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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2013-04-16 14:08:50 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-07 20:33:07 -0700
commitdab8388184da849e3fa51eafbcd4ddf85910bd2c (patch)
treea5699b4fb5ac16ba88f3d8de3ff090f0acc04ab1 /arch
parent4a605ff63b16199d20be2209ac6f48f7125bc8f5 (diff)
downloadvexpress-lsk-dab8388184da849e3fa51eafbcd4ddf85910bd2c.tar.gz
xen/smp/spinlock: Fix leakage of the spinlock interrupt line for every CPU online/offline
commit 66ff0fe9e7bda8aec99985b24daad03652f7304e upstream. While we don't use the spinlock interrupt line (see for details commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23 - xen: disable PV spinlocks on HVM) - we should still do the proper init / deinit sequence. We did not do that correctly and for the CPU init for PVHVM guest we would allocate an interrupt line - but failed to deallocate the old interrupt line. This resulted in leakage of an irq_desc but more importantly this splat as we online an offlined CPU: genirq: Flags mismatch irq 71. 0002cc20 (spinlock1) vs. 0002cc20 (spinlock1) Pid: 2542, comm: init.late Not tainted 3.9.0-rc6upstream #1 Call Trace: [<ffffffff811156de>] __setup_irq+0x23e/0x4a0 [<ffffffff81194191>] ? kmem_cache_alloc_trace+0x221/0x250 [<ffffffff811161bb>] request_threaded_irq+0xfb/0x160 [<ffffffff8104c6f0>] ? xen_spin_trylock+0x20/0x20 [<ffffffff813a8423>] bind_ipi_to_irqhandler+0xa3/0x160 [<ffffffff81303758>] ? kasprintf+0x38/0x40 [<ffffffff8104c6f0>] ? xen_spin_trylock+0x20/0x20 [<ffffffff810cad35>] ? update_max_interval+0x15/0x40 [<ffffffff816605db>] xen_init_lock_cpu+0x3c/0x78 [<ffffffff81660029>] xen_hvm_cpu_notify+0x29/0x33 [<ffffffff81676bdd>] notifier_call_chain+0x4d/0x70 [<ffffffff810bb2a9>] __raw_notifier_call_chain+0x9/0x10 [<ffffffff8109402b>] __cpu_notify+0x1b/0x30 [<ffffffff8166834a>] _cpu_up+0xa0/0x14b [<ffffffff816684ce>] cpu_up+0xd9/0xec [<ffffffff8165f754>] store_online+0x94/0xd0 [<ffffffff8141d15b>] dev_attr_store+0x1b/0x20 [<ffffffff81218f44>] sysfs_write_file+0xf4/0x170 [<ffffffff811a2864>] vfs_write+0xb4/0x130 [<ffffffff811a302a>] sys_write+0x5a/0xa0 [<ffffffff8167ada9>] system_call_fastpath+0x16/0x1b cpu 1 spinlock event irq -16 smpboot: Booting Node 0 Processor 1 APIC 0x2 And if one looks at the /proc/interrupts right after offlining (CPU1): 70: 0 0 xen-percpu-ipi spinlock0 71: 0 0 xen-percpu-ipi spinlock1 77: 0 0 xen-percpu-ipi spinlock2 There is the oddity of the 'spinlock1' still being present. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/xen/smp.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index f80e69cc77b..22c800af180 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -662,6 +662,7 @@ 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_uninit_lock_cpu(cpu);
xen_teardown_timer(cpu);
native_cpu_die(cpu);
}