perf probe: Add variable filter support

Add filters support for available variable list.

Default filter is "!__k???tab_*&!__crc_*" for filtering out
automatically generated symbols.

The format of filter rule is "[!]GLOBPATTERN", so you can use wild
cards. If the filter rule starts with '!', matched variables are filter
out.

e.g.:
 # perf probe -V schedule --externs --filter=cpu*
Available variables at schedule
        @<schedule+0>
                cpumask_var_t   cpu_callout_mask
                cpumask_var_t   cpu_core_map
                cpumask_var_t   cpu_isolated_map
                cpumask_var_t   cpu_sibling_map
                int     cpu_number
                long unsigned int*      cpu_bit_bitmap
		...

Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Chase Douglas <chase.douglas@canonical.com>
Cc: Franck Bui-Huu <fbuihuu@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20110120141539.25915.43401.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ committer note: Removed the elf.h include as it was fixed up in e80711c]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 40 insertions, 26 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 859d377a3df3..077e0518f0f7 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -451,12 +451,14 @@ end:
 }
 
 static int show_available_vars_at(int fd, struct perf_probe_event *pev,
-				  int max_vls, bool externs)
+				  int max_vls, struct strfilter *_filter,
+				  bool externs)
 {
 	char *buf;
-	int ret, i;
+	int ret, i, nvars;
 	struct str_node *node;
 	struct variable_list *vls = NULL, *vl;
+	const char *var;
 
 	buf = synthesize_perf_probe_point(&pev->point);
 	if (!buf)
@@ -464,36 +466,45 @@ static int show_available_vars_at(int fd, struct perf_probe_event *pev,
 	pr_debug("Searching variables at %s\n", buf);
 
 	ret = find_available_vars_at(fd, pev, &vls, max_vls, externs);
-	if (ret > 0) {
-		/* Some variables were found */
-		fprintf(stdout, "Available variables at %s\n", buf);
-		for (i = 0; i < ret; i++) {
-			vl = &vls[i];
-			/*
-			 * A probe point might be converted to
-			 * several trace points.
-			 */
-			fprintf(stdout, "\t@<%s+%lu>\n", vl->point.symbol,
-				vl->point.offset);
-			free(vl->point.symbol);
-			if (vl->vars) {
-				strlist__for_each(node, vl->vars)
+	if (ret <= 0) {
+		pr_err("Failed to find variables at %s (%d)\n", buf, ret);
+		goto end;
+	}
+	/* Some variables are found */
+	fprintf(stdout, "Available variables at %s\n", buf);
+	for (i = 0; i < ret; i++) {
+		vl = &vls[i];
+		/*
+		 * A probe point might be converted to
+		 * several trace points.
+		 */
+		fprintf(stdout, "\t@<%s+%lu>\n", vl->point.symbol,
+			vl->point.offset);
+		free(vl->point.symbol);
+		nvars = 0;
+		if (vl->vars) {
+			strlist__for_each(node, vl->vars) {
+				var = strchr(node->s, '\t') + 1;
+				if (strfilter__compare(_filter, var)) {
 					fprintf(stdout, "\t\t%s\n", node->s);
-				strlist__delete(vl->vars);
-			} else
-				fprintf(stdout, "(No variables)\n");
+					nvars++;
+				}
+			}
+			strlist__delete(vl->vars);
 		}
-		free(vls);
-	} else
-		pr_err("Failed to find variables at %s (%d)\n", buf, ret);
-
+		if (nvars == 0)
+			fprintf(stdout, "\t\t(No matched variables)\n");
+	}
+	free(vls);
+end:
 	free(buf);
 	return ret;
 }
 
 /* Show available variables on given probe point */
 int show_available_vars(struct perf_probe_event *pevs, int npevs,
-			int max_vls, const char *module, bool externs)
+			int max_vls, const char *module,
+			struct strfilter *_filter, bool externs)
 {
 	int i, fd, ret = 0;
 
@@ -510,7 +521,8 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs,
 	setup_pager();
 
 	for (i = 0; i < npevs && ret >= 0; i++)
-		ret = show_available_vars_at(fd, &pevs[i], max_vls, externs);
+		ret = show_available_vars_at(fd, &pevs[i], max_vls, _filter,
+					     externs);
 
 	close(fd);
 	return ret;
@@ -556,7 +568,9 @@ int show_line_range(struct line_range *lr __unused, const char *module __unused)
 
 int show_available_vars(struct perf_probe_event *pevs __unused,
 			int npevs __unused, int max_vls __unused,
-			const char *module __unused, bool externs __unused)
+			const char *module __unused,
+			struct strfilter *filter __unused,
+			bool externs __unused)
 {
 	pr_warning("Debuginfo-analysis is not supported.\n");
 	return -ENOSYS;