From patchwork Thu Jul 22 12:48:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 12394039 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 311BAC63799 for ; Thu, 22 Jul 2021 12:49:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24DFD613AF for ; Thu, 22 Jul 2021 12:49:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232050AbhGVMJG (ORCPT ); Thu, 22 Jul 2021 08:09:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:33360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232072AbhGVMI6 (ORCPT ); Thu, 22 Jul 2021 08:08:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A342061248; Thu, 22 Jul 2021 12:49:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626958173; bh=sbFUoNBeqxQyz+PoOvMtvTqFiIliAD9FROV/pedTT4o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HsOLil3/+9VmaYbtHSQRgpLmxFSE3bBBio3nSPGemC+GYEG1bOZAk4AFpp2qCsJ8L iSy9J6Krq522LD+k2cVVGxJMx67i1VQqFVs8GL9DJhOT4vPueJ0kCQhD6/tXlIs8oz vHfb6tY7nUOeLU2ngNR7QkQRw1M4yHxWgNAOOZKjwcHyjjk5CmSZcaw24EBbc796MD Czg56vYWKr4zEzXrUlQbcPErVFIZqbYOo/i19WN0uQbSs58zjWzGYMFCnv8efowCuT J0qsO+PiMOqS0q/SKUVcHnBPNWWDCmZiVlKn6k9EhG00thh7YCD+APPA6hXNsz+XsK DJwvW+din+56Q== From: Arnd Bergmann To: linux-arch@vger.kernel.org Cc: Arnd Bergmann , "James E.J. Bottomley" , Al Viro , Anton Ivanov , Brian Cain , Chris Zankel , Christian Borntraeger , Christoph Hellwig , Guo Ren , Heiko Carstens , Helge Deller , Jeff Dike , Linus Walleij , Max Filippov , Michal Simek , Richard Weinberger , Thomas Bogendoerfer , Vasily Gorbik , Vineet Gupta , Yoshinori Sato , linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-s390@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, uclinux-h8-devel@lists.sourceforge.jp, Geert Uytterhoeven Subject: [PATCH v3 7/9] asm-generic: uaccess: remove inline strncpy_from_user/strnlen_user Date: Thu, 22 Jul 2021 14:48:12 +0200 Message-Id: <20210722124814.778059-8-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210722124814.778059-1-arnd@kernel.org> References: <20210722124814.778059-1-arnd@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Arnd Bergmann The inline version is used on three NOMMU architectures and is particularly inefficient when it scans the string one byte at a time twice. It also lacks a check for user_addr_max(), but this is probably ok on NOMMU targets. Consolidate the asm-generic implementation with the library version that is used everywhere else. This version is generalized enough to work efficiently on both MMU and NOMMU targets, and using the same code everywhere reduces the potential for subtle bugs. Reviewed-by: Geert Uytterhoeven Acked-by: Geert Uytterhoeven Signed-off-by: Arnd Bergmann Reviewed-by: Christoph Hellwig --- arch/h8300/Kconfig | 2 ++ arch/m68k/Kconfig | 4 +-- arch/riscv/Kconfig | 4 +-- include/asm-generic/uaccess.h | 46 ++++++----------------------------- 4 files changed, 14 insertions(+), 42 deletions(-) diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig index 3e3e0f16f7e0..53dfd2d47e0e 100644 --- a/arch/h8300/Kconfig +++ b/arch/h8300/Kconfig @@ -11,6 +11,8 @@ config H8300 select GENERIC_IRQ_SHOW select FRAME_POINTER select GENERIC_CPU_DEVICES + select GENERIC_STRNCPY_FROM_USER + select GENERIC_STRNLEN_USER select MODULES_USE_ELF_RELA select COMMON_CLK select ARCH_WANT_FRAME_POINTERS diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 96989ad46f66..37a65bed6dfa 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -16,8 +16,8 @@ config M68K select GENERIC_CPU_DEVICES select GENERIC_IOMAP select GENERIC_IRQ_SHOW - select GENERIC_STRNCPY_FROM_USER if MMU - select GENERIC_STRNLEN_USER if MMU + select GENERIC_STRNCPY_FROM_USER + select GENERIC_STRNLEN_USER select HAVE_AOUT if MMU select HAVE_ASM_MODVERSIONS select HAVE_DEBUG_BUGVERBOSE diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 8fcceb8eda07..47bbbcab91b2 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -56,8 +56,8 @@ config RISCV select GENERIC_PTDUMP if MMU select GENERIC_SCHED_CLOCK select GENERIC_SMP_IDLE_THREAD - select GENERIC_STRNCPY_FROM_USER if MMU - select GENERIC_STRNLEN_USER if MMU + select GENERIC_STRNCPY_FROM_USER + select GENERIC_STRNLEN_USER select GENERIC_TIME_VSYSCALL if MMU && 64BIT select HANDLE_DOMAIN_IRQ select HAVE_ARCH_AUDITSYSCALL diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index 2f8a5d3bbd57..df60871ce2e8 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -119,6 +119,11 @@ static inline void set_fs(mm_segment_t fs) #ifndef uaccess_kernel #define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) #endif + +#ifndef user_addr_max +#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE) +#endif + #endif /* CONFIG_SET_FS */ #define access_ok(addr, size) __access_ok((unsigned long)(addr),(size)) @@ -243,44 +248,6 @@ static inline int __get_user_fn(size_t size, const void __user *ptr, void *x) extern int __get_user_bad(void) __attribute__((noreturn)); -/* - * Copy a null terminated string from userspace. - */ -#ifndef strncpy_from_user -static inline long -strncpy_from_user(char *dst, const char __user *src, long count) -{ - char *tmp; - - if (!access_ok(src, 1)) - return -EFAULT; - - strncpy(dst, (const char __force *)src, count); - for (tmp = dst; *tmp && count > 0; tmp++, count--) - ; - return (tmp - dst); -} -#endif - -#ifndef strnlen_user -/* - * Return the size of a string (including the ending 0) - * - * Return 0 on exception, a value greater than N if too long - * - * Unlike strnlen, strnlen_user includes the nul terminator in - * its returned count. Callers should check for a returned value - * greater than N as an indication the string is too long. - */ -static inline long strnlen_user(const char __user *src, long n) -{ - if (!access_ok(src, 1)) - return 0; - - return strnlen(src, n) + 1; -} -#endif - /* * Zero Userspace */ @@ -305,4 +272,7 @@ clear_user(void __user *to, unsigned long n) #include +long strncpy_from_user(char *dst, const char __user *src, long count); +long strnlen_user(const char __user *src, long n); + #endif /* __ASM_GENERIC_UACCESS_H */