From bcbf0d566b6e59a6e873bfe415cc415111a819e2 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko <glider@google.com> Date: Thu, 11 Aug 2016 15:33:06 -0700 Subject: [PATCH] kasan: remove the unnecessary WARN_ONCE from quarantine.c It's quite unlikely that the user will so little memory that the per-CPU quarantines won't fit into the given fraction of the available memory. Even in that case he won't be able to do anything with the information given in the warning. Link: http://lkml.kernel.org/r/1470929182-101413-1-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- mm/kasan/quarantine.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index b6728a33a4ac..baabaad4a4aa 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -217,11 +217,8 @@ void quarantine_reduce(void) new_quarantine_size = (READ_ONCE(totalram_pages) << PAGE_SHIFT) / QUARANTINE_FRACTION; percpu_quarantines = QUARANTINE_PERCPU_SIZE * num_online_cpus(); - if (WARN_ONCE(new_quarantine_size < percpu_quarantines, - "Too little memory, disabling global KASAN quarantine.\n")) - new_quarantine_size = 0; - else - new_quarantine_size -= percpu_quarantines; + new_quarantine_size = (new_quarantine_size < percpu_quarantines) ? + 0 : new_quarantine_size - percpu_quarantines; WRITE_ONCE(quarantine_size, new_quarantine_size); last = global_quarantine.head;