From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752444AbeDXEQU (ORCPT ); Tue, 24 Apr 2018 00:16:20 -0400 Received: from ozlabs.org ([203.11.71.1]:41637 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751642AbeDXEQL (ORCPT ); Tue, 24 Apr 2018 00:16:11 -0400 From: Michael Ellerman To: linuxppc-dev@ozlabs.org Cc: npiggin@gmail.com, msuchanek@suse.de, linux-kernel@vger.kernel.org Subject: [PATCH 5/6] powerpc: Use barrier_nospec in copy_from_user() Date: Tue, 24 Apr 2018 14:15:58 +1000 Message-Id: <20180424041559.32410-5-mpe@ellerman.id.au> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180424041559.32410-1-mpe@ellerman.id.au> References: <20180424041559.32410-1-mpe@ellerman.id.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Based on the x86 commit doing the same. See commit 304ec1b05031 ("x86/uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospec") and b3bbfb3fb5d2 ("x86: Introduce __uaccess_begin_nospec() and uaccess_try_nospec") for more detail. In all cases we are ordering the load from the potentially user-controlled pointer vs a previous branch based on an access_ok() check or similar. Base on a patch from Michal Suchanek. Signed-off-by: Michal Suchanek Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/uaccess.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index a62ee663b2c8..6dc3d2eeea4a 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -252,6 +252,7 @@ do { \ __chk_user_ptr(ptr); \ if (!is_kernel_addr((unsigned long)__gu_addr)) \ might_fault(); \ + barrier_nospec(); \ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ (x) = (__typeof__(*(ptr)))__gu_val; \ __gu_err; \ @@ -263,8 +264,10 @@ do { \ unsigned long __gu_val = 0; \ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ might_fault(); \ - if (access_ok(VERIFY_READ, __gu_addr, (size))) \ + if (access_ok(VERIFY_READ, __gu_addr, (size))) { \ + barrier_nospec(); \ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ + } \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ __gu_err; \ }) @@ -275,6 +278,7 @@ do { \ unsigned long __gu_val; \ const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ __chk_user_ptr(ptr); \ + barrier_nospec(); \ __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ __gu_err; \ @@ -302,15 +306,19 @@ static inline unsigned long raw_copy_from_user(void *to, switch (n) { case 1: + barrier_nospec(); __get_user_size(*(u8 *)to, from, 1, ret); break; case 2: + barrier_nospec(); __get_user_size(*(u16 *)to, from, 2, ret); break; case 4: + barrier_nospec(); __get_user_size(*(u32 *)to, from, 4, ret); break; case 8: + barrier_nospec(); __get_user_size(*(u64 *)to, from, 8, ret); break; } @@ -318,6 +326,7 @@ static inline unsigned long raw_copy_from_user(void *to, return 0; } + barrier_nospec(); return __copy_tofrom_user((__force void __user *)to, from, n); } -- 2.14.1