From: Juergen Gross <jgross@suse.com>
To: Wen Yang <wen.yang99@zte.com.cn>,
boris.ostrovsky@oracle.com, sstabellini@kernel.org
Cc: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org,
zhong.weidong@zte.com.cn, Julia Lawall <julia.lawall@lip6.fr>
Subject: Re: [PATCH v3] pvcalls-front: Avoid __get_free_pages(GFP_KERNEL) under spinlock
Date: Fri, 30 Nov 2018 15:13:04 +0100 [thread overview]
Message-ID: <3ae24ccf-d7ce-cfb8-8363-e9eb647bbffe@suse.com> (raw)
In-Reply-To: <20181130110107.31468-1-wen.yang99@zte.com.cn>
On 30/11/2018 12:01, Wen Yang wrote:
> The problem is that we call this with a spin lock held.
> The call tree is:
> pvcalls_front_accept() holds bedata->socket_lock.
> -> create_active()
> -> __get_free_pages() uses GFP_KERNEL
>
> The create_active() function is only called from pvcalls_front_accept()
> with a spin_lock held, The allocation is not allowed to sleep and
> GFP_KERNEL is not sufficient.
>
> This issue was detected by using the Coccinelle software.
>
> v2: Add a function doing the allocations which is called
> outside the lock and passing the allocated data to
> create_active().
> v3: Use the matching deallocators i.e., free_page()
> and free_pages(), respectively.
>
> Suggested-by: Juergen Gross <jgross@suse.com>
> Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
> CC: Julia Lawall <julia.lawall@lip6.fr>
> CC: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> CC: Juergen Gross <jgross@suse.com>
> CC: Stefano Stabellini <sstabellini@kernel.org>
> CC: xen-devel@lists.xenproject.org
> CC: linux-kernel@vger.kernel.org
> ---
This patch is malformed. Please send it via an appropriate tool/mailer.
See e.g. Documentation/process/submitting-patches.rst or
Documentation/process/email-clients.rst in the Linux kernel source tree.
Juergen
next prev parent reply other threads:[~2018-11-30 14:13 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-30 11:01 [PATCH v3] pvcalls-front: Avoid __get_free_pages(GFP_KERNEL) under spinlock Wen Yang
2018-11-30 14:13 ` Juergen Gross [this message]
2018-11-30 17:48 ` Boris Ostrovsky
2018-11-30 22:51 ` Stefano Stabellini
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