[PATCH bpf] selftests/bpf: fix incorrect users of create_and_get_cgroup

[PATCH bpf] selftests/bpf: fix incorrect users of create_and_get_cgroup

[Stanislav Fomichev]

create_and_get_cgroup returns 0 on error, fix the users that assume
negative value in case of an error.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
 tools/testing/selftests/bpf/get_cgroup_id_user.c | 2 +-
 tools/testing/selftests/bpf/test_sockmap.c       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/get_cgroup_id_user.c b/tools/testing/selftests/bpf/get_cgroup_id_user.c
index e8da7b39158d..dfaa9b353ac3 100644
--- a/tools/testing/selftests/bpf/get_cgroup_id_user.c
+++ b/tools/testing/selftests/bpf/get_cgroup_id_user.c
@@ -64,7 +64,7 @@ int main(int argc, char **argv)
 		return 1;
 
 	cgroup_fd = create_and_get_cgroup(TEST_CGROUP);
-	if (CHECK(cgroup_fd < 0, "create_and_get_cgroup", "err %d errno %d\n",
+	if (CHECK(!cgroup_fd, "create_and_get_cgroup", "err %d errno %d\n",
 		  cgroup_fd, errno))
 		goto cleanup_cgroup_env;
 
diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
index e85a771f607b..2384896e8112 100644
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -1676,7 +1676,7 @@ static int __test_suite(int cg_fd, char *bpf_file)
 		}
 
 		cg_fd = create_and_get_cgroup(CG_PATH);
-		if (cg_fd < 0) {
+		if (!cg_fd) {
 			fprintf(stderr,
 				"ERROR: (%i) open cg path failed: %s\n",
 				cg_fd, optarg);
-- 
2.20.1.415.g653613c723-goog

Re: [PATCH bpf] selftests/bpf: fix incorrect users of create_and_get_cgroup

[Y Song]

On Thu, Jan 3, 2019 at 12:02 PM Stanislav Fomichev <sdf@google.com> wrote:
>
> create_and_get_cgroup returns 0 on error, fix the users that assume
> negative value in case of an error.
>
> Signed-off-by: Stanislav Fomichev <sdf@google.com>

Thanks for the fix!
Acked-by: Yonghong Song <yhs@fb.com>

> ---
>  tools/testing/selftests/bpf/get_cgroup_id_user.c | 2 +-
>  tools/testing/selftests/bpf/test_sockmap.c       | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)

Re: [PATCH bpf] selftests/bpf: fix incorrect users of create_and_get_cgroup

[Alexei Starovoitov]

On Thu, Jan 03, 2019 at 10:57:17AM -0800, Stanislav Fomichev wrote:
> create_and_get_cgroup returns 0 on error, fix the users that assume
> negative value in case of an error.
> 
> Signed-off-by: Stanislav Fomichev <sdf@google.com>
> ---
>  tools/testing/selftests/bpf/get_cgroup_id_user.c | 2 +-
>  tools/testing/selftests/bpf/test_sockmap.c       | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/get_cgroup_id_user.c b/tools/testing/selftests/bpf/get_cgroup_id_user.c
> index e8da7b39158d..dfaa9b353ac3 100644
> --- a/tools/testing/selftests/bpf/get_cgroup_id_user.c
> +++ b/tools/testing/selftests/bpf/get_cgroup_id_user.c
> @@ -64,7 +64,7 @@ int main(int argc, char **argv)
>  		return 1;
>  
>  	cgroup_fd = create_and_get_cgroup(TEST_CGROUP);
> -	if (CHECK(cgroup_fd < 0, "create_and_get_cgroup", "err %d errno %d\n",
> +	if (CHECK(!cgroup_fd, "create_and_get_cgroup", "err %d errno %d\n",

fd can be zero.
Hence I prefer to fix it the other way to avoid this corner case.
Pls fix create_and_get_cgroup() to return -1 in case of error.
The diff will be much bigger, but overall it's imo cleaner.
Also pls add Fixes tag.

Thanks

Re: [PATCH bpf] selftests/bpf: fix incorrect users of create_and_get_cgroup

[Stanislav Fomichev]

On 01/04, Alexei Starovoitov wrote:
> On Thu, Jan 03, 2019 at 10:57:17AM -0800, Stanislav Fomichev wrote:
> > create_and_get_cgroup returns 0 on error, fix the users that assume
> > negative value in case of an error.
> > 
> > Signed-off-by: Stanislav Fomichev <sdf@google.com>
> > ---
> >  tools/testing/selftests/bpf/get_cgroup_id_user.c | 2 +-
> >  tools/testing/selftests/bpf/test_sockmap.c       | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tools/testing/selftests/bpf/get_cgroup_id_user.c b/tools/testing/selftests/bpf/get_cgroup_id_user.c
> > index e8da7b39158d..dfaa9b353ac3 100644
> > --- a/tools/testing/selftests/bpf/get_cgroup_id_user.c
> > +++ b/tools/testing/selftests/bpf/get_cgroup_id_user.c
> > @@ -64,7 +64,7 @@ int main(int argc, char **argv)
> >  		return 1;
> >  
> >  	cgroup_fd = create_and_get_cgroup(TEST_CGROUP);
> > -	if (CHECK(cgroup_fd < 0, "create_and_get_cgroup", "err %d errno %d\n",
> > +	if (CHECK(!cgroup_fd, "create_and_get_cgroup", "err %d errno %d\n",
> 
> fd can be zero.
Assumed it was fine for the test where we never close stdin.

> Hence I prefer to fix it the other way to avoid this corner case.
> Pls fix create_and_get_cgroup() to return -1 in case of error.
> The diff will be much bigger, but overall it's imo cleaner.
Agree, will sent a v2 shortly.

> Also pls add Fixes tag.
> 
> Thanks
>