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[PATCH] kexec: x86 shutdown APICs during crash_shutdown

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In the case of a crash/panic an architecture specific function
machine_crash_shutdown is called.  This patch adds to the x86 machine_crash
function the standard kernel code for shutting down apics.

Every line of code added to that function increases the risk that we will call
code after a kernel panic that is not safe.

This patch should not make it to the stable kernel without a being reviewed a
lot more.  It is unclear how much a hardned kernel can take when it comes to
misconfigured apics.  So since a normal kernel has problems this patch does a
clean shutdown.

It is my expectation this patch will be dropped from future generations of the
kexec work.  But for the moment it is a crutch to keep from breaking
everything.

Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Eric W. Biederman 2005-06-25 14:58:00 -07:00 committed by Linus Torvalds
parent 2c818b45a2
commit 63d30298ef
1 changed files with 7 additions and 0 deletions
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7
arch/i386/kernel/crash.c
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@ -23,6 +23,7 @@
#include <asm/hardirq.h>
#include <asm/nmi.h>
#include <asm/hw_irq.h>
#include <asm/apic.h>
#include <mach_ipi.h>
#define MAX_NOTE_BYTES 1024
@ -115,6 +116,7 @@ static int crash_nmi_callback(struct pt_regs *regs, int cpu)
{
local_irq_disable();
crash_save_this_cpu(regs, cpu);
disable_local_APIC();
atomic_dec(&waiting_for_crash_ipi);
/* Assume hlt works */
__asm__("hlt");
@ -153,6 +155,7 @@ static void nmi_shootdown_cpus(void)
}
/* Leave the nmi callback set */
disable_local_APIC();
}
#else
static void nmi_shootdown_cpus(void)
@ -174,5 +177,9 @@ void machine_crash_shutdown(void)
/* The kernel is broken so disable interrupts */
local_irq_disable();
nmi_shootdown_cpus();
lapic_shutdown();
#if defined(CONFIG_X86_IO_APIC)
disable_IO_APIC();
#endif
crash_save_self();
}