> On Oct 2, 2019, at 5:04 AM, Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx> 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@xxxxxxxxxx> Acked-by: Song Liu <songliubraving@xxxxxx>
