From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757504Ab1LGREW (ORCPT ); Wed, 7 Dec 2011 12:04:22 -0500 Received: from cantor2.suse.de ([195.135.220.15]:39514 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757555Ab1LGRER (ORCPT ); Wed, 7 Dec 2011 12:04:17 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Dec 7 08:56:02 2011 Message-Id: <20111207165602.407872916@clark.kroah.org> User-Agent: quilt/0.50-23.1 Date: Wed, 07 Dec 2011 08:54:57 -0800 From: Greg KH To: , Cc: , , , Robert Richter Subject: [24/27] oprofile, x86: Fix crash when unloading module (nmi timer mode) In-Reply-To: <20111207165611.GA19872@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Robert Richter commit 97f7f8189fe54e3cfe324ef9ad35064f3d2d3bff upstream. If oprofile uses the nmi timer interrupt there is a crash while unloading the module. The bug can be triggered with oprofile build as module and kernel parameter nolapic set. This patch fixes this. oprofile: using NMI timer interrupt. BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: [] unregister_syscore_ops+0x41/0x58 PGD 42dbca067 PUD 41da6a067 PMD 0 Oops: 0002 [#1] PREEMPT SMP CPU 5 Modules linked in: oprofile(-) [last unloaded: oprofile] Pid: 2518, comm: modprobe Not tainted 3.1.0-rc7-00019-gb2fb49d #19 Advanced Micro Device Anaheim/Anaheim RIP: 0010:[] [] unregister_syscore_ops+0x41/0x58 RSP: 0018:ffff88041ef71e98 EFLAGS: 00010296 RAX: 0000000000000000 RBX: ffffffffa0017100 RCX: dead000000200200 RDX: 0000000000000000 RSI: dead000000100100 RDI: ffffffff8178c620 RBP: ffff88041ef71ea8 R08: 0000000000000001 R09: 0000000000000082 R10: 0000000000000000 R11: ffff88041ef71de8 R12: 0000000000000080 R13: fffffffffffffff5 R14: 0000000000000001 R15: 0000000000610210 FS: 00007fc902f20700(0000) GS:ffff88042fd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000008 CR3: 000000041cdb6000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process modprobe (pid: 2518, threadinfo ffff88041ef70000, task ffff88041d348040) Stack: ffff88041ef71eb8 ffffffffa0017790 ffff88041ef71eb8 ffffffffa0013532 ffff88041ef71ec8 ffffffffa00132d6 ffff88041ef71ed8 ffffffffa00159b2 ffff88041ef71f78 ffffffff81073115 656c69666f72706f 0000000000610200 Call Trace: [] op_nmi_exit+0x15/0x17 [oprofile] [] oprofile_arch_exit+0xe/0x10 [oprofile] [] oprofile_exit+0x1e/0x20 [oprofile] [] sys_delete_module+0x1c3/0x22f [] ? trace_hardirqs_on_thunk+0x3a/0x3f [] system_call_fastpath+0x16/0x1b Code: 20 c6 78 81 e8 c5 cc 23 00 48 8b 13 48 8b 43 08 48 be 00 01 10 00 00 00 ad de 48 b9 00 02 20 00 00 00 ad de 48 c7 c7 20 c6 78 81 89 42 08 48 89 10 48 89 33 48 89 4b 08 e8 a6 c0 23 00 5a 5b RIP [] unregister_syscore_ops+0x41/0x58 RSP CR2: 0000000000000008 ---[ end trace 43a541a52956b7b0 ]--- Signed-off-by: Robert Richter Signed-off-by: Greg Kroah-Hartman --- arch/x86/oprofile/init.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/arch/x86/oprofile/init.c +++ b/arch/x86/oprofile/init.c @@ -21,6 +21,7 @@ extern int op_nmi_timer_init(struct opro extern void op_nmi_exit(void); extern void x86_backtrace(struct pt_regs * const regs, unsigned int depth); +static int nmi_timer; int __init oprofile_arch_init(struct oprofile_operations *ops) { @@ -31,8 +32,9 @@ int __init oprofile_arch_init(struct opr #ifdef CONFIG_X86_LOCAL_APIC ret = op_nmi_init(ops); #endif + nmi_timer = (ret != 0); #ifdef CONFIG_X86_IO_APIC - if (ret < 0) + if (nmi_timer) ret = op_nmi_timer_init(ops); #endif ops->backtrace = x86_backtrace; @@ -44,6 +46,7 @@ int __init oprofile_arch_init(struct opr void oprofile_arch_exit(void) { #ifdef CONFIG_X86_LOCAL_APIC - op_nmi_exit(); + if (!nmi_timer) + op_nmi_exit(); #endif }