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[GIT PULL 00/10] perf/urgent fixes

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  [GIT PULL 00/10] perf/urgent fixes Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-12 22:10 +0200
    [PATCH 04/10] perf tools: Use readdir() instead of deprecated readdir_r() Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-12 22:10 +0200
    [PATCH 07/10] tools lib traceevent: Do not reassign parg after collapse_tree() Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-12 22:10 +0200
    [PATCH 08/10] perf evsel: Improve EPERM error handling in open_strerror() Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-12 22:10 +0200
    [PATCH 09/10] perf evsel: Handle EACCESS + perf_event_paranoid=2 in fallback() Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-12 22:10 +0200
    [PATCH 10/10] perf stat: Fallback to user only counters when perf_event_paranoid > 1 Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-12 22:10 +0200
    [PATCH 02/10] perf script: Use readdir() instead of deprecated readdir_r() Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-12 22:10 +0200
    [PATCH 01/10] perf tools: Use readdir() instead of deprecated readdir_r() Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-12 22:10 +0200
    [PATCH 03/10] perf thread_map: Use readdir() instead of deprecated readdir_r() Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-12 22:10 +0200
    [PATCH 06/10] perf probe: Check if dwarf_getlocations() is available Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-12 22:10 +0200
      Re: [PATCH 06/10] perf probe: Check if dwarf_getlocations() is  available Masami Hiramatsu <mhiramat@kernel.org> - 2016-05-13 04:40 +0200
        Re: [PATCH 06/10] perf probe: Check if dwarf_getlocations() is  available Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-05-13 13:50 +0200
    Re: [GIT PULL 00/10] perf/urgent fixes Ingo Molnar <mingo@kernel.org> - 2016-05-13 07:40 +0200

#1400330 — [GIT PULL 00/10] perf/urgent fixes

Hi Ingo,

	Please consider pulling, test built on:

alldeps-fedora-rawhide: Ok
alldeps-ubuntu-14.04: Ok
alldeps-ubuntu-16.04: Ok
alldeps-fedora-20: Ok
alldeps-ubuntu-12.04: Ok
minimal-debian-experimental-x-mips64: Ok
minimal-debian-experimental-x-mips64el: Ok
minimal-debian-experimental-x-mipsel: Ok
minimal-ubuntu-x-arm: Ok
minimal-ubuntu-x-arm64: Ok
minimal-ubuntu-x-ppc64: Ok
minimal-ubuntu-x-ppc64el: Ok
alldeps-debian: Ok
alldeps-mageia: Ok
alldeps-rhel7: Ok
alldeps-centos: Ok
alldeps-opensuse: Ok

- Arnaldo

The following changes since commit 9f448cd3cbcec8995935e60b27802ae56aac8cc0:

  perf/core: Disable the event on a truncated AUX record (2016-05-12 14:46:11 +0200)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-urgent-for-mingo-20160512

for you to fetch changes up to 42ef8a78c1f49f53f29f0f3a6f9a5bcbc653233e:

  perf stat: Fallback to user only counters when perf_event_paranoid > 1 (2016-05-12 16:25:18 -0300)

----------------------------------------------------------------
perf/urgent fixes:

User visible:

- Fallback to usermode only counters when perf_event_paranoid > 1, which
  is the case now (Arnaldo Carvalho de Melo)

- Do not reassign parg after collapse_tree() in libtraceevent, which
  may cause tool crashes (Steven Rostedt)

Build fixes:

- Fix the build on Fedora Rawhide, where readdir_r() is deprecated and
  also wrt -Werror=unused-const-variable= + x86_32_regoffset_table on
  !x86_64 (Arnaldo Carvalho de Melo)

- Fix the build on Ubuntu 12.04.5, where dwarf_getlocations() isn't
  available, i.e. libdw-dev < 0.157 (Arnaldo Carvalho de Melo)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

----------------------------------------------------------------
Arnaldo Carvalho de Melo (9):
      perf tools: Use readdir() instead of deprecated readdir_r()
      perf script: Use readdir() instead of deprecated readdir_r()
      perf thread_map: Use readdir() instead of deprecated readdir_r()
      perf tools: Use readdir() instead of deprecated readdir_r()
      perf dwarf: Guard !x86_64 definitions under #ifdef else clause
      perf probe: Check if dwarf_getlocations() is available
      perf evsel: Improve EPERM error handling in open_strerror()
      perf evsel: Handle EACCESS + perf_event_paranoid=2 in fallback()
      perf stat: Fallback to user only counters when perf_event_paranoid > 1

Steven Rostedt (1):
      tools lib traceevent: Do not reassign parg after collapse_tree()

 tools/build/Makefile.feature                  |  2 +
 tools/build/feature/Makefile                  |  4 ++
 tools/build/feature/test-all.c                |  5 ++
 tools/build/feature/test-dwarf_getlocations.c | 12 +++++
 tools/lib/traceevent/parse-filter.c           |  4 +-
 tools/perf/arch/x86/util/dwarf-regs.c         |  8 +--
 tools/perf/builtin-script.c                   | 70 +++++++++++++--------------
 tools/perf/builtin-stat.c                     |  7 ++-
 tools/perf/config/Makefile                    |  6 +++
 tools/perf/util/dwarf-aux.c                   |  9 ++++
 tools/perf/util/event.c                       | 12 ++---
 tools/perf/util/evsel.c                       | 23 ++++++++-
 tools/perf/util/parse-events.c                | 60 +++++++++++------------
 tools/perf/util/thread_map.c                  |  8 +--
 14 files changed, 145 insertions(+), 85 deletions(-)
 create mode 100644 tools/build/feature/test-dwarf_getlocations.c

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#1400331 — [PATCH 04/10] perf tools: Use readdir() instead of deprecated readdir_r()

From: Arnaldo Carvalho de Melo <acme@redhat.com>

The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case when parsing tracepoint event definitions, to
avoid breaking the build with glibc-2.23.90 (upcoming 2.24), use it
instead of readdir_r().

See: http://man7.org/linux/man-pages/man3/readdir.3.html

"However, in modern implementations (including the glibc implementation),
concurrent calls to readdir() that specify different directory streams
are thread-safe.  In cases where multiple threads must read from the
same directory stream, using readdir() with external synchronization is
still preferable to the use of the deprecated readdir_r(3) function."

