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author | Matthew Wilcox <mawilcox@microsoft.com> | 2018-06-07 17:05:13 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-07 17:34:34 -0700 |
commit | 128227e7fe4087b60f1bd31f762e61237eb23790 (patch) | |
tree | ccf03475b150751d98f4f901339a3871dafe8240 /mm/slub.c | |
parent | e56ee574bc46b9734066008b3dc105bd7d4cbc0c (diff) | |
download | lwn-128227e7fe4087b60f1bd31f762e61237eb23790.tar.gz lwn-128227e7fe4087b60f1bd31f762e61237eb23790.zip |
slab: __GFP_ZERO is incompatible with a constructor
__GFP_ZERO requests that the object be initialised to all-zeroes, while
the purpose of a constructor is to initialise an object to a particular
pattern. We cannot do both. Add a warning to catch any users who
mistakenly pass a __GFP_ZERO flag when allocating a slab with a
constructor.
Link: http://lkml.kernel.org/r/20180412191322.GA21205@bombadil.infradead.org
Fixes: d07dbea46405 ("Slab allocators: support __GFP_ZERO in all allocators")
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slub.c')
-rw-r--r-- | mm/slub.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/slub.c b/mm/slub.c index 44aa7847324a..dc960401ce90 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2444,6 +2444,8 @@ static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags, struct kmem_cache_cpu *c = *pc; struct page *page; + WARN_ON_ONCE(s->ctor && (flags & __GFP_ZERO)); + freelist = get_partial(s, flags, node, c); if (freelist) |