Commit 78b0b690 authored Jan 29, 2019 by James Morse Committed by Rafael J. Wysocki Feb 07, 2019

ACPI / APEI: Don't wait to serialise with oops messages when panic()ing

oops_begin() exists to group printk() messages with the oops message
printed by die(). To reach this caller we know that platform firmware
took this error first, then notified the OS via NMI with a 'panic'
severity.

Don't wait for another CPU to release the die-lock before panic()ing,
our only goal is to print this fatal error and panic().

This code is always called in_nmi(), and since commit 42a0bb3f
("printk/nmi: generic solution for safe printk in NMI"), it has been
safe to call printk() from this context. Messages are batched in a
per-cpu buffer and printed via irq-work, or a call back from panic().

Link: https://patchwork.kernel.org/patch/10313555/


Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent ee9fa8f3

drivers/acpi/apei/ghes.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -33,7 +33,6 @@
		#include <linux/interrupt.h>
		#include <linux/timer.h>
		#include <linux/cper.h>
		#include <linux/kdebug.h>
		#include <linux/platform_device.h>
		#include <linux/mutex.h>
		#include <linux/ratelimit.h>
		@@ -949,7 +948,6 @@ static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs)

		sev = ghes_severity(ghes->estatus->error_severity);
		if (sev >= GHES_SEV_PANIC) {
		oops_begin();
		ghes_print_queued_estatus();
		__ghes_panic(ghes);
		}

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