Noticed while building on a Fedora Rawhide docker container.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-wddn49r6bz6wq4ee3dxbl7lo@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/parse-events.c | 60 +++++++++++++++++++++---------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 4c19d5e79d8c..bcbc983d4b12 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -138,11 +138,11 @@ struct event_symbol event_symbols_sw[PERF_COUNT_SW_MAX] = {
 #define PERF_EVENT_TYPE(config)		__PERF_EVENT_FIELD(config, TYPE)
 #define PERF_EVENT_ID(config)		__PERF_EVENT_FIELD(config, EVENT)
 
-#define for_each_subsystem(sys_dir, sys_dirent, sys_next)	       \
-	while (!readdir_r(sys_dir, &sys_dirent, &sys_next) && sys_next)	       \
-	if (sys_dirent.d_type == DT_DIR &&				       \
-	   (strcmp(sys_dirent.d_name, ".")) &&				       \
-	   (strcmp(sys_dirent.d_name, "..")))
+#define for_each_subsystem(sys_dir, sys_dirent)			\
+	while ((sys_dirent = readdir(sys_dir)) != NULL)		\
+		if (sys_dirent->d_type == DT_DIR &&		\
+		    (strcmp(sys_dirent->d_name, ".")) &&	\
+		    (strcmp(sys_dirent->d_name, "..")))
 
 static int tp_event_has_id(struct dirent *sys_dir, struct dirent *evt_dir)
 {
@@ -159,12 +159,12 @@ static int tp_event_has_id(struct dirent *sys_dir, struct dirent *evt_dir)
 	return 0;
 }
 
-#define for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next)	       \
-	while (!readdir_r(evt_dir, &evt_dirent, &evt_next) && evt_next)        \
-	if (evt_dirent.d_type == DT_DIR &&				       \
-	   (strcmp(evt_dirent.d_name, ".")) &&				       \
-	   (strcmp(evt_dirent.d_name, "..")) &&				       \
-	   (!tp_event_has_id(&sys_dirent, &evt_dirent)))
+#define for_each_event(sys_dirent, evt_dir, evt_dirent)		\
+	while ((evt_dirent = readdir(evt_dir)) != NULL)		\
+		if (evt_dirent->d_type == DT_DIR &&		\
+		    (strcmp(evt_dirent->d_name, ".")) &&	\
+		    (strcmp(evt_dirent->d_name, "..")) &&	\
+		    (!tp_event_has_id(sys_dirent, evt_dirent)))
 
 #define MAX_EVENT_LENGTH 512
 
@@ -173,7 +173,7 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
 {
 	struct tracepoint_path *path = NULL;
 	DIR *sys_dir, *evt_dir;
-	struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
+	struct dirent *sys_dirent, *evt_dirent;
 	char id_buf[24];
 	int fd;
 	u64 id;
@@ -184,18 +184,18 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
 	if (!sys_dir)
 		return NULL;
 
-	for_each_subsystem(sys_dir, sys_dirent, sys_next) {
+	for_each_subsystem(sys_dir, sys_dirent) {
 
 		snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,
-			 sys_dirent.d_name);
+			 sys_dirent->d_name);
 		evt_dir = opendir(dir_path);
 		if (!evt_dir)
 			continue;
 
-		for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
+		for_each_event(sys_dirent, evt_dir, evt_dirent) {
 
 			snprintf(evt_path, MAXPATHLEN, "%s/%s/id", dir_path,
-				 evt_dirent.d_name);
+				 evt_dirent->d_name);
 			fd = open(evt_path, O_RDONLY);
 			if (fd < 0)
 				continue;
@@ -220,9 +220,9 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
 					free(path);
 					return NULL;
 				}
-				strncpy(path->system, sys_dirent.d_name,
+				strncpy(path->system, sys_dirent->d_name,
 					MAX_EVENT_LENGTH);
-				strncpy(path->name, evt_dirent.d_name,
+				strncpy(path->name, evt_dirent->d_name,
 					MAX_EVENT_LENGTH);
 				return path;
 			}
@@ -1812,7 +1812,7 @@ void print_tracepoint_events(const char *subsys_glob, const char *event_glob,
 			     bool name_only)
 {
 	DIR *sys_dir, *evt_dir;
-	struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
+	struct dirent *sys_dirent, *evt_dirent;
 	char evt_path[MAXPATHLEN];
 	char dir_path[MAXPATHLEN];
 	char **evt_list = NULL;
@@ -1830,20 +1830,20 @@ restart:
 			goto out_close_sys_dir;
 	}
 
-	for_each_subsystem(sys_dir, sys_dirent, sys_next) {
+	for_each_subsystem(sys_dir, sys_dirent) {
 		if (subsys_glob != NULL &&
-		    !strglobmatch(sys_dirent.d_name, subsys_glob))
+		    !strglobmatch(sys_dirent->d_name, subsys_glob))
 			continue;
 
 		snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,
-			 sys_dirent.d_name);
+			 sys_dirent->d_name);
 		evt_dir = opendir(dir_path);
 		if (!evt_dir)
 			continue;
 
-		for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
+		for_each_event(sys_dirent, evt_dir, evt_dirent) {
 			if (event_glob != NULL &&
-			    !strglobmatch(evt_dirent.d_name, event_glob))
+			    !strglobmatch(evt_dirent->d_name, event_glob))
 				continue;
 
 			if (!evt_num_known) {
@@ -1852,7 +1852,7 @@ restart:
 			}
 
 			snprintf(evt_path, MAXPATHLEN, "%s:%s",
-				 sys_dirent.d_name, evt_dirent.d_name);
+				 sys_dirent->d_name, evt_dirent->d_name);
 
 			evt_list[evt_i] = strdup(evt_path);
 			if (evt_list[evt_i] == NULL)
@@ -1905,7 +1905,7 @@ out_close_sys_dir:
 int is_valid_tracepoint(const char *event_string)
 {
 	DIR *sys_dir, *evt_dir;
-	struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
+	struct dirent *sys_dirent, *evt_dirent;
 	char evt_path[MAXPATHLEN];
 	char dir_path[MAXPATHLEN];
 
@@ -1913,17 +1913,17 @@ int is_valid_tracepoint(const char *event_string)
 	if (!sys_dir)
 		return 0;
 
-	for_each_subsystem(sys_dir, sys_dirent, sys_next) {
+	for_each_subsystem(sys_dir, sys_dirent) {
 
 		snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,
-			 sys_dirent.d_name);
+			 sys_dirent->d_name);
 		evt_dir = opendir(dir_path);
 		if (!evt_dir)
 			continue;
 
-		for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
+		for_each_event(sys_dirent, evt_dir, evt_dirent) {
 			snprintf(evt_path, MAXPATHLEN, "%s:%s",
-				 sys_dirent.d_name, evt_dirent.d_name);
+				 sys_dirent->d_name, evt_dirent->d_name);
 			if (!strcmp(evt_path, event_string)) {
 				closedir(evt_dir);
 				closedir(sys_dir);
-- 
2.5.5

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#1400332 — [PATCH 07/10] tools lib traceevent: Do not reassign parg after collapse_tree()

From: Steven Rostedt <rostedt@goodmis.org>

At the end of process_filter(), collapse_tree() was changed to update
the parg parameter, but the reassignment after the call wasn't removed.

What happens is that the "current_op" gets modified and freed and parg
is assigned to the new allocated argument. But after the call to
collapse_tree(), parg is assigned again to the just freed "current_op",
and this causes the tool to crash.

The current_op variable must also be assigned to NULL in case of error,
otherwise it will cause it to be free()ed twice.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org # 3.14+
Fixes: 42d6194d133c ("tools lib traceevent: Refactor process_filter()")
Link: http://lkml.kernel.org/r/20160511150936.678c18a1@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/lib/traceevent/parse-filter.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/lib/traceevent/parse-filter.c b/tools/lib/traceevent/parse-filter.c
index 0144b3d1bb77..88cccea3ca99 100644
--- a/tools/lib/traceevent/parse-filter.c
+++ b/tools/lib/traceevent/parse-filter.c
@@ -1164,11 +1164,11 @@ process_filter(struct event_format *event, struct filter_arg **parg,
 		current_op = current_exp;
 
 	ret = collapse_tree(current_op, parg, error_str);
+	/* collapse_tree() may free current_op, and updates parg accordingly */
+	current_op = NULL;
 	if (ret < 0)
 		goto fail;
 
-	*parg = current_op;
-
 	free(token);
 	return 0;
 
-- 
2.5.5

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#1400336 — [PATCH 08/10] perf evsel: Improve EPERM error handling in open_strerror()

From: Arnaldo Carvalho de Melo <acme@redhat.com>

We were showing a hardcoded default value for the kernel.perf_event_paranoid
sysctl, now that it became more paranoid (1 -> 2 [1]), this would need to be
updated, instead show the current value:

  [acme@jouet linux]$ perf record ls
  Error:
  You may not have permission to collect stats.

