[ 023/136 ] xen/smp: Fix leakage of timer interrupt line for every CPUonline/offline.

From: Steven Rostedt
Date: Fri May 17 2013 - 22:27:17 EST stable review patch.
If anyone has any objections, please let me know.


From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

[ Upstream commit 888b65b4bc5e7fcbbb967023300cd5d44dba1950 ]

In the PVHVM path when we do CPU online/offline path we would
leak the timer%d IRQ line everytime we do a offline event. The
online path (xen_hvm_setup_cpu_clockevents via
x86_cpuinit.setup_percpu_clockev) would allocate a new interrupt
line for the timer%d.

But we would still use the old interrupt line leading to:

kernel BUG at /home/konrad/ssd/konrad/linux/kernel/hrtimer.c:1261!
invalid opcode: 0000 [#1] SMP
RIP: 0010:[<ffffffff810b9e21>] [<ffffffff810b9e21>] hrtimer_interrupt+0x261/0x270
.. snip..
[<ffffffff810445ef>] xen_timer_interrupt+0x2f/0x1b0
[<ffffffff81104825>] ? stop_machine_cpu_stop+0xb5/0xf0
[<ffffffff8111434c>] handle_irq_event_percpu+0x7c/0x240
[<ffffffff811175b9>] handle_percpu_irq+0x49/0x70
[<ffffffff813a74a3>] __xen_evtchn_do_upcall+0x1c3/0x2f0
[<ffffffff813a760a>] xen_evtchn_do_upcall+0x2a/0x40
[<ffffffff8167c26d>] xen_hvm_callback_vector+0x6d/0x80
[<ffffffff81666d01>] ? start_secondary+0x193/0x1a8
[<ffffffff81666cfd>] ? start_secondary+0x18f/0x1a8

There is also the oddity (timer1) in the /proc/interrupts after
offlining CPU1:

64: 1121 0 xen-percpu-virq timer0
78: 0 0 xen-percpu-virq timer1
84: 0 2483 xen-percpu-virq timer2

This patch fixes it.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
arch/x86/xen/smp.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index f58dca7..3fc224d 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -667,6 +667,7 @@ static void xen_hvm_cpu_die(unsigned int cpu)
unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL);
unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);
+ xen_teardown_timer(cpu);


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/