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| author | Pekka Enberg <penberg@kernel.org> | 2011-02-14 17:46:21 +0200 |
|---|---|---|
| committer | Pekka Enberg <penberg@kernel.org> | 2011-02-14 17:46:21 +0200 |
| commit | 3ff84a7f36554b257cd57325b1a7c1fa4b49fbe3 (patch) | |
| tree | 29296589f7ad5478e8b52bcab29c1e294ab751b3 /mm/slab.c | |
| parent | 1bae4ce27c9c90344f23c65ea6966c50ffeae2f5 (diff) | |
| download | lwn-3ff84a7f36554b257cd57325b1a7c1fa4b49fbe3.tar.gz lwn-3ff84a7f36554b257cd57325b1a7c1fa4b49fbe3.zip | |
Revert "slab: Fix missing DEBUG_SLAB last user"
This reverts commit 5c5e3b33b7cb959a401f823707bee006caadd76e.
The commit breaks ARM thusly:
| Mount-cache hash table entries: 512
| slab error in verify_redzone_free(): cache `idr_layer_cache': memory outside object was overwritten
| Backtrace:
| [<c0227088>] (dump_backtrace+0x0/0x110) from [<c0431afc>] (dump_stack+0x18/0x1c)
| [<c0431ae4>] (dump_stack+0x0/0x1c) from [<c0293304>] (__slab_error+0x28/0x30)
| [<c02932dc>] (__slab_error+0x0/0x30) from [<c0293a74>] (cache_free_debugcheck+0x1c0/0x2b8)
| [<c02938b4>] (cache_free_debugcheck+0x0/0x2b8) from [<c0293f78>] (kmem_cache_free+0x3c/0xc0)
| [<c0293f3c>] (kmem_cache_free+0x0/0xc0) from [<c032b1c8>] (ida_get_new_above+0x19c/0x1c0)
| [<c032b02c>] (ida_get_new_above+0x0/0x1c0) from [<c02af7ec>] (alloc_vfsmnt+0x54/0x144)
| [<c02af798>] (alloc_vfsmnt+0x0/0x144) from [<c0299830>] (vfs_kern_mount+0x30/0xec)
| [<c0299800>] (vfs_kern_mount+0x0/0xec) from [<c0299908>] (kern_mount_data+0x1c/0x20)
| [<c02998ec>] (kern_mount_data+0x0/0x20) from [<c02146c4>] (sysfs_init+0x68/0xc8)
| [<c021465c>] (sysfs_init+0x0/0xc8) from [<c02137d4>] (mnt_init+0x90/0x1b0)
| [<c0213744>] (mnt_init+0x0/0x1b0) from [<c0213388>] (vfs_caches_init+0x100/0x140)
| [<c0213288>] (vfs_caches_init+0x0/0x140) from [<c0208c0c>] (start_kernel+0x2e8/0x368)
| [<c0208924>] (start_kernel+0x0/0x368) from [<c0208034>] (__enable_mmu+0x0/0x2c)
| c0113268: redzone 1:0xd84156c5c032b3ac, redzone 2:0xd84156c5635688c0.
| slab error in cache_alloc_debugcheck_after(): cache `idr_layer_cache': double free, or memory outside object was overwritten
| ...
| c011307c: redzone 1:0x9f91102ffffffff, redzone 2:0x9f911029d74e35b
| slab: Internal list corruption detected in cache 'idr_layer_cache'(24), slabp c0113000(16). Hexdump:
|
| 000: 20 4f 10 c0 20 4f 10 c0 7c 00 00 00 7c 30 11 c0
| 010: 10 00 00 00 10 00 00 00 00 00 c9 17 fe ff ff ff
| 020: fe ff ff ff fe ff ff ff fe ff ff ff fe ff ff ff
| 030: fe ff ff ff fe ff ff ff fe ff ff ff fe ff ff ff
| 040: fe ff ff ff fe ff ff ff fe ff ff ff fe ff ff ff
| 050: fe ff ff ff fe ff ff ff fe ff ff ff 11 00 00 00
| 060: 12 00 00 00 13 00 00 00 14 00 00 00 15 00 00 00
| 070: 16 00 00 00 17 00 00 00 c0 88 56 63
| kernel BUG at /home/rmk/git/linux-2.6-rmk/mm/slab.c:2928!
Reference: https://lkml.org/lkml/2011/2/7/238
Cc: <stable@kernel.org> # 2.6.35.y and later
Reported-and-analyzed-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Diffstat (limited to 'mm/slab.c')
| -rw-r--r-- | mm/slab.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/mm/slab.c b/mm/slab.c index 37961d1f584f..4c6e2e31ced0 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2288,8 +2288,8 @@ kmem_cache_create (const char *name, size_t size, size_t align, if (ralign < align) { ralign = align; } - /* disable debug if not aligning with REDZONE_ALIGN */ - if (ralign & (__alignof__(unsigned long long) - 1)) + /* disable debug if necessary */ + if (ralign > __alignof__(unsigned long long)) flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); /* * 4) Store it. @@ -2315,8 +2315,8 @@ kmem_cache_create (const char *name, size_t size, size_t align, */ if (flags & SLAB_RED_ZONE) { /* add space for red zone words */ - cachep->obj_offset += align; - size += align + sizeof(unsigned long long); + cachep->obj_offset += sizeof(unsigned long long); + size += 2 * sizeof(unsigned long long); } if (flags & SLAB_STORE_USER) { /* user store requires one word storage behind the end of |