On Tue, Nov 29, 2016 at 01:43:59PM -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-rc5+ #59 > Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.01.00.0 > ffffffff81c03e78 ffffffff81337905 0000000000000000 0000000000000000 > ffffffff81c03eb8 ffffffff8107d9c1 00000545810aac4a 0000000000000000 > 00000000000000f0 0000000000000000 000081cb6440f1d0 0000000000000001 > Call Trace: > [<ffffffff81337905>] dump_stack+0x63/0x8e > [<ffffffff8107d9c1>] __warn+0xd1/0xf0 > [<ffffffff8107daad>] warn_slowpath_null+0x1d/0x20 > [<ffffffff810522b5>] setup_local_APIC+0x275/0x370 > [<ffffffff810523be>] apic_ap_setup+0xe/0x20 > [<ffffffff8104f5a8>] start_secondary+0x48/0x180 > [<ffffffff81d89aa0>] ? set_init_arg+0x55/0x55 > [<ffffffff81d89120>] ? early_idt_handler_array+0x120/0x120 > [<ffffffff81d895d6>] ? x86_64_start_reservations+0x2a/0x2c > [<ffffffff81d89715>] ? x86_64_start_kernel+0x13d/0x14c > ---[ end trace 7b6555b6343ef9ee ]--- Please remove all hex numbers from the splat - they're useless in the commit message. > 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@xxxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxx> > Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > Cc: Len Brown <lenb@xxxxxxxxxx> > Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx> > Cc: Tyler Baicar <tbaicar@xxxxxxxxxxxxxx> > Cc: Punit Agrawal <punit.agrawal@xxxxxxx> > Cc: Don Zickus <dzickus@xxxxxxxxxx> > Cc: linux-acpi@xxxxxxxxxxxxxxx > --- > drivers/acpi/apei/ghes.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > index 0d099a24f776..39c45efbcb3d 100644 > --- a/drivers/acpi/apei/ghes.c > +++ b/drivers/acpi/apei/ghes.c > @@ -858,17 +858,18 @@ static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) > if (sev >= GHES_SEV_PANIC) > __ghes_panic(ghes); > > + ret = NMI_HANDLED; > + Make that more explicit: if (ghes_read_estatus(ghes, 1)) { ghes_clear_estatus(ghes); continue; } else { ret = NMI_HANDLED; } > if (!(ghes->flags & GHES_TO_CLEAR)) > continue; > > __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; > -- Otherwise looks ok, thanks. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) -- -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html