  Consider tweaking /proc/sys/kernel/perf_event_paranoid,
  which controls use of the performance events system by
  unprivileged users (without CAP_SYS_ADMIN).

  The current value is 2:

    -1: Allow use of (almost) all events by all users
  >= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
  >= 1: Disallow CPU event access by users without CAP_SYS_ADMIN
  >= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN
  [acme@jouet linux]$

[1] 0161028b7c8a ("perf/core: Change the default paranoia level to 2")

Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-0gc4rdpg8d025r5not8s8028@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/evsel.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 738ce226002b..a5f339d447cc 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2382,12 +2382,13 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
 		 "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n"
 		 "which controls use of the performance events system by\n"
 		 "unprivileged users (without CAP_SYS_ADMIN).\n\n"
-		 "The default value is 1:\n\n"
+		 "The current value is %d:\n\n"
 		 "  -1: Allow use of (almost) all events by all users\n"
 		 ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n"
 		 ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
 		 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN",
-				 target->system_wide ? "system-wide " : "");
+				 target->system_wide ? "system-wide " : "",
+				 perf_event_paranoid());
 	case ENOENT:
 		return scnprintf(msg, size, "The %s event is not supported.",
 				 perf_evsel__name(evsel));
-- 
2.5.5

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#1400337 — [PATCH 09/10] perf evsel: Handle EACCESS + perf_event_paranoid=2 in fallback()

From: Arnaldo Carvalho de Melo <acme@redhat.com>

Now with the default for the kernel.perf_event_paranoid sysctl being 2 [1]
we need to fall back to :u, i.e. to set perf_event_attr.exclude_kernel
to 1.

Before:

  [acme@jouet linux]$ perf record usleep 1
  Error:
  You may not have permission to collect stats.

  Consider tweaking /proc/sys/kernel/perf_event_paranoid,
  which controls use of the performance events system by
  unprivileged users (without CAP_SYS_ADMIN).

  The current value is 2:

    -1: Allow use of (almost) all events by all users
  >= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
  >= 1: Disallow CPU event access by users without CAP_SYS_ADMIN
  >= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN
  [acme@jouet linux]$

After:

  [acme@jouet linux]$ perf record usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.016 MB perf.data (7 samples) ]
  [acme@jouet linux]$ perf evlist
  cycles:u
  [acme@jouet linux]$ perf evlist -v
  cycles:u: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, exclude_kernel: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
  [acme@jouet linux]$

And if the user turns on verbose mode, an explanation will appear:

  [acme@jouet linux]$ perf record -v usleep 1
  Warning:
  kernel.perf_event_paranoid=2, trying to fall back to excluding kernel samples
  mmap size 528384B
  [ perf record: Woken up 1 times to write data ]
  Looking at the vmlinux_path (8 entries long)
  Using /lib/modules/4.6.0-rc7+/build/vmlinux for symbols
  [ perf record: Captured and wrote 0.016 MB perf.data (7 samples) ]
  [acme@jouet linux]$

[1] 0161028b7c8a ("perf/core: Change the default paranoia level to 2")

Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-b20jmx4dxt5hpaa9t2rroi0o@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/evsel.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index a5f339d447cc..645dc1828836 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2345,6 +2345,8 @@ out:
 bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
 			  char *msg, size_t msgsize)
 {
+	int paranoid;
+
 	if ((err == ENOENT || err == ENXIO || err == ENODEV) &&
 	    evsel->attr.type   == PERF_TYPE_HARDWARE &&
 	    evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
@@ -2364,6 +2366,22 @@ bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
 
 		zfree(&evsel->name);
 		return true;
+	} else if (err == EACCES && !evsel->attr.exclude_kernel &&
+		   (paranoid = perf_event_paranoid()) > 1) {
+		const char *name = perf_evsel__name(evsel);
+		char *new_name;
+
+		if (asprintf(&new_name, "%s%su", name, strchr(name, ':') ? "" : ":") < 0)
+			return false;
+
+		if (evsel->name)
+			free(evsel->name);
+		evsel->name = new_name;
+		scnprintf(msg, msgsize,
+"kernel.perf_event_paranoid=%d, trying to fall back to excluding kernel samples", paranoid);
+		evsel->attr.exclude_kernel = 1;
+
+		return true;
 	}
 
 	return false;
-- 
2.5.5

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#1400338 — [PATCH 10/10] perf stat: Fallback to user only counters when perf_event_paranoid > 1

From: Arnaldo Carvalho de Melo <acme@redhat.com>

After 0161028b7c8a ("perf/core: Change the default paranoia level to 2")
'perf stat' fails for users without CAP_SYS_ADMIN, so just use
'perf_evsel__fallback()' to have the same behaviour as 'perf record',
i.e. set perf_event_attr.exclude_kernel to 1.

Now:

  [acme@jouet linux]$ perf stat usleep 1

   Performance counter stats for 'usleep 1':

          0.352536      task-clock:u (msec)  #   0.423 CPUs utilized
                 0      context-switches:u   #   0.000 K/sec
                 0      cpu-migrations:u     #   0.000 K/sec
                49      page-faults:u        #   0.139 M/sec
           309,407      cycles:u             #   0.878 GHz
           243,791      instructions:u       #   0.79  insn per cycle
            49,622      branches:u           # 140.757 M/sec
             3,884      branch-misses:u      #   7.83% of all branches

       0.000834174 seconds time elapsed

  [acme@jouet linux]$

Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-b20jmx4dxt5hpaa9t2rroi0o@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-stat.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 1f19f2f999c8..307e8a1a003c 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -528,6 +528,7 @@ static int __run_perf_stat(int argc, const char **argv)
 		perf_evlist__set_leader(evsel_list);
 
 	evlist__for_each(evsel_list, counter) {
+try_again:
 		if (create_perf_stat_counter(counter) < 0) {
 			/*
 			 * PPC returns ENXIO for HW counters until 2.6.37
@@ -544,7 +545,11 @@ static int __run_perf_stat(int argc, const char **argv)
 				if ((counter->leader != counter) ||
 				    !(counter->leader->nr_members > 1))
 					continue;
-			}
+			} else if (perf_evsel__fallback(counter, errno, msg, sizeof(msg))) {
+                                if (verbose)
+                                        ui__warning("%s\n", msg);
+                                goto try_again;
+                        }
 
 			perf_evsel__open_strerror(counter, &target,
 						  errno, msg, sizeof(msg));
-- 
2.5.5

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#1400339 — [PATCH 02/10] perf script: Use readdir() instead of deprecated readdir_r()

From: Arnaldo Carvalho de Melo <acme@redhat.com>

The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case in 'perf script', so, to avoid breaking the build
with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r().

