Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  debug_core,kdb: fix crash when arch does not have single step
  kgdb,x86: use macro HBP_NUM to replace magic number 4
  kgdb,mips: remove unused kgdb_cpu_doing_single_step operations
  mm,kdb,kgdb: Add a debug reference for the kdb kmap usage
  KGDB: Remove set but unused newPC
  ftrace,kdb: Allow dumping a specific cpu's buffer with ftdump
  ftrace,kdb: Extend kdb to be able to dump the ftrace buffer
  kgdb,powerpc: Replace hardcoded offset by BREAK_INSTR_SIZE
  arm,kgdb: Add ability to trap into debugger on notify_die
  gdbstub: do not directly use dbg_reg_def[] in gdb_cmd_reg_set()
  gdbstub: Implement gdbserial 'p' and 'P' packets
  kgdb,arm: Individual register get/set for arm
  kgdb,mips: Individual register get/set for mips
  kgdb,x86: Individual register get/set for x86
  kgdb,kdb: individual register set and and get API
  gdbstub: Optimize kgdb's "thread:" response for the gdb serial protocol
  kgdb: remove custom hex_to_bin()implementation

7 files changed, 343 insertions, 228 deletions

diff --git a/arch/arm/include/asm/kgdb.h b/arch/arm/include/asm/kgdb.h
index 67af4b841984..08265993227f 100644
--- a/arch/arm/include/asm/kgdb.h
+++ b/arch/arm/include/asm/kgdb.h
@@ -70,11 +70,11 @@ extern int kgdb_fault_expected;
 #define _GP_REGS		16
 #define _FP_REGS		8
 #define _EXTRA_REGS		2
-#define GDB_MAX_REGS		(_GP_REGS + (_FP_REGS * 3) + _EXTRA_REGS)
+#define DBG_MAX_REG_NUM		(_GP_REGS + (_FP_REGS * 3) + _EXTRA_REGS)
 
 #define KGDB_MAX_NO_CPUS	1
 #define BUFMAX			400
-#define NUMREGBYTES		(GDB_MAX_REGS << 2)
+#define NUMREGBYTES		(DBG_MAX_REG_NUM << 2)
 #define NUMCRITREGBYTES		(32 << 2)
 
 #define _R0			0
@@ -93,7 +93,7 @@ extern int kgdb_fault_expected;
 #define _SPT			13
 #define _LR			14
 #define _PC			15
-#define _CPSR			(GDB_MAX_REGS - 1)
+#define _CPSR			(DBG_MAX_REG_NUM - 1)
 
 /*
  * So that we can denote the end of a frame for tracing,
diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c
index c868a8864117..778c2f7024ff 100644
--- a/arch/arm/kernel/kgdb.c
+++ b/arch/arm/kernel/kgdb.c
@@ -10,57 +10,62 @@
  *           Deepak Saxena <dsaxena@plexity.net>
  */
 #include <linux/irq.h>
+#include <linux/kdebug.h>
 #include <linux/kgdb.h>
 #include <asm/traps.h>
 
-/* Make a local copy of the registers passed into the handler (bletch) */
-void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
 {
-	int regno;
-
-	/* Initialize all to zero. */
-	for (regno = 0; regno < GDB_MAX_REGS; regno++)
-		gdb_regs[regno] = 0;
+	{ "r0", 4, offsetof(struct pt_regs, ARM_r0)},
+	{ "r1", 4, offsetof(struct pt_regs, ARM_r1)},
+	{ "r2", 4, offsetof(struct pt_regs, ARM_r2)},
+	{ "r3", 4, offsetof(struct pt_regs, ARM_r3)},
+	{ "r4", 4, offsetof(struct pt_regs, ARM_r4)},
+	{ "r5", 4, offsetof(struct pt_regs, ARM_r5)},
+	{ "r6", 4, offsetof(struct pt_regs, ARM_r6)},
+	{ "r7", 4, offsetof(struct pt_regs, ARM_r7)},
+	{ "r8", 4, offsetof(struct pt_regs, ARM_r8)},
+	{ "r9", 4, offsetof(struct pt_regs, ARM_r9)},
+	{ "r10", 4, offsetof(struct pt_regs, ARM_r10)},
+	{ "fp", 4, offsetof(struct pt_regs, ARM_fp)},
+	{ "ip", 4, offsetof(struct pt_regs, ARM_ip)},
+	{ "sp", 4, offsetof(struct pt_regs, ARM_sp)},
+	{ "lr", 4, offsetof(struct pt_regs, ARM_lr)},
+	{ "pc", 4, offsetof(struct pt_regs, ARM_pc)},
+	{ "f0", 12, -1 },
+	{ "f1", 12, -1 },
+	{ "f2", 12, -1 },
+	{ "f3", 12, -1 },
+	{ "f4", 12, -1 },
+	{ "f5", 12, -1 },
+	{ "f6", 12, -1 },
+	{ "f7", 12, -1 },
+	{ "fps", 4, -1 },
+	{ "cpsr", 4, offsetof(struct pt_regs, ARM_cpsr)},
+};
 
