2009-03-07 05:08:49

by K.Prasad

[permalink] [raw]
Subject: [Patch 09/11] Cleanup HW Breakpoint registers before kexec

From: Alan Stern <[email protected]>

This patch disables Hardware breakpoints before doing a 'kexec' on the machine.

[K.Prasad: Split-out from the bigger patch and minor changes following
re-basing]

Signed-off-by: K.Prasad <[email protected]>
Signed-off-by: Alan Stern <[email protected]>
---
arch/x86/kernel/machine_kexec_32.c | 2 ++
arch/x86/kernel/machine_kexec_64.c | 2 ++
2 files changed, 4 insertions(+)

Index: linux-2.6-tip/arch/x86/kernel/machine_kexec_32.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/machine_kexec_32.c
+++ linux-2.6-tip/arch/x86/kernel/machine_kexec_32.c
@@ -25,6 +25,7 @@
#include <asm/desc.h>
#include <asm/system.h>
#include <asm/cacheflush.h>
+#include <asm/debugreg.h>

static void set_idt(void *newidt, __u16 limit)
{
@@ -202,6 +203,7 @@ void machine_kexec(struct kimage *image)

/* Interrupts aren't acceptable while we reboot */
local_irq_disable();
+ disable_debug_registers();

if (image->preserve_context) {
#ifdef CONFIG_X86_IO_APIC
Index: linux-2.6-tip/arch/x86/kernel/machine_kexec_64.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/machine_kexec_64.c
+++ linux-2.6-tip/arch/x86/kernel/machine_kexec_64.c
@@ -17,6 +17,7 @@
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/io.h>
+#include <asm/debugreg.h>

static void init_level2_page(pmd_t *level2p, unsigned long addr)
{
@@ -234,6 +235,7 @@ void machine_kexec(struct kimage *image)

/* Interrupts aren't acceptable while we reboot */
local_irq_disable();
+ disable_debug_registers();

control_page = page_address(image->control_code_page) + PAGE_SIZE;
memcpy(control_page, relocate_kernel, PAGE_SIZE);