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From:   Catalin Marinas <catalin.marinas@arm.com>
To:     Will Deacon <will@kernel.org>, Oleg Nesterov <oleg@redhat.com>,
        Mark Brown <broonie@kernel.org>
Cc:     David Spickett <David.Spickett@arm.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org
Subject: Re: [PATCH] arm64/ptrace: Ensure that SME is set up for target when writing SSVE state
Date:   Thu, 17 Aug 2023 19:54:27 +0100
Message-Id: <169229846427.1184154.14407026846596603141.b4-ty@arm.com>
In-Reply-To: <20230810-arm64-fix-ptrace-race-v1-1-a5361fad2bd6@kernel.org>
References: <20230810-arm64-fix-ptrace-race-v1-1-a5361fad2bd6@kernel.org>
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On Thu, 10 Aug 2023 12:28:19 +0100, Mark Brown wrote:
> When we use NT_ARM_SSVE to either enable streaming mode or change the
> vector length for a process we do not currently do anything to ensure that
> there is storage allocated for the SME specific register state.  If the
> task had not previously used SME or we changed the vector length then
> the task will not have had TIF_SME set or backing storage for ZA/ZT
> allocated, resulting in inconsistent register sizes when saving state
> and spurious traps which flush the newly set register state.
> 
> [...]

Applied to arm64 (for-next/fixes), thanks!

[1/1] arm64/ptrace: Ensure that SME is set up for target when writing SSVE state
      https://git.kernel.org/arm64/c/5d0a8d2fba50

-- 
Catalin