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From: David Hildenbrand <david@redhat.com>
To: Mateusz Guzik <mjguzik@gmail.com>, linux-kernel@vger.kernel.org
Cc: torvalds@linux-foundation.org, brauner@kernel.org,
	ebiederm@xmission.com, akpm@linux-foundation.org,
	linux-mm@kvack.org, koct9i@gmail.com, oleg@redhat.com,
	dave@stgolabs.net
Subject: Re: [PATCH] kernel/fork: stop playing lockless games for exe_file replacement
Date: Mon, 14 Aug 2023 09:55:03 +0200	[thread overview]
Message-ID: <00dd353b-e5aa-69fb-6b52-cb59028ea90a@redhat.com> (raw)
In-Reply-To: <20230813123333.1705833-1-mjguzik@gmail.com>

On 13.08.23 14:33, Mateusz Guzik wrote:
> xchg originated in 6e399cd144d8 ("prctl: avoid using mmap_sem for
> exe_file serialization"). While the commit message does not explain
> *why* the change, clearly the intent was to use mmap_sem less in this
> codepath. I found the original submission [1] which ultimately claims it
> cleans things up.

More details are apparently in v1 of that patch:

https://lore.kernel.org/lkml/1424979417.10344.14.camel@stgolabs.net/

Regarding your patch: adding more mmap_write_lock() where avoidable, I'm 
not so sure.

Your patch doesn't look (to me) like it is removing a lot of complexity.

-- 
Cheers,

David / dhildenb



  reply	other threads:[~2023-08-14  7:55 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-13 12:33 Mateusz Guzik
2023-08-14  7:55 ` David Hildenbrand [this message]
2023-08-14  8:21   ` Mateusz Guzik
2023-08-14  8:29     ` David Hildenbrand
2023-08-14  8:54       ` Mateusz Guzik
2023-08-14 15:38         ` David Hildenbrand
2023-08-14 15:05 ` Oleg Nesterov
2023-08-14 15:20   ` Oleg Nesterov
2023-08-14 15:37     ` David Hildenbrand
2023-08-14 15:58       ` Oleg Nesterov
2023-08-14 16:09         ` David Hildenbrand

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