linux-kernel - [RFC Patch 5/9] Use wrapper routines around debug registers in processor related functions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 5 Dec 2008 00:43:25 +0530
From:	"K.Prasad" <prasad@...ux.vnet.ibm.com>
To:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Cc:	Alan Stern <stern@...land.harvard.edu>,
	Roland McGrath <roland@...hat.com>, akpm@...ux-foundation.org,
	mingo@...e.hu, richardj_moore@...ibm.com
Subject: [RFC Patch 5/9] Use wrapper routines around debug registers in
	processor related functions

This patch enables the use of wrapper routines to access the debug/breakpoint
registers.

Signed-off-by: K.Prasad <prasad@...ux.vnet.ibm.com>
Signed-off-by: Alan Stern <stern@...land.harvard.edu>
---
 arch/x86/kernel/smpboot.c |    3 +++
 arch/x86/power/cpu_32.c   |   16 +++-------------
 arch/x86/power/cpu_64.c   |   15 +++------------
 3 files changed, 9 insertions(+), 25 deletions(-)

Index: linux-2.6.28-rc5-bkpt-latest/arch/x86/power/cpu_32.c
===================================================================
--- linux-2.6.28-rc5-bkpt-latest.orig/arch/x86/power/cpu_32.c
+++ linux-2.6.28-rc5-bkpt-latest/arch/x86/power/cpu_32.c
@@ -12,6 +12,7 @@
 #include <asm/mtrr.h>
 #include <asm/mce.h>
 #include <asm/xcr.h>
+#include <asm/debugreg.h>
 
 static struct saved_context saved_context;
 
@@ -47,6 +48,7 @@ static void __save_processor_state(struc
 	ctxt->cr2 = read_cr2();
 	ctxt->cr3 = read_cr3();
 	ctxt->cr4 = read_cr4_safe();
+	disable_debug_registers();
 }
 
 /* Needed by apm.c */
@@ -79,19 +81,7 @@ static void fix_processor_context(void)
 	load_TR_desc();				/* This does ltr */
 	load_LDT(&current->active_mm->context);	/* This does lldt */
 
-	/*
-	 * Now maybe reload the debug registers
-	 */
-	if (current->thread.debugreg7) {
-		set_debugreg(current->thread.debugreg0, 0);
-		set_debugreg(current->thread.debugreg1, 1);
-		set_debugreg(current->thread.debugreg2, 2);
-		set_debugreg(current->thread.debugreg3, 3);
-		/* no 4 and 5 */
-		set_debugreg(current->thread.debugreg6, 6);
-		set_debugreg(current->thread.debugreg7, 7);
-	}
-
+	load_debug_registers();
 }
 
 static void __restore_processor_state(struct saved_context *ctxt)
Index: linux-2.6.28-rc5-bkpt-latest/arch/x86/power/cpu_64.c
===================================================================
--- linux-2.6.28-rc5-bkpt-latest.orig/arch/x86/power/cpu_64.c
+++ linux-2.6.28-rc5-bkpt-latest/arch/x86/power/cpu_64.c
@@ -15,6 +15,7 @@
 #include <asm/pgtable.h>
 #include <asm/mtrr.h>
 #include <asm/xcr.h>
+#include <asm/debugreg.h>
 
 static void fix_processor_context(void);
 
@@ -70,6 +71,7 @@ static void __save_processor_state(struc
 	ctxt->cr3 = read_cr3();
 	ctxt->cr4 = read_cr4();
 	ctxt->cr8 = read_cr8();
+	disable_debug_registers();
 }
 
 void save_processor_state(void)
@@ -158,16 +160,5 @@ static void fix_processor_context(void)
 	load_TR_desc();				/* This does ltr */
 	load_LDT(&current->active_mm->context);	/* This does lldt */
 
-	/*
-	 * Now maybe reload the debug registers
-	 */
-	if (current->thread.debugreg7){
-                loaddebug(&current->thread, 0);
-                loaddebug(&current->thread, 1);
-                loaddebug(&current->thread, 2);
-                loaddebug(&current->thread, 3);
-                /* no 4 and 5 */
-                loaddebug(&current->thread, 6);
-                loaddebug(&current->thread, 7);
-	}
+	load_debug_registers();
 }
Index: linux-2.6.28-rc5-bkpt-latest/arch/x86/kernel/smpboot.c
===================================================================
--- linux-2.6.28-rc5-bkpt-latest.orig/arch/x86/kernel/smpboot.c
+++ linux-2.6.28-rc5-bkpt-latest/arch/x86/kernel/smpboot.c
@@ -62,6 +62,7 @@
 #include <asm/mtrr.h>
 #include <asm/vmi.h>
 #include <asm/genapic.h>
+#include <asm/debugreg.h>
 #include <linux/mc146818rtc.h>
 
 #include <mach_apic.h>
@@ -350,6 +351,7 @@ static void __cpuinit start_secondary(vo
 	setup_secondary_clock();
 
 	wmb();
+	load_debug_registers();
 	cpu_idle();
 }
 
@@ -1356,6 +1358,7 @@ void cpu_disable_common(void)
 	remove_cpu_from_maps(cpu);
 	unlock_vector_lock();
 	fixup_irqs(cpu_online_map);
+	disable_debug_registers();
 }
 
 int native_cpu_disable(void)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/