See: http://man7.org/linux/man-pages/man3/readdir.3.html

"However, in modern implementations (including the glibc implementation),
concurrent calls to readdir() that specify different directory streams
are thread-safe.  In cases where multiple threads must read from the
same directory stream, using readdir() with external synchronization is
still preferable to the use of the deprecated readdir_r(3) function."

Noticed while building on a Fedora Rawhide docker container.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-mt3xz7n2hl49ni2vx7kuq74g@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-script.c | 70 ++++++++++++++++++++++-----------------------
 1 file changed, 34 insertions(+), 36 deletions(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 3770c3dffe5e..52826696c852 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1415,21 +1415,19 @@ static int is_directory(const char *base_path, const struct dirent *dent)
 	return S_ISDIR(st.st_mode);
 }
 
-#define for_each_lang(scripts_path, scripts_dir, lang_dirent, lang_next)\
-	while (!readdir_r(scripts_dir, &lang_dirent, &lang_next) &&	\
-	       lang_next)						\
-		if ((lang_dirent.d_type == DT_DIR ||			\
-		     (lang_dirent.d_type == DT_UNKNOWN &&		\
-		      is_directory(scripts_path, &lang_dirent))) &&	\
-		    (strcmp(lang_dirent.d_name, ".")) &&		\
-		    (strcmp(lang_dirent.d_name, "..")))
-
-#define for_each_script(lang_path, lang_dir, script_dirent, script_next)\
-	while (!readdir_r(lang_dir, &script_dirent, &script_next) &&	\
-	       script_next)						\
-		if (script_dirent.d_type != DT_DIR &&			\
-		    (script_dirent.d_type != DT_UNKNOWN ||		\
-		     !is_directory(lang_path, &script_dirent)))
+#define for_each_lang(scripts_path, scripts_dir, lang_dirent)		\
+	while ((lang_dirent = readdir(scripts_dir)) != NULL)		\
+		if ((lang_dirent->d_type == DT_DIR ||			\
+		     (lang_dirent->d_type == DT_UNKNOWN &&		\
+		      is_directory(scripts_path, lang_dirent))) &&	\
+		    (strcmp(lang_dirent->d_name, ".")) &&		\
+		    (strcmp(lang_dirent->d_name, "..")))
+
+#define for_each_script(lang_path, lang_dir, script_dirent)		\
+	while ((script_dirent = readdir(lang_dir)) != NULL)		\
+		if (script_dirent->d_type != DT_DIR &&			\
+		    (script_dirent->d_type != DT_UNKNOWN ||		\
+		     !is_directory(lang_path, script_dirent)))
 
 
 #define RECORD_SUFFIX			"-record"
@@ -1575,7 +1573,7 @@ static int list_available_scripts(const struct option *opt __maybe_unused,
 				  const char *s __maybe_unused,
 				  int unset __maybe_unused)
 {
-	struct dirent *script_next, *lang_next, script_dirent, lang_dirent;
+	struct dirent *script_dirent, *lang_dirent;
 	char scripts_path[MAXPATHLEN];
 	DIR *scripts_dir, *lang_dir;
 	char script_path[MAXPATHLEN];
@@ -1590,19 +1588,19 @@ static int list_available_scripts(const struct option *opt __maybe_unused,
 	if (!scripts_dir)
 		return -1;
 
-	for_each_lang(scripts_path, scripts_dir, lang_dirent, lang_next) {
+	for_each_lang(scripts_path, scripts_dir, lang_dirent) {
 		snprintf(lang_path, MAXPATHLEN, "%s/%s/bin", scripts_path,
-			 lang_dirent.d_name);
+			 lang_dirent->d_name);
 		lang_dir = opendir(lang_path);
 		if (!lang_dir)
 			continue;
 
-		for_each_script(lang_path, lang_dir, script_dirent, script_next) {
-			script_root = get_script_root(&script_dirent, REPORT_SUFFIX);
+		for_each_script(lang_path, lang_dir, script_dirent) {
+			script_root = get_script_root(script_dirent, REPORT_SUFFIX);
 			if (script_root) {
 				desc = script_desc__findnew(script_root);
 				snprintf(script_path, MAXPATHLEN, "%s/%s",
-					 lang_path, script_dirent.d_name);
+					 lang_path, script_dirent->d_name);
 				read_script_info(desc, script_path);
 				free(script_root);
 			}
@@ -1690,7 +1688,7 @@ static int check_ev_match(char *dir_name, char *scriptname,
  */
 int find_scripts(char **scripts_array, char **scripts_path_array)
 {
-	struct dirent *script_next, *lang_next, script_dirent, lang_dirent;
+	struct dirent *script_dirent, *lang_dirent;
 	char scripts_path[MAXPATHLEN], lang_path[MAXPATHLEN];
 	DIR *scripts_dir, *lang_dir;
 	struct perf_session *session;
@@ -1713,9 +1711,9 @@ int find_scripts(char **scripts_array, char **scripts_path_array)
 		return -1;
 	}
 
-	for_each_lang(scripts_path, scripts_dir, lang_dirent, lang_next) {
+	for_each_lang(scripts_path, scripts_dir, lang_dirent) {
 		snprintf(lang_path, MAXPATHLEN, "%s/%s", scripts_path,
-			 lang_dirent.d_name);
+			 lang_dirent->d_name);
 #ifdef NO_LIBPERL
 		if (strstr(lang_path, "perl"))
 			continue;
@@ -1729,16 +1727,16 @@ int find_scripts(char **scripts_array, char **scripts_path_array)
 		if (!lang_dir)
 			continue;
 
-		for_each_script(lang_path, lang_dir, script_dirent, script_next) {
+		for_each_script(lang_path, lang_dir, script_dirent) {
 			/* Skip those real time scripts: xxxtop.p[yl] */
-			if (strstr(script_dirent.d_name, "top."))
+			if (strstr(script_dirent->d_name, "top."))
 				continue;
 			sprintf(scripts_path_array[i], "%s/%s", lang_path,
-				script_dirent.d_name);
-			temp = strchr(script_dirent.d_name, '.');
+				script_dirent->d_name);
+			temp = strchr(script_dirent->d_name, '.');
 			snprintf(scripts_array[i],
-				(temp - script_dirent.d_name) + 1,
-				"%s", script_dirent.d_name);
+				(temp - script_dirent->d_name) + 1,
+				"%s", script_dirent->d_name);
 
 			if (check_ev_match(lang_path,
 					scripts_array[i], session))
@@ -1756,7 +1754,7 @@ int find_scripts(char **scripts_array, char **scripts_path_array)
 
 static char *get_script_path(const char *script_root, const char *suffix)
 {
-	struct dirent *script_next, *lang_next, script_dirent, lang_dirent;
+	struct dirent *script_dirent, *lang_dirent;
 	char scripts_path[MAXPATHLEN];
 	char script_path[MAXPATHLEN];
 	DIR *scripts_dir, *lang_dir;
@@ -1769,21 +1767,21 @@ static char *get_script_path(const char *script_root, const char *suffix)
 	if (!scripts_dir)
 		return NULL;
 
