[PATCH perf/core v11 20/23] perf probe: Support @BUILDID or @FILE suffix for SDT events

[Masami Hiramatsu]

Support @BUILDID or @FILE suffix for SDT events. This allows
perf to add probes on SDTs/pre-cached events on given FILE
or the file which has given BUILDID (also, this complements
BUILDID.)
For example, both gcc and libstdc++ has same SDTs as below.
If you would like to add a probe on sdt_libstdcxx:catch on gcc,
you can do as below.

  
  # perf list sdt | tail -n 6
sdt_libstdcxx:catch@/usr/bin/gcc(0cc207fc4b27) [SDT event]
sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
sdt_libstdcxx:rethrow@/usr/bin/gcc(0cc207fc4b27)   [SDT event]
sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
sdt_libstdcxx:throw@/usr/bin/gcc(0cc207fc4b27) [SDT event]
sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
  # perf probe -a %sdt_libstdcxx:catch@0cc
  Added new event:
sdt_libstdcxx:catch  (on %catch in /usr/bin/gcc)

  You can now use it in all perf tools, such as:

perf record -e sdt_libstdcxx:catch -aR sleep 1
  

Signed-off-by: Masami Hiramatsu 
---
 tools/perf/util/build-id.c|   43 +
 tools/perf/util/build-id.h|1 +
 tools/perf/util/probe-event.c |   17 ++--
 3 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index a28ef39..7b78a33 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -523,6 +523,49 @@ err_out:
goto out_free;
 }
 
+static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
+{
+   size_t i;
+
+   for (i = 0; i < len; i++) {
+   if (!isxdigit(maybe_sbuild_id[i]))
+   return false;
+   }
+   return true;
+}
+
+/* Return the valid complete build-id */
+char *build_id_cache__complement(const char *incomplete_sbuild_id)
+{
+   struct strlist *bidlist;
+   struct str_node *nd, *cand = NULL;
+   char *sbuild_id = NULL;
+   size_t len = strlen(incomplete_sbuild_id);
+
+   if (len >= SBUILD_ID_SIZE ||
+   !str_is_build_id(incomplete_sbuild_id, len))
+   return NULL;
+
+   bidlist = build_id_cache__list_all(true);
+   if (!bidlist)
+   return NULL;
+
+   strlist__for_each(nd, bidlist) {
+   if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
+   continue;
+   if (cand) { /* Error: There are more than 2 candidates. */
+   cand = NULL;
+   break;
+   }
+   cand = nd;
+   }
+   if (cand)
+   sbuild_id = strdup(cand->s);
+   strlist__delete(bidlist);
+
+   return sbuild_id;
+}
+
 char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
   bool is_kallsyms, bool is_vdso)
 {
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index 64e740f..d279906 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -35,6 +35,7 @@ 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(bool validonly);
+char *build_id_cache__complement(const char *incomplete_sbuild_id);
 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-event.c b/tools/perf/util/probe-event.c
index 81e22f1..fa3cbb3 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1253,8 +1253,21 @@ static int parse_perf_probe_point(char *arg, struct 
perf_probe_event *pev)
ptr = strpbrk(arg, ";=@+%");
if (pev->sdt) {
if (ptr) {
-   semantic_error("%s must contain only an SDT event 
name.\n", arg);
-   return -EINVAL;
+   if (*ptr != '@') {
+   semantic_error("%s must be an SDT name.\n",
+  arg);
+   return -EINVAL;
+   }
+   /* This must be a target file name or build id */
+   tmp = build_id_cache__complement(ptr + 1);
+   if (tmp) {
+   pev->target = build_id_cache__origname(tmp);
+   free(tmp);
+   } else
+   pev->target = strdup(ptr + 1);
+   if (!pev->target)
+   return -ENOMEM;
+   *ptr = '\0';
}
ret = parse_perf_probe_event_name(, pev);
if (ret == 0) {

[PATCH perf/core v11 20/23] perf probe: Support @BUILDID or @FILE suffix for SDT events

[Masami Hiramatsu]

Support @BUILDID or @FILE suffix for SDT events. This allows
perf to add probes on SDTs/pre-cached events on given FILE
or the file which has given BUILDID (also, this complements
BUILDID.)
For example, both gcc and libstdc++ has same SDTs as below.
If you would like to add a probe on sdt_libstdcxx:catch on gcc,
you can do as below.

