From: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
To: Mark Rutland <mark.rutland@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
Matthias Brugger <matthias.bgg@gmail.com>
Cc: <chinwen.chang@mediatek.com>, <nicholas.tang@mediatek.com>,
<james.hsu@mediatek.com>,
Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-mediatek@lists.infradead.org>
Subject: [PATCH v2] arm64: update PAC description for kernel
Date: Wed, 1 Dec 2021 11:40:10 +0800 [thread overview]
Message-ID: <20211201034014.20048-1-Kuan-Ying.Lee@mediatek.com> (raw)
Remove the paragraph which has nothing to do with the kernel and
add PAC description related to kernel.
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
---
v1 -> v2:
- Remove compiler option description
- Add PAC description for kernel
Documentation/arm64/pointer-authentication.rst | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/Documentation/arm64/pointer-authentication.rst b/Documentation/arm64/pointer-authentication.rst
index f127666ea3a8..e5dad2e40aa8 100644
--- a/Documentation/arm64/pointer-authentication.rst
+++ b/Documentation/arm64/pointer-authentication.rst
@@ -53,11 +53,10 @@ The number of bits that the PAC occupies in a pointer is 55 minus the
virtual address size configured by the kernel. For example, with a
virtual address size of 48, the PAC is 7 bits wide.
-Recent versions of GCC can compile code with APIAKey-based return
-address protection when passed the -msign-return-address option. This
-uses instructions in the HINT space (unless -march=armv8.3-a or higher
-is also passed), and such code can run on systems without the pointer
-authentication extension.
+When ARM64_PTR_AUTH_KERNEL is selected, the kernel will be compiled
+with HINT space pointer authentication instructions protecting
+function returns. Kernels built with this option will work on hardware
+with or without pointer authentication support.
In addition to exec(), keys can also be reinitialized to random values
using the PR_PAC_RESET_KEYS prctl. A bitmask of PR_PAC_APIAKEY,
--
2.18.0
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek
next reply other threads:[~2021-12-01 3:45 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-01 3:40 Kuan-Ying Lee [this message]
2021-12-02 10:06 ` [PATCH v2] arm64: update PAC description for kernel Mark Rutland
2021-12-02 10:08 ` Will Deacon
2021-12-02 10:59 ` Will Deacon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20211201034014.20048-1-Kuan-Ying.Lee@mediatek.com \
--to=kuan-ying.lee@mediatek.com \
--cc=catalin.marinas@arm.com \
--cc=chinwen.chang@mediatek.com \
--cc=corbet@lwn.net \
--cc=james.hsu@mediatek.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=mark.rutland@arm.com \
--cc=matthias.bgg@gmail.com \
--cc=nicholas.tang@mediatek.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox