From eb5bf81330a722d0079d28eed13d3a9355d938bf Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 20 Jun 2019 00:08:08 +0900 Subject: tracing/kprobe: Add per-probe delete from event Allow user to delete a probe from event. This is done by head match. For example, if we have 2 probes on an event $ cat kprobe_events p:kprobes/testprobe _do_fork r1=%ax r2=%dx p:kprobes/testprobe idle_fork r1=%ax r2=%cx Then you can remove one of them by passing the head of definition which identify the probe. $ echo "-:kprobes/testprobe idle_fork" >> kprobe_events Link: http://lkml.kernel.org/r/156095688848.28024.15798690082378432435.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 25 ++++++++++++++++++++++++- kernel/trace/trace_probe.c | 18 ++++++++++++++++++ kernel/trace/trace_probe.h | 2 ++ 3 files changed, 44 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index f43098bf62dd..18c4175b6585 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -137,13 +137,36 @@ static bool trace_kprobe_is_busy(struct dyn_event *ev) return trace_probe_is_enabled(&tk->tp); } +static bool trace_kprobe_match_command_head(struct trace_kprobe *tk, + int argc, const char **argv) +{ + char buf[MAX_ARGSTR_LEN + 1]; + + if (!argc) + return true; + + if (!tk->symbol) + snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr); + else if (tk->rp.kp.offset) + snprintf(buf, sizeof(buf), "%s+%u", + trace_kprobe_symbol(tk), tk->rp.kp.offset); + else + snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk)); + if (strcmp(buf, argv[0])) + return false; + argc--; argv++; + + return trace_probe_match_command_args(&tk->tp, argc, argv); +} + static bool trace_kprobe_match(const char *system, const char *event, int argc, const char **argv, struct dyn_event *ev) { struct trace_kprobe *tk = to_trace_kprobe(ev); return strcmp(trace_probe_name(&tk->tp), event) == 0 && - (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0); + (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) && + trace_kprobe_match_command_head(tk, argc, argv); } static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 651a1449acde..f8c3c65c035d 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -1047,3 +1047,21 @@ int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) return 0; } + +bool trace_probe_match_command_args(struct trace_probe *tp, + int argc, const char **argv) +{ + char buf[MAX_ARGSTR_LEN + 1]; + int i; + + if (tp->nr_args < argc) + return false; + + for (i = 0; i < argc; i++) { + snprintf(buf, sizeof(buf), "%s=%s", + tp->args[i].name, tp->args[i].comm); + if (strcmp(buf, argv[i])) + return false; + } + return true; +} diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 39926e8a344b..2dcc4e317787 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -332,6 +332,8 @@ int trace_probe_remove_file(struct trace_probe *tp, struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp, struct trace_event_file *file); int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b); +bool trace_probe_match_command_args(struct trace_probe *tp, + int argc, const char **argv); #define trace_probe_for_each_link(pos, tp) \ list_for_each_entry(pos, &(tp)->event->files, list) -- cgit v1.2.3