From 4b3ec5a3f4b1d5c9d64b9ab704042400d050d432 Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Tue, 2 Aug 2016 14:02:43 -0700 Subject: [PATCH] mm/kasan: don't reduce quarantine in atomic contexts Currently we call quarantine_reduce() for ___GFP_KSWAPD_RECLAIM (implied by __GFP_RECLAIM) allocation. So, basically we call it on almost every allocation. quarantine_reduce() sometimes is heavy operation, and calling it with disabled interrupts may trigger hard LOCKUP: NMI watchdog: Watchdog detected hard LOCKUP on cpu 2irq event stamp: 1411258 Call Trace: dump_stack+0x68/0x96 watchdog_overflow_callback+0x15b/0x190 __perf_event_overflow+0x1b1/0x540 perf_event_overflow+0x14/0x20 intel_pmu_handle_irq+0x36a/0xad0 perf_event_nmi_handler+0x2c/0x50 nmi_handle+0x128/0x480 default_do_nmi+0xb2/0x210 do_nmi+0x1aa/0x220 end_repeat_nmi+0x1a/0x1e <> __kernel_text_address+0x86/0xb0 print_context_stack+0x7b/0x100 dump_trace+0x12b/0x350 save_stack_trace+0x2b/0x50 set_track+0x83/0x140 free_debug_processing+0x1aa/0x420 __slab_free+0x1d6/0x2e0 ___cache_free+0xb6/0xd0 qlist_free_all+0x83/0x100 quarantine_reduce+0x177/0x1b0 kasan_kmalloc+0xf3/0x100 Reduce the quarantine_reduce iff direct reclaim is allowed. Fixes: 55834c59098d("mm: kasan: initial memory quarantine implementation") Link: http://lkml.kernel.org/r/1470062715-14077-2-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin Reported-by: Dave Jones Acked-by: Alexander Potapenko Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/kasan/kasan.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index 3019cecc0833..c99ef40ebdfa 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -565,7 +565,7 @@ void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size, unsigned long redzone_start; unsigned long redzone_end; - if (flags & __GFP_RECLAIM) + if (gfpflags_allow_blocking(flags)) quarantine_reduce(); if (unlikely(object == NULL)) @@ -596,7 +596,7 @@ void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags) unsigned long redzone_start; unsigned long redzone_end; - if (flags & __GFP_RECLAIM) + if (gfpflags_allow_blocking(flags)) quarantine_reduce(); if (unlikely(ptr == NULL)) -- 2.20.1