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;