Hi Leon, kernel test robot noticed the following build warnings: [auto build test WARNING on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Leon-Hwang/bpf-Prevent-tailcall-infinite-loop-caused-by-freplace/20241006-210309 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master patch link: https://lore.kernel.org/r/20241006130130.77125-2-leon.hwang%40linux.dev patch subject: [PATCH bpf-next v5 1/3] bpf: Prevent tailcall infinite loop caused by freplace config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20241008/202410080455.vy5GT8Vz-lkp@xxxxxxxxx/config) compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241008/202410080455.vy5GT8Vz-lkp@xxxxxxxxx/reproduce) 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> | Closes: https://lore.kernel.org/oe-kbuild-all/202410080455.vy5GT8Vz-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from kernel/fork.c:53: In file included from include/linux/security.h:35: >> include/linux/bpf.h:1392:5: warning: no previous prototype for function 'bpf_extension_link_prog' [-Wmissing-prototypes] 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1392:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ | static >> include/linux/bpf.h:1398:5: warning: no previous prototype for function 'bpf_extension_unlink_prog' [-Wmissing-prototypes] 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1398:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ | static 2 warnings generated. -- In file included from kernel/cpu.c:41: In file included from include/trace/events/power.h:12: In file included from include/linux/trace_events.h:10: In file included from include/linux/perf_event.h:62: In file included from include/linux/security.h:35: >> include/linux/bpf.h:1392:5: warning: no previous prototype for function 'bpf_extension_link_prog' [-Wmissing-prototypes] 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1392:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ | static >> include/linux/bpf.h:1398:5: warning: no previous prototype for function 'bpf_extension_unlink_prog' [-Wmissing-prototypes] 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1398:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ | static kernel/cpu.c:112:20: warning: unused function 'cpuhp_lock_acquire' [-Wunused-function] 112 | static inline void cpuhp_lock_acquire(bool bringup) { } | ^~~~~~~~~~~~~~~~~~ kernel/cpu.c:113:20: warning: unused function 'cpuhp_lock_release' [-Wunused-function] 113 | static inline void cpuhp_lock_release(bool bringup) { } | ^~~~~~~~~~~~~~~~~~ 4 warnings generated. -- In file included from kernel/sched/core.c:14: In file included from include/linux/syscalls_api.h:1: In file included from include/linux/syscalls.h:93: In file included from include/trace/syscall.h:7: In file included from include/linux/trace_events.h:10: In file included from include/linux/perf_event.h:62: In file included from include/linux/security.h:35: >> include/linux/bpf.h:1392:5: warning: no previous prototype for function 'bpf_extension_link_prog' [-Wmissing-prototypes] 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1392:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ | static >> include/linux/bpf.h:1398:5: warning: no previous prototype for function 'bpf_extension_unlink_prog' [-Wmissing-prototypes] 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1398:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ | static kernel/sched/core.c:3595:20: warning: unused function 'rq_has_pinned_tasks' [-Wunused-function] 3595 | static inline bool rq_has_pinned_tasks(struct rq *rq) | ^~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:5751:20: warning: unused function 'sched_tick_start' [-Wunused-function] 5751 | static inline void sched_tick_start(int cpu) { } | ^~~~~~~~~~~~~~~~ kernel/sched/core.c:5752:20: warning: unused function 'sched_tick_stop' [-Wunused-function] 5752 | static inline void sched_tick_stop(int cpu) { } | ^~~~~~~~~~~~~~~ kernel/sched/core.c:6470:20: warning: unused function 'sched_core_cpu_starting' [-Wunused-function] 6470 | static inline void sched_core_cpu_starting(unsigned int cpu) {} | ^~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:6471:20: warning: unused function 'sched_core_cpu_deactivate' [-Wunused-function] 6471 | static inline void sched_core_cpu_deactivate(unsigned int cpu) {} | ^~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:6472:20: warning: unused function 'sched_core_cpu_dying' [-Wunused-function] 6472 | static inline void sched_core_cpu_dying(unsigned int cpu) {} | ^~~~~~~~~~~~~~~~~~~~ 8 warnings generated. -- In file included from kernel/sched/fair.c:54: In file included from kernel/sched/sched.h:61: In file included from include/linux/syscalls_api.h:1: In file included from include/linux/syscalls.h:93: In file included from include/trace/syscall.h:7: In file included from include/linux/trace_events.h:10: In file included from include/linux/perf_event.h:62: In file included from include/linux/security.h:35: >> include/linux/bpf.h:1392:5: warning: no previous prototype for function 'bpf_extension_link_prog' [-Wmissing-prototypes] 