From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC854C19F2B for ; Wed, 27 Jul 2022 16:45:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240050AbiG0QpA (ORCPT ); Wed, 27 Jul 2022 12:45:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240121AbiG0QoI (ORCPT ); Wed, 27 Jul 2022 12:44:08 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9239A51A24; Wed, 27 Jul 2022 09:30:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 70C56B821C5; Wed, 27 Jul 2022 16:30:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCB8FC433D6; Wed, 27 Jul 2022 16:30:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939435; bh=AJqytMV64rUASa1fC+FJDWlVKl+qrP5oT4VUCR05xaY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RPyvm3ySCXJqroclLKKHCyK4KsAcDeryglq7EthZiQhTG03kheqU6PTdf3xBKtGc2 D1WkrRUiKfAh8gT3w6IZZgr1iZMP+MuUgQysH2DNGe3/U9WAeVQkW38WyxuP/a7SJb 0HIDhrYM3LZb/jEpCeypaeBvu8dWaOgaMi40VFOQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Al Viro , Sasha Levin Subject: [PATCH 5.4 68/87] x86: get rid of small constant size cases in raw_copy_{to,from}_user() Date: Wed, 27 Jul 2022 18:11:01 +0200 Message-Id: <20220727161011.803180178@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161008.993711844@linuxfoundation.org> References: <20220727161008.993711844@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro [ Upstream commit 4b842e4e25b12951fa10dedb4bc16bc47e3b850c ] Very few call sites where that would be triggered remain, and none of those is anywhere near hot enough to bother. Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- arch/x86/include/asm/uaccess.h | 12 ---- arch/x86/include/asm/uaccess_32.h | 27 -------- arch/x86/include/asm/uaccess_64.h | 108 +----------------------------- 3 files changed, 2 insertions(+), 145 deletions(-) diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 61d93f062a36..a19effb98fdc 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -378,18 +378,6 @@ do { \ : "=r" (err), ltype(x) \ : "m" (__m(addr)), "i" (errret), "0" (err)) -#define __get_user_asm_nozero(x, addr, err, itype, rtype, ltype, errret) \ - asm volatile("\n" \ - "1: mov"itype" %2,%"rtype"1\n" \ - "2:\n" \ - ".section .fixup,\"ax\"\n" \ - "3: mov %3,%0\n" \ - " jmp 2b\n" \ - ".previous\n" \ - _ASM_EXTABLE_UA(1b, 3b) \ - : "=r" (err), ltype(x) \ - : "m" (__m(addr)), "i" (errret), "0" (err)) - /* * This doesn't do __uaccess_begin/end - the exception handling * around it must do that. diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h index ba2dc1930630..388a40660c7b 100644 --- a/arch/x86/include/asm/uaccess_32.h +++ b/arch/x86/include/asm/uaccess_32.h @@ -23,33 +23,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n) static __always_inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) { - if (__builtin_constant_p(n)) { - unsigned long ret; - - switch (n) { - case 1: - ret = 0; - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u8 *)to, from, ret, - "b", "b", "=q", 1); - __uaccess_end(); - return ret; - case 2: - ret = 0; - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u16 *)to, from, ret, - "w", "w", "=r", 2); - __uaccess_end(); - return ret; - case 4: - ret = 0; - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u32 *)to, from, ret, - "l", "k", "=r", 4); - __uaccess_end(); - return ret; - } - } return __copy_user_ll(to, (__force const void *)from, n); } diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 5cd1caa8bc65..bc10e3dc64fe 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -65,117 +65,13 @@ copy_to_user_mcsafe(void *to, const void *from, unsigned len) static __always_inline __must_check unsigned long raw_copy_from_user(void *dst, const void __user *src, unsigned long size) { - int ret = 0; - - if (!__builtin_constant_p(size)) - return copy_user_generic(dst, (__force void *)src, size); - switch (size) { - case 1: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u8 *)dst, (u8 __user *)src, - ret, "b", "b", "=q", 1); - __uaccess_end(); - return ret; - case 2: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u16 *)dst, (u16 __user *)src, - ret, "w", "w", "=r", 2); - __uaccess_end(); - return ret; - case 4: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u32 *)dst, (u32 __user *)src, - ret, "l", "k", "=r", 4); - __uaccess_end(); - return ret; - case 8: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src, - ret, "q", "", "=r", 8); - __uaccess_end(); - return ret; - case 10: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src, - ret, "q", "", "=r", 10); - if (likely(!ret)) - __get_user_asm_nozero(*(u16 *)(8 + (char *)dst), - (u16 __user *)(8 + (char __user *)src), - ret, "w", "w", "=r", 2); - __uaccess_end(); - return ret; - case 16: - __uaccess_begin_nospec(); - __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src, - ret, "q", "", "=r", 16); - if (likely(!ret)) - __get_user_asm_nozero(*(u64 *)(8 + (char *)dst), - (u64 __user *)(8 + (char __user *)src), - ret, "q", "", "=r", 8); - __uaccess_end(); - return ret; - default: - return copy_user_generic(dst, (__force void *)src, size); - } + return copy_user_generic(dst, (__force void *)src, size); } static __always_inline __must_check unsigned long raw_copy_to_user(void __user *dst, const void *src, unsigned long size) { - int ret = 0; - - if (!__builtin_constant_p(size)) - return copy_user_generic((__force void *)dst, src, size); - switch (size) { - case 1: - __uaccess_begin(); - __put_user_asm(*(u8 *)src, (u8 __user *)dst, - ret, "b", "b", "iq", 1); - __uaccess_end(); - return ret; - case 2: - __uaccess_begin(); - __put_user_asm(*(u16 *)src, (u16 __user *)dst, - ret, "w", "w", "ir", 2); - __uaccess_end(); - return ret; - case 4: - __uaccess_begin(); - __put_user_asm(*(u32 *)src, (u32 __user *)dst, - ret, "l", "k", "ir", 4); - __uaccess_end(); - return ret; - case 8: - __uaccess_begin(); - __put_user_asm(*(u64 *)src, (u64 __user *)dst, - ret, "q", "", "er", 8); - __uaccess_end(); - return ret; - case 10: - __uaccess_begin(); - __put_user_asm(*(u64 *)src, (u64 __user *)dst, - ret, "q", "", "er", 10); - if (likely(!ret)) { - asm("":::"memory"); - __put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst, - ret, "w", "w", "ir", 2); - } - __uaccess_end(); - return ret; - case 16: - __uaccess_begin(); - __put_user_asm(*(u64 *)src, (u64 __user *)dst, - ret, "q", "", "er", 16); - if (likely(!ret)) { - asm("":::"memory"); - __put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst, - ret, "q", "", "er", 8); - } - __uaccess_end(); - return ret; - default: - return copy_user_generic((__force void *)dst, src, size); - } + return copy_user_generic((__force void *)dst, src, size); } static __always_inline __must_check -- 2.35.1