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| author | Prarit Bhargava <prarit@redhat.com> | 2016-11-30 16:19:39 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-12-02 02:20:02 +0300 |
| commit | a545715d2dae8d071c5b06af947b07ffa846b288 (patch) | |
| tree | f89a13f51216c9d40045e204bf2b2caf525502cf | |
| parent | e5517c2a5a49ed5e99047008629f1cd60246ea0e (diff) | |
| download | linux-a545715d2dae8d071c5b06af947b07ffa846b288.tar.xz | |
ACPI / APEI: Fix NMI notification handling
When removing and adding cpu 0 on a system with GHES NMI the following stack
trace is seen when re-adding the cpu:
WARNING: CPU: 0 PID: 0 at arch/x86/kernel/apic/apic.c:1349 setup_local_APIC+
Modules linked in: nfsv3 rpcsec_gss_krb5 nfsv4 nfs fscache coretemp intel_ra
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc6+ #2
Call Trace:
dump_stack+0x63/0x8e
__warn+0xd1/0xf0
warn_slowpath_null+0x1d/0x20
setup_local_APIC+0x275/0x370
apic_ap_setup+0xe/0x20
start_secondary+0x48/0x180
set_init_arg+0x55/0x55
early_idt_handler_array+0x120/0x120
x86_64_start_reservations+0x2a/0x2c
x86_64_start_kernel+0x13d/0x14c
During the cpu bringup, wakeup_cpu_via_init_nmi() is called and issues an
NMI on CPU 0. The GHES NMI handler, ghes_notify_nmi() runs the
ghes_proc_irq_work work queue which ends up setting IRQ_WORK_VECTOR
(0xf6). The "faulty" IR line set at arch/x86/kernel/apic/apic.c:1349 is also
0xf6 (specifically APIC IRR for irqs 255 to 224 is 0x400000) which confirms
that something has set the IRQ_WORK_VECTOR line prior to the APIC being
initialized.
Commit 2383844d4850 ("GHES: Elliminate double-loop in the NMI handler")
incorrectly modified the behavior such that the handler returns
NMI_HANDLED only if an error was processed, and incorrectly runs the ghes
work queue for every NMI.
This patch modifies the ghes_proc_irq_work() to run as it did prior to
2383844d4850 ("GHES: Elliminate double-loop in the NMI handler") by
properly returning NMI_HANDLED and only calling the work queue if
NMI_HANDLED has been set.
Fixes: 2383844d4850 (GHES: Elliminate double-loop in the NMI handler)
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/apei/ghes.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 0d099a24f776..e53bef6cf53c 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -852,6 +852,8 @@ static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) if (ghes_read_estatus(ghes, 1)) { ghes_clear_estatus(ghes); continue; + } else { + ret = NMI_HANDLED; } sev = ghes_severity(ghes->estatus->error_severity); @@ -863,12 +865,11 @@ static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) __process_error(ghes); ghes_clear_estatus(ghes); - - ret = NMI_HANDLED; } #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG - irq_work_queue(&ghes_proc_irq_work); + if (ret == NMI_HANDLED) + irq_work_queue(&ghes_proc_irq_work); #endif atomic_dec(&ghes_in_nmi); return ret; |