The patch titled
shmem: initialize struct shmem_sb_info to zero
has been added to the -mm tree. Its filename is
shmem-initialize-struct-shmem_sb_info-to-zero.patch
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See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: shmem: initialize struct shmem_sb_info to zero
From: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
Fixes the following kmemcheck false positive (the compiler is using
a 32-bit mov to load the 16-bit sbinfo->mode in shmem_fill_super):
[ 0.337000] Total of 1 processors activated (3088.38 BogoMIPS).
[ 0.352000] CPU0 attaching NULL sched-domain.
[ 0.360000] WARNING: kmemcheck: Caught 32-bit read from uninitialized
memory (9f8020fc)
[ 0.361000]
a44240820000000041f6998100000000000000000000000000000000ff030000
[ 0.368000] i i i i i i i i i i i i i i i i u u u u i i i i i i i i i i u
u
[ 0.375000] ^
[ 0.376000]
[ 0.377000] Pid: 9, comm: khelper Not tainted (2.6.31-tip #206) P4DC6
[ 0.378000] EIP: 0060:[<810a3a95>] EFLAGS: 00010246 CPU: 0
[ 0.379000] EIP is at shmem_fill_super+0xb5/0x120
[ 0.380000] EAX: 00000000 EBX: 9f845400 ECX: 824042a4 EDX: 8199f641
[ 0.381000] ESI: 9f8020c0 EDI: 9f845400 EBP: 9f81af68 ESP: 81cd6eec
[ 0.382000] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[ 0.383000] CR0: 8005003b CR2: 9f806200 CR3: 01ccd000 CR4: 000006d0
[ 0.384000] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[ 0.385000] DR6: ffff4ff0 DR7: 00000400
[ 0.386000] [<810c25fc>] get_sb_nodev+0x3c/0x80
[ 0.388000] [<810a3514>] shmem_get_sb+0x14/0x20
[ 0.390000] [<810c207f>] vfs_kern_mount+0x4f/0x120
[ 0.392000] [<81b2849e>] init_tmpfs+0x7e/0xb0
[ 0.394000] [<81b11597>] do_basic_setup+0x17/0x30
[ 0.396000] [<81b11907>] kernel_init+0x57/0xa0
[ 0.398000] [<810039b7>] kernel_thread_helper+0x7/0x10
[ 0.400000] [<ffffffff>] 0xffffffff
[ 0.402000] khelper used greatest stack depth: 2820 bytes left
[ 0.407000] calling init_mmap_min_addr+0x0/0x10 @ 1
[ 0.408000] initcall init_mmap_min_addr+0x0/0x10 returned 0 after 0 usecs
Reported-by: Ingo Molnar <mingo@xxxxxxx>
Analysed-by: Vegard Nossum <vegard.nossum@xxxxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
Acked-by: Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff -puN mm/shmem.c~shmem-initialize-struct-shmem_sb_info-to-zero mm/shmem.c
--- a/mm/shmem.c~shmem-initialize-struct-shmem_sb_info-to-zero
+++ a/mm/shmem.c
@@ -2311,17 +2311,14 @@ int shmem_fill_super(struct super_block
int err = -ENOMEM;
/* Round up to L1_CACHE_BYTES to resist false sharing */
- sbinfo = kmalloc(max((int)sizeof(struct shmem_sb_info),
+ sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info),
L1_CACHE_BYTES), GFP_KERNEL);
if (!sbinfo)
return -ENOMEM;
- sbinfo->max_blocks = 0;
- sbinfo->max_inodes = 0;
sbinfo->mode = S_IRWXUGO | S_ISVTX;
sbinfo->uid = current_fsuid();
sbinfo->gid = current_fsgid();
- sbinfo->mpol = NULL;
sb->s_fs_info = sbinfo;
#ifdef CONFIG_TMPFS
_
Patches currently in -mm which might be from penberg@xxxxxxxxxxxxxx are
origin.patch
proc-kcore-work-around-a-bug.patch
repeatable-slab-corruption-with-ltp-msgctl08.patch
linux-next.patch
fs-fix-overflow-in-sys_mount-for-in-kernel-calls.patch
mm-kmem_cache_create-make-it-easier-to-catch-null-cache-names.patch
revert-proc-kcore-work-around-a-bug.patch
mm-replace-various-uses-of-num_physpages-by-totalram_pages.patch
page-allocator-split-per-cpu-list-into-one-list-per-migrate-type.patch
page-allocator-maintain-rolling-count-of-pages-to-free-from-the-pcp.patch
shmem-initialize-struct-shmem_sb_info-to-zero.patch
move-magic-numbers-into-magich.patch
move-magic-numbers-into-magich-update.patch
slab-leaks3-default-y.patch
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