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 E02BF63D5; Sat, 30 Dec 2023 12:01:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="uB7/Ymtu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 266F8C433C8; Sat, 30 Dec 2023 12:01:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1703937671; bh=ehpL6nb6uVaMhPt1UjCtdkYm9BFkfxOTUv1Jf9092vo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uB7/Ymtutu+zw0Xk62S8sDmt2dW7vlMmLtXDvS5X25n2AqlVIsnx5CJIynuztn3hf HAPSSP3gRPlLEvpYS55LCYQbXJq083fZtwAhp67Uoldq5qi8ga93Mt9uRhoElZEkJP f6pVsIcqaJfuUbLwLXOZnw+3kFpeNaC6Xk3A/EQM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Heiko Carstens , Hendrik Brueckner , Alexander Gordeev , Sasha Levin Subject: [PATCH 6.6 018/156] s390/vx: fix save/restore of fpu kernel context Date: Sat, 30 Dec 2023 11:57:52 +0000 Message-ID: <20231230115812.978052225@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231230115812.333117904@linuxfoundation.org> References: <20231230115812.333117904@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Heiko Carstens [ Upstream commit e6b2dab41888332bf83f592131e7ea07756770a4 ] The KERNEL_FPR mask only contains a flag for the first eight vector registers. However floating point registers overlay parts of the first sixteen vector registers. This could lead to vector register corruption if a kernel fpu context uses any of the vector registers 8 to 15 and is interrupted or calls a KERNEL_FPR context. If that context uses also vector registers 8 to 15, their contents will be corrupted on return. Luckily this is currently not a real bug, since the kernel has only one KERNEL_FPR user with s390_adjust_jiffies() and it is only using floating point registers 0 to 2. Fix this by using the correct bits for KERNEL_FPR. Fixes: 7f79695cc1b6 ("s390/fpu: improve kernel_fpu_[begin|end]") Signed-off-by: Heiko Carstens Reviewed-by: Hendrik Brueckner Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin --- arch/s390/include/asm/fpu/api.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/include/asm/fpu/api.h b/arch/s390/include/asm/fpu/api.h index b714ed0ef6885..9acf48e53a87f 100644 --- a/arch/s390/include/asm/fpu/api.h +++ b/arch/s390/include/asm/fpu/api.h @@ -79,7 +79,7 @@ static inline int test_fp_ctl(u32 fpc) #define KERNEL_VXR_HIGH (KERNEL_VXR_V16V23|KERNEL_VXR_V24V31) #define KERNEL_VXR (KERNEL_VXR_LOW|KERNEL_VXR_HIGH) -#define KERNEL_FPR (KERNEL_FPC|KERNEL_VXR_V0V7) +#define KERNEL_FPR (KERNEL_FPC|KERNEL_VXR_LOW) struct kernel_fpu; -- 2.43.0