From: Manfred Spraul <manfred@colorfullife.com>
To: Jiri Slaby <jirislaby@kernel.org>,
cgel.zte@gmail.com, Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org, arnd@arndb.de, chi.minghao@zte.com.cn,
dbueso@suse.de, linux-kernel@vger.kernel.org,
rdunlap@infradead.org, shakeelb@google.com,
unixbhaskar@gmail.com, vvs@virtuozzo.com, zealci@zte.com.cn
Subject: Re: [PATCH v2] ipc/sem: do not sleep with a spin lock held
Date: Mon, 3 Jan 2022 18:17:58 +0100 [thread overview]
Message-ID: <2cfe35d4-3220-dd60-88d3-90b86eb5084a@colorfullife.com> (raw)
In-Reply-To: <97e94a27-6f9f-1a21-cf3e-11d97f74cbd8@kernel.org>
Hi Jiri,
On 1/3/22 10:27, Jiri Slaby wrote:
> On 23. 12. 21, 4:12, cgel.zte@gmail.com wrote:
>> From: Minghao Chi <chi.minghao@zte.com.cn>
>>
>> We can't call kvfree() with a spin lock held, so defer it.
>
> Sorry, defer what?
>
First drop the spinlock, then call kvfree().
> There are attempts to fix kvfree instead, not sure which of these
> approaches (fix kvfree or its callers) won in the end?
>
Exactly. We have three options - but noone volunteered yet to decide:
- change ipc/sem.c [minimal change]
- change kvfree() to use vfree_atomic() [would also fix other changes
that did s/kfree/kvfree/]
- Modify the vma handling so that it becomes safe to call vfree() while
holding a spinlock. [perfect approach, but I'm concerned about side effects]
--
Manfred
next prev parent reply other threads:[~2022-01-03 17:18 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-22 8:10 [PATCH] ipc/sem: do not sleep with a spin lock held cgel.zte
2021-12-22 11:45 ` Manfred Spraul
2021-12-22 15:31 ` Vasily Averin
2021-12-22 15:50 ` Vasily Averin
2021-12-22 17:06 ` Manfred Spraul
2021-12-22 17:38 ` Vasily Averin
2021-12-22 19:08 ` Vasily Averin
2021-12-23 2:37 ` [PATCH v2] " cgel.zte
2021-12-23 2:56 ` cgel.zte
2021-12-23 3:12 ` cgel.zte
2022-01-03 9:27 ` Jiri Slaby
2022-01-03 17:17 ` Manfred Spraul [this message]
2022-01-04 18:20 ` Shakeel Butt
2022-01-04 18:20 ` Shakeel Butt
2022-01-04 20:18 ` Manfred Spraul
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