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 Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** 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 -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html