Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755201Ab2HTD7m (ORCPT ); Sun, 19 Aug 2012 23:59:42 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:39891 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755008Ab2HTD7d (ORCPT ); Sun, 19 Aug 2012 23:59:33 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg KH , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Heiko Carstens , Martin Schwidefsky Subject: [ 02/46] s390/compat: fix mmap compat system calls Date: Sun, 19 Aug 2012 20:58:38 -0700 Message-Id: <20120820035832.598136284@linuxfoundation.org> X-Mailer: git-send-email 1.7.10.2.565.gbd578b5 In-Reply-To: <20120820035832.274275502@linuxfoundation.org> References: <20120820035832.274275502@linuxfoundation.org> User-Agent: quilt/0.60-20.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2091 Lines: 60 From: Greg KH 3.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Heiko Carstens commit e85871218513c54f7dfdb6009043cb638f2fecbe upstream. The native 31 bit and the compat behaviour for the mmap system calls differ: In native 31 bit mode the passed in address for the mmap system call will be unmodified passed to sys_mmap_pgoff(). In compat mode however the passed in address will be modified with compat_ptr() which masks out the most significant bit. The result is that in native 31 bit mode each mmap request (with MAP_FIXED) will fail where the most significat bit is set, while in compat mode it may succeed. This odd behaviour was introduced with d3815898 "[S390] mmap: add missing compat_ptr conversion to both mmap compat syscalls". To restore a consistent behaviour accross native and compat mode this patch functionally reverts the above mentioned commit. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/compat_linux.c | 2 -- 1 file changed, 2 deletions(-) --- a/arch/s390/kernel/compat_linux.c +++ b/arch/s390/kernel/compat_linux.c @@ -622,7 +622,6 @@ asmlinkage unsigned long old32_mmap(stru return -EFAULT; if (a.offset & ~PAGE_MASK) return -EINVAL; - a.addr = (unsigned long) compat_ptr(a.addr); return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT); } @@ -633,7 +632,6 @@ asmlinkage long sys32_mmap2(struct mmap_ if (copy_from_user(&a, arg, sizeof(a))) return -EFAULT; - a.addr = (unsigned long) compat_ptr(a.addr); return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset); } -- 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/