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From: "K.Prasad" <prasad@linux.vnet.ibm.com>
To: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>,
	Roland McGrath <roland@redhat.com>,
	akpm@linux-foundation.org, mingo@elte.hu,
	jason.wessel@windriver.com, avi@qumranet.com,
	richardj_moore@uk.ibm.com
Subject: [RFC Patch 9/9] Cleanup HW Breakpoint registers before kexec
Date: Thu, 9 Oct 2008 00:57:00 +0530	[thread overview]
Message-ID: <20081008192700.GI4989@in.ibm.com> (raw)
In-Reply-To: <20081008192044.GA4510@in.ibm.com>


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

Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
---
 arch/x86/kernel/machine_kexec_32.c |    2 ++
 arch/x86/kernel/machine_kexec_64.c |    2 ++
 2 files changed, 4 insertions(+)

Index: linux-bkpt-lkml-27-rc9/arch/x86/kernel/machine_kexec_32.c
===================================================================
--- linux-bkpt-lkml-27-rc9.orig/arch/x86/kernel/machine_kexec_32.c
+++ linux-bkpt-lkml-27-rc9/arch/x86/kernel/machine_kexec_32.c
@@ -24,6 +24,7 @@
 #include <asm/desc.h>
 #include <asm/system.h>
 #include <asm/cacheflush.h>
+#include <asm/debugreg.h>
 
 #define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
 static u32 kexec_pgd[1024] PAGE_ALIGNED;
@@ -131,6 +132,7 @@ 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-bkpt-lkml-27-rc9/arch/x86/kernel/machine_kexec_64.c
===================================================================
--- linux-bkpt-lkml-27-rc9.orig/arch/x86/kernel/machine_kexec_64.c
+++ linux-bkpt-lkml-27-rc9/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>
 
 #define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
 static u64 kexec_pgd[512] PAGE_ALIGNED;
@@ -190,6 +191,7 @@ 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);

  parent reply	other threads:[~2008-10-08 19:27 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-08 19:20 [RFC Patch 0/9] Hardware Breakpoint interfaces - v2 K.Prasad
2008-10-08 19:23 ` [RFC Patch 1/9] Introducing generic hardware breakpoint handler interfaces K.Prasad
2008-10-16  2:49   ` Roland McGrath
2008-10-16  3:45     ` K.Prasad
2008-10-18  0:34       ` Roland McGrath
2008-10-16 14:38     ` Alan Stern
2008-10-17 23:58       ` Roland McGrath
2008-10-18 15:23         ` Alan Stern
2008-10-08 19:23 ` [RFC Patch 2/9] x86 architecture implementation of Hardware Breakpoint interfaces K.Prasad
2008-10-16  2:57   ` Roland McGrath
2008-10-08 19:24 ` [RFC Patch 3/9] Modifying generic debug exception to use virtual debug registers K.Prasad
2008-10-16  0:25   ` Roland McGrath
2008-10-16 14:12     ` Alan Stern
2008-10-16 19:22       ` Roland McGrath
2008-10-17 15:55         ` Alan Stern
2008-10-17 23:24           ` Roland McGrath
2008-10-17 23:27             ` Roland McGrath
2008-10-18 15:21             ` Alan Stern
2008-12-04 12:13               ` K.Prasad
2008-10-08 19:24 ` [RFC Patch 4/9] Modify kprobe exception handler to recognise single-stepping by HW Breakpoint handler K.Prasad
2008-10-08 19:25 ` [RFC Patch 5/9] Use wrapper routines around debug registers in processor related functions K.Prasad
2008-10-08 19:25 ` [RFC Patch 6/9] Use virtual debug registers in process/thread handling code K.Prasad
2008-10-16  1:44   ` Roland McGrath
2008-10-16 14:27     ` Alan Stern
2008-10-18  0:08       ` Roland McGrath
2008-10-18 15:34         ` Alan Stern
2008-12-03  4:54           ` Roland McGrath
2008-12-04  1:05           ` Roland McGrath
2008-12-04 12:23             ` K.Prasad
2008-10-08 19:26 ` [RFC Patch 7/9] Modify signal handling code to refrain from re-enabling HW Breakpoints K.Prasad
2008-10-08 19:26 ` [RFC Patch 8/9] Modify Ptrace to use wrapper routines to access breakpoint registers K.Prasad
2008-10-16  1:44   ` Roland McGrath
2008-12-04 17:30     ` K.Prasad
2008-10-08 19:27 ` K.Prasad [this message]
  -- strict thread matches above, loose matches on Subject: below --
2008-12-04 19:08 [RFC Patch 0/9] Hardware Breakpoint interfaces - v2 K.Prasad
2008-12-04 19:17 ` [RFC Patch 9/9] Cleanup HW Breakpoint registers before kexec K.Prasad
2008-10-07 11:38 [RFC Patch 0/9] Hardware Breakpoint interfaces K.Prasad
2008-10-07 11:46 ` [RFC Patch 9/9] Cleanup HW Breakpoint registers before kexec K.Prasad

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