From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: linx.z.chen@intel.com
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
cpw@sgi.com, kirill.shutemov@linux.intel.com, linux-mm@kvack.org,
yanmin_zhang@linux.intel.com, shuox.liu@intel.com
Subject: RE: [PATCH] mm/pagewalk.c: Fix walk_page_range access wrong PTEs
Date: Fri, 18 Oct 2013 14:20:42 +0300 (EEST) [thread overview]
Message-ID: <20131018112042.AD31EE0090@blue.fi.intel.com> (raw)
In-Reply-To: <1382084117-25599-1-git-send-email-linx.z.chen@intel.com>
linx.z.chen@ wrote:
> From: Chen LinX <linx.z.chen@intel.com>
>
> When walk_page_range walk a memory map's page tables, it'll skip VM_PFNMAP area,
> then variable 'next' will to assign to vma->vm_end, it maybe larger than 'end'.
> In next loop, 'addr' will be larger than 'next'. Then in /proc/XXXX/pagemap file
> reading procedure, the 'addr' will growing forever in pagemap_pte_range,
> pte_to_pagemap_entry will access wrong pte.
>
> [ 93.387934] BUG: Bad page map in process procrank pte:8437526f pmd:785de067
> [ 93.387936] addr:9108d000 vm_flags:00200073 anon_vma:f0d99020 mapping: (null) index:9108d
> [ 93.387938] CPU: 1 PID: 4974 Comm: procrank Tainted: G B W O 3.10.1+ #1
> [ 93.387942] f0d983c8 f0d983c8 e8271e48 c281ef4b e8271e84 c20ee794 c2a3f150 9108d000
> [ 93.387946] 00200073 f0d99020 00000000 0009108d e8342d90 8437526f 0009108d 00000000
> [ 93.387950] 00000000 00084375 fffa4234 e8271e98 c20ef836 00000000 e8271f28 f0d983c8
> [ 93.387951] Call Trace:
> [ 93.387953] [<c281ef4b>] dump_stack+0x16/0x18
> [ 93.387956] [<c20ee794>] print_bad_pte+0x114/0x1b0
> [ 93.387959] [<c20ef836>] vm_normal_page+0x56/0x60
> [ 93.387961] [<c21594ba>] pagemap_pte_range+0x17a/0x1d0
> [ 93.387963] [<c2159340>] ? m_next+0x70/0x70
> [ 93.387966] [<c20fc60e>] walk_page_range+0x19e/0x2c0
> [ 93.387969] [<c20432c4>] ? ptrace_may_access+0x24/0x40
> [ 93.387971] [<c2159a4e>] pagemap_read+0x16e/0x200
> [ 93.387973] [<c2159340>] ? m_next+0x70/0x70
> [ 93.387976] [<c2158be0>] ? quota_send_warning+0x1f0/0x1f0
> [ 93.387979] [<c2158c30>] ? pagemap_pte_hole+0x50/0x50
> [ 93.387981] [<c21598e0>] ? clear_refs_pte_range+0xc0/0xc0
> [ 93.387984] [<c210c534>] vfs_read+0x84/0x150
> [ 93.387986] [<c21598e0>] ? clear_refs_pte_range+0xc0/0xc0
> [ 93.387988] [<c210c77a>] SyS_read+0x4a/0x80
> [ 93.387991] [<c28267c8>] syscall_call+0x7/0xb
> [ 93.387996] [<c2820000>] ? e1000_regdump+0x6f/0x37c
> [ 102.866190] [<c259fcd3>] ? cpuidle_idle_call+0x93/0x1b0
> [ 102.872124] [<c28297fa>] ? atomic_notifier_call_chain+0x1a/0x20
> [ 102.878834] [<c2008478>] ? arch_cpu_idle+0x8/0x20
> [ 102.884183] [<c207950d>] ? cpu_startup_entry+0x4d/0x1b0
> [ 102.890116] [<c280ecbd>] ? rest_init+0x5d/0x60
> [ 102.895174] [<c2b989f8>] ? start_kernel+0x31b/0x321
> [ 102.900717] [<c2b98512>] ? repair_env_string+0x51/0x51
> [ 102.906551] [<c2b98356>] ? i386_start_kernel+0x12c/0x12f
>
> Signed-off-by: Liu ShuoX <shuox.liu@intel.com>
> Signed-off-by: Chen LinX <linx.z.chen@intel.com>
Looks reasonable for me.
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
--
Kirill A. Shutemov
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next prev parent reply other threads:[~2013-10-18 11:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-18 8:15 linx.z.chen
2013-10-18 11:20 ` Kirill A. Shutemov [this message]
2013-10-18 14:31 ` Naoya Horiguchi
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