diff options
Diffstat (limited to 'kernel/trace/trace_eprobe.c')
| -rw-r--r-- | kernel/trace/trace_eprobe.c | 107 |
1 files changed, 97 insertions, 10 deletions
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 1783e3478912..c08bde9871ec 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -26,6 +26,9 @@ struct trace_eprobe { /* tracepoint event */ const char *event_name; + /* filter string for the tracepoint */ + char *filter_str; + struct trace_event_call *event; struct dyn_event devent; @@ -664,14 +667,15 @@ static struct event_trigger_data * new_eprobe_trigger(struct trace_eprobe *ep, struct trace_event_file *file) { struct event_trigger_data *trigger; + struct event_filter *filter = NULL; struct eprobe_data *edata; + int ret; edata = kzalloc(sizeof(*edata), GFP_KERNEL); trigger = kzalloc(sizeof(*trigger), GFP_KERNEL); if (!trigger || !edata) { - kfree(edata); - kfree(trigger); - return ERR_PTR(-ENOMEM); + ret = -ENOMEM; + goto error; } trigger->flags = EVENT_TRIGGER_FL_PROBE; @@ -686,13 +690,25 @@ new_eprobe_trigger(struct trace_eprobe *ep, struct trace_event_file *file) trigger->cmd_ops = &event_trigger_cmd; INIT_LIST_HEAD(&trigger->list); - RCU_INIT_POINTER(trigger->filter, NULL); + + if (ep->filter_str) { + ret = create_event_filter(file->tr, file->event_call, + ep->filter_str, false, &filter); + if (ret) + goto error; + } + RCU_INIT_POINTER(trigger->filter, filter); edata->file = file; edata->ep = ep; trigger->private_data = edata; return trigger; +error: + free_event_filter(filter); + kfree(edata); + kfree(trigger); + return ERR_PTR(ret); } static int enable_eprobe(struct trace_eprobe *ep, @@ -726,6 +742,7 @@ static int disable_eprobe(struct trace_eprobe *ep, { struct event_trigger_data *trigger = NULL, *iter; struct trace_event_file *file; + struct event_filter *filter; struct eprobe_data *edata; file = find_event_file(tr, ep->event_system, ep->event_name); @@ -752,6 +769,10 @@ static int disable_eprobe(struct trace_eprobe *ep, /* Make sure nothing is using the edata or trigger */ tracepoint_synchronize_unregister(); + filter = rcu_access_pointer(trigger->filter); + + if (filter) + free_event_filter(filter); kfree(edata); kfree(trigger); @@ -927,12 +948,62 @@ static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[ return ret; } +static int trace_eprobe_parse_filter(struct trace_eprobe *ep, int argc, const char *argv[]) +{ + struct event_filter *dummy; + int i, ret, len = 0; + char *p; + + if (argc == 0) { + trace_probe_log_err(0, NO_EP_FILTER); + return -EINVAL; + } + + /* Recover the filter string */ + for (i = 0; i < argc; i++) + len += strlen(argv[i]) + 1; + + ep->filter_str = kzalloc(len, GFP_KERNEL); + if (!ep->filter_str) + return -ENOMEM; + + p = ep->filter_str; + for (i = 0; i < argc; i++) { + ret = snprintf(p, len, "%s ", argv[i]); + if (ret < 0) + goto error; + if (ret > len) { + ret = -E2BIG; + goto error; + } + p += ret; + len -= ret; + } + p[-1] = '\0'; + + /* + * Ensure the filter string can be parsed correctly. Note, this + * filter string is for the original event, not for the eprobe. + */ + ret = create_event_filter(top_trace_array(), ep->event, ep->filter_str, + true, &dummy); + free_event_filter(dummy); + if (ret) + goto error; + + return 0; +error: + kfree(ep->filter_str); + ep->filter_str = NULL; + return ret; +} + static int __trace_eprobe_create(int argc, const char *argv[]) { /* * Argument syntax: - * e[:[GRP/][ENAME]] SYSTEM.EVENT [FETCHARGS] - * Fetch args: + * e[:[GRP/][ENAME]] SYSTEM.EVENT [FETCHARGS] [if FILTER] + * Fetch args (no space): * <name>=$<field>[:TYPE] */ const char *event = NULL, *group = EPROBE_EVENT_SYSTEM; @@ -942,8 +1013,8 @@ static int __trace_eprobe_create(int argc, const char *argv[]) char buf1[MAX_EVENT_NAME_LEN]; char buf2[MAX_EVENT_NAME_LEN]; char gbuf[MAX_EVENT_NAME_LEN]; - int ret = 0; - int i; + int ret = 0, filter_idx = 0; + int i, filter_cnt; if (argc < 2 || argv[0][0] != 'e') return -ECANCELED; @@ -968,11 +1039,19 @@ static int __trace_eprobe_create(int argc, const char *argv[]) } if (!event) { - strscpy(buf1, argv[1], MAX_EVENT_NAME_LEN); - sanitize_event_name(buf1); + strscpy(buf1, sys_event, MAX_EVENT_NAME_LEN); event = buf1; } + for (i = 2; i < argc; i++) { + if (!strcmp(argv[i], "if")) { + filter_idx = i + 1; + filter_cnt = argc - filter_idx; + argc = i; + break; + } + } + mutex_lock(&event_mutex); event_call = find_and_get_event(sys_name, sys_event); ep = alloc_event_probe(group, event, event_call, argc - 2); @@ -988,6 +1067,14 @@ static int __trace_eprobe_create(int argc, const char *argv[]) goto error; } + if (filter_idx) { + trace_probe_log_set_index(filter_idx); + ret = trace_eprobe_parse_filter(ep, filter_cnt, argv + filter_idx); + if (ret) + goto parse_error; + } else + ep->filter_str = NULL; + argc -= 2; argv += 2; /* parse arguments */ for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { |