From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org Subject: [ 41/45] m68k: Truncate base in do_div() Date: Sun, 18 Aug 2013 13:36:30 -0700 Message-Id: <20130818203623.850246787@linuxfoundation.org> In-Reply-To: <20130818203620.996166594@linuxfoundation.org> References: <20130818203620.996166594@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andreas Schwab commit ea077b1b96e073eac5c3c5590529e964767fc5f7 upstream. Explicitly truncate the second operand of do_div() to 32 bits to guard against bogus code calling it with a 64-bit divisor. [Thorsten] After upgrading from 3.2 to 3.10, mounting a btrfs volume fails with: btrfs: setting nodatacow, compression disabled btrfs: enabling auto recovery btrfs: disk space caching is enabled --- arch/m68k/include/asm/div64.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/arch/m68k/include/asm/div64.h +++ b/arch/m68k/include/asm/div64.h @@ -15,16 +15,17 @@ unsigned long long n64; \ } __n; \ unsigned long __rem, __upper; \ + unsigned long __base = (base); \ \ __n.n64 = (n); \ if ((__upper = __n.n32[0])) { \ asm ("divul.l %2,%1:%0" \ - : "=d" (__n.n32[0]), "=d" (__upper) \ - : "d" (base), "0" (__n.n32[0])); \ + : "=d" (__n.n32[0]), "=d" (__upper) \ + : "d" (__base), "0" (__n.n32[0])); \ } \ asm ("divu.l %2,%1:%0" \ - : "=d" (__n.n32[1]), "=d" (__rem) \ - : "d" (base), "1" (__upper), "0" (__n.n32[1])); \ + : "=d" (__n.n32[1]), "=d" (__rem) \ + : "d" (__base), "1" (__upper), "0" (__n.n32[1])); \ (n) = __n.n64; \ __rem; \ })