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* [PATCH 1/2] perf tests: Fix incorrect free and false TEST_OK result
@ 2015-12-10  5:52 Wang Nan
  2015-12-10  5:52 ` [PATCH 2/2] perf tools: Prevent calling machine__delete() on non-allocated machine Wang Nan
  0 siblings, 1 reply; 5+ messages in thread
From: Wang Nan @ 2015-12-10  5:52 UTC (permalink / raw)
  To: acme, masami.hiramatsu.pt, jolsa
  Cc: linux-kernel, pi3orama, lizefan, Wang Nan,
	Arnaldo Carvalho de Melo, Namhyung Kim

Commit cc1121ab9687d660cc02f50b1a4974112f87a8e6 ('perf machine: Fix
machine.vmlinux_maps to make sure to clear the old one') reveals a bug
in 'perf test' that in all test cases which use setup_fake_machine()
incorrectly call free() when failure, because all users of
setup_fake_machine() use static allocated 'machines' structure, but
setup_fake_machine() calls machine__delete() which try to free() it.

If a normal user try those test cases this problem can be seen:
 $ cat /proc/sys/kernel/kptr_restrict
 1
 $ ./perf test 'hist'
 15: Test matching and linking multiple hists                 :*** Error in `./perf': munmap_chunk(): invalid pointer: 0x00007ffd6e900090 ***
 ======= Backtrace: =========
 /lib64/libc.so.6(+0x6eeef)[0x7fcec97e1eef]
 /lib64/libc.so.6(+0x78cae)[0x7fcec97ebcae]
 ./perf(setup_fake_machine+0x1cd)[0x4721ad]
 ./perf(test__hists_link+0xbf)[0x472d3f]
 ./perf[0x4648df]
 ./perf(cmd_test+0x589)[0x464ec9]
 ./perf[0x47fd11]
 ./perf(main+0x5f6)[0x432b96]
 /lib64/libc.so.6(__libc_start_main+0xf5)[0x7fcec9794bd5]
 ./perf[0x432cc5]
 ======= Memory map: ========
 ...
 25: Test filtering hist entries                              :*** Error in `./perf': munmap_chunk(): invalid pointer: 0x00007ffd6e900080 ***
 ======= Backtrace: =========
 /lib64/libc.so.6(+0x6eeef)[0x7fcec97e1eef]
 /lib64/libc.so.6(+0x78cae)[0x7fcec97ebcae]
 ./perf(setup_fake_machine+0x1cd)[0x4721ad]
 ./perf(test__hists_filter+0xc6)[0x4730f6]
 ./perf[0x4648df]
 ./perf(cmd_test+0x589)[0x464ec9]
 ./perf[0x47fd11]
 ./perf(main+0x5f6)[0x432b96]
 /lib64/libc.so.6(__libc_start_main+0xf5)[0x7fcec9794bd5]
 ./perf[0x432cc5]
 ======= Memory map: ========
 ...
 ...

Actually, all users of 'machines__init()' should avoid calling
machine__delete(). We can further add a flag in machine structure to
enforce this restriction.

After changing machine__delete() to machine__exit() another problem
arises:

 $ ./perf test 'hist'
 15: Test matching and linking multiple hists                 : Ok
 25: Test filtering hist entries                              : Ok
 28: Test output sorting of hist entries                      : Ok
 29: Test cumulation of child hist entries                    : Ok

The result is not true:

 $ ./perf test -v 'hist'
 15: Test matching and linking multiple hists                 :
 --- start ---
 test child forked, pid 17657
 Not enough memory for machine setup
 Not enough memory for machine setup
 test child finished with 0
 ---- end ----
 Test matching and linking multiple hists: Ok
 25: Test filtering hist entries                              :
 --- start ---
 test child forked, pid 17658
 Not enough memory for machine setup
 Not enough memory for machine setup
 test child finished with 0
 ---- end ----
 Test filtering hist entries: Ok
 28: Test output sorting of hist entries                      :
 --- start ---
 test child forked, pid 17659
 Not enough memory for machine setup
 Not enough memory for machine setup
 test child finished with 0
 ---- end ----
 Test output sorting of hist entries: Ok
 29: Test cumulation of child hist entries                    :
 --- start ---
 test child forked, pid 17660
 Not enough memory for machine setup
 Not enough memory for machine setup
 test child finished with 0
 ---- end ----
 Test cumulation of child hist entries: Ok

Because the test body is not executed at all.