  
  # perf list sdt | tail -n 6
sdt_libstdcxx:catch@/usr/bin/gcc(0cc207fc4b27) [SDT event]
sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
sdt_libstdcxx:rethrow@/usr/bin/gcc(0cc207fc4b27)   [SDT event]
sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
sdt_libstdcxx:throw@/usr/bin/gcc(0cc207fc4b27) [SDT event]
sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
  # perf probe -a %sdt_libstdcxx:catch@0cc
  Added new event:
sdt_libstdcxx:catch  (on %catch in /usr/bin/gcc)

  You can now use it in all perf tools, such as:

perf record -e sdt_libstdcxx:catch -aR sleep 1
  

Signed-off-by: Masami Hiramatsu 
---
 tools/perf/util/build-id.c|   43 +
 tools/perf/util/build-id.h|1 +
 tools/perf/util/probe-event.c |   17 ++--
 3 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index a28ef39..7b78a33 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -523,6 +523,49 @@ err_out:
goto out_free;
 }
 
+static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
+{
+   size_t i;
+
+   for (i = 0; i < len; i++) {
+   if (!isxdigit(maybe_sbuild_id[i]))
+   return false;
+   }
+   return true;
+}
+
+/* Return the valid complete build-id */
+char *build_id_cache__complement(const char *incomplete_sbuild_id)
+{
+   struct strlist *bidlist;
+   struct str_node *nd, *cand = NULL;
+   char *sbuild_id = NULL;
+   size_t len = strlen(incomplete_sbuild_id);
+
+   if (len >= SBUILD_ID_SIZE ||
+   !str_is_build_id(incomplete_sbuild_id, len))
+   return NULL;
+
+   bidlist = build_id_cache__list_all(true);
+   if (!bidlist)
+   return NULL;
+
+   strlist__for_each(nd, bidlist) {
+   if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
+   continue;
+   if (cand) { /* Error: There are more than 2 candidates. */
+   cand = NULL;
+   break;
+   }
+   cand = nd;
+   }
+   if (cand)
+   sbuild_id = strdup(cand->s);
+   strlist__delete(bidlist);
+
+   return sbuild_id;
+}
+
 char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
   bool is_kallsyms, bool is_vdso)
 {
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index 64e740f..d279906 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -35,6 +35,7 @@ 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(bool validonly);
+char *build_id_cache__complement(const char *incomplete_sbuild_id);
 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-event.c b/tools/perf/util/probe-event.c
index 81e22f1..fa3cbb3 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1253,8 +1253,21 @@ static int parse_perf_probe_point(char *arg, struct 
perf_probe_event *pev)
ptr = strpbrk(arg, ";=@+%");
if (pev->sdt) {
if (ptr) {
-   semantic_error("%s must contain only an SDT event 
name.\n", arg);
-   return -EINVAL;
+   if (*ptr != '@') {
+   semantic_error("%s must be an SDT name.\n",
+  arg);
+   return -EINVAL;
+   }
+   /* This must be a target file name or build id */
+   tmp = build_id_cache__complement(ptr + 1);
+   if (tmp) {
+   pev->target = build_id_cache__origname(tmp);
+   free(tmp);
+   } else
+   pev->target = strdup(ptr + 1);
+   if (!pev->target)
+   return -ENOMEM;
+   *ptr = '\0';
}
ret = parse_perf_probe_event_name(, pev);
if (ret == 0) {