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| author | Nick Piggin <npiggin@suse.de> | 2009-06-15 13:35:10 +0300 |
|---|---|---|
| committer | Pekka Enberg <penberg@cs.helsinki.fi> | 2009-06-15 13:55:26 +0300 |
| commit | 964cf35c88f93b4927dbc4e950dfa4d880c7f9d1 (patch) | |
| tree | a5be2d66c2a53e9483007f7581bb5170f50d6ff7 | |
| parent | 45e3e1935e2857c54783291107d33323b3ef33c8 (diff) | |
| download | linux-964cf35c88f93b4927dbc4e950dfa4d880c7f9d1.tar.gz linux-964cf35c88f93b4927dbc4e950dfa4d880c7f9d1.tar.bz2 linux-964cf35c88f93b4927dbc4e950dfa4d880c7f9d1.zip | |
SLUB: Fix early boot GFP_DMA allocations
Recent change to use slab allocations earlier exposed a bug where
SLUB can call schedule_work and try to call sysfs before it is
safe to do so.
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
| -rw-r--r-- | mm/slub.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/mm/slub.c b/mm/slub.c index 30354bfeb43d..dcbfda0b02ed 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2610,6 +2610,7 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags) struct kmem_cache *s; char *text; size_t realsize; + unsigned long slabflags; s = kmalloc_caches_dma[index]; if (s) @@ -2631,9 +2632,18 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags) (unsigned int)realsize); s = kmalloc(kmem_size, flags & ~SLUB_DMA); + /* + * Must defer sysfs creation to a workqueue because we don't know + * what context we are called from. Before sysfs comes up, we don't + * need to do anything because our sysfs initcall will start by + * adding all existing slabs to sysfs. + */ + slabflags = SLAB_CACHE_DMA; + if (slab_state >= SYSFS) + slabflags |= __SYSFS_ADD_DEFERRED; + if (!s || !text || !kmem_cache_open(s, flags, text, - realsize, ARCH_KMALLOC_MINALIGN, - SLAB_CACHE_DMA|__SYSFS_ADD_DEFERRED, NULL)) { + realsize, ARCH_KMALLOC_MINALIGN, slabflags, NULL)) { kfree(s); kfree(text); goto unlock_out; @@ -2642,7 +2652,8 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags) list_add(&s->list, &slab_caches); kmalloc_caches_dma[index] = s; - schedule_work(&sysfs_add_work); + if (slab_state >= SYSFS) + schedule_work(&sysfs_add_work); unlock_out: up_write(&slub_lock); |