-	for_each_lang(scripts_path, scripts_dir, lang_dirent, lang_next) {
+	for_each_lang(scripts_path, scripts_dir, lang_dirent) {
 		snprintf(lang_path, MAXPATHLEN, "%s/%s/bin", scripts_path,
-			 lang_dirent.d_name);
+			 lang_dirent->d_name);
 		lang_dir = opendir(lang_path);
 		if (!lang_dir)
 			continue;
 
-		for_each_script(lang_path, lang_dir, script_dirent, script_next) {
-			__script_root = get_script_root(&script_dirent, suffix);
+		for_each_script(lang_path, lang_dir, script_dirent) {
+			__script_root = get_script_root(script_dirent, suffix);
 			if (__script_root && !strcmp(script_root, __script_root)) {
 				free(__script_root);
 				closedir(lang_dir);
 				closedir(scripts_dir);
 				snprintf(script_path, MAXPATHLEN, "%s/%s",
-					 lang_path, script_dirent.d_name);
+					 lang_path, script_dirent->d_name);
 				return strdup(script_path);
 			}
 			free(__script_root);
-- 
2.5.5

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#1400340 — [PATCH 01/10] perf tools: Use readdir() instead of deprecated readdir_r()

From: Arnaldo Carvalho de Melo <acme@redhat.com>

The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case when synthesizing events for pre-existing threads
by traversing /proc, so, to avoid breaking the build with glibc-2.23.90
(upcoming 2.24), use it instead of readdir_r().

See: http://man7.org/linux/man-pages/man3/readdir.3.html

"However, in modern implementations (including the glibc implementation),
concurrent calls to readdir() that specify different directory streams
are thread-safe.  In cases where multiple threads must read from the
same directory stream, using readdir() with external synchronization is
still preferable to the use of the deprecated readdir_r(3) function."

Noticed while building on a Fedora Rawhide docker container.

   CC       /tmp/build/perf/util/event.o
  util/event.c: In function '__event__synthesize_thread':
  util/event.c:466:2: error: 'readdir_r' is deprecated [-Werror=deprecated-declarations]
    while (!readdir_r(tasks, &dirent, &next) && next) {
    ^~~~~
  In file included from /usr/include/features.h:368:0,
                   from /usr/include/stdint.h:25,
                   from /usr/lib/gcc/x86_64-redhat-linux/6.0.0/include/stdint.h:9,
                   from /git/linux/tools/include/linux/types.h:6,
                   from util/event.c:1:
  /usr/include/dirent.h:189:12: note: declared here

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-i1vj7nyjp2p750rirxgrfd3c@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/event.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index dad55d04ffdd..edcf4ed4e99c 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -433,7 +433,7 @@ static int __event__synthesize_thread(union perf_event *comm_event,
 {
 	char filename[PATH_MAX];
 	DIR *tasks;
-	struct dirent dirent, *next;
+	struct dirent *dirent;
 	pid_t tgid, ppid;
 	int rc = 0;
 
@@ -462,11 +462,11 @@ static int __event__synthesize_thread(union perf_event *comm_event,
 		return 0;
 	}
 
-	while (!readdir_r(tasks, &dirent, &next) && next) {
+	while ((dirent = readdir(tasks)) != NULL) {
 		char *end;
 		pid_t _pid;
 
-		_pid = strtol(dirent.d_name, &end, 10);
+		_pid = strtol(dirent->d_name, &end, 10);
 		if (*end)
 			continue;
 
@@ -575,7 +575,7 @@ int perf_event__synthesize_threads(struct perf_tool *tool,
 {
 	DIR *proc;
 	char proc_path[PATH_MAX];
-	struct dirent dirent, *next;
+	struct dirent *dirent;
 	union perf_event *comm_event, *mmap_event, *fork_event;
 	int err = -1;
 
@@ -600,9 +600,9 @@ int perf_event__synthesize_threads(struct perf_tool *tool,
 	if (proc == NULL)
 		goto out_free_fork;
 
-	while (!readdir_r(proc, &dirent, &next) && next) {
+	while ((dirent = readdir(proc)) != NULL) {
 		char *end;
-		pid_t pid = strtol(dirent.d_name, &end, 10);
+		pid_t pid = strtol(dirent->d_name, &end, 10);
 
 		if (*end) /* only interested in proper numerical dirents */
 			continue;
-- 
2.5.5

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#1400342 — [PATCH 03/10] perf thread_map: Use readdir() instead of deprecated readdir_r()

From: Arnaldo Carvalho de Melo <acme@redhat.com>

The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case in thread_map, so, to avoid breaking the build
with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r().

See: http://man7.org/linux/man-pages/man3/readdir.3.html

"However, in modern implementations (including the glibc implementation),
concurrent calls to readdir() that specify different directory streams
are thread-safe.  In cases where multiple threads must read from the
same directory stream, using readdir() with external synchronization is
still preferable to the use of the deprecated readdir_r(3) function."

Noticed while building on a Fedora Rawhide docker container.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-del8h2a0f40z75j4r42l96l0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/thread_map.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c
index 08afc6909953..267112b4e3db 100644
--- a/tools/perf/util/thread_map.c
+++ b/tools/perf/util/thread_map.c
@@ -94,7 +94,7 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
 	DIR *proc;
 	int max_threads = 32, items, i;
 	char path[256];
-	struct dirent dirent, *next, **namelist = NULL;
+	struct dirent *dirent, **namelist = NULL;
 	struct thread_map *threads = thread_map__alloc(max_threads);
 
 	if (threads == NULL)
@@ -107,16 +107,16 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
 	threads->nr = 0;
 	atomic_set(&threads->refcnt, 1);
 
-	while (!readdir_r(proc, &dirent, &next) && next) {
+	while ((dirent = readdir(proc)) != NULL) {
 		char *end;
 		bool grow = false;
 		struct stat st;
-		pid_t pid = strtol(dirent.d_name, &end, 10);
+		pid_t pid = strtol(dirent->d_name, &end, 10);
 
 		if (*end) /* only interested in proper numerical dirents */
 			continue;
 
-		snprintf(path, sizeof(path), "/proc/%s", dirent.d_name);
+		snprintf(path, sizeof(path), "/proc/%s", dirent->d_name);
 
 		if (stat(path, &st) != 0)
 			continue;
-- 
2.5.5

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#1400343 — [PATCH 06/10] perf probe: Check if dwarf_getlocations() is available

From: Arnaldo Carvalho de Melo <acme@redhat.com>

If not, tell the user that:

  config/Makefile:273: Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157

And return -ENOTSUPP in die_get_var_range(), failing features that
need it, like the one pointed out above.