-	gdb_regs[_R0]		= kernel_regs->ARM_r0;
-	gdb_regs[_R1]		= kernel_regs->ARM_r1;
-	gdb_regs[_R2]		= kernel_regs->ARM_r2;
-	gdb_regs[_R3]		= kernel_regs->ARM_r3;
-	gdb_regs[_R4]		= kernel_regs->ARM_r4;
-	gdb_regs[_R5]		= kernel_regs->ARM_r5;
-	gdb_regs[_R6]		= kernel_regs->ARM_r6;
-	gdb_regs[_R7]		= kernel_regs->ARM_r7;
-	gdb_regs[_R8]		= kernel_regs->ARM_r8;
-	gdb_regs[_R9]		= kernel_regs->ARM_r9;
-	gdb_regs[_R10]		= kernel_regs->ARM_r10;
-	gdb_regs[_FP]		= kernel_regs->ARM_fp;
-	gdb_regs[_IP]		= kernel_regs->ARM_ip;
-	gdb_regs[_SPT]		= kernel_regs->ARM_sp;
-	gdb_regs[_LR]		= kernel_regs->ARM_lr;
-	gdb_regs[_PC]		= kernel_regs->ARM_pc;
-	gdb_regs[_CPSR]		= kernel_regs->ARM_cpsr;
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return NULL;
+
+	if (dbg_reg_def[regno].offset != -1)
+		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
+		       dbg_reg_def[regno].size);
+	else
+		memset(mem, 0, dbg_reg_def[regno].size);
+	return dbg_reg_def[regno].name;
 }
 
-/* Copy local gdb registers back to kgdb regs, for later copy to kernel */
-void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
+int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
 {
-	kernel_regs->ARM_r0	= gdb_regs[_R0];
-	kernel_regs->ARM_r1	= gdb_regs[_R1];
-	kernel_regs->ARM_r2	= gdb_regs[_R2];
-	kernel_regs->ARM_r3	= gdb_regs[_R3];
-	kernel_regs->ARM_r4	= gdb_regs[_R4];
-	kernel_regs->ARM_r5	= gdb_regs[_R5];
-	kernel_regs->ARM_r6	= gdb_regs[_R6];
-	kernel_regs->ARM_r7	= gdb_regs[_R7];
-	kernel_regs->ARM_r8	= gdb_regs[_R8];
-	kernel_regs->ARM_r9	= gdb_regs[_R9];
-	kernel_regs->ARM_r10	= gdb_regs[_R10];
-	kernel_regs->ARM_fp	= gdb_regs[_FP];
-	kernel_regs->ARM_ip	= gdb_regs[_IP];
-	kernel_regs->ARM_sp	= gdb_regs[_SPT];
-	kernel_regs->ARM_lr	= gdb_regs[_LR];
-	kernel_regs->ARM_pc	= gdb_regs[_PC];
-	kernel_regs->ARM_cpsr	= gdb_regs[_CPSR];
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return -EINVAL;
+
+	if (dbg_reg_def[regno].offset != -1)
+		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
+		       dbg_reg_def[regno].size);
+	return 0;
 }
 
 void
@@ -176,6 +181,33 @@ void kgdb_roundup_cpus(unsigned long flags)
        local_irq_disable();
 }
 
