From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Brian Masney <bmasney@redhat.com>,
Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Sasha Levin <sashal@kernel.org>,
xen-devel@lists.xenproject.org
Subject: [PATCH AUTOSEL 4.19 07/15] x86/xen: don't unbind uninitialized lock_kicker_irq
Date: Wed, 25 Nov 2020 10:37:04 -0500 [thread overview]
Message-ID: <20201125153712.810655-7-sashal@kernel.org> (raw)
In-Reply-To: <20201125153712.810655-1-sashal@kernel.org>
From: Brian Masney <bmasney@redhat.com>
[ Upstream commit 65cae18882f943215d0505ddc7e70495877308e6 ]
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>
---
arch/x86/xen/spinlock.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 717b4847b473f..6fffb86a32add 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -101,10 +101,20 @@ void xen_init_lock_cpu(int cpu)
void xen_uninit_lock_cpu(int cpu)
{
+ int irq;
+
if (!xen_pvspin)
return;
- unbind_from_irqhandler(per_cpu(lock_kicker_irq, cpu), NULL);
+ /*
+ * When booting the kernel with 'mitigations=auto,nosmt', the secondary
+ * CPUs are not activated, and lock_kicker_irq is not initialized.
+ */
+ irq = per_cpu(lock_kicker_irq, cpu);
+ if (irq == -1)
+ return;
+
+ unbind_from_irqhandler(irq, NULL);
per_cpu(lock_kicker_irq, cpu) = -1;
kfree(per_cpu(irq_name, cpu));
per_cpu(irq_name, cpu) = NULL;
--
2.27.0
next prev parent reply other threads:[~2020-11-25 15:37 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-25 15:36 [PATCH AUTOSEL 4.19 01/15] HID: cypress: Support Varmilo Keyboards' media hotkeys Sasha Levin
2020-11-25 15:36 ` [PATCH AUTOSEL 4.19 02/15] HID: add support for Sega Saturn Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 03/15] Input: i8042 - allow insmod to succeed on devices without an i8042 controller Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 04/15] HID: hid-sensor-hub: Fix issue with devices with no report ID Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 05/15] HID: add HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE for Gamevice devices Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 06/15] dmaengine: xilinx_dma: use readl_poll_timeout_atomic variant Sasha Levin
2020-11-25 15:37 ` Sasha Levin [this message]
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 08/15] HID: Add Logitech Dinovo Edge battery quirk Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 09/15] proc: don't allow async path resolution of /proc/self components Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 10/15] nvme: free sq/cq dbbuf pointers when dbbuf set fails Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 11/15] dmaengine: pl330: _prep_dma_memcpy: Fix wrong burst size Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 12/15] scsi: libiscsi: Fix NOP race condition Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 13/15] scsi: target: iscsi: Fix cmd abort fabric stop race Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 14/15] perf/x86: fix sysfs type mismatches Sasha Levin
2020-11-25 15:37 ` [PATCH AUTOSEL 4.19 15/15] xtensa: uaccess: Add missing __user to strncpy_from_user() prototype Sasha Levin
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