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From: linmiaohe <linmiaohe@huawei.com>
To: Kees Cook <keescook@chromium.org>
Cc: "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-security-module@vger.kernel.org" 
	<linux-security-module@vger.kernel.org>
Subject: Re: [PATCH] mm/migrate: Avoid possible unnecessary ptrace_may_access() call in kernel_move_pages()
Date: Thu, 20 Aug 2020 02:18:21 +0000	[thread overview]
Message-ID: <9ce6209f41b64734b2cac748783aa441@huawei.com> (raw)

Kees Cook <keescook@chromium.org> wrote:
>On Mon, Aug 17, 2020 at 07:59:33AM -0400, Miaohe Lin wrote:
>> There is no need to check if this process has the right to modify the 
>> specified process when they are same.
>> 
>> Signed-off-by: Hongxiang Lou <louhongxiang@huawei.com>
>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
>
>NAK, please don't do this -- the ptrace and security hooks already do these kinds of self-introspection checks, and I'd like to keep a central place to perform these kinds of checks.
>

Many thanks for your reply.
We also avoid get_task_struct/ put_task_struct pair of atomic ops, rcu_lock, task_lock and so on this way.

>Is there a specific problem you've encountered that this fixes?
>

I'am sorry but there's no specific problem. I do this mainly to skip the unnecessary ptrace and security hooks.

>--
>Kees Cook

Thanks again.


             reply	other threads:[~2020-08-20  2:18 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-20  2:18 linmiaohe [this message]
2020-08-20 21:21 ` [PATCH] mm/migrate: Avoid possible unnecessary ptrace_may_access() call in kernel_move_pages() Kees Cook
  -- strict thread matches above, loose matches on Subject: below --
2020-08-18  2:25 linmiaohe
2020-08-17 11:59 Miaohe Lin
2020-08-17 12:32 ` Matthew Wilcox
2020-08-19 18:04 ` Kees Cook

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