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x86/xen: don't unbind uninitialized lock_kicker_irq
[ Upstream commit 65cae18882
]
When booting a hyperthreaded system with the kernel parameter
'mitigations=auto,nosmt', the following warning occurs:
WARNING: CPU: 0 PID: 1 at drivers/xen/events/events_base.c:1112 unbind_from_irqhandler+0x4e/0x60
...
Hardware name: Xen HVM domU, BIOS 4.2.amazon 08/24/2006
...
Call Trace:
xen_uninit_lock_cpu+0x28/0x62
xen_hvm_cpu_die+0x21/0x30
takedown_cpu+0x9c/0xe0
? trace_suspend_resume+0x60/0x60
cpuhp_invoke_callback+0x9a/0x530
_cpu_up+0x11a/0x130
cpu_up+0x7e/0xc0
bringup_nonboot_cpus+0x48/0x50
smp_init+0x26/0x79
kernel_init_freeable+0xea/0x229
? rest_init+0xaa/0xaa
kernel_init+0xa/0x106
ret_from_fork+0x35/0x40
The secondary CPUs are not activated with the nosmt mitigations and only
the primary thread on each CPU core is used. In this situation,
xen_hvm_smp_prepare_cpus(), and more importantly xen_init_lock_cpu(), is
not called, so the lock_kicker_irq is not initialized for the secondary
CPUs. Let's fix this by exiting early in xen_uninit_lock_cpu() if the
irq is not set to avoid the warning from above for each secondary CPU.
Signed-off-by: Brian Masney <bmasney@redhat.com>
Link: https://lore.kernel.org/r/20201107011119.631442-1-bmasney@redhat.com
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
parent
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commit
204dbc26f1
1 changed files with 11 additions and 1 deletions
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@ -93,10 +93,20 @@ void xen_init_lock_cpu(int cpu)
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void xen_uninit_lock_cpu(int cpu)
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{
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int irq;
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if (!xen_pvspin)
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return;
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unbind_from_irqhandler(per_cpu(lock_kicker_irq, cpu), NULL);
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/*
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* When booting the kernel with 'mitigations=auto,nosmt', the secondary
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* CPUs are not activated, and lock_kicker_irq is not initialized.
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*/
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irq = per_cpu(lock_kicker_irq, cpu);
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if (irq == -1)
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return;
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unbind_from_irqhandler(irq, NULL);
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per_cpu(lock_kicker_irq, cpu) = -1;
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kfree(per_cpu(irq_name, cpu));
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per_cpu(irq_name, cpu) = NULL;
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