Commits
Prarit Bhargava committed a545715d2da
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>