Re: [PATCH 2/6] mm/kasan: don't reduce quarantine in atomic contexts
From: Alexander Potapenko <glider@google.com>
Date: 2016-08-02 11:51:56
Also in:
lkml
On Mon, Aug 1, 2016 at 4:45 PM, Andrey Ryabinin [off-list ref] wrote:
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> [<ffffffff98a48532>] dump_stack+0x68/0x96
[<ffffffff98357fbb>] watchdog_overflow_callback+0x15b/0x190
[<ffffffff9842f7d1>] __perf_event_overflow+0x1b1/0x540
[<ffffffff98455b14>] perf_event_overflow+0x14/0x20
[<ffffffff9801976a>] intel_pmu_handle_irq+0x36a/0xad0
[<ffffffff9800ba4c>] perf_event_nmi_handler+0x2c/0x50
[<ffffffff98057058>] nmi_handle+0x128/0x480
[<ffffffff980576d2>] default_do_nmi+0xb2/0x210
[<ffffffff980579da>] do_nmi+0x1aa/0x220
[<ffffffff99a0bb07>] end_repeat_nmi+0x1a/0x1e
<<EOE>> [<ffffffff981871e6>] __kernel_text_address+0x86/0xb0
[<ffffffff98055c4b>] print_context_stack+0x7b/0x100
[<ffffffff98054e9b>] dump_trace+0x12b/0x350
[<ffffffff98076ceb>] save_stack_trace+0x2b/0x50
[<ffffffff98573003>] set_track+0x83/0x140
[<ffffffff98575f4a>] free_debug_processing+0x1aa/0x420
[<ffffffff98578506>] __slab_free+0x1d6/0x2e0
[<ffffffff9857a9b6>] ___cache_free+0xb6/0xd0
[<ffffffff9857db53>] qlist_free_all+0x83/0x100
[<ffffffff9857df07>] quarantine_reduce+0x177/0x1b0
[<ffffffff9857c423>] kasan_kmalloc+0xf3/0x100
Reduce the quarantine_reduce iff direct reclaim is allowed.
Fixes: 55834c59098d("mm: kasan: initial memory quarantine implementation")
Reported-by: Dave Jones <redacted>
Signed-off-by: Andrey Ryabinin <redacted>Acked-by: Alexander Potapenko <glider@google.com>
quoted hunk ↗ jump to hunk
--- 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 3019cec..c99ef40 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)) --2.7.3
-- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>