Commit 4b3ec5a3 authored by Andrey Ryabinin's avatar Andrey Ryabinin Committed by Linus Torvalds
Browse files

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:
  <NMI>   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
  <<EOE>>   __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: 55834c59("mm: kasan: initial memory quarantine implementation")
Link: http://lkml.kernel.org/r/1470062715-14077-2-git-send-email-aryabinin@virtuozzo.com

Signed-off-by: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: default avatarDave Jones <davej@codemonkey.org.uk>
Acked-by: default avatarAlexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4a3d308d
......@@ -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))
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment