From: "Richard Earnshaw (lists)" <Richard.Earnshaw@arm.com>
To: Wilco Dijkstra <Wilco.Dijkstra@arm.com>,
GCC Patches <gcc-patches@gcc.gnu.org>
Cc: Richard Sandiford <Richard.Sandiford@arm.com>,
Ramana Radhakrishnan <ramana.gcc@googlemail.com>
Subject: Re: [PATCH] AArch64: Remove BTI from outline atomics
Date: Tue, 26 Sep 2023 15:15:27 +0100 [thread overview]
Message-ID: <c82af97b-b0f6-58d4-107d-b91731baf646@arm.com> (raw)
In-Reply-To: <PAWPR08MB8982AEB5FE30726A1FDB466283C3A@PAWPR08MB8982.eurprd08.prod.outlook.com>
On 26/09/2023 14:46, Wilco Dijkstra wrote:
>
> The outline atomic functions have hidden visibility and can only be called
> directly. Therefore we can remove the BTI at function entry. This improves
> security by reducing the number of indirect entry points in a binary.
> The BTI markings on the objects are still emitted.
Please can you add a comment to that effect in the source code. OK with that change.
R.
>
> Passes regress, OK for commit?
>
> libgcc/ChangeLog:
> * config/aarch64/lse.S (BTI_C): Remove define.
>
> ---
>
> diff --git a/libgcc/config/aarch64/lse.S b/libgcc/config/aarch64/lse.S
> index ba05047ff02b6fc5752235bffa924fc4a2f48c04..dbfb83fb09083641bf06c50b631a5f27bdf61b80 100644
> --- a/libgcc/config/aarch64/lse.S
> +++ b/libgcc/config/aarch64/lse.S
> @@ -163,8 +163,6 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
> #define tmp3 14
> #define tmp4 13
>
> -#define BTI_C hint 34
> -
> /* Start and end a function. */
> .macro STARTFN name
> .text
> @@ -174,7 +172,6 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
> .type \name, %function
> .cfi_startproc
> \name:
> - BTI_C
> .endm
>
> .macro ENDFN name
prev parent reply other threads:[~2023-09-26 14:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <PAWPR08MB8982EDEA30B35BFB7178002283C3A@PAWPR08MB8982.eurprd08.prod.outlook.com>
2023-09-26 13:46 ` Wilco Dijkstra
2023-09-26 14:15 ` Richard Earnshaw (lists) [this message]
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