From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DBE55847D for ; Wed, 9 Aug 2023 10:49:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B207C433C8; Wed, 9 Aug 2023 10:49:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691578150; bh=B1JbXKcGI7cr6P6giT4nARUL76oNhIvPlJYyBMp1dn4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qR7Zsywjfu7NEV4Bllx1sXGMuxACuVcshuRlMzFnZlIlQuzRSNeDlyab2Qi+qCp1l BYIozcTAxmOICJ43lY4khN5+gMmYCNMucRaFAGfotUa5wePgv8kyOpSGITNhbZk36B j293tfb2H8xvaN8lf84hoh2M+Uvg9HSflcX4W6io= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Spickett , Mark Brown , Catalin Marinas Subject: [PATCH 6.4 123/165] arm64/fpsimd: Clear SME state in the target task when setting the VL Date: Wed, 9 Aug 2023 12:40:54 +0200 Message-ID: <20230809103646.826769550@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103642.720851262@linuxfoundation.org> References: <20230809103642.720851262@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Mark Brown commit c9bb40b7f786662e33d71afe236442b0b61f0446 upstream. When setting SME vector lengths we clear TIF_SME to reenable SME traps, doing a reallocation of the backing storage on next use. We do this using clear_thread_flag() which operates on the current thread, meaning that when setting the vector length via ptrace we may both not force traps for the target task and force a spurious flush of any SME state that the tracing task may have. Clear the flag in the target task. Fixes: e12310a0d30f ("arm64/sme: Implement ptrace support for streaming mode SVE registers") Reported-by: David Spickett Signed-off-by: Mark Brown Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-tif-sme-v1-1-88312fd6fbfd@kernel.org Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/fpsimd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -910,7 +910,7 @@ int vec_set_vector_length(struct task_st */ task->thread.svcr &= ~(SVCR_SM_MASK | SVCR_ZA_MASK); - clear_thread_flag(TIF_SME); + clear_tsk_thread_flag(task, TIF_SME); free_sme = true; } }