[PATCH bpf-next] selftests/bpf: initialize duration variable before using

[PATCH bpf-next] selftests/bpf: initialize duration variable before using

[Stanislav Fomichev]

From: John Sperbeck <jsperbeck@google.com>

The 'duration' variable is referenced in the CHECK() macro, and there are
some uses of the macro before 'duration' is set.  The clang compiler
(validly) complains about this.

Sample error:

.../selftests/bpf/prog_tests/fexit_test.c:23:6: warning: variable 'duration' is uninitialized when used here [-Wuninitialized]
        if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.../selftests/bpf/test_progs.h:134:25: note: expanded from macro 'CHECK'
        if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        _CHECK(condition, tag, duration, format)
                               ^~~~~~~~

Signed-off-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
 tools/testing/selftests/bpf/prog_tests/fentry_test.c   | 2 +-
 tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c | 2 +-
 tools/testing/selftests/bpf/prog_tests/fexit_test.c    | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/fentry_test.c b/tools/testing/selftests/bpf/prog_tests/fentry_test.c
index e1a379f5f7d2..5cc06021f27d 100644
--- a/tools/testing/selftests/bpf/prog_tests/fentry_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/fentry_test.c
@@ -9,7 +9,7 @@ void test_fentry_test(void)
 	struct test_pkt_access *pkt_skel = NULL;
 	struct fentry_test *fentry_skel = NULL;
 	int err, pkt_fd, i;
-	__u32 duration, retval;
+	__u32 duration = 0, retval;
 	__u64 *result;
 
 	pkt_skel = test_pkt_access__open_and_load();
diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
index db5c74d2ce6d..cde463af7071 100644
--- a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
+++ b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
@@ -11,7 +11,7 @@ static void test_fexit_bpf2bpf_common(const char *obj_file,
 	int err, pkt_fd, i;
 	struct bpf_link **link = NULL;
 	struct bpf_program **prog = NULL;
-	__u32 duration, retval;
+	__u32 duration = 0, retval;
 	struct bpf_map *data_map;
 	const int zero = 0;
 	u64 *result = NULL;
diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_test.c b/tools/testing/selftests/bpf/prog_tests/fexit_test.c
index f99013222c74..d2c3655dd7a3 100644
--- a/tools/testing/selftests/bpf/prog_tests/fexit_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/fexit_test.c
@@ -13,7 +13,7 @@ void test_fexit_test(void)
 	int err, pkt_fd, kfree_skb_fd, i;
 	struct bpf_link *link[6] = {};
 	struct bpf_program *prog[6];
-	__u32 duration, retval;
+	__u32 duration = 0, retval;
 	struct bpf_map *data_map;
 	const int zero = 0;
 	u64 result[6];
-- 
2.25.0.341.g760bfbb309-goog

Re: [PATCH bpf-next] selftests/bpf: initialize duration variable before using

[Martin Lau]

On Thu, Jan 23, 2020 at 03:51:44PM -0800, Stanislav Fomichev wrote:
> From: John Sperbeck <jsperbeck@google.com>
> 
> The 'duration' variable is referenced in the CHECK() macro, and there are
> some uses of the macro before 'duration' is set.  The clang compiler
Acked-by: Martin KaFai Lau <kafai@fb.com>

Re: [PATCH bpf-next] selftests/bpf: initialize duration variable before using

[Daniel Borkmann]

On 1/24/20 12:51 AM, Stanislav Fomichev wrote:
> From: John Sperbeck <jsperbeck@google.com>
> 
> The 'duration' variable is referenced in the CHECK() macro, and there are
> some uses of the macro before 'duration' is set.  The clang compiler
> (validly) complains about this.
> 
> Sample error:
> 
> .../selftests/bpf/prog_tests/fexit_test.c:23:6: warning: variable 'duration' is uninitialized when used here [-Wuninitialized]
>          if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
>              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> .../selftests/bpf/test_progs.h:134:25: note: expanded from macro 'CHECK'
>          if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
>              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>          _CHECK(condition, tag, duration, format)
>                                 ^~~~~~~~
> 
> Signed-off-by: John Sperbeck <jsperbeck@google.com>
> Signed-off-by: Stanislav Fomichev <sdf@google.com>

Applied, thanks!