This fixes the build on older systems, such as Ubuntu 12.04.5.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Vinson Lee <vlee@freedesktop.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-9l7luqkq4gfnx7vrklkq4obs@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/build/Makefile.feature                  |  2 ++
 tools/build/feature/Makefile                  |  4 ++++
 tools/build/feature/test-all.c                |  5 +++++
 tools/build/feature/test-dwarf_getlocations.c | 12 ++++++++++++
 tools/perf/config/Makefile                    |  6 ++++++
 tools/perf/util/dwarf-aux.c                   |  9 +++++++++
 6 files changed, 38 insertions(+)
 create mode 100644 tools/build/feature/test-dwarf_getlocations.c

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 6b7707270aa3..9f878619077a 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -30,6 +30,7 @@ endef
 FEATURE_TESTS_BASIC :=			\
 	backtrace			\
 	dwarf				\
+	dwarf_getlocations		\
 	fortify-source			\
 	sync-compare-and-swap		\
 	glibc				\
@@ -78,6 +79,7 @@ endif
 
 FEATURE_DISPLAY ?=			\
 	dwarf				\
+	dwarf_getlocations		\
 	glibc				\
 	gtk2				\
 	libaudit			\
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index c5f4c417428d..4ae94dbfdab9 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -3,6 +3,7 @@ FILES=					\
 	test-backtrace.bin		\
 	test-bionic.bin			\
 	test-dwarf.bin			\
+	test-dwarf_getlocations.bin	\
 	test-fortify-source.bin		\
 	test-sync-compare-and-swap.bin	\
 	test-glibc.bin			\
@@ -82,6 +83,9 @@ endif
 $(OUTPUT)test-dwarf.bin:
 	$(BUILD) $(DWARFLIBS)
 
+$(OUTPUT)test-dwarf_getlocations.bin:
+	$(BUILD) $(DWARFLIBS)
+
 $(OUTPUT)test-libelf-mmap.bin:
 	$(BUILD) -lelf
 
diff --git a/tools/build/feature/test-all.c b/tools/build/feature/test-all.c
index e499a36c1e4a..a282e8cb84f3 100644
--- a/tools/build/feature/test-all.c
+++ b/tools/build/feature/test-all.c
@@ -41,6 +41,10 @@
 # include "test-dwarf.c"
 #undef main
 
+#define main main_test_dwarf_getlocations
+# include "test-dwarf_getlocations.c"
+#undef main
+
 #define main main_test_libelf_getphdrnum
 # include "test-libelf-getphdrnum.c"
 #undef main
@@ -143,6 +147,7 @@ int main(int argc, char *argv[])
 	main_test_libelf_mmap();
 	main_test_glibc();
 	main_test_dwarf();
+	main_test_dwarf_getlocations();
 	main_test_libelf_getphdrnum();
 	main_test_libunwind();
 	main_test_libaudit();
diff --git a/tools/build/feature/test-dwarf_getlocations.c b/tools/build/feature/test-dwarf_getlocations.c
new file mode 100644
index 000000000000..70162699dd43
--- /dev/null
+++ b/tools/build/feature/test-dwarf_getlocations.c
@@ -0,0 +1,12 @@
+#include <stdlib.h>
+#include <elfutils/libdw.h>
+
+int main(void)
+{
+	Dwarf_Addr base, start, end;
+	Dwarf_Attribute attr;
+	Dwarf_Op *op;
+        size_t nops;
+	ptrdiff_t offset = 0;
+        return (int)dwarf_getlocations(&attr, offset, &base, &start, &end, &op, &nops);
+}
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index f7d7f5a1cad5..6f8f6430f2bf 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -268,6 +268,12 @@ else
     ifneq ($(feature-dwarf), 1)
       msg := $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev);
       NO_DWARF := 1
+    else
+      ifneq ($(feature-dwarf_getlocations), 1)
+        msg := $(warning Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157);
+      else
+        CFLAGS += -DHAVE_DWARF_GETLOCATIONS
+      endif # dwarf_getlocations
     endif # Dwarf support
   endif # libelf support
 endif # NO_LIBELF
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index 577e600c8eb1..aea189b41cc8 100644
--- a/tools/perf/util/dwarf-aux.c
+++ b/tools/perf/util/dwarf-aux.c
@@ -959,6 +959,7 @@ int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
 	return 0;
 }
 
+#ifdef HAVE_DWARF_GETLOCATIONS
 /**
  * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
  * @sp_die: a subprogram DIE
@@ -1080,3 +1081,11 @@ int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
 
 	return ret;
 }
+#else
+int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
+		      Dwarf_Die *vr_die __maybe_unused,
+		      struct strbuf *buf __maybe_unused)
+{
+	return -ENOTSUP;
+}
+#endif
-- 
2.5.5

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#1400458 — Re: [PATCH 06/10] perf probe: Check if dwarf_getlocations() is available

On Thu, 12 May 2016 17:03:51 -0300
Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> If not, tell the user that:
> 
>   config/Makefile:273: Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157
> 
> And return -ENOTSUPP in die_get_var_range(), failing features that
> need it, like the one pointed out above.
> 
> This fixes the build on older systems, such as Ubuntu 12.04.5.
> 

Hmm, would we better to use similar technique for dwarf_cfi_addrframe?
the commit 7752f1b096e1
("perf probe: Don't compile CFI related code if elfutils is old")
uses _ELFUTILS_PREREQ() macro for checking the elfutils version directly.

Anyway, this looks good to me.

