linux-hardening - Re: [PATCH v2] ARM: unwind: improve unwinders for noreturn case

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Date: Fri, 22 Mar 2024 00:08:54 +0000
From: "Russell King (Oracle)" <linux@...linux.org.uk>
To: Ard Biesheuvel <ardb@...nel.org>
Cc: David Laight <David.Laight@...lab.com>,
	Jiangfeng Xiao <xiaojiangfeng@...wei.com>,
	"arnd@...db.de" <arnd@...db.de>,
	"keescook@...omium.org" <keescook@...omium.org>,
	"haibo.li@...iatek.com" <haibo.li@...iatek.com>,
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	"dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
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	"willy@...radead.org" <willy@...radead.org>
Subject: Re: [PATCH v2] ARM: unwind: improve unwinders for noreturn case

On Thu, Mar 21, 2024 at 11:43:41PM +0100, Ard Biesheuvel wrote:
> Given that this particular issue would just disappear if the compiler
> would just insert a BRK after the BL, I'd prefer to explore first
> whether we can get this fixed on the compiler side.

Arm32 doesn't have a BRK instruction. What would be appropriate after
the no-return BL would be OS specific.

Maybe a branch to "abort" would be a good idea though.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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