Re: [WARNING] lockdep and kmemcheck_alloc_shadow
From: David Rientjes <rientjes@google.com>
Date: 2012-06-11 09:56:07
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On Sun, 20 May 2012, David Rientjes wrote:
Agreed, slab handles this correctly and it looks like slub ends up disabling irqs too early. Does this fix it? If so, we'll need to annotate it for stable as Ben noted.
Steven, did you have a chance to see if this fixes the issue for you? Can I add your Tested-by?
quoted hunk ↗ jump to hunk
mm, slub: ensure irqs are not disabled for kmemcheck allocation kmemcheck_alloc_shadow() cannot be called with irqs disabled, which is possible with __GFP_WAIT. Ensure we always have them enabled at allocation time like slab does. Reported-by: Steven Rostedt <rostedt@goodmis.org> Suggested-by: Ben Hutchings <redacted> Signed-off-by: David Rientjes <rientjes@google.com> ---diff --git a/mm/slub.c b/mm/slub.c --- a/mm/slub.c +++ b/mm/slub.c@@ -1314,13 +1314,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) stat(s, ORDER_FALLBACK); } - if (flags & __GFP_WAIT) - local_irq_disable(); - - if (!page) - return NULL; - - if (kmemcheck_enabled + if (page && kmemcheck_enabled && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) { int pages = 1 << oo_order(oo);@@ -1336,6 +1330,11 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) kmemcheck_mark_unallocated_pages(page, pages); } + if (flags & __GFP_WAIT) + local_irq_disable(); + if (!page) + return NULL; + page->objects = oo_objects(oo); mod_zone_page_state(page_zone(page), (s->flags & SLAB_RECLAIM_ACCOUNT) ?