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Vinson Lee <vlee@freedesktop.org>
> Cc: Wang Nan <wangnan0@huawei.com>
> Link: http://lkml.kernel.org/n/tip-9l7luqkq4gfnx7vrklkq4obs@git.kernel.org
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ---
>  tools/build/Makefile.feature                  |  2 ++
>  tools/build/feature/Makefile                  |  4 ++++
>  tools/build/feature/test-all.c                |  5 +++++
>  tools/build/feature/test-dwarf_getlocations.c | 12 ++++++++++++
>  tools/perf/config/Makefile                    |  6 ++++++
>  tools/perf/util/dwarf-aux.c                   |  9 +++++++++
>  6 files changed, 38 insertions(+)
>  create mode 100644 tools/build/feature/test-dwarf_getlocations.c
> 
> diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
> index 6b7707270aa3..9f878619077a 100644
> --- a/tools/build/Makefile.feature
> +++ b/tools/build/Makefile.feature
> @@ -30,6 +30,7 @@ endef
>  FEATURE_TESTS_BASIC :=			\
>  	backtrace			\
>  	dwarf				\
> +	dwarf_getlocations		\
>  	fortify-source			\
>  	sync-compare-and-swap		\
>  	glibc				\
> @@ -78,6 +79,7 @@ endif
>  
>  FEATURE_DISPLAY ?=			\
>  	dwarf				\
> +	dwarf_getlocations		\
>  	glibc				\
>  	gtk2				\
>  	libaudit			\
> diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
> index c5f4c417428d..4ae94dbfdab9 100644
> --- a/tools/build/feature/Makefile
> +++ b/tools/build/feature/Makefile
> @@ -3,6 +3,7 @@ FILES=					\
>  	test-backtrace.bin		\
>  	test-bionic.bin			\
>  	test-dwarf.bin			\
> +	test-dwarf_getlocations.bin	\
>  	test-fortify-source.bin		\
>  	test-sync-compare-and-swap.bin	\
>  	test-glibc.bin			\
> @@ -82,6 +83,9 @@ endif
>  $(OUTPUT)test-dwarf.bin:
>  	$(BUILD) $(DWARFLIBS)
>  
> +$(OUTPUT)test-dwarf_getlocations.bin:
> +	$(BUILD) $(DWARFLIBS)
> +
>  $(OUTPUT)test-libelf-mmap.bin:
>  	$(BUILD) -lelf
>  
> diff --git a/tools/build/feature/test-all.c b/tools/build/feature/test-all.c
> index e499a36c1e4a..a282e8cb84f3 100644
> --- a/tools/build/feature/test-all.c
> +++ b/tools/build/feature/test-all.c
> @@ -41,6 +41,10 @@
>  # include "test-dwarf.c"
>  #undef main
>  
> +#define main main_test_dwarf_getlocations
> +# include "test-dwarf_getlocations.c"
> +#undef main
> +
>  #define main main_test_libelf_getphdrnum
>  # include "test-libelf-getphdrnum.c"
>  #undef main
> @@ -143,6 +147,7 @@ int main(int argc, char *argv[])
>  	main_test_libelf_mmap();
>  	main_test_glibc();
>  	main_test_dwarf();
> +	main_test_dwarf_getlocations();
>  	main_test_libelf_getphdrnum();
>  	main_test_libunwind();
>  	main_test_libaudit();
> diff --git a/tools/build/feature/test-dwarf_getlocations.c b/tools/build/feature/test-dwarf_getlocations.c
> new file mode 100644
> index 000000000000..70162699dd43
> --- /dev/null
> +++ b/tools/build/feature/test-dwarf_getlocations.c
> @@ -0,0 +1,12 @@
> +#include <stdlib.h>
> +#include <elfutils/libdw.h>
> +
> +int main(void)
> +{
> +	Dwarf_Addr base, start, end;
> +	Dwarf_Attribute attr;
> +	Dwarf_Op *op;
> +        size_t nops;
> +	ptrdiff_t offset = 0;
> +        return (int)dwarf_getlocations(&attr, offset, &base, &start, &end, &op, &nops);
> +}
> diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
> index f7d7f5a1cad5..6f8f6430f2bf 100644
> --- a/tools/perf/config/Makefile
> +++ b/tools/perf/config/Makefile
> @@ -268,6 +268,12 @@ else
>      ifneq ($(feature-dwarf), 1)
>        msg := $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev);
>        NO_DWARF := 1
> +    else
> +      ifneq ($(feature-dwarf_getlocations), 1)
> +        msg := $(warning Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157);
> +      else
> +        CFLAGS += -DHAVE_DWARF_GETLOCATIONS
> +      endif # dwarf_getlocations
>      endif # Dwarf support
>    endif # libelf support
>  endif # NO_LIBELF
> diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
> index 577e600c8eb1..aea189b41cc8 100644
> --- a/tools/perf/util/dwarf-aux.c
> +++ b/tools/perf/util/dwarf-aux.c
> @@ -959,6 +959,7 @@ int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
>  	return 0;
>  }
>  
> +#ifdef HAVE_DWARF_GETLOCATIONS
>  /**
>   * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
>   * @sp_die: a subprogram DIE
> @@ -1080,3 +1081,11 @@ int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
>  
>  	return ret;
>  }
> +#else
> +int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
> +		      Dwarf_Die *vr_die __maybe_unused,
> +		      struct strbuf *buf __maybe_unused)
> +{
> +	return -ENOTSUP;
> +}
> +#endif
> -- 
> 2.5.5
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>

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#1400715 — Re: [PATCH 06/10] perf probe: Check if dwarf_getlocations() is available

Em Fri, May 13, 2016 at 11:38:52AM +0900, Masami Hiramatsu escreveu:
> On Thu, 12 May 2016 17:03:51 -0300
> Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> 
> > From: Arnaldo Carvalho de Melo <acme@redhat.com>
> > 
> > If not, tell the user that:
> > 
> >   config/Makefile:273: Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157
> > 
> > And return -ENOTSUPP in die_get_var_range(), failing features that
> > need it, like the one pointed out above.
> > 
> > This fixes the build on older systems, such as Ubuntu 12.04.5.
> > 
> 
> Hmm, would we better to use similar technique for dwarf_cfi_addrframe?
> the commit 7752f1b096e1
> ("perf probe: Don't compile CFI related code if elfutils is old")
> uses _ELFUTILS_PREREQ() macro for checking the elfutils version directly.

I'll take a look at this.
 
> Anyway, this looks good to me.
> 
> Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thanks for verifying this and the other one!

- Arnaldo
 
> > Cc: Adrian Hunter <adrian.hunter@intel.com>
> > Cc: David Ahern <dsahern@gmail.com>
> > Cc: Jiri Olsa <jolsa@kernel.org>
> > Cc: Namhyung Kim <namhyung@kernel.org>
> > Cc: Vinson Lee <vlee@freedesktop.org>
> > Cc: Wang Nan <wangnan0@huawei.com>
> > Link: http://lkml.kernel.org/n/tip-9l7luqkq4gfnx7vrklkq4obs@git.kernel.org
> > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> > ---
> >  tools/build/Makefile.feature                  |  2 ++
> >  tools/build/feature/Makefile                  |  4 ++++
> >  tools/build/feature/test-all.c                |  5 +++++
> >  tools/build/feature/test-dwarf_getlocations.c | 12 ++++++++++++
> >  tools/perf/config/Makefile                    |  6 ++++++
> >  tools/perf/util/dwarf-aux.c                   |  9 +++++++++
> >  6 files changed, 38 insertions(+)
> >  create mode 100644 tools/build/feature/test-dwarf_getlocations.c
> > 
> > diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
> > index 6b7707270aa3..9f878619077a 100644
> > --- a/tools/build/Makefile.feature
> > +++ b/tools/build/Makefile.feature
> > @@ -30,6 +30,7 @@ endef
> >  FEATURE_TESTS_BASIC :=			\
> >  	backtrace			\
> >  	dwarf				\
> > +	dwarf_getlocations		\
> >  	fortify-source			\
> >  	sync-compare-and-swap		\
> >  	glibc				\
> > @@ -78,6 +79,7 @@ endif
> >  
> >  FEATURE_DISPLAY ?=			\
> >  	dwarf				\
> > +	dwarf_getlocations		\
> >  	glibc				\
> >  	gtk2				\
> >  	libaudit			\
> > diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
> > index c5f4c417428d..4ae94dbfdab9 100644
> > --- a/tools/build/feature/Makefile
> > +++ b/tools/build/feature/Makefile
> > @@ -3,6 +3,7 @@ FILES=					\
> >  	test-backtrace.bin		\
> >  	test-bionic.bin			\
> >  	test-dwarf.bin			\
> > +	test-dwarf_getlocations.bin	\
> >  	test-fortify-source.bin		\
> >  	test-sync-compare-and-swap.bin	\
> >  	test-glibc.bin			\
> > @@ -82,6 +83,9 @@ endif
> >  $(OUTPUT)test-dwarf.bin:
> >  	$(BUILD) $(DWARFLIBS)
> >  
> > +$(OUTPUT)test-dwarf_getlocations.bin:
> > +	$(BUILD) $(DWARFLIBS)
> > +
> >  $(OUTPUT)test-libelf-mmap.bin:
> >  	$(BUILD) -lelf
> >  
> > diff --git a/tools/build/feature/test-all.c b/tools/build/feature/test-all.c
> > index e499a36c1e4a..a282e8cb84f3 100644
> > --- a/tools/build/feature/test-all.c
> > +++ b/tools/build/feature/test-all.c
> > @@ -41,6 +41,10 @@
> >  # include "test-dwarf.c"
> >  #undef main
> >  
> > +#define main main_test_dwarf_getlocations
> > +# include "test-dwarf_getlocations.c"
> > +#undef main
> > +
> >  #define main main_test_libelf_getphdrnum
> >  # include "test-libelf-getphdrnum.c"
> >  #undef main
> > @@ -143,6 +147,7 @@ int main(int argc, char *argv[])
> >  	main_test_libelf_mmap();
> >  	main_test_glibc();
> >  	main_test_dwarf();
> > +	main_test_dwarf_getlocations();
> >  	main_test_libelf_getphdrnum();
> >  	main_test_libunwind();
> >  	main_test_libaudit();
> > diff --git a/tools/build/feature/test-dwarf_getlocations.c b/tools/build/feature/test-dwarf_getlocations.c
> > new file mode 100644
> > index 000000000000..70162699dd43
> > --- /dev/null
> > +++ b/tools/build/feature/test-dwarf_getlocations.c
> > @@ -0,0 +1,12 @@
> > +#include <stdlib.h>
> > +#include <elfutils/libdw.h>
> > +
> > +int main(void)
> > +{
> > +	Dwarf_Addr base, start, end;
> > +	Dwarf_Attribute attr;
> > +	Dwarf_Op *op;
> > +        size_t nops;
> > +	ptrdiff_t offset = 0;
> > +        return (int)dwarf_getlocations(&attr, offset, &base, &start, &end, &op, &nops);
> > +}
> > diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
> > index f7d7f5a1cad5..6f8f6430f2bf 100644
> > --- a/tools/perf/config/Makefile
> > +++ b/tools/perf/config/Makefile
> > @@ -268,6 +268,12 @@ else
> >      ifneq ($(feature-dwarf), 1)
> >        msg := $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev);
> >        NO_DWARF := 1
> > +    else
> > +      ifneq ($(feature-dwarf_getlocations), 1)
> > +        msg := $(warning Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157);
> > +      else
> > +        CFLAGS += -DHAVE_DWARF_GETLOCATIONS
> > +      endif # dwarf_getlocations
> >      endif # Dwarf support
> >    endif # libelf support
> >  endif # NO_LIBELF
> > diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
> > index 577e600c8eb1..aea189b41cc8 100644
> > --- a/tools/perf/util/dwarf-aux.c
> > +++ b/tools/perf/util/dwarf-aux.c
> > @@ -959,6 +959,7 @@ int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf)
> >  	return 0;
> >  }
> >  
> > +#ifdef HAVE_DWARF_GETLOCATIONS
> >  /**
> >   * die_get_var_innermost_scope - Get innermost scope range of given variable DIE
> >   * @sp_die: a subprogram DIE
> > @@ -1080,3 +1081,11 @@ int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf *buf)
> >  
> >  	return ret;
> >  }
> > +#else
> > +int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
> > +		      Dwarf_Die *vr_die __maybe_unused,
> > +		      struct strbuf *buf __maybe_unused)
> > +{
> > +	return -ENOTSUP;
> > +}
> > +#endif
> > -- 
> > 2.5.5
> > 
> 
> 
> -- 
> Masami Hiramatsu <mhiramat@kernel.org>

