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| author | Matthew Wilcox <mawilcox@microsoft.com> | 2018-06-07 17:05:13 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-07 17:34:34 -0700 |
| commit | 128227e7fe4087b60f1bd31f762e61237eb23790 (patch) | |
| tree | ccf03475b150751d98f4f901339a3871dafe8240 /mm/slob.c | |
| parent | e56ee574bc46b9734066008b3dc105bd7d4cbc0c (diff) | |
| download | linux-rpi3-128227e7fe4087b60f1bd31f762e61237eb23790.tar.gz linux-rpi3-128227e7fe4087b60f1bd31f762e61237eb23790.tar.bz2 linux-rpi3-128227e7fe4087b60f1bd31f762e61237eb23790.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/slob.c')
| -rw-r--r-- | mm/slob.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/slob.c b/mm/slob.c index 623e8a5c46ce..307c2c9feb44 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -555,8 +555,10 @@ static void *slob_alloc_node(struct kmem_cache *c, gfp_t flags, int node) flags, node); } - if (b && c->ctor) + if (b && c->ctor) { + WARN_ON_ONCE(flags & __GFP_ZERO); c->ctor(b); + } kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags); return b; |