Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751818Ab3CREaa (ORCPT ); Mon, 18 Mar 2013 00:30:30 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33365 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751106Ab3CREaC (ORCPT ); Mon, 18 Mar 2013 00:30:02 -0400 Message-Id: <20130318042145.161537310@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 18 Mar 2013 04:21:53 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, Russell King , Paolo Pisati Subject: [ 09/82] ARM: fix scheduling while atomic warning in alignment handling code In-Reply-To: <20130318042144.234468645@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:d98f:da4e:f620:7bea X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3061 Lines: 82 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Russell King commit b255188f90e2bade1bd11a986dd1ca4861869f4d upstream. Paolo Pisati reports that IPv6 triggers this warning: BUG: scheduling while atomic: swapper/0/0/0x40000100 Modules linked in: [] (unwind_backtrace+0x0/0xf0) from [] (__schedule_bug+0x48/0x5c) [] (__schedule_bug+0x48/0x5c) from [] (__schedule+0x700/0x740) [] (__schedule+0x700/0x740) from [] (__cond_resched+0x24/0x34) [] (__cond_resched+0x24/0x34) from [] (_cond_resched+0x3c/0x44) [] (_cond_resched+0x3c/0x44) from [] (do_alignment+0x178/0x78c) [] (do_alignment+0x178/0x78c) from [] (do_DataAbort+0x34/0x98) [] (do_DataAbort+0x34/0x98) from [] (__dabt_svc+0x40/0x60) Exception stack(0xc0763d70 to 0xc0763db8) 3d60: e97e805e e97e806e 2c000000 11000000 3d80: ea86bb00 0000002c 00000011 e97e807e c076d2a8 e97e805e e97e806e 0000002c 3da0: 3d000000 c0763dbc c04b98fc c02a8490 00000113 ffffffff [] (__dabt_svc+0x40/0x60) from [] (__csum_ipv6_magic+0x8/0xc8) Fix this by using probe_kernel_address() stead of __get_user(). Reported-by: Paolo Pisati Tested-by: Paolo Pisati Signed-off-by: Russell King Signed-off-by: Ben Hutchings --- arch/arm/mm/alignment.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c @@ -749,7 +749,6 @@ do_alignment(unsigned long addr, unsigne unsigned long instr = 0, instrptr; int (*handler)(unsigned long addr, unsigned long instr, struct pt_regs *regs); unsigned int type; - mm_segment_t fs; unsigned int fault; u16 tinstr = 0; int isize = 4; @@ -760,16 +759,15 @@ do_alignment(unsigned long addr, unsigne instrptr = instruction_pointer(regs); - fs = get_fs(); - set_fs(KERNEL_DS); if (thumb_mode(regs)) { - fault = __get_user(tinstr, (u16 *)(instrptr & ~1)); + u16 *ptr = (u16 *)(instrptr & ~1); + fault = probe_kernel_address(ptr, tinstr); if (!fault) { if (cpu_architecture() >= CPU_ARCH_ARMv7 && IS_T32(tinstr)) { /* Thumb-2 32-bit */ u16 tinst2 = 0; - fault = __get_user(tinst2, (u16 *)(instrptr+2)); + fault = probe_kernel_address(ptr + 1, tinst2); instr = (tinstr << 16) | tinst2; thumb2_32b = 1; } else { @@ -778,8 +776,7 @@ do_alignment(unsigned long addr, unsigne } } } else - fault = __get_user(instr, (u32 *)instrptr); - set_fs(fs); + fault = probe_kernel_address(instrptr, instr); if (fault) { type = TYPE_FAULT; -- 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/