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#1400504

* Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> Hi Ingo,
> 
> 	Please consider pulling, test built on:
> 
> alldeps-fedora-rawhide: Ok
> alldeps-ubuntu-14.04: Ok
> alldeps-ubuntu-16.04: Ok
> alldeps-fedora-20: Ok
> alldeps-ubuntu-12.04: Ok
> minimal-debian-experimental-x-mips64: Ok
> minimal-debian-experimental-x-mips64el: Ok
> minimal-debian-experimental-x-mipsel: Ok
> minimal-ubuntu-x-arm: Ok
> minimal-ubuntu-x-arm64: Ok
> minimal-ubuntu-x-ppc64: Ok
> minimal-ubuntu-x-ppc64el: Ok
> alldeps-debian: Ok
> alldeps-mageia: Ok
> alldeps-rhel7: Ok
> alldeps-centos: Ok
> alldeps-opensuse: Ok
> 
> - Arnaldo
> 
> The following changes since commit 9f448cd3cbcec8995935e60b27802ae56aac8cc0:
> 
>   perf/core: Disable the event on a truncated AUX record (2016-05-12 14:46:11 +0200)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-urgent-for-mingo-20160512
> 
> for you to fetch changes up to 42ef8a78c1f49f53f29f0f3a6f9a5bcbc653233e:
> 
>   perf stat: Fallback to user only counters when perf_event_paranoid > 1 (2016-05-12 16:25:18 -0300)
> 
> ----------------------------------------------------------------
> perf/urgent fixes:
> 
> User visible:
> 
> - Fallback to usermode only counters when perf_event_paranoid > 1, which
>   is the case now (Arnaldo Carvalho de Melo)
> 
> - Do not reassign parg after collapse_tree() in libtraceevent, which
>   may cause tool crashes (Steven Rostedt)
> 
> Build fixes:
> 
> - Fix the build on Fedora Rawhide, where readdir_r() is deprecated and
>   also wrt -Werror=unused-const-variable= + x86_32_regoffset_table on
>   !x86_64 (Arnaldo Carvalho de Melo)
> 
> - Fix the build on Ubuntu 12.04.5, where dwarf_getlocations() isn't
>   available, i.e. libdw-dev < 0.157 (Arnaldo Carvalho de Melo)
> 
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> ----------------------------------------------------------------
> Arnaldo Carvalho de Melo (9):
>       perf tools: Use readdir() instead of deprecated readdir_r()
>       perf script: Use readdir() instead of deprecated readdir_r()
>       perf thread_map: Use readdir() instead of deprecated readdir_r()
>       perf tools: Use readdir() instead of deprecated readdir_r()
>       perf dwarf: Guard !x86_64 definitions under #ifdef else clause
>       perf probe: Check if dwarf_getlocations() is available
>       perf evsel: Improve EPERM error handling in open_strerror()
>       perf evsel: Handle EACCESS + perf_event_paranoid=2 in fallback()
>       perf stat: Fallback to user only counters when perf_event_paranoid > 1
> 
> Steven Rostedt (1):
>       tools lib traceevent: Do not reassign parg after collapse_tree()
> 
>  tools/build/Makefile.feature                  |  2 +
>  tools/build/feature/Makefile                  |  4 ++
>  tools/build/feature/test-all.c                |  5 ++
>  tools/build/feature/test-dwarf_getlocations.c | 12 +++++
>  tools/lib/traceevent/parse-filter.c           |  4 +-
>  tools/perf/arch/x86/util/dwarf-regs.c         |  8 +--
>  tools/perf/builtin-script.c                   | 70 +++++++++++++--------------
>  tools/perf/builtin-stat.c                     |  7 ++-
>  tools/perf/config/Makefile                    |  6 +++
>  tools/perf/util/dwarf-aux.c                   |  9 ++++
>  tools/perf/util/event.c                       | 12 ++---
>  tools/perf/util/evsel.c                       | 23 ++++++++-
>  tools/perf/util/parse-events.c                | 60 +++++++++++------------
>  tools/perf/util/thread_map.c                  |  8 +--
>  14 files changed, 145 insertions(+), 85 deletions(-)
>  create mode 100644 tools/build/feature/test-dwarf_getlocations.c

Pulled, thanks a lot Arnaldo!

	Ingo

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