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From: ebiederm@xmission.com (Eric W. Biederman)
To: Miaohe Lin <linmiaohe@huawei.com>
Cc: <christian.brauner@ubuntu.com>, <akpm@linux-foundation.org>,
	<peterz@infradead.org>, <mingo@kernel.org>,
	<christian@kellner.me>, <surenb@google.com>, <areber@redhat.com>,
	<shakeelb@google.com>, <cyphar@cyphar.com>, <tglx@linutronix.de>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] fork: Use helper function mapping_allow_writable() in dup_mmap()
Date: Sun, 13 Sep 2020 11:18:55 -0500	[thread overview]
Message-ID: <87r1r5wsy8.fsf@x220.int.ebiederm.org> (raw)
In-Reply-To: <20200913092415.24408-1-linmiaohe@huawei.com> (Miaohe Lin's message of "Sun, 13 Sep 2020 05:24:15 -0400")

Miaohe Lin <linmiaohe@huawei.com> writes:

> Use helper function mapping_allow_writable() to atomic_inc
> i_mmap_writable.

Why?


> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> ---
>  kernel/fork.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 4b328aecabb2..a0586716e327 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -558,7 +558,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
>  				atomic_dec(&inode->i_writecount);
>  			i_mmap_lock_write(mapping);
>  			if (tmp->vm_flags & VM_SHARED)
> -				atomic_inc(&mapping->i_mmap_writable);
> +				mapping_allow_writable(mapping);
>  			flush_dcache_mmap_lock(mapping);
>  			/* insert tmp into the share list, just after mpnt */
>  			vma_interval_tree_insert_after(tmp, mpnt,

  reply	other threads:[~2020-09-13 16:19 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-13  9:24 Miaohe Lin
2020-09-13 16:18 ` Eric W. Biederman [this message]
2020-09-15 15:47 ` Christian Brauner
2020-09-14  1:38 linmiaohe
2020-09-14 12:03 ` Eric W. Biederman
2020-09-15  9:25 linmiaohe
2020-09-16  1:39 linmiaohe

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