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Wed, 16 Feb 2022 13:17:27 +0000 Received: from sin.source.kernel.org ([145.40.73.55]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nKKBJ-0075to-4k; Wed, 16 Feb 2022 13:17:19 +0000 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 sin.source.kernel.org (Postfix) with ESMTPS id 5ABD2CE26F6; Wed, 16 Feb 2022 13:17:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F2C4C340F9; Wed, 16 Feb 2022 13:17:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645017433; bh=XYviTV8III28kBrCQmsfuK51xOc09ZOif7iEHrUTuIg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RtZeNhuMWLMdUCgp7sQPtFKueCz8UIMqyfmOJ7eTRpRAZj+EX1IydRbAp51tHxwWq 5ne2vxMm/JuLMAmzyha4cuHaIahixOHFYVc5gGcfZri8EF8XqsDBKKhTiX2FVDpISR Pagw3akqo4xNGkF8Pb3UNLVmcr6ZFwFviZKx75YteMrlQ/LSVcu+z3apLlbK8geLHf v3iSy1y9VzaMo/+yVZXWf0Swp3oDEXhPv7eE6oQXabEKWYYUYMRDAqB7mO4dBnJnsi bzLr4K/tjkFnSoB/60v9gCoDQiRG0gDzcN5E85Rk8eBnmYUibpTvgJRV9oTUxC2Xso Mffr2yyPA6wPQ== From: Arnd Bergmann To: Linus Torvalds , Christoph Hellwig , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, arnd@arndb.de, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk Cc: linux@armlinux.org.uk, will@kernel.org, guoren@kernel.org, bcain@codeaurora.org, geert@linux-m68k.org, monstr@monstr.eu, tsbogend@alpha.franken.de, nickhu@andestech.com, green.hu@gmail.com, dinguyen@kernel.org, shorne@gmail.com, deller@gmx.de, mpe@ellerman.id.au, peterz@infradead.org, mingo@redhat.com, mark.rutland@arm.com, hca@linux.ibm.com, dalias@libc.org, davem@davemloft.net, richard@nod.at, x86@kernel.org, jcmvbkbc@gmail.com, ebiederm@xmission.com, akpm@linux-foundation.org, ardb@kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org Subject: [PATCH v2 09/18] mips: use simpler access_ok() Date: Wed, 16 Feb 2022 14:13:23 +0100 Message-Id: <20220216131332.1489939-10-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20220216131332.1489939-1-arnd@kernel.org> References: <20220216131332.1489939-1-arnd@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220216_051717_589865_DECABAC9 X-CRM114-Status: GOOD ( 19.43 ) X-Spam-Score: -5.4 (-----) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: From: Arnd Bergmann Before unifying the mips version of __access_ok() with the generic code, this converts it to the same algorithm. This is a change in behavior on mips64, as now address in the user segment, the lower 2 [...] Content analysis details: (-5.4 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [145.40.73.55 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.2 DKIMWL_WL_HIGH DKIMwl.org - High trust sender X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: Arnd Bergmann Before unifying the mips version of __access_ok() with the generic code, this converts it to the same algorithm. This is a change in behavior on mips64, as now address in the user segment, the lower 2^62 bytes, is taken to be valid, relying on a page fault for addresses that are within that segment but not valid on that CPU. The new version should be the most effecient way to do this, but it gets rid of the special handling for size=0 that most other architectures ignore as well. Signed-off-by: Arnd Bergmann --- arch/mips/include/asm/uaccess.h | 22 ++++------------------ 1 file changed, 4 insertions(+), 18 deletions(-) diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h index db9a8e002b62..d7c89dc3426c 100644 --- a/arch/mips/include/asm/uaccess.h +++ b/arch/mips/include/asm/uaccess.h @@ -19,6 +19,7 @@ #ifdef CONFIG_32BIT #define __UA_LIMIT 0x80000000UL +#define TASK_SIZE_MAX __UA_LIMIT #define __UA_ADDR ".word" #define __UA_LA "la" @@ -33,6 +34,7 @@ extern u64 __ua_limit; #define __UA_LIMIT __ua_limit +#define TASK_SIZE_MAX XKSSEG #define __UA_ADDR ".dword" #define __UA_LA "dla" @@ -42,22 +44,6 @@ extern u64 __ua_limit; #endif /* CONFIG_64BIT */ -/* - * Is a address valid? This does a straightforward calculation rather - * than tests. - * - * Address valid if: - * - "addr" doesn't have any high-bits set - * - AND "size" doesn't have any high-bits set - * - AND "addr+size" doesn't have any high-bits set - * - OR we are in kernel mode. - * - * __ua_size() is a trick to avoid runtime checking of positive constant - * sizes; for those we already know at compile time that the size is ok. - */ -#define __ua_size(size) \ - ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size)) - /* * access_ok: - Checks if a user space pointer is valid * @addr: User space pointer to start of block to check @@ -79,9 +65,9 @@ extern u64 __ua_limit; static inline int __access_ok(const void __user *p, unsigned long size) { unsigned long addr = (unsigned long)p; - unsigned long end = addr + size - !!size; + unsigned long limit = TASK_SIZE_MAX; - return (__UA_LIMIT & (addr | end | __ua_size(size))) == 0; + return (size <= limit) && (addr <= (limit - size)); } #define access_ok(addr, size) \