The reason is that *ALL* hists test cases forget to reset err after
using it to hold an error code:

  err = TEST_FAIL;
  ...
  err = parse_events(evlist, "cpu-clock", NULL);
  if (err)
      goto out;
  /* err is already 0 here */
  ...
  machine = setup_fake_machine(&machines);
  if (!machine)
      goto out;
  ...
 out:
  ...
  return err;

This patch ensure err is reset.

In case when kptr_restrict prevent normal user get kernel address, this
test should be skipped, not fail. This patch use linux/err.h to store
error code in return value of setup_fake_machine(), and let 'EACCES' to
indicate this problem.

Also, the debug message 'Not enough memory for machine setup' is not
true and should be fixed.

Here is the final result:
 $ ./perf test 'hist'
 15: Test matching and linking multiple hists                 : Skip
 25: Test filtering hist entries                              : Skip
 28: Test output sorting of hist entries                      : Skip
 29: Test cumulation of child hist entries                    : Skip

 $ ./perf test -v 'hist'
 15: Test matching and linking multiple hists                 :
 --- start ---
 test child forked, pid 20177
 Failed to create kernel maps
 Hint: Check /proc/sys/kernel/kptr_restrict.
 Failed for machine setup
 test child finished with -2
 ---- end ----
 Test matching and linking multiple hists: Skip
 25: Test filtering hist entries
 ...

 $ sudo ./perf test hist
 15: Test matching and linking multiple hists                 : Ok
 25: Test filtering hist entries                              : Ok
 28: Test output sorting of hist entries                      : Ok
 29: Test cumulation of child hist entries                    : Ok

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/tests/hists_common.c   | 15 ++++++++++-----
 tools/perf/tests/hists_common.h   |  1 +
 tools/perf/tests/hists_cumulate.c |  6 +++++-
 tools/perf/tests/hists_filter.c   |  6 +++++-
 tools/perf/tests/hists_link.c     |  6 +++++-
 tools/perf/tests/hists_output.c   |  6 +++++-
 6 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/tools/perf/tests/hists_common.c b/tools/perf/tests/hists_common.c
index 46f453b..4cd8cad 100644
--- a/tools/perf/tests/hists_common.c
+++ b/tools/perf/tests/hists_common.c
@@ -81,14 +81,19 @@ struct machine *setup_fake_machine(struct machines *machines)
 {
 	struct machine *machine = machines__find(machines, HOST_KERNEL_ID);
 	size_t i;
+	int err = -ENOMEM;
 
 	if (machine == NULL) {
 		pr_debug("Not enough memory for machine setup\n");
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 	}
 
 	if (machine__create_kernel_maps(machine)) {
-		pr_debug("Not enough memory for machine setup\n");
+		pr_debug("Failed to create kernel maps\n");
+		if (symbol_conf.kptr_restrict) {
+			pr_debug("Hint: Check /proc/sys/kernel/kptr_restrict.\n");
+			err = -EACCES;
+		}
 		goto out;
 	}
 
@@ -153,10 +158,10 @@ struct machine *setup_fake_machine(struct machines *machines)
 	return machine;
 
 out:
-	pr_debug("Not enough memory for machine setup\n");
+	pr_debug("Failed for machine setup\n");
 	machine__delete_threads(machine);
-	machine__delete(machine);
-	return NULL;
+	machine__exit(machine);
+	return ERR_PTR(err);
 }
 
 void print_hists_in(struct hists *hists)
diff --git a/tools/perf/tests/hists_common.h b/tools/perf/tests/hists_common.h
index 888254e..0252eae 100644
--- a/tools/perf/tests/hists_common.h
+++ b/tools/perf/tests/hists_common.h
@@ -1,5 +1,6 @@
 #ifndef __PERF_TESTS__HISTS_COMMON_H__
 #define __PERF_TESTS__HISTS_COMMON_H__
+#include <linux/err.h>
 
 struct machine;
 struct machines;
diff --git a/tools/perf/tests/hists_cumulate.c b/tools/perf/tests/hists_cumulate.c
index 8292948..c211075 100644
--- a/tools/perf/tests/hists_cumulate.c
+++ b/tools/perf/tests/hists_cumulate.c
@@ -706,13 +706,17 @@ int test__hists_cumulate(int subtest __maybe_unused)
 	err = parse_events(evlist, "cpu-clock", NULL);
 	if (err)
 		goto out;
+	err = TEST_FAIL;
 
 	machines__init(&machines);
 
