Commit 90df0249 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

perf trace: Expand strings in filters to integers 

So that one can try things like:

  # perf trace -e msr:* --filter="msr!=FS_BASE && msr != IA32_TSC_DEADLINE && msr != 0x830 && msr != 0x83f && msr !=IA32_SPEC_CTRL" --filter-pids 3750

That, at this point in the patchset, without any strtoul in place for
tracepoint arguments, will result in:

  No resolver (strtoul) for "msr" in "msr:read_msr", can't set filter "(msr!=FS_BASE && msr != IA32_TSC_DEADLINE && msr != 0x830 && msr != 0x83f && msr !=IA32_SPEC_CTRL) && (common_pid != 25407 && common_pid != 3750)"
  #

See you in the next cset!

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-dx5j70fv2rgkeezd1cb3hv2p@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent d0a3a104

tools/perf/builtin-trace.c

+130 −0
Original line number Diff line number Diff line
@@ -3484,6 +3484,133 @@ static int ordered_events__deliver_event(struct ordered_events *oe, 
	return __trace__deliver_event(trace, event->event);

}



static struct syscall_arg_fmt *perf_evsel__syscall_arg_fmt(struct evsel *evsel, char *arg)

{

	struct tep_format_field *field;

	struct syscall_arg_fmt *fmt = evsel->priv;



	if (evsel->tp_format == NULL || fmt == NULL)

		return NULL;



	for (field = evsel->tp_format->format.fields; field; field = field->next, ++fmt)

		if (strcmp(field->name, arg) == 0)

			return fmt;



	return NULL;

}



static int trace__expand_filter(struct trace *trace __maybe_unused, struct evsel *evsel)

{

	char *tok, *left = evsel->filter, *new_filter = evsel->filter;



	while ((tok = strpbrk(left, "=<>!")) != NULL) {

		char *right = tok + 1, *right_end;



		if (*right == '=')

			++right;



		while (isspace(*right))

			++right;



		if (*right == '\0')

			break;



		while (!isalpha(*left))

			if (++left == tok) {

				/*

				 * Bail out, can't find the name of the argument that is being

				 * used in the filter, let it try to set this filter, will fail later.

				 */

				return 0;

			}



		right_end = right + 1;

		while (isalnum(*right_end) || *right_end == '_')

			++right_end;



		if (isalpha(*right)) {

			struct syscall_arg_fmt *fmt;

			int left_size = tok - left,

			    right_size = right_end - right;

			char arg[128];



			while (isspace(left[left_size - 1]))

				--left_size;



			scnprintf(arg, sizeof(arg), "%.*s", left_size, left);



			fmt = perf_evsel__syscall_arg_fmt(evsel, arg);

			if (fmt == NULL) {

				pr_debug("\"%s\" not found in \"%s\", can't set filter \"%s\"\n",

					 arg, evsel->name, evsel->filter);

				return -1;

			}



			pr_debug2("trying to expand \"%s\" \"%.*s\" \"%.*s\" -> ",

				 arg, (int)(right - tok), tok, right_size, right);



			if (fmt->strtoul) {

				u64 val;

				if (fmt->strtoul(right, right_size, NULL, &val)) {

					char *n, expansion[19];

					int expansion_lenght = scnprintf(expansion, sizeof(expansion), "%#" PRIx64, val);

					int expansion_offset = right - new_filter;



					pr_debug("%s", expansion);



					if (asprintf(&n, "%.*s%s%s", expansion_offset, new_filter, expansion, right_end) < 0) {

						pr_debug(" out of memory!\n");

						free(new_filter);

						return -1;

					}

					if (new_filter != evsel->filter)

						free(new_filter);

					left = n + expansion_offset + expansion_lenght;

					new_filter = n;

				} else {

					pr_err("\"%.*s\" not found for \"%s\" in \"%s\", can't set filter \"%s\"\n",

					       right_size, right, arg, evsel->name, evsel->filter);

					return -1;

				}

			} else {

				pr_err("No resolver (strtoul) for \"%s\" in \"%s\", can't set filter \"%s\"\n",

				       arg, evsel->name, evsel->filter);

				return -1;

			}



			pr_debug("\n");

		} else {

			left = right_end;

		}

	}



	if (new_filter != evsel->filter) {

		pr_debug("New filter for %s: %s\n", evsel->name, new_filter);

		perf_evsel__set_filter(evsel, new_filter);

		free(new_filter);

	}



	return 0;

}



static int trace__expand_filters(struct trace *trace, struct evsel **err_evsel)

{

	struct evlist *evlist = trace->evlist;

	struct evsel *evsel;



	evlist__for_each_entry(evlist, evsel) {

		if (evsel->filter == NULL)

			continue;



		if (trace__expand_filter(trace, evsel)) {

			*err_evsel = evsel;

			return -1;

		}

	}



	return 0;

}



static int trace__run(struct trace *trace, int argc, const char **argv)

{

	struct evlist *evlist = trace->evlist;
@@ -3625,6 +3752,9 @@ static int trace__run(struct trace *trace, int argc, const char **argv) 
	 */

	trace->fd_path_disabled = !trace__syscall_enabled(trace, syscalltbl__id(trace->sctbl, "close"));



	err = trace__expand_filters(trace, &evsel);

	if (err)

		goto out_delete_evlist;

	err = perf_evlist__apply_filters(evlist, &evsel);

	if (err < 0)

		goto out_error_apply_filters;

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