+static int __kgdb_notify(struct die_args *args, unsigned long cmd)
+{
+	struct pt_regs *regs = args->regs;
+
+	if (kgdb_handle_exception(1, args->signr, cmd, regs))
+		return NOTIFY_DONE;
+	return NOTIFY_STOP;
+}
+static int
+kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
+{
+	unsigned long flags;
+	int ret;
+
+	local_irq_save(flags);
+	ret = __kgdb_notify(ptr, cmd);
+	local_irq_restore(flags);
+
+	return ret;
+}
+
+static struct notifier_block kgdb_notifier = {
+	.notifier_call	= kgdb_notify,
+	.priority	= -INT_MAX,
+};
+
+
 /**
  *	kgdb_arch_init - Perform any architecture specific initalization.
  *
@@ -184,6 +216,11 @@ void kgdb_roundup_cpus(unsigned long flags)
  */
 int kgdb_arch_init(void)
 {
+	int ret = register_die_notifier(&kgdb_notifier);
+
+	if (ret != 0)
+		return ret;
+
 	register_undef_hook(&kgdb_brkpt_hook);
 	register_undef_hook(&kgdb_compiled_brkpt_hook);
 
@@ -200,6 +237,7 @@ void kgdb_arch_exit(void)
 {
 	unregister_undef_hook(&kgdb_brkpt_hook);
 	unregister_undef_hook(&kgdb_compiled_brkpt_hook);
+	unregister_die_notifier(&kgdb_notifier);
 }
 
 /*
diff --git a/arch/mips/include/asm/kgdb.h b/arch/mips/include/asm/kgdb.h
index 19002d605ac4..e6c0b0e14ccb 100644
--- a/arch/mips/include/asm/kgdb.h
+++ b/arch/mips/include/asm/kgdb.h
@@ -8,28 +8,27 @@
 #if (_MIPS_ISA == _MIPS_ISA_MIPS1) || (_MIPS_ISA == _MIPS_ISA_MIPS2) || \
 	(_MIPS_ISA == _MIPS_ISA_MIPS32)
 
-#define KGDB_GDB_REG_SIZE 32
+#define KGDB_GDB_REG_SIZE	32
+#define GDB_SIZEOF_REG		sizeof(u32)
 
 #elif (_MIPS_ISA == _MIPS_ISA_MIPS3) || (_MIPS_ISA == _MIPS_ISA_MIPS4) || \
 	(_MIPS_ISA == _MIPS_ISA_MIPS64)
 
 #ifdef CONFIG_32BIT
-#define KGDB_GDB_REG_SIZE 32
+#define KGDB_GDB_REG_SIZE	32
+#define GDB_SIZEOF_REG		sizeof(u32)
 #else /* CONFIG_CPU_32BIT */
-#define KGDB_GDB_REG_SIZE 64
+#define KGDB_GDB_REG_SIZE	64
+#define GDB_SIZEOF_REG		sizeof(u64)
 #endif
 #else
 #error "Need to set KGDB_GDB_REG_SIZE for MIPS ISA"
 #endif /* _MIPS_ISA */
 
 #define BUFMAX			2048
-#if (KGDB_GDB_REG_SIZE == 32)
-#define NUMREGBYTES		(90*sizeof(u32))
-#define NUMCRITREGBYTES		(12*sizeof(u32))
-#else
-#define NUMREGBYTES		(90*sizeof(u64))
-#define NUMCRITREGBYTES		(12*sizeof(u64))
-#endif
+#define DBG_MAX_REG_NUM		72
+#define NUMREGBYTES		(DBG_MAX_REG_NUM * sizeof(GDB_SIZEOF_REG))
+#define NUMCRITREGBYTES		(12 * sizeof(GDB_SIZEOF_REG))
 #define BREAK_INSTR_SIZE	4
 #define CACHE_FLUSH_IS_SAFE	0
 
diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c
index 9b78ff6e9b84..1f4e2fa64140 100644
--- a/arch/mips/kernel/kgdb.c
+++ b/arch/mips/kernel/kgdb.c
@@ -50,6 +50,151 @@ static struct hard_trap_info {
 	{ 0, 0}			/* Must be last */
 };
 
