[3.10-rc1 SLUB?] mm: kmemcheck warning.
From: Tetsuo Handa
Date: Tue May 14 2013 - 08:05:28 EST
I got below warning.
WARNING: kmemcheck: Caught 8-bit read from uninitialized memory (ffff880077361b28)
7500000000000000a8f5fc760088ffff00000000000000000000000000000000
u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u
^
RIP: 0010:[<ffffffff812a94d9>] [<ffffffff812a94d9>] __rb_insert_augmented+0x49/0x1c0
RSP: 0018:ffff880079cadbc8 EFLAGS: 00010286
RAX: ffff8800773619c8 RBX: ffff880076980bb8 RCX: ffff880077361b28
RDX: ffffffff81116630 RSI: ffff880076980bb8 RDI: ffff880076fcf5a8
RBP: ffff880079cadbf8 R08: ffff8800773619d0 R09: 0000000000000238
R10: 0000000000000236 R11: 2222222222222222 R12: ffff880076fcf5a8
R13: ffff880077361918 R14: 0000000000000000 R15: ffff880077115a40
FS: 0000000000000000(0000) GS:ffff88007b200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88007a6346c8 CR3: 0000000077365000 CR4: 00000000000407f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
[<ffffffff81116c4f>] vma_interval_tree_insert+0x7f/0x90
[<ffffffff81120013>] __vma_link_file+0x43/0x70
[<ffffffff811218f9>] vma_adjust+0xf9/0x690
[<ffffffff81121f91>] __split_vma+0x101/0x1e0
[<ffffffff811227b7>] do_munmap+0x1f7/0x3a0
[<ffffffff8112322a>] mmap_region+0x28a/0x630
[<ffffffff8112389d>] do_mmap_pgoff+0x2cd/0x420
[<ffffffff8110ec28>] vm_mmap_pgoff+0xa8/0xd0
[<ffffffff811204b6>] SyS_mmap_pgoff+0x136/0x230
[<ffffffff81006ed9>] SyS_mmap+0x29/0x30
[<ffffffff817a7512>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
WARNING: kmemcheck: Caught 64-bit read from uninitialized memory (ffff880077361b40)
3902000000000000481b36770088ffff481b36770088ffff0000000000000000
u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u
^
RIP: 0010:[<ffffffff8111705f>] [<ffffffff8111705f>] vma_interval_tree_remove+0x17f/0x270
RSP: 0018:ffff880079cadc08 EFLAGS: 00010286
RAX: 0000000000000239 RBX: 0000000000000239 RCX: ffff880077361b28
RDX: ffff880076fcf550 RSI: ffff880076980bb8 RDI: 0000000000000000
RBP: ffff880079cadc18 R08: 0000000000000000 R09: 0000000000000238
R10: 0000000000000236 R11: ffff8800773619c8 R12: ffff88007a197a20
R13: 0000003452a3a000 R14: 0000000000000000 R15: ffff880077115a40
FS: 0000000000000000(0000) GS:ffff88007b200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88007a6346c8 CR3: 0000000077365000 CR4: 00000000000407f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
[<ffffffff811219f7>] vma_adjust+0x1f7/0x690
[<ffffffff81121f91>] __split_vma+0x101/0x1e0
[<ffffffff811227b7>] do_munmap+0x1f7/0x3a0
[<ffffffff8112322a>] mmap_region+0x28a/0x630
[<ffffffff8112389d>] do_mmap_pgoff+0x2cd/0x420
[<ffffffff8110ec28>] vm_mmap_pgoff+0xa8/0xd0
[<ffffffff811204b6>] SyS_mmap_pgoff+0x136/0x230
[<ffffffff81006ed9>] SyS_mmap+0x29/0x30
[<ffffffff817a7512>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
Kernel config is at http://I-love.SAKURA.ne.jp/tmp/config-3.10-rc1-kmemcheck
Full dmesg is at http://I-love.SAKURA.ne.jp/tmp/dmesg-3.10-rc1-kmemcheck.txt
By applying below patch, "uninitialized memory" warnings are gone. But it seems
that memory corruption bug is remaining. Thus, 'some field of "struct anon_vma"
and "struct anon_vma_chain" are not initialized' might be caused by SLUB's
problem. (Full dmesg after applying below patch is at
http://I-love.SAKURA.ne.jp/tmp/dmesg-3.10-rc1-kmemcheck2.txt )
Regards.
--------------------
>From 8d4d6df4d112c1b38bf880a3a63d0336c9b7d0e3 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Date: Wed, 14 May 2013 16:32:05 +0900
Subject: [PATCH] mm: Fix kmemcheck warning.
Some field of "struct anon_vma" and "struct anon_vma_chain" are not
initialized, resulting kmemcheck warning.
(NOTE: This will likely be a wrong fix. Don't apply blindly.)
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
---
mm/rmap.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index 6280da8..e2fc40d 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -69,7 +69,7 @@ static inline struct anon_vma *anon_vma_alloc(void)
{
struct anon_vma *anon_vma;
- anon_vma = kmem_cache_alloc(anon_vma_cachep, GFP_KERNEL);
+ anon_vma = kmem_cache_zalloc(anon_vma_cachep, GFP_KERNEL);
if (anon_vma) {
atomic_set(&anon_vma->refcount, 1);
/*
@@ -113,7 +113,7 @@ static inline void anon_vma_free(struct anon_vma *anon_vma)
static inline struct anon_vma_chain *anon_vma_chain_alloc(gfp_t gfp)
{
- return kmem_cache_alloc(anon_vma_chain_cachep, gfp);
+ return kmem_cache_zalloc(anon_vma_chain_cachep, gfp);
}
static void anon_vma_chain_free(struct anon_vma_chain *anon_vma_chain)
--
1.7.1
--
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