Hi Siddharth, kernel test robot noticed the following build warnings: url: https://github.com/intel-lab-lkp/linux/commits/Siddharth-Chintamaneni/Added-selftests-to-check-deadlocks-in-queue-and-stack-map/20240430-142201 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master patch link: https://lore.kernel.org/r/20240429165658.1305969-1-sidchintamaneni%40gmail.com patch subject: [PATCH bpf-next 1/2] Patch to Fix deadlocks in queue and stack maps config: i386-randconfig-141-20240504 (https://download.01.org/0day-ci/archive/20240504/202405041108.2Up5HT0H-lkp@xxxxxxxxx/config) compiler: clang version 18.1.4 (https://github.com/llvm/llvm-project e6c3289804a67ea0bb6a86fadbe454dd93b8d855) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202405041108.2Up5HT0H-lkp@xxxxxxxxx/ smatch warnings: kernel/bpf/queue_stack_maps.c:273 queue_stack_map_push_elem() warn: inconsistent returns 'irq_flags'. vim +/irq_flags +273 kernel/bpf/queue_stack_maps.c f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 219 f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 220 /* Called from syscall or from eBPF program */ d7ba4cc900bf1e JP Kobryn 2023-03-22 221 static long queue_stack_map_push_elem(struct bpf_map *map, void *value, f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 222 u64 flags) f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 223 { f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 224 struct bpf_queue_stack *qs = bpf_queue_stack(map); f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 225 unsigned long irq_flags; f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 226 int err = 0; f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 227 void *dst; f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 228 568ce03b978beb Siddharth Chintamaneni 2024-04-29 229 preempt_disable(); 568ce03b978beb Siddharth Chintamaneni 2024-04-29 230 local_irq_save(irq_flags); 568ce03b978beb Siddharth Chintamaneni 2024-04-29 231 if (unlikely(__this_cpu_inc_return(*(qs->map_locked)) != 1)) { 568ce03b978beb Siddharth Chintamaneni 2024-04-29 232 __this_cpu_dec(*(qs->map_locked)); 568ce03b978beb Siddharth Chintamaneni 2024-04-29 233 local_irq_restore(irq_flags); 568ce03b978beb Siddharth Chintamaneni 2024-04-29 234 preempt_enable(); 568ce03b978beb Siddharth Chintamaneni 2024-04-29 235 return -EBUSY; 568ce03b978beb Siddharth Chintamaneni 2024-04-29 236 } 568ce03b978beb Siddharth Chintamaneni 2024-04-29 237 preempt_enable(); 568ce03b978beb Siddharth Chintamaneni 2024-04-29 238 f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 239 /* BPF_EXIST is used to force making room for a new element in case the f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 240 * map is full f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 241 */ f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 242 bool replace = (flags & BPF_EXIST); f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 243 f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 244 /* Check supported flags for queue and stack maps */ f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 245 if (flags & BPF_NOEXIST || flags > BPF_EXIST) f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 246 return -EINVAL; local_irq_restore(irq_flags) before returning. f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 247 a34a9f1a19afe9 Toke Høiland-Jørgensen 2023-09-11 248 if (in_nmi()) { a34a9f1a19afe9 Toke Høiland-Jørgensen 2023-09-11 249 if (!raw_spin_trylock_irqsave(&qs->lock, irq_flags)) _irqsave can't be nested. Has this code been tested? Perhaps it works because the callers always call this with IRQs disabled. a34a9f1a19afe9 Toke Høiland-Jørgensen 2023-09-11 250 return -EBUSY; a34a9f1a19afe9 Toke Høiland-Jørgensen 2023-09-11 251 } else { f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 252 raw_spin_lock_irqsave(&qs->lock, irq_flags); a34a9f1a19afe9 Toke Høiland-Jørgensen 2023-09-11 253 } f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 254 f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 255 if (queue_stack_map_is_full(qs)) { f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 256 if (!replace) { f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 257 err = -E2BIG; f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 258 goto out; f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 259 } f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 260 /* advance tail pointer to overwrite oldest element */ f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 261 if (unlikely(++qs->tail >= qs->size)) f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 262 qs->tail = 0; f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 263 } f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 264 f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 265 dst = &qs->elements[qs->head * qs->map.value_size]; f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 266 memcpy(dst, value, qs->map.value_size); f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 267 f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 268 if (unlikely(++qs->head >= qs->size)) f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 269 qs->head = 0; f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 270 f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 271 out: f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 272 raw_spin_unlock_irqrestore(&qs->lock, irq_flags); f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 @273 return err; f1a2e44a3aeccb Mauricio Vasquez B 2018-10-18 274 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
