Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933694Ab3CLWlv (ORCPT ); Tue, 12 Mar 2013 18:41:51 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60375 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756062Ab3CLWd2 (ORCPT ); Tue, 12 Mar 2013 18:33:28 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chris Metcalf Subject: [ 064/100] tile: work around bug in the generic sys_llseek Date: Tue, 12 Mar 2013 15:31:49 -0700 Message-Id: <20130312223129.862950606@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130312223122.884099393@linuxfoundation.org> References: <20130312223122.884099393@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2703 Lines: 73 3.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chris Metcalf commit 5a114b98661e3aaa0ac085eb931584dce3b0ef9b upstream. sys_llseek should specify the high and low 32-bit seek values as "unsigned int" but instead it specifies "unsigned long". Since compat syscall arguments are always sign-extended on tile, this means that a seek value of 0xffffffff will be incorrectly interpreted as a value of -1ULL. To avoid the risk of breaking binary compatibility on architectures that already use sys_llseek this way, we follow the same path as MIPS and provide a wrapper override. Signed-off-by: Chris Metcalf Signed-off-by: Greg Kroah-Hartman --- arch/tile/include/asm/compat.h | 3 +++ arch/tile/kernel/compat.c | 13 +++++++++++++ 2 files changed, 16 insertions(+) --- a/arch/tile/include/asm/compat.h +++ b/arch/tile/include/asm/compat.h @@ -296,6 +296,9 @@ long compat_sys_sync_file_range2(int fd, long compat_sys_fallocate(int fd, int mode, u32 offset_lo, u32 offset_hi, u32 len_lo, u32 len_hi); +long compat_sys_llseek(unsigned int fd, unsigned int offset_high, + unsigned int offset_low, loff_t __user * result, + unsigned int origin); /* Assembly trampoline to avoid clobbering r0. */ long _compat_sys_rt_sigreturn(void); --- a/arch/tile/kernel/compat.c +++ b/arch/tile/kernel/compat.c @@ -76,6 +76,18 @@ long compat_sys_fallocate(int fd, int mo ((loff_t)len_hi << 32) | len_lo); } +/* + * Avoid bug in generic sys_llseek() that specifies offset_high and + * offset_low as "unsigned long", thus making it possible to pass + * a sign-extended high 32 bits in offset_low. + */ +long compat_sys_llseek(unsigned int fd, unsigned int offset_high, + unsigned int offset_low, loff_t __user * result, + unsigned int origin) +{ + return sys_llseek(fd, offset_high, offset_low, result, origin); +} + /* Provide the compat syscall number to call mapping. */ #undef __SYSCALL #define __SYSCALL(nr, call) [nr] = (call), @@ -83,6 +95,7 @@ long compat_sys_fallocate(int fd, int mo /* See comments in sys.c */ #define compat_sys_fadvise64_64 sys32_fadvise64_64 #define compat_sys_readahead sys32_readahead +#define sys_llseek compat_sys_llseek /* Call the assembly trampolines where necessary. */ #define compat_sys_rt_sigreturn _compat_sys_rt_sigreturn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/