From a4b5d580e07875f9be29f62a57c67fbbdbb40ba2 Mon Sep 17 00:00:00 2001 From: Josh Triplett Date: Mon, 7 Apr 2014 15:39:13 -0700 Subject: [PATCH] bug: Make BUG() always stop the machine When !CONFIG_BUG and !HAVE_ARCH_BUG, define the generic BUG() as an infinite loop rather than a no-op. This avoids undefined behavior if execution ever actually reaches BUG(), and avoids warnings about code after BUG() (such as on non-void functions calling BUG() and then not returning). bloat-o-meter results: add/remove: 0/0 grow/shrink: 43/10 up/down: 235/-98 (137) function old new delta umount_collect 119 138 +19 notify_change 306 324 +18 xstate_enable_boot_cpu 252 269 +17 kunmap 54 70 +16 balloon_page_dequeue 112 126 +14 mm_take_all_locks 223 233 +10 list_lru_walk_node 143 152 +9 vma_adjust 1059 1067 +8 pcpu_setup_first_chunk 1130 1138 +8 mm_drop_all_locks 143 151 +8 ns_capable 55 62 +7 anon_transport_class_unregister 8 15 +7 srcu_init_notifier_head 35 41 +6 shrink_dcache_for_umount 174 180 +6 kunmap_high 99 105 +6 end_page_writeback 43 49 +6 do_exit 1339 1345 +6 __kfifo_dma_out_prepare_r 86 92 +6 __kfifo_dma_in_prepare_r 90 96 +6 fixup_user_fault 120 125 +5 repair_env_string 73 77 +4 read_cache_pages_invalidate_page 56 60 +4 isolate_lru_pages.isra 142 146 +4 do_notify_parent_cldstop 255 259 +4 cpu_init 370 374 +4 utimes_common 270 272 +2 tasklet_hi_action 91 93 +2 tasklet_action 91 93 +2 set_pte_vaddr 46 48 +2 find_get_pages_tag 202 204 +2 early_iounmap 185 187 +2 __native_set_fixmap 36 38 +2 __get_user_pages 822 824 +2 __early_ioremap 299 301 +2 yield_task_stop 1 2 +1 tick_resume 37 38 +1 switched_to_stop 1 2 +1 switched_to_idle 1 2 +1 prio_changed_stop 1 2 +1 prio_changed_idle 1 2 +1 pm_qos_power_read 111 112 +1 arch_cpu_idle_dead 1 2 +1 __insert_vmap_area 140 141 +1 sys_renameat 614 612 -2 mm_fault_error 297 295 -2 SyS_renameat 614 612 -2 sys_linkat 416 413 -3 SyS_linkat 416 413 -3 chmod_common 129 122 -7 proc_cap_handler 240 225 -15 __schedule 849 831 -18 sys_madvise 1077 1054 -23 SyS_madvise 1077 1054 -23 Signed-off-by: Josh Triplett Reported-by: Arnd Bergmann Acked-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/bug.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index a97fa11..630dd23 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -138,7 +138,7 @@ extern void warn_slowpath_null(const char *file, const int line); #else /* !CONFIG_BUG */ #ifndef HAVE_ARCH_BUG -#define BUG() do {} while (0) +#define BUG() do {} while (1) #endif #ifndef HAVE_ARCH_BUG_ON -- 2.7.4