 	/* setup threads/dso/map/symbols also */
 	machine = setup_fake_machine(&machines);
-	if (!machine)
+	if (IS_ERR(machine)) {
+		if (PTR_ERR(machine) == -EACCES)
+			err = TEST_SKIP;
 		goto out;
+	}
 
 	if (verbose > 1)
 		machine__fprintf(machine, stderr);
diff --git a/tools/perf/tests/hists_filter.c b/tools/perf/tests/hists_filter.c
index ccb5b49..795a04d 100644
--- a/tools/perf/tests/hists_filter.c
+++ b/tools/perf/tests/hists_filter.c
@@ -120,6 +120,7 @@ int test__hists_filter(int subtest __maybe_unused)
 	err = parse_events(evlist, "task-clock", NULL);
 	if (err)
 		goto out;
+	err = TEST_FAIL;
 
 	/* default sort order (comm,dso,sym) will be used */
 	if (setup_sorting() < 0)
@@ -129,8 +130,11 @@ int test__hists_filter(int subtest __maybe_unused)
 
 	/* setup threads/dso/map/symbols also */
 	machine = setup_fake_machine(&machines);
-	if (!machine)
+	if (IS_ERR(machine)) {
+		if (PTR_ERR(machine) == -EACCES)
+			err = TEST_SKIP;
 		goto out;
+	}
 
 	if (verbose > 1)
 		machine__fprintf(machine, stderr);
diff --git a/tools/perf/tests/hists_link.c b/tools/perf/tests/hists_link.c
index 6243e2b..f5f37ef9 100644
--- a/tools/perf/tests/hists_link.c
+++ b/tools/perf/tests/hists_link.c
@@ -293,6 +293,7 @@ int test__hists_link(int subtest __maybe_unused)
 	if (err)
 		goto out;
 
+	err = TEST_FAIL;
 	/* default sort order (comm,dso,sym) will be used */
 	if (setup_sorting() < 0)
 		goto out;
@@ -301,8 +302,11 @@ int test__hists_link(int subtest __maybe_unused)
 
 	/* setup threads/dso/map/symbols also */
 	machine = setup_fake_machine(&machines);
-	if (!machine)
+	if (IS_ERR(machine)) {
+		if (PTR_ERR(machine) == -EACCES)
+			err = TEST_SKIP;
 		goto out;
+	}
 
 	if (verbose > 1)
 		machine__fprintf(machine, stderr);
diff --git a/tools/perf/tests/hists_output.c b/tools/perf/tests/hists_output.c
index 248beec..cc570cf 100644
--- a/tools/perf/tests/hists_output.c
+++ b/tools/perf/tests/hists_output.c
@@ -597,13 +597,17 @@ int test__hists_output(int subtest __maybe_unused)
 	err = parse_events(evlist, "cpu-clock", NULL);
 	if (err)
 		goto out;
+	err = TEST_FAIL;
 
 	machines__init(&machines);
 
 	/* setup threads/dso/map/symbols also */
 	machine = setup_fake_machine(&machines);
-	if (!machine)
+	if (IS_ERR(machine)) {
+		if (PTR_ERR(machine) == -EACCES)
+			err = TEST_SKIP;
 		goto out;
+	}
 
 	if (verbose > 1)
 		machine__fprintf(machine, stderr);
-- 
1.8.3.4


^ permalink raw reply related	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2015-12-10 10:12 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-12-10  5:52 [PATCH 1/2] perf tests: Fix incorrect free and false TEST_OK result Wang Nan
2015-12-10  5:52 ` [PATCH 2/2] perf tools: Prevent calling machine__delete() on non-allocated machine Wang Nan
2015-12-10  9:24   ` Wangnan (F)
2015-12-10  9:26   ` [PATCH 2/2 (v2)] " Wang Nan
2015-12-10 10:12     ` 平松雅巳 / HIRAMATU，MASAMI

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