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| author | Robert Richter <robert.richter@amd.com> | 2011-10-10 16:21:10 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-12-09 09:21:50 -0800 |
| commit | b669d5d9173f5f8d0e84744bc03e19d7f94f36ed (patch) | |
| tree | 62c423f48f1ed85aa136a70c1279ca91acc7cb63 | |
| parent | 98e64d37b7cf1b2ce17ac7fd65da16fb708ff738 (diff) | |
| download | lwn-b669d5d9173f5f8d0e84744bc03e19d7f94f36ed.tar.gz lwn-b669d5d9173f5f8d0e84744bc03e19d7f94f36ed.zip | |
oprofile, x86: Fix crash when unloading module (nmi timer mode)
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: [<ffffffff8123c226>] 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:[<ffffffff8123c226>] [<ffffffff8123c226>] 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:
[<ffffffffa0013532>] op_nmi_exit+0x15/0x17 [oprofile]
[<ffffffffa00132d6>] oprofile_arch_exit+0xe/0x10 [oprofile]
[<ffffffffa00159b2>] oprofile_exit+0x1e/0x20 [oprofile]
[<ffffffff81073115>] sys_delete_module+0x1c3/0x22f
[<ffffffff811bf09e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff8148070b>] 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 [<ffffffff8123c226>] unregister_syscore_ops+0x41/0x58
RSP <ffff88041ef71e98>
CR2: 0000000000000008
---[ end trace 43a541a52956b7b0 ]---
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | arch/x86/oprofile/init.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/oprofile/init.c b/arch/x86/oprofile/init.c index cdfe4c54deca..f148cf652678 100644 --- a/arch/x86/oprofile/init.c +++ b/arch/x86/oprofile/init.c @@ -21,6 +21,7 @@ extern int op_nmi_timer_init(struct oprofile_operations *ops); 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 oprofile_operations *ops) #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 oprofile_operations *ops) void oprofile_arch_exit(void) { #ifdef CONFIG_X86_LOCAL_APIC - op_nmi_exit(); + if (!nmi_timer) + op_nmi_exit(); #endif } |