From: Wanpeng Li <kernellwp@gmail.com>
To: linux-kernel@vger.kernel.org, <x86@kernel.org>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
"H. Peter Anvin" <hpa@zytor.com>, Joerg Roedel <joro@8bytes.org>
Subject: [PATCH v3] x86/apic: Fix modify_irte NULL pointer
Date: Tue, 23 Aug 2016 20:07:19 +0800 [thread overview]
Message-ID: <1471954039-3942-1-git-send-email-wanpeng.li@hotmail.com> (raw)
From: Wanpeng Li <wanpeng.li@hotmail.com>
native_smp_prepare_cpus
-> default_setup_apic_routing
-> enable_IR_x2apic
-> irq_remapping_prepare
-> intel_prepare_irq_remapping
-> intel_setup_irq_remapping
IR table is setup even if "noapic" boot parameter is added.
As a result:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8d5a5e58>] modify_irte+0x58/0x140
PGD 209638067 PUD 2105f4067 PMD 0
Oops: 0000 [#1] SMP
RIP: 0010:[<ffffffff8d5a5e58>] [<ffffffff8d5a5e58>] modify_irte+0x58/0x140
Call Trace:
intel_ir_set_affinity+0xa3/0xb0
msi_domain_set_affinity+0x21/0x70
? __irq_set_affinity+0x34/0x70
irq_do_set_affinity+0x1d/0x70
irq_set_affinity_locked+0xc2/0x100
__irq_set_affinity+0x47/0x70
write_irq_affinity.isra.7+0xcc/0xf0
irq_affinity_proc_write+0x19/0x20
proc_reg_write+0x3d/0x70
? rcu_sync_lockdep_assert+0x2f/0x60
__vfs_write+0x28/0x120
? percpu_down_read+0x5c/0xa0
? __sb_start_write+0xca/0xe0
? __sb_start_write+0xca/0xe0
vfs_write+0xb5/0x1b0
SyS_write+0x49/0xa0
do_syscall_64+0x81/0x220
entry_SYSCALL64_slow_path+0x25/0x25
RIP [<ffffffff8d5a5e58>] modify_irte+0x58/0x140
RSP <ffff8e9ad01b7c78>
CR2: 0000000000000000
This patch fix it by disabling IOAPIC support if "noapic" is on the kernel
command line.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
v2 -> v3:
* update changelog
* skip ioapic instead of the whole APIC
v1 -> v2:
* not call any of the apic functions when apic is disabled
arch/x86/kernel/apic/apic.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index cea4fc1..50c95af 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1623,6 +1623,9 @@ void __init enable_IR_x2apic(void)
unsigned long flags;
int ret, ir_stat;
+ if (skip_ioapic_setup)
+ return;
+
ir_stat = irq_remapping_prepare();
if (ir_stat < 0 && !x2apic_supported())
return;
--
1.9.1
next reply other threads:[~2016-08-23 12:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-23 12:07 Wanpeng Li [this message]
2016-08-24 7:52 ` [tip:x86/urgent] x86/apic: Do not init irq remapping if ioapic is disabled tip-bot for Wanpeng Li
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