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
+{
+	{ "zero", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[0]) },
+	{ "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[1]) },
+	{ "v0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[2]) },
+	{ "v1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[3]) },
+	{ "a0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[4]) },
+	{ "a1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[5]) },
+	{ "a2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[6]) },
+	{ "a3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[7]) },
+	{ "t0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[8]) },
+	{ "t1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[9]) },
+	{ "t2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[10]) },
+	{ "t3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[11]) },
+	{ "t4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[12]) },
+	{ "t5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[13]) },
+	{ "t6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[14]) },
+	{ "t7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[15]) },
+	{ "s0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[16]) },
+	{ "s1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[17]) },
+	{ "s2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[18]) },
+	{ "s3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[19]) },
+	{ "s4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[20]) },
+	{ "s5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[21]) },
+	{ "s6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[22]) },
+	{ "s7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[23]) },
+	{ "t8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[24]) },
+	{ "t9", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[25]) },
+	{ "k0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[26]) },
+	{ "k1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[27]) },
+	{ "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[28]) },
+	{ "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[29]) },
+	{ "s8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[30]) },
+	{ "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[31]) },
+	{ "sr", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_status) },
+	{ "lo", GDB_SIZEOF_REG, offsetof(struct pt_regs, lo) },
+	{ "hi", GDB_SIZEOF_REG, offsetof(struct pt_regs, hi) },
+	{ "bad", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_badvaddr) },
+	{ "cause", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_cause) },
+	{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_epc) },
+	{ "f0", GDB_SIZEOF_REG, 0 },
+	{ "f1", GDB_SIZEOF_REG, 1 },
+	{ "f2", GDB_SIZEOF_REG, 2 },
+	{ "f3", GDB_SIZEOF_REG, 3 },
+	{ "f4", GDB_SIZEOF_REG, 4 },
+	{ "f5", GDB_SIZEOF_REG, 5 },
+	{ "f6", GDB_SIZEOF_REG, 6 },
+	{ "f7", GDB_SIZEOF_REG, 7 },
+	{ "f8", GDB_SIZEOF_REG, 8 },
+	{ "f9", GDB_SIZEOF_REG, 9 },
+	{ "f10", GDB_SIZEOF_REG, 10 },
+	{ "f11", GDB_SIZEOF_REG, 11 },
+	{ "f12", GDB_SIZEOF_REG, 12 },
+	{ "f13", GDB_SIZEOF_REG, 13 },
+	{ "f14", GDB_SIZEOF_REG, 14 },
+	{ "f15", GDB_SIZEOF_REG, 15 },
+	{ "f16", GDB_SIZEOF_REG, 16 },
+	{ "f17", GDB_SIZEOF_REG, 17 },
+	{ "f18", GDB_SIZEOF_REG, 18 },
+	{ "f19", GDB_SIZEOF_REG, 19 },
+	{ "f20", GDB_SIZEOF_REG, 20 },
+	{ "f21", GDB_SIZEOF_REG, 21 },
+	{ "f22", GDB_SIZEOF_REG, 22 },
+	{ "f23", GDB_SIZEOF_REG, 23 },
+	{ "f24", GDB_SIZEOF_REG, 24 },
+	{ "f25", GDB_SIZEOF_REG, 25 },
+	{ "f26", GDB_SIZEOF_REG, 26 },
+	{ "f27", GDB_SIZEOF_REG, 27 },
+	{ "f28", GDB_SIZEOF_REG, 28 },
+	{ "f29", GDB_SIZEOF_REG, 29 },
+	{ "f30", GDB_SIZEOF_REG, 30 },
+	{ "f31", GDB_SIZEOF_REG, 31 },
+	{ "fsr", GDB_SIZEOF_REG, 0 },
+	{ "fir", GDB_SIZEOF_REG, 0 },
+};
+
+int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	int fp_reg;
+
+	if (regno < 0 || regno >= DBG_MAX_REG_NUM)
+		return -EINVAL;
+
+	if (dbg_reg_def[regno].offset != -1 && regno < 38) {
+		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
+		       dbg_reg_def[regno].size);
+	} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
+		/* FP registers 38 -> 69 */
+		if (!(regs->cp0_status & ST0_CU1))
+			return 0;
+		if (regno == 70) {
+			/* Process the fcr31/fsr (register 70) */
+			memcpy((void *)&current->thread.fpu.fcr31, mem,
+			       dbg_reg_def[regno].size);
+			goto out_save;
+		} else if (regno == 71) {
+			/* Ignore the fir (register 71) */
+			goto out_save;
+		}
+		fp_reg = dbg_reg_def[regno].offset;
+		memcpy((void *)&current->thread.fpu.fpr[fp_reg], mem,
+		       dbg_reg_def[regno].size);
+out_save:
+		restore_fp(current);
+	}
+
+	return 0;
+}
+
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	int fp_reg;
+
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return NULL;
+
+	if (dbg_reg_def[regno].offset != -1 && regno < 38) {
+		/* First 38 registers */
+		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
+		       dbg_reg_def[regno].size);
+	} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
+		/* FP registers 38 -> 69 */
+		if (!(regs->cp0_status & ST0_CU1))
+			goto out;
+		save_fp(current);
+		if (regno == 70) {
+			/* Process the fcr31/fsr (register 70) */
+			memcpy(mem, (void *)&current->thread.fpu.fcr31,
+			       dbg_reg_def[regno].size);
+			goto out;
+		} else if (regno == 71) {
+			/* Ignore the fir (register 71) */
+			memset(mem, 0, dbg_reg_def[regno].size);
+			goto out;
+		}
+		fp_reg = dbg_reg_def[regno].offset;
+		memcpy(mem, (void *)&current->thread.fpu.fpr[fp_reg],
+		       dbg_reg_def[regno].size);
+	}
+
+out:
+	return dbg_reg_def[regno].name;
+
+}
+
 void arch_kgdb_breakpoint(void)
 {
 	__asm__ __volatile__(
@@ -84,64 +229,6 @@ static int compute_signal(int tt)
 	return SIGHUP;		/* default for things we don't know about */
 }
 
