp)) + return -ENODEV; + enabled = trace_probe_is_enabled(tp); + + /* This also changes "enabled" state */ + if (file) { + ret = trace_probe_add_file(tp, file); + if (ret) + return ret; + } else + trace_probe_set_flag(tp, TP_FLAG_PROFILE); + + if (!enabled) { + list_for_each_entry(tf, trace_probe_probe_list(tp), tp.list) { + ret = __register_trace_fprobe(tf); + if (ret < 0) + return ret; + } + } + + return 0; +} + +/* + * Disable trace_probe + * if the file is NULL, disable "perf" handler, or disable "trace" handler. + */ +static int disable_trace_fprobe(struct trace_event_call *call, + struct trace_event_file *file) +{ + struct trace_fprobe *tf; + struct trace_probe *tp; + + tp = trace_probe_primary_from_call(call); + if (WARN_ON_ONCE(!tp)) + return -ENODEV; + + if (file) { + if (!trace_probe_get_file_link(tp, file)) + return -ENOENT; + if (!trace_probe_has_single_file(tp)) + goto out; + trace_probe_clear_flag(tp, TP_FLAG_TRACE); + } else + trace_probe_clear_flag(tp, TP_FLAG_PROFILE); + + if (!trace_probe_is_enabled(tp)) { + list_for_each_entry(tf, trace_probe_probe_list(tp), tp.list) { + unregister_fprobe(&tf->fp); + } + } + + out: + if (file) + /* + * Synchronization is done in below function. For perf event, + * file == NULL and perf_trace_event_unreg() calls + * tracepoint_synchronize_unregister() to ensure synchronize + * event. We don't need to care about it. + */ + trace_probe_remove_file(tp, file); + + return 0; +} + +/* * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. */ static int fprobe_register(struct trace_event_call *event, |