diff options
| author | Maneesh Soni <maneesh@in.ibm.com> | 2006-03-14 15:03:14 +0530 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-14 08:26:44 -0800 |
| commit | 67963132638e67ad3c5aa16765e6f3f2f3cdd85c (patch) | |
| tree | 799409dacd6f604d6500bac693da5cb3fafb71cb /arch/i386/kernel/apic.c | |
| parent | cbf0ec6ee001ab89471397ac84105b2e3b2fd986 (diff) | |
[PATCH] Plug kdump shutdown race window
lapic_shutdown() re-enables interrupts which is un-desirable for panic
case, so use local_irq_save() and local_irq_restore() to keep the irqs
disabled for kexec on panic case, and close a possible race window while
kdump shutdown as shown in this stack trace
-- BUG: spinlock lockup on CPU#1, bash/4396, c52781a0
[<c01c1870>] _raw_spin_lock+0xb7/0xd2
[<c029e148>] _spin_lock+0x6/0x8
[<c011b33f>] scheduler_tick+0xe7/0x328
[<c0128a7c>] update_process_times+0x51/0x5d
[<c0114592>] smp_apic_timer_interrupt+0x4f/0x58
[<c01141ff>] lapic_shutdown+0x76/0x7e
[<c0104d7c>] apic_timer_interrupt+0x1c/0x30
[<c01141ff>] lapic_shutdown+0x76/0x7e
[<c0116659>] machine_crash_shutdown+0x83/0xaa
[<c013cc36>] crash_kexec+0xc1/0xe3
[<c029e148>] _spin_lock+0x6/0x8
[<c013cc22>] crash_kexec+0xad/0xe3
[<c0215280>] __handle_sysrq+0x84/0xfd
[<c018d937>] write_sysrq_trigger+0x2c/0x35
[<c015e47b>] vfs_write+0xa2/0x13b
[<c015ea73>] sys_write+0x3b/0x64
[<c0103c69>] syscall_call+0x7/0xb
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386/kernel/apic.c')
| -rw-r--r-- | arch/i386/kernel/apic.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c index f39e09ef64ec..776c90989e06 100644 --- a/arch/i386/kernel/apic.c +++ b/arch/i386/kernel/apic.c @@ -570,16 +570,18 @@ void __devinit setup_local_APIC(void) */ void lapic_shutdown(void) { + unsigned long flags; + if (!cpu_has_apic) return; - local_irq_disable(); + local_irq_save(flags); clear_local_APIC(); if (enabled_via_apicbase) disable_local_APIC(); - local_irq_enable(); + local_irq_restore(flags); } #ifdef CONFIG_PM |