-void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
-{
-	int reg;
-
-#if (KGDB_GDB_REG_SIZE == 32)
-	u32 *ptr = (u32 *)gdb_regs;
-#else
-	u64 *ptr = (u64 *)gdb_regs;
-#endif
-
-	for (reg = 0; reg < 32; reg++)
-		*(ptr++) = regs->regs[reg];
-
-	*(ptr++) = regs->cp0_status;
-	*(ptr++) = regs->lo;
-	*(ptr++) = regs->hi;
-	*(ptr++) = regs->cp0_badvaddr;
-	*(ptr++) = regs->cp0_cause;
-	*(ptr++) = regs->cp0_epc;
-
-	/* FP REGS */
-	if (!(current && (regs->cp0_status & ST0_CU1)))
-		return;
-
-	save_fp(current);
-	for (reg = 0; reg < 32; reg++)
-		*(ptr++) = current->thread.fpu.fpr[reg];
-}
-
-void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
-{
-	int reg;
-
-#if (KGDB_GDB_REG_SIZE == 32)
-	const u32 *ptr = (u32 *)gdb_regs;
-#else
-	const u64 *ptr = (u64 *)gdb_regs;
-#endif
-
-	for (reg = 0; reg < 32; reg++)
-		regs->regs[reg] = *(ptr++);
-
-	regs->cp0_status = *(ptr++);
-	regs->lo = *(ptr++);
-	regs->hi = *(ptr++);
-	regs->cp0_badvaddr = *(ptr++);
-	regs->cp0_cause = *(ptr++);
-	regs->cp0_epc = *(ptr++);
-
-	/* FP REGS from current */
-	if (!(current && (regs->cp0_status & ST0_CU1)))
-		return;
-
-	for (reg = 0; reg < 32; reg++)
-		current->thread.fpu.fpr[reg] = *(ptr++);
-	restore_fp(current);
-}
-
 /*
  * Similar to regs_to_gdb_regs() except that process is sleeping and so
  * we may not be able to get all the info.
@@ -242,7 +329,7 @@ static struct notifier_block kgdb_notifier = {
 };
 
 /*
- * Handle the 's' and 'c' commands
+ * Handle the 'c' command
  */
 int kgdb_arch_handle_exception(int vector, int signo, int err_code,
 			       char *remcom_in_buffer, char *remcom_out_buffer,
@@ -250,20 +337,14 @@ int kgdb_arch_handle_exception(int vector, int signo, int err_code,
 {
 	char *ptr;
 	unsigned long address;
-	int cpu = smp_processor_id();
 
 	switch (remcom_in_buffer[0]) {
-	case 's':
 	case 'c':
 		/* handle the optional parameter */
 		ptr = &remcom_in_buffer[1];
 		if (kgdb_hex2long(&ptr, &address))
 			regs->cp0_epc = address;
 
-		atomic_set(&kgdb_cpu_doing_single_step, -1);
-		if (remcom_in_buffer[0] == 's')
-			atomic_set(&kgdb_cpu_doing_single_step, cpu);
-
 		return 0;
 	}
 
