Commit eb5bf813 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)
Browse files

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: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 41af3cf5

kernel/trace/trace_kprobe.c

+24 −1
Original line number Original line Diff line number Diff line
@@ -137,13 +137,36 @@ static bool trace_kprobe_is_busy(struct dyn_event *ev) 
	return trace_probe_is_enabled(&tk->tp);

	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,

static bool trace_kprobe_match(const char *system, const char *event,

			int argc, const char **argv, struct dyn_event *ev)

			int argc, const char **argv, struct dyn_event *ev)

{

{

	struct trace_kprobe *tk = to_trace_kprobe(ev);

	struct trace_kprobe *tk = to_trace_kprobe(ev);





	return strcmp(trace_probe_name(&tk->tp), event) == 0 &&

	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)

static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)

kernel/trace/trace_probe.c

+18 −0
Original line number Original line Diff line number Diff line
@@ -1047,3 +1047,21 @@ int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) 




	return 0;

	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;

}

kernel/trace/trace_probe.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -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 event_file_link *trace_probe_get_file_link(struct trace_probe *tp,

						struct trace_event_file *file);

						struct trace_event_file *file);

int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);

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)	\

#define trace_probe_for_each_link(pos, tp)	\

	list_for_each_entry(pos, &(tp)->event->files, list)

	list_for_each_entry(pos, &(tp)->event->files, list)

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