From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: Re: [PATCH 09/14] m68k: drop custom __access_ok() Date: Tue, 15 Feb 2022 00:37:41 +0000 Message-ID: References: <20220214163452.1568807-1-arnd@kernel.org> <20220214163452.1568807-10-arnd@kernel.org> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20220214163452.1568807-10-arnd@kernel.org> Sender: Al Viro List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Arnd Bergmann Cc: 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, 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-arm-kernel@lists.in On Mon, Feb 14, 2022 at 05:34:47PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann > > While most m68k platforms use separate address spaces for user > and kernel space, at least coldfire does not, and the other > ones have a TASK_SIZE that is less than the entire 4GB address > range. > > Using the generic implementation of __access_ok() stops coldfire > user space from trivially accessing kernel memory, and is probably > the right thing elsewhere for consistency as well. Perhaps simply wrap that sucker into #ifdef CONFIG_CPU_HAS_ADDRESS_SPACES (and trim the comment down to "coldfire and 68000 will pick generic variant")? > Signed-off-by: Arnd Bergmann > --- > arch/m68k/include/asm/uaccess.h | 13 ------------- > 1 file changed, 13 deletions(-) > > diff --git a/arch/m68k/include/asm/uaccess.h b/arch/m68k/include/asm/uaccess.h > index d6bb5720365a..64914872a5c9 100644 > --- a/arch/m68k/include/asm/uaccess.h > +++ b/arch/m68k/include/asm/uaccess.h > @@ -10,19 +10,6 @@ > #include > #include > #include > - > -/* We let the MMU do all checking */ > -static inline int __access_ok(const void __user *addr, > - unsigned long size) > -{ > - /* > - * XXX: for !CONFIG_CPU_HAS_ADDRESS_SPACES this really needs to check > - * for TASK_SIZE! > - * Removing this helper is probably sufficient. > - */ > - return 1; > -} > -#define __access_ok __access_ok > #include > > /* > -- > 2.29.2 >