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From: Konstantin Khlebnikov <khlebnikov@openvz.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Eric Paris <eparis@redhat.com>
Subject: Re: [PATCH 6/7] mm: kill vma flag VM_EXECUTABLE
Date: Mon, 02 Apr 2012 20:19:59 +0400	[thread overview]
Message-ID: <4F79D1AF.7080100@openvz.org> (raw)
In-Reply-To: <20120402144821.GA3334@redhat.com>

Oleg Nesterov wrote:
> On 04/02, Konstantin Khlebnikov wrote:
>>
>> In this patch I leave mm->exe_file lockless.
>> After exec/fork we can change it only for current task and only if mm->mm_users == 1.
>>
>> something like this:
>>
>> task_lock(current);
>
> OK, this protects against the race with get_task_mm()
>
>> if (atomic_read(&current->mm->mm_users) == 1)
>
> this means PR_SET_MM_EXE_FILE can fail simply because someone did
> get_task_mm(). Or the caller is multithreaded.

This is sad, seems like we should keep mm->exe_file protection by mm->mmap_sem.
So, I'll rework this patch...

>
>> 	set_mm_exe_file(current->mm, new_file);
>
> No, fput() can sleep.

Yep

>
> Oleg.
>
> --
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  parent reply	other threads:[~2012-04-02 16:20 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-31  9:25 [PATCH 0/7] mm: vma->vm_flags diet Konstantin Khlebnikov
2012-03-31  9:29 ` [PATCH 1/7] mm, x86, PAT: rework linear pfn-mmap tracking Konstantin Khlebnikov
2012-03-31 17:09   ` [PATCH 1/7 v2] " Konstantin Khlebnikov
2012-04-03  0:46     ` [x86 PAT PATCH 0/2] x86 PAT vm_flag code refactoring Suresh Siddha
2012-04-03  0:46       ` [x86 PAT PATCH 1/2] x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines Suresh Siddha
2012-04-03  5:37         ` Konstantin Khlebnikov
2012-04-03 23:31           ` Suresh Siddha
2012-04-04  4:43             ` Konstantin Khlebnikov
2012-04-05 11:56             ` Konstantin Khlebnikov
2012-04-06  0:01               ` [v3 VM_PAT PATCH 0/3] x86 VM_PAT series Suresh Siddha
2012-04-06  0:01                 ` [v3 VM_PAT PATCH 1/3] x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines Suresh Siddha
2012-04-06  0:01                 ` [v3 VM_PAT PATCH 2/3] x86, pat: separate the pfn attribute tracking for remap_pfn_range and vm_insert_pfn Suresh Siddha
2012-04-06  0:01                 ` [v3 VM_PAT PATCH 3/3] mm, x86, PAT: rework linear pfn-mmap tracking Suresh Siddha
2012-04-03  0:46       ` [x86 PAT PATCH 2/2] " Suresh Siddha
2012-04-03  5:48         ` Konstantin Khlebnikov
2012-04-03  5:55           ` Konstantin Khlebnikov
2012-04-03  6:03       ` [x86 PAT PATCH 0/2] x86 PAT vm_flag code refactoring Konstantin Khlebnikov
2012-04-03 23:14         ` Suresh Siddha
2012-04-04  4:40           ` Konstantin Khlebnikov
2012-03-31  9:29 ` [PATCH 2/7] mm: introduce vma flag VM_ARCH_1 Konstantin Khlebnikov
2012-03-31 22:25   ` Benjamin Herrenschmidt
2012-03-31  9:29 ` [PATCH 3/7] mm: kill vma flag VM_CAN_NONLINEAR Konstantin Khlebnikov
2012-03-31 17:01   ` Linus Torvalds
2012-03-31  9:29 ` [PATCH 4/7] mm: kill vma flag VM_INSERTPAGE Konstantin Khlebnikov
2012-03-31  9:29 ` [PATCH 5/7] mm, drm/udl: fixup vma flags on mmap Konstantin Khlebnikov
2012-03-31  9:29 ` [PATCH 6/7] mm: kill vma flag VM_EXECUTABLE Konstantin Khlebnikov
2012-03-31 20:13   ` Oleg Nesterov
2012-03-31 20:39     ` Cyrill Gorcunov
2012-04-02  9:46       ` Konstantin Khlebnikov
2012-04-02  9:54         ` Cyrill Gorcunov
2012-04-02 10:13           ` Konstantin Khlebnikov
2012-04-02 14:48         ` Oleg Nesterov
2012-04-02 16:02           ` Cyrill Gorcunov
2012-04-02 16:19           ` Konstantin Khlebnikov [this message]
2012-04-02 16:27             ` Cyrill Gorcunov
2012-04-02 17:14               ` Konstantin Khlebnikov
2012-04-02 18:05                 ` Cyrill Gorcunov
2012-04-02 23:04     ` Matt Helsley
2012-04-03  5:10       ` Konstantin Khlebnikov
2012-04-03 18:16         ` Matt Helsley
2012-04-03 19:32           ` Cyrill Gorcunov
2012-04-05 20:29             ` Matt Helsley
2012-04-05 20:53               ` Cyrill Gorcunov
2012-04-05 21:04               ` Konstantin Khlebnikov
2012-04-05 21:44                 ` Matt Helsley
2012-04-05 21:55                   ` Linus Torvalds
2012-04-06  4:36                     ` Konstantin Khlebnikov
2012-04-02 23:18   ` Matt Helsley
2012-04-03  5:06     ` Konstantin Khlebnikov
2012-04-06 22:48       ` Andrew Morton
2012-03-31  9:29 ` [PATCH 7/7] mm: move madvise vma flags to the end Konstantin Khlebnikov
2012-03-31 14:06 ` [PATCH 0/7] mm: vma->vm_flags diet Andi Kleen

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