From: Alejandro Colomar <alx@kernel.org>
To: Florent Revest <revest@chromium.org>
Cc: linux-man@vger.kernel.org, joey.gouly@arm.com,
akpm@linux-foundation.org, keescook@chromium.org,
catalin.marinas@arm.com
Subject: Re: [PATCH] prctl.2: Document PR_SET_MDWE and PR_GET_MDWE
Date: Sun, 8 Oct 2023 23:39:03 +0200 [thread overview]
Message-ID: <ZSMhd-TnoKm2u1vK@debian> (raw)
In-Reply-To: <20231003155010.3651349-1-revest@chromium.org>
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Hi Florent,
On Tue, Oct 03, 2023 at 05:50:10PM +0200, Florent Revest wrote:
> Memory-Deny-Write-Execute is a W^X process control originally introduced
> by Joey Gouly. I'm the author of the PR_MDWE_NO_INHERIT flag.
>
> Signed-off-by: Florent Revest <revest@chromium.org>
> ---
> man2/prctl.2 | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/man2/prctl.2 b/man2/prctl.2
> index d845b0905..67e6e2ff0 100644
> --- a/man2/prctl.2
> +++ b/man2/prctl.2
> @@ -2041,6 +2041,33 @@ the copy will be truncated.
> Return (as the function result)
> the full length of the auxiliary vector.
> \fIarg4\fP and \fIarg5\fP must be 0.
> +.TP
> +.BR PR_SET_MDWE " (since Linux 6.3)"
> +.\" commit b507808ebce23561d4ff8c2aa1fb949fe402bc61
> +Set the process' Memory-Deny-Write-Execute protection mask.
> +.IR arg2
> +must be a bitmask of:
> +.RS
> +.\"
> +.TP
> +.B PR_MDWE_REFUSE_EXEC_GAIN
> +New memory mapping protections can't be writable and executable. Non-executable
Please use semantic newlines.
$ MANWIDTH=72 man man-pages | sed -n '/Use semantic newlines/,/^$/p'
Use semantic newlines
In the source of a manual page, new sentences should be started
on new lines, long sentences should be split into lines at
clause breaks (commas, semicolons, colons, and so on), and long
clauses should be split at phrase boundaries. This convention,
sometimes known as "semantic newlines", makes it easier to see
the effect of patches, which often operate at the level of in‐
dividual sentences, clauses, or phrases.
Thanks,
Alex
> +mappings can't become executable.
> +.TP
> +.B PR_MDWE_NO_INHERIT " (since Linux 6.6)"
> +.\" commit 2a87e5520554034e8c423479740f95bea4a086a0
> +Do not propagate MDWE protection to child processes on
> +.BR fork (2).
> +.TP
> +Once protection bits are set, they can not be changed.
> +.RE
> +.TP
> +.BR PR_GET_MDWE " (since Linux 6.3)"
> +.\" commit b507808ebce23561d4ff8c2aa1fb949fe402bc61
> +Return (as the function result) the Memory-Deny-Write-Execute protection mask.
> +(See
> +.B PR_SET_MDWE
> +for information on the protection mask bits.)
> .SH RETURN VALUE
> On success,
> .BR PR_CAP_AMBIENT + PR_CAP_AMBIENT_IS_SET ,
> --
> 2.42.0.582.g8ccd20d70d-goog
>
--
<https://www.alejandro-colomar.es/>
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next prev parent reply other threads:[~2023-10-08 21:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-03 15:50 [PATCH] prctl.2: Document PR_SET_MDWE and PR_GET_MDWE Florent Revest
2023-10-08 21:39 ` Alejandro Colomar [this message]
2023-10-11 11:15 ` Florent Revest
2023-10-09 16:34 ` Catalin Marinas
2023-10-11 11:12 ` Florent Revest
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