On Wed, Nov 30, 2016 at 08:19:39AM -0500, Prarit Bhargava wrote: > 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. > > v2: Borislav, setting of NMI_HANDLED moved & cleaned up changelog. > > Fixes: 2383844d4850 ("GHES: Elliminate double-loop in the NMI handler") > Signed-off-by: Prarit Bhargava <pra...@redhat.com> > Cc: Borislav Petkov <b...@suse.de> > Cc: Rafael J. Wysocki <rafael.j.wyso...@intel.com> > Cc: Len Brown <l...@kernel.org> > Cc: Paul Gortmaker <paul.gortma...@windriver.com> > Cc: Tyler Baicar <tbai...@codeaurora.org> > Cc: Punit Agrawal <punit.agra...@arm.com> > Cc: Don Zickus <dzic...@redhat.com> > --- > drivers/acpi/apei/ghes.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-)
Reviewed-by: Borislav Petkov <b...@suse.de> -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.