| Message ID | 1457994978-1057495-1-git-send-email-arnd@arndb.de |
|---|---|
| State | Accepted |
| Commit | cfe02a8a973e7e5f66926b8ae38dfce404b19e29 |
| Headers | show |
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 155c88470543..3348a36c3694 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -258,6 +258,9 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css, */ static bool cgroup_ssid_enabled(int ssid) { + if (CGROUP_SUBSYS_COUNT == 0) + return 0; + return static_key_enabled(cgroup_subsys_enabled_key[ssid]); }
When all subsystems are disabled, gcc notices that cgroup_subsys_enabled_key is a zero-length array and that any access to it must be out of bounds: In file included from ../include/linux/cgroup.h:19:0, from ../kernel/cgroup.c:31: ../kernel/cgroup.c: In function 'cgroup_add_cftypes': ../kernel/cgroup.c:261:53: error: array subscript is above array bounds [-Werror=array-bounds] return static_key_enabled(cgroup_subsys_enabled_key[ssid]); ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~ ../include/linux/jump_label.h:271:40: note: in definition of macro 'static_key_enabled' static_key_count((struct static_key *)x) > 0; \ ^ We should never call the function in this particular case, so this is not a bug. In order to silence the warning, this adds an explicit check for the CGROUP_SUBSYS_COUNT==0 case. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- kernel/cgroup.c | 3 +++ 1 file changed, 3 insertions(+) -- 2.7.0