From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59126 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932293AbeDVOSr (ORCPT ); Sun, 22 Apr 2018 10:18:47 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Hogan , Matt Redfearn , Ralf Baechle , linux-mips@linux-mips.org Subject: [PATCH 4.4 82/97] MIPS: uaccess: Add micromips clobbers to bzero invocation Date: Sun, 22 Apr 2018 15:54:00 +0200 Message-Id: <20180422135309.683857392@linuxfoundation.org> In-Reply-To: <20180422135304.577223025@linuxfoundation.org> References: <20180422135304.577223025@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matt Redfearn commit b3d7e55c3f886493235bfee08e1e5a4a27cbcce8 upstream. The micromips implementation of bzero additionally clobbers registers t7 & t8. Specify this in the clobbers list when invoking bzero. Fixes: 26c5e07d1478 ("MIPS: microMIPS: Optimise 'memset' core library function.") Reported-by: James Hogan Signed-off-by: Matt Redfearn Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: # 3.10+ Patchwork: https://patchwork.linux-mips.org/patch/19110/ Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman --- arch/mips/include/asm/uaccess.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/arch/mips/include/asm/uaccess.h +++ b/arch/mips/include/asm/uaccess.h @@ -1238,6 +1238,13 @@ __clear_user(void __user *addr, __kernel { __kernel_size_t res; +#ifdef CONFIG_CPU_MICROMIPS +/* micromips memset / bzero also clobbers t7 & t8 */ +#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$15", "$24", "$31" +#else +#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$31" +#endif /* CONFIG_CPU_MICROMIPS */ + if (eva_kernel_access()) { __asm__ __volatile__( "move\t$4, %1\n\t" @@ -1247,7 +1254,7 @@ __clear_user(void __user *addr, __kernel "move\t%0, $6" : "=r" (res) : "r" (addr), "r" (size) - : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31"); + : bzero_clobbers); } else { might_fault(); __asm__ __volatile__( @@ -1258,7 +1265,7 @@ __clear_user(void __user *addr, __kernel "move\t%0, $6" : "=r" (res) : "r" (addr), "r" (size) - : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31"); + : bzero_clobbers); } return res;