| Message ID | 20191002120404.26962-3-ivan.khoronzhuk@linaro.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | c588146378962786ddeec817f7736a53298a7b01 |
| Headers | show |
| Series | selftest/bpf: remove warns for enable_all_controllers | expand |
> On Oct 2, 2019, at 5:04 AM, Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> wrote: > > The "path" buf is supposed to contain path + printf msg up to 24 bytes. > It will be cut anyway, but compiler generates truncation warns like: > > " > samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c: In > function ‘setup_cgroup_environment’: > samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:52:34: > warning: ‘/cgroup.controllers’ directive output may be truncated > writing 19 bytes into a region of size between 1 and 4097 > [-Wformat-truncation=] > snprintf(path, sizeof(path), "%s/cgroup.controllers", cgroup_path); > ^~~~~~~~~~~~~~~~~~~ > samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:52:2: > note: ‘snprintf’ output between 20 and 4116 bytes into a destination > of size 4097 > snprintf(path, sizeof(path), "%s/cgroup.controllers", cgroup_path); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:72:34: > warning: ‘/cgroup.subtree_control’ directive output may be truncated > writing 23 bytes into a region of size between 1 and 4097 > [-Wformat-truncation=] > snprintf(path, sizeof(path), "%s/cgroup.subtree_control", > ^~~~~~~~~~~~~~~~~~~~~~~ > cgroup_path); > samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:72:2: > note: ‘snprintf’ output between 24 and 4120 bytes into a destination > of size 4097 > snprintf(path, sizeof(path), "%s/cgroup.subtree_control", > cgroup_path); > " > > In order to avoid warns, lets decrease buf size for cgroup workdir on > 24 bytes with assumption to include also "/cgroup.subtree_control" to > the address. The cut will never happen anyway. > > Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> Acked-by: Song Liu <songliubraving@fb.com>
diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index 4d74f3c4619b..0fb910df5387 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -98,7 +98,7 @@ static int enable_all_controllers(char *cgroup_path) */ int setup_cgroup_environment(void) { - char cgroup_workdir[PATH_MAX + 1]; + char cgroup_workdir[PATH_MAX - 24]; format_cgroup_path(cgroup_workdir, "");
The "path" buf is supposed to contain path + printf msg up to 24 bytes. It will be cut anyway, but compiler generates truncation warns like: " samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c: In function ‘setup_cgroup_environment’: samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:52:34: warning: ‘/cgroup.controllers’ directive output may be truncated writing 19 bytes into a region of size between 1 and 4097 [-Wformat-truncation=] snprintf(path, sizeof(path), "%s/cgroup.controllers", cgroup_path); ^~~~~~~~~~~~~~~~~~~ samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:52:2: note: ‘snprintf’ output between 20 and 4116 bytes into a destination of size 4097 snprintf(path, sizeof(path), "%s/cgroup.controllers", cgroup_path); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:72:34: warning: ‘/cgroup.subtree_control’ directive output may be truncated writing 23 bytes into a region of size between 1 and 4097 [-Wformat-truncation=] snprintf(path, sizeof(path), "%s/cgroup.subtree_control", ^~~~~~~~~~~~~~~~~~~~~~~ cgroup_path); samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:72:2: note: ‘snprintf’ output between 24 and 4120 bytes into a destination of size 4097 snprintf(path, sizeof(path), "%s/cgroup.subtree_control", cgroup_path); " In order to avoid warns, lets decrease buf size for cgroup workdir on 24 bytes with assumption to include also "/cgroup.subtree_control" to the address. The cut will never happen anyway. Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> --- tools/testing/selftests/bpf/cgroup_helpers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)