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1392:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ | static >> include/linux/bpf.h:1398:5: warning: no previous prototype for function 'bpf_extension_unlink_prog' [-Wmissing-prototypes] 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1398:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ | static kernel/sched/fair.c:481:20: warning: unused function 'list_del_leaf_cfs_rq' [-Wunused-function] 481 | static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq) | ^~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c:502:19: warning: unused function 'tg_is_idle' [-Wunused-function] 502 | static inline int tg_is_idle(struct task_group *tg) | ^~~~~~~~~~ kernel/sched/fair.c:526:19: warning: unused function 'max_vruntime' [-Wunused-function] 526 | static inline u64 max_vruntime(u64 max_vruntime, u64 vruntime) | ^~~~~~~~~~~~ kernel/sched/fair.c:1389:20: warning: unused function 'is_core_idle' [-Wunused-function] 1389 | static inline bool is_core_idle(int cpu) | ^~~~~~~~~~~~ kernel/sched/fair.c:3650:20: warning: unused function 'account_numa_enqueue' [-Wunused-function] 3650 | static inline void account_numa_enqueue(struct rq *rq, struct task_struct *p) | ^~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c:3654:20: warning: unused function 'account_numa_dequeue' [-Wunused-function] 3654 | static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p) | ^~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c:3658:20: warning: unused function 'update_scan_period' [-Wunused-function] 3658 | static inline void update_scan_period(struct task_struct *p, int new_cpu) | ^~~~~~~~~~~~~~~~~~ kernel/sched/fair.c:5225:20: warning: unused function 'cfs_rq_is_decayed' [-Wunused-function] 5225 | static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq) | ^~~~~~~~~~~~~~~~~ kernel/sched/fair.c:5240:20: warning: unused function 'remove_entity_load_avg' [-Wunused-function] 5240 | static inline void remove_entity_load_avg(struct sched_entity *se) {} | ^~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c:6753:20: warning: unused function 'cfs_bandwidth_used' [-Wunused-function] 6753 | static inline bool cfs_bandwidth_used(void) | ^~~~~~~~~~~~~~~~~~ kernel/sched/fair.c:6761:20: warning: unused function 'sync_throttle' [-Wunused-function] 6761 | static inline void sync_throttle(struct task_group *tg, int cpu) {} | ^~~~~~~~~~~~~ kernel/sched/fair.c:6774:19: warning: unused function 'throttled_lb_pair' [-Wunused-function] 6774 | static inline int throttled_lb_pair(struct task_group *tg, | ^~~~~~~~~~~~~~~~~ kernel/sched/fair.c:6785:37: warning: unused function 'tg_cfs_bandwidth' [-Wunused-function] 6785 | static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) | ^~~~~~~~~~~~~~~~ kernel/sched/fair.c:6789:20: warning: unused function 'destroy_cfs_bandwidth' [-Wunused-function] 6789 | static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} | ^~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c:6790:20: warning: unused function 'update_runtime_enabled' [-Wunused-function] 6790 | static inline void update_runtime_enabled(struct rq *rq) {} | ^~~~~~~~~~~~~~~~~~~~~~ kernel/sched/fair.c:6791:20: warning: unused function 'unthrottle_offline_cfs_rqs' [-Wunused-function] 6791 | static inline void unthrottle_offline_cfs_rqs(struct rq *rq) {} | ^~~~~~~~~~~~~~~~~~~~~~~~~~ 18 warnings generated. -- In file included from kernel/time/hrtimer.c:30: In file included from include/linux/syscalls.h:93: In file included from include/trace/syscall.h:7: In file included from include/linux/trace_events.h:10: In file included from include/linux/perf_event.h:62: In file included from include/linux/security.h:35: >> include/linux/bpf.h:1392:5: warning: no previous prototype for function 'bpf_extension_link_prog' [-Wmissing-prototypes] 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1392:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ | static >> include/linux/bpf.h:1398:5: warning: no previous prototype for function 'bpf_extension_unlink_prog' [-Wmissing-prototypes] 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1398:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ | static kernel/time/hrtimer.c:121:21: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] 121 | [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME, | ^~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:119:27: note: previous initialization is here 119 | [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, | ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:122:22: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] 122 | [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC, | ^~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:119:27: note: previous initialization is here 119 | [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, | ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:123:21: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] 123 | [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME, | ^~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:119:27: note: previous initialization is here 119 | [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, | ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:124:17: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] 124 | [CLOCK_TAI] = HRTIMER_BASE_TAI, | ^~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:119:27: note: previous initialization is here 119 | [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, | ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:278:20: warning: unused function 'is_migration_base' [-Wunused-function] 278 | static inline bool is_migration_base(struct hrtimer_clock_base *base) | ^~~~~~~~~~~~~~~~~ 7 warnings generated. -- In file included from kernel/events/core.c:34: In file included from include/linux/syscalls.h:93: In file included from include/trace/syscall.h:7: In file included from include/linux/trace_events.h:10: In file included from include/linux/perf_event.h:62: In file included from include/linux/security.h:35: >> include/linux/bpf.h:1392:5: warning: no previous prototype for function 'bpf_extension_link_prog' [-Wmissing-prototypes] 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1392:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1392 | int bpf_extension_link_prog(struct bpf_tramp_link *link, | ^ | static >> include/linux/bpf.h:1398:5: warning: no previous prototype for function 'bpf_extension_unlink_prog' [-Wmissing-prototypes] 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ include/linux/bpf.h:1398:1: note: declare 'static' if the function is not intended to be used outside of this translation unit 1398 | int bpf_extension_unlink_prog(struct bpf_tramp_link *link, | ^ | static kernel/events/core.c:9789:19: warning: unused function 'perf_event_set_bpf_handler' [-Wunused-function] 9789 | static inline int perf_event_set_bpf_handler(struct perf_event *event, | ^~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/events/core.c:9796:20: warning: unused function 'perf_event_free_bpf_handler' [-Wunused-function] 9796 | static inline void perf_event_free_bpf_handler(struct perf_event *event) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ 4 warnings generated. vim +/bpf_extension_link_prog +1392 include/linux/bpf.h 1348 1349 #define DEFINE_BPF_DISPATCHER(name) \ 1350 __BPF_DISPATCHER_SC(name); \ 1351 noinline __bpfcall unsigned int bpf_dispatcher_##name##_func( \ 1352 const void *ctx, \ 1353 const struct bpf_insn *insnsi, \ 1354 bpf_func_t bpf_func) \ 1355 { \ 1356 return __BPF_DISPATCHER_CALL(name); \ 1357 } \ 1358 EXPORT_SYMBOL(bpf_dispatcher_##name##_func); \ 1359 struct bpf_dispatcher bpf_dispatcher_##name = \ 1360 BPF_DISPATCHER_INIT(bpf_dispatcher_##name); 1361 1362 #define DECLARE_BPF_DISPATCHER(name) \ 1363 unsigned int bpf_dispatcher_##name##_func( \ 1364 const void *ctx, \ 1365 const struct bpf_insn *insnsi, \ 1366 bpf_func_t bpf_func); \ 1367 extern struct bpf_dispatcher bpf_dispatcher_##name; 1368 1369 #define BPF_DISPATCHER_FUNC(name) bpf_dispatcher_##name##_func 1370 #define BPF_DISPATCHER_PTR(name) (&bpf_dispatcher_##name) 1371 void bpf_dispatcher_change_prog(struct bpf_dispatcher *d, struct bpf_prog *from, 1372 struct bpf_prog *to); 1373 /* Called only from JIT-enabled code, so there's no need for stubs. */ 1374 void bpf_image_ksym_add(void *data, unsigned int size, struct bpf_ksym *ksym); 1375 void bpf_image_ksym_del(struct bpf_ksym *ksym); 1376 void bpf_ksym_add(struct bpf_ksym *ksym); 1377 void bpf_ksym_del(struct bpf_ksym *ksym); 1378 int bpf_jit_charge_modmem(u32 size); 1379 void bpf_jit_uncharge_modmem(u32 size); 1380 bool bpf_prog_has_trampoline(const struct bpf_prog *prog); 1381 #else 1382 static inline int bpf_trampoline_link_prog(struct bpf_tramp_link *link, 1383 struct bpf_trampoline *tr) 1384 { 1385 return -ENOTSUPP; 1386 } 1387 static inline int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, 1388 struct bpf_trampoline *tr) 1389 { 1390 return -ENOTSUPP; 1391 } > 1392 int bpf_extension_link_prog(struct bpf_tramp_link *link, 1393 struct bpf_trampoline *tr, 1394 struct bpf_prog *tgt_prog) 1395 { 1396 return -ENOTSUPP; 1397 } > 1398 int bpf_extension_unlink_prog(struct bpf_tramp_link *link, 1399 struct bpf_trampoline *tr, 1400 struct bpf_prog *tgt_prog) 1401 { 1402 return -ENOTSUPP; 1403 } 1404 static inline struct bpf_trampoline *bpf_trampoline_get(u64 key, 1405 struct bpf_attach_target_info *tgt_info) 1406 { 1407 return NULL; 1408 } 1409 static inline void bpf_trampoline_put(struct bpf_trampoline *tr) {} 1410 #define DEFINE_BPF_DISPATCHER(name) 1411 #define DECLARE_BPF_DISPATCHER(name) 1412 #define BPF_DISPATCHER_FUNC(name) bpf_dispatcher_nop_func 1413 #define BPF_DISPATCHER_PTR(name) NULL 1414 static inline void bpf_dispatcher_change_prog(struct bpf_dispatcher *d, 1415 struct bpf_prog *from, 1416 struct bpf_prog *to) {} 1417 static inline bool is_bpf_image_address(unsigned long address) 1418 { 1419 return false; 1420 } 1421 static inline bool bpf_prog_has_trampoline(const struct bpf_prog *prog) 1422 { 1423 return false; 1424 } 1425 #endif 1426 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
