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Date:   Fri, 28 Oct 2022 13:19:00 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Joey Gouly <joey.gouly@arm.com>
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Lennart Poettering <lennart@poettering.net>,
        Zbigniew =?utf-8?Q?J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Szabolcs Nagy <szabolcs.nagy@arm.com>,
        Mark Brown <broonie@kernel.org>,
        Jeremy Linton <jeremy.linton@arm.com>,
        Topi Miettinen <toiwoton@gmail.com>, linux-mm@kvack.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-abi-devel@lists.sourceforge.net, nd@arm.com, shuah@kernel.org
Subject: Re: [PATCH v1 2/2] kselftest: vm: add tests for
 memory-deny-write-execute
Message-ID: <202210281316.C83D6B5649@keescook>
References: <20221026150457.36957-1-joey.gouly@arm.com>
 <20221026150457.36957-3-joey.gouly@arm.com>
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On Wed, Oct 26, 2022 at 04:04:57PM +0100, Joey Gouly wrote:
> [...]
> +# define PR_MDWE_FLAG_MMAP              1
> [...]
> +	// Enable MDWE and then run the tests again.
> +	ret = prctl(PR_SET_MDWE, PR_MDWE_FLAG_MMAP, 0, 0, 0);
> +	if (ret < 0) {
> +		ksft_print_msg("PR_SET_MDWE failed or unsupported!\n");
> +		goto exit;
> +	}
> +
> +	ret = prctl(PR_GET_MDWE, PR_MDWE_FLAG_MMAP, 0, 0, 0);
> +	if (ret == 0)
> +		ksft_exit_fail_msg("PR_GET_MDWE failed!");

This flag (PR_MDWE_FLAG_MMAP), while defined in uapi, wasn't actually
being used in the proposed prctl() api. :)

-- 
Kees Cook