perf probe: Make --list show only available cached events

Make "perf probe --cache --list" show only available cached events by
checking build-id validity.

E.g. without this patch:
  ----
  $ ./perf probe --cache --add oldevent=cmd_probe
  $ make #(to update ./perf)
  $ ./perf probe --cache --add newevent=cmd_probe
  $ ./perf probe --cache --list
  /home/mhiramat/ksrc/linux/tools/perf/perf (061e90539bac69
  probe_perf:newevent=cmd_probe
  /home/mhiramat/ksrc/linux/tools/perf/perf (c2e44d614e33e1
  probe_perf:oldevent=cmd_probe
  ----
It shows both of old and new events but user can not use old one.
With this;
  ----
  $ ./perf probe --cache -l
  /home/mhiramat/ksrc/linux/tools/perf/perf (061e90539bac69
  probe_perf:newevent=cmd_probe
  ----

This shows only new events which are on the existing binary.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831789417.17065.17896487479879669610.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 35 insertions, 4 deletions

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index c6d890ad2c1a..ee5b42173ba3 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -370,7 +370,7 @@ static int del_perf_probe_caches(struct strfilter *filter)
         struct str_node *nd;
         int ret;
 
-        bidlist = build_id_cache__list_all();
+        bidlist = build_id_cache__list_all(false);
         if (!bidlist) {
                 ret = -errno;
                 pr_debug("Failed to get buildids: %d\n", ret);
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 1e504e40dac8..36b4279a9002 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -206,6 +206,31 @@ out:
         return ret;
 }
 
+/* Check if the given build_id cache is valid on current running system */
+static bool build_id_cache__valid_id(char *sbuild_id)
+{
+        char real_sbuild_id[SBUILD_ID_SIZE] = "";
+        char *pathname;
+        int ret = 0;
+        bool result = false;
+
+        pathname = build_id_cache__origname(sbuild_id);
+        if (!pathname)
+                return false;
+
+        if (!strcmp(pathname, DSO__NAME_KALLSYMS))
+                ret = sysfs__sprintf_build_id("/", real_sbuild_id);
+        else if (pathname[0] == '/')
+                ret = filename__sprintf_build_id(pathname, real_sbuild_id);
+        else
+                ret = -EINVAL;  /* Should we support other special DSO cache? */
+        if (ret >= 0)
+                result = (strcmp(sbuild_id, real_sbuild_id) == 0);
+        free(pathname);
+
+        return result;
+}
+
 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso)
 {
         return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : "elf");
@@ -433,13 +458,17 @@ static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
         return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
 }
 
-struct strlist *build_id_cache__list_all(void)
+struct strlist *build_id_cache__list_all(bool validonly)
 {
         struct strlist *toplist, *linklist = NULL, *bidlist;
         struct str_node *nd, *nd2;
         char *topdir, *linkdir = NULL;
         char sbuild_id[SBUILD_ID_SIZE];
 
+        /* for filename__ functions */
+        if (validonly)
+                symbol__init(NULL);
+
         /* Open the top-level directory */
         if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
                 return NULL;
@@ -470,6 +499,8 @@ struct strlist *build_id_cache__list_all(void)
                         if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
                                      nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
                                 goto err_out;
+                        if (validonly && !build_id_cache__valid_id(sbuild_id))
+                                continue;
                         if (strlist__add(bidlist, sbuild_id) < 0)
                                 goto err_out;
                 }
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index b742e271ea2c..64e740f4bc28 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -34,7 +34,7 @@ char *build_id_cache__origname(const char *sbuild_id);
 char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size);
 char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
                                bool is_kallsyms, bool is_vdso);
-struct strlist *build_id_cache__list_all(void);
+struct strlist *build_id_cache__list_all(bool validonly);
 int build_id_cache__list_build_ids(const char *pathname,
                                    struct strlist **result);
 bool build_id_cache__cached(const char *sbuild_id);
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index fc16b172579f..a5059dc3921a 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -808,7 +808,7 @@ int probe_cache__show_all_caches(struct strfilter *filter)
         pr_debug("list cache with filter: %s\n", buf);
         free(buf);
 
-        bidlist = build_id_cache__list_all();
+        bidlist = build_id_cache__list_all(true);
         if (!bidlist) {
                 pr_debug("Failed to get buildids: %d\n", errno);
                 return -EINVAL;