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index 82a7b228c81a..7f61a3ac787c 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -129,7 +129,7 @@ static int kgdb_handle_breakpoint(struct pt_regs *regs)
 		return 0;
 
 	if (*(u32 *) (regs->nip) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
-		regs->nip += 4;
+		regs->nip += BREAK_INSTR_SIZE;
 
 	return 1;
 }
diff --git a/arch/x86/include/asm/kgdb.h b/arch/x86/include/asm/kgdb.h
index 006da3687cdc..396f5b5fc4d7 100644
--- a/arch/x86/include/asm/kgdb.h
+++ b/arch/x86/include/asm/kgdb.h
@@ -39,9 +39,11 @@ enum regnames {
 	GDB_FS,			/* 14 */
 	GDB_GS,			/* 15 */
 };
+#define GDB_ORIG_AX		41
+#define DBG_MAX_REG_NUM		16
 #define NUMREGBYTES		((GDB_GS+1)*4)
 #else /* ! CONFIG_X86_32 */
-enum regnames64 {
+enum regnames {
 	GDB_AX,			/* 0 */
 	GDB_BX,			/* 1 */
 	GDB_CX,			/* 2 */
@@ -59,15 +61,15 @@ enum regnames64 {
 	GDB_R14,		/* 14 */
 	GDB_R15,		/* 15 */
 	GDB_PC,			/* 16 */
+	GDB_PS,			/* 17 */
+	GDB_CS,			/* 18 */
+	GDB_SS,			/* 19 */
 };
-
-enum regnames32 {
-	GDB_PS = 34,
-	GDB_CS,
-	GDB_SS,
-};
-#define NUMREGBYTES		((GDB_SS+1)*4)
-#endif /* CONFIG_X86_32 */
+#define GDB_ORIG_AX		57
+#define DBG_MAX_REG_NUM		20
+/* 17 64 bit regs and 3 32 bit regs */
+#define NUMREGBYTES		((17 * 8) + (3 * 4))
+#endif /* ! CONFIG_X86_32 */
 
 static inline void arch_kgdb_breakpoint(void)
 {
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 01ab17ae2ae7..ef10940e1af0 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -49,55 +49,94 @@
 #include <asm/system.h>
 #include <asm/apic.h>
 
