Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH v2] ACPI / APEI: Fix NMI notification handling | Date | Thu, 01 Dec 2016 22:17:54 +0100 |
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On Thursday, December 01, 2016 09:07:39 PM Borislav Petkov wrote: > 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 <prarit@redhat.com> > > Cc: Borislav Petkov <bp@suse.de> > > Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Cc: Len Brown <lenb@kernel.org> > > Cc: Paul Gortmaker <paul.gortmaker@windriver.com> > > Cc: Tyler Baicar <tbaicar@codeaurora.org> > > Cc: Punit Agrawal <punit.agrawal@arm.com> > > Cc: Don Zickus <dzickus@redhat.com> > > --- > > drivers/acpi/apei/ghes.c | 7 ++++--- > > 1 file changed, 4 insertions(+), 3 deletions(-) > > Reviewed-by: Borislav Petkov <bp@suse.de>
I guess I should pick up this one, then?
Thanks, Rafael
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