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From: Christoph Hellwig <hch@infradead.org>
To: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc: linux-kernel@vger.kernel.org,
	Nicolas Geoffray <ngeoffray@google.com>,
	kernel-team@android.com,
	Andrew Morton <akpm@linux-foundation.org>,
	Hugh Dickins <hughd@google.com>,
	linux-kselftest@vger.kernel.org, linux-mm@kvack.org,
	Shuah Khan <shuah@kernel.org>
Subject: Re: [PATCH 1/2] memfd: Fix COW issue on MAP_PRIVATE and F_SEAL_FUTURE_WRITE mappings
Date: Thu, 7 Nov 2019 22:33:08 -0800	[thread overview]
Message-ID: <20191108063308.GB18778@infradead.org> (raw)
In-Reply-To: <20191107195355.80608-1-joel@joelfernandes.org>

> -		 * Since the F_SEAL_FUTURE_WRITE seals allow for a MAP_SHARED
> -		 * read-only mapping, take care to not allow mprotect to revert
> -		 * protections.
> +		 * Since an F_SEAL_FUTURE_WRITE sealed memfd can be mapped as
> +		 * MAP_SHARED and read-only, take care to not allow mprotect to
> +		 * revert protections on such mappings. Do this only for shared
> +		 * mappings. For private mappings, don't need to mask VM_MAYWRITE

This adds an > 80 char line.

  parent reply	other threads:[~2019-11-08  6:33 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-07 19:53 Joel Fernandes (Google)
2019-11-07 19:53 ` [PATCH 2/2] memfd: Add test for COW " Joel Fernandes (Google)
2019-11-08  1:00 ` [PATCH 1/2] memfd: Fix COW issue " Andrew Morton
2019-11-08  2:06   ` Joel Fernandes
2019-11-08  3:25     ` Andrew Morton
2019-11-08  6:37     ` Greg KH
2019-11-08 15:34       ` Joel Fernandes
2019-11-08  6:33 ` Christoph Hellwig [this message]
2019-11-08 15:35   ` Joel Fernandes

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