-/**
- *	pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
- *	@gdb_regs: A pointer to hold the registers in the order GDB wants.
- *	@regs: The &struct pt_regs of the current process.
- *
- *	Convert the pt_regs in @regs into the format for registers that
- *	GDB expects, stored in @gdb_regs.
- */
-void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
 {
-#ifndef CONFIG_X86_32
-	u32 *gdb_regs32 = (u32 *)gdb_regs;
+#ifdef CONFIG_X86_32
+	{ "ax", 4, offsetof(struct pt_regs, ax) },
+	{ "cx", 4, offsetof(struct pt_regs, cx) },
+	{ "dx", 4, offsetof(struct pt_regs, dx) },
+	{ "bx", 4, offsetof(struct pt_regs, bx) },
+	{ "sp", 4, offsetof(struct pt_regs, sp) },
+	{ "bp", 4, offsetof(struct pt_regs, bp) },
+	{ "si", 4, offsetof(struct pt_regs, si) },
+	{ "di", 4, offsetof(struct pt_regs, di) },
+	{ "ip", 4, offsetof(struct pt_regs, ip) },
+	{ "flags", 4, offsetof(struct pt_regs, flags) },
+	{ "cs", 4, offsetof(struct pt_regs, cs) },
+	{ "ss", 4, offsetof(struct pt_regs, ss) },
+	{ "ds", 4, offsetof(struct pt_regs, ds) },
+	{ "es", 4, offsetof(struct pt_regs, es) },
+	{ "fs", 4, -1 },
+	{ "gs", 4, -1 },
+#else
+	{ "ax", 8, offsetof(struct pt_regs, ax) },
+	{ "bx", 8, offsetof(struct pt_regs, bx) },
+	{ "cx", 8, offsetof(struct pt_regs, cx) },
+	{ "dx", 8, offsetof(struct pt_regs, dx) },
+	{ "si", 8, offsetof(struct pt_regs, dx) },
+	{ "di", 8, offsetof(struct pt_regs, di) },
+	{ "bp", 8, offsetof(struct pt_regs, bp) },
+	{ "sp", 8, offsetof(struct pt_regs, sp) },
+	{ "r8", 8, offsetof(struct pt_regs, r8) },
+	{ "r9", 8, offsetof(struct pt_regs, r9) },
+	{ "r10", 8, offsetof(struct pt_regs, r10) },
+	{ "r11", 8, offsetof(struct pt_regs, r11) },
+	{ "r12", 8, offsetof(struct pt_regs, r12) },
+	{ "r13", 8, offsetof(struct pt_regs, r13) },
+	{ "r14", 8, offsetof(struct pt_regs, r14) },
+	{ "r15", 8, offsetof(struct pt_regs, r15) },
+	{ "ip", 8, offsetof(struct pt_regs, ip) },
+	{ "flags", 4, offsetof(struct pt_regs, flags) },
+	{ "cs", 4, offsetof(struct pt_regs, cs) },
+	{ "ss", 4, offsetof(struct pt_regs, ss) },
 #endif
-	gdb_regs[GDB_AX]	= regs->ax;
-	gdb_regs[GDB_BX]	= regs->bx;
-	gdb_regs[GDB_CX]	= regs->cx;
-	gdb_regs[GDB_DX]	= regs->dx;
-	gdb_regs[GDB_SI]	= regs->si;
-	gdb_regs[GDB_DI]	= regs->di;
-	gdb_regs[GDB_BP]	= regs->bp;
-	gdb_regs[GDB_PC]	= regs->ip;
+};
+
+int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	if (
 #ifdef CONFIG_X86_32
-	gdb_regs[GDB_PS]	= regs->flags;
-	gdb_regs[GDB_DS]	= regs->ds;
-	gdb_regs[GDB_ES]	= regs->es;
-	gdb_regs[GDB_CS]	= regs->cs;
-	gdb_regs[GDB_FS]	= 0xFFFF;
-	gdb_regs[GDB_GS]	= 0xFFFF;
-	if (user_mode_vm(regs)) {
-		gdb_regs[GDB_SS] = regs->ss;
-		gdb_regs[GDB_SP] = regs->sp;
-	} else {
-		gdb_regs[GDB_SS] = __KERNEL_DS;
-		gdb_regs[GDB_SP] = kernel_stack_pointer(regs);
+	    regno == GDB_SS || regno == GDB_FS || regno == GDB_GS ||
+#endif
+	    regno == GDB_SP || regno == GDB_ORIG_AX)
+		return 0;
+
+	if (dbg_reg_def[regno].offset != -1)
+		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
+		       dbg_reg_def[regno].size);
+	return 0;
+}
+
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	if (regno == GDB_ORIG_AX) {
+		memcpy(mem, &regs->orig_ax, sizeof(regs->orig_ax));
+		return "orig_ax";
 	}
-#else
-	gdb_regs[GDB_R8]	= regs->r8;
-	gdb_regs[GDB_R9]	= regs->r9;
-	gdb_regs[GDB_R10]	= regs->r10;
-	gdb_regs[GDB_R11]	= regs->r11;
-	gdb_regs[GDB_R12]	= regs->r12;
-	gdb_regs[GDB_R13]	= regs->r13;
-	gdb_regs[GDB_R14]	= regs->r14;
-	gdb_regs[GDB_R15]	= regs->r15;
-	gdb_regs32[GDB_PS]	= regs->flags;
-	gdb_regs32[GDB_CS]	= regs->cs;
-	gdb_regs32[GDB_SS]	= regs->ss;
-	gdb_regs[GDB_SP]	= kernel_stack_pointer(regs);
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return NULL;
+
+	if (dbg_reg_def[regno].offset != -1)
+		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
+		       dbg_reg_def[regno].size);
+
+	switch (regno) {
+#ifdef CONFIG_X86_32
+	case GDB_SS:
+		if (!user_mode_vm(regs))
+			*(unsigned long *)mem = __KERNEL_DS;
+		break;
+	case GDB_SP:
+		if (!user_mode_vm(regs))
+			*(unsigned long *)mem = kernel_stack_pointer(regs);
+		break;
+	case GDB_GS:
+	case GDB_FS:
+		*(unsigned long *)mem = 0xFFFF;
+		break;
 #endif
+	}
+	return dbg_reg_def[regno].name;
 }
 
 /**
@@ -150,54 +189,13 @@ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
 	gdb_regs[GDB_SP]	= p->thread.sp;
 }
 
-/**
- *	gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
- *	@gdb_regs: A pointer to hold the registers we've received from GDB.
- *	@regs: A pointer to a &struct pt_regs to hold these values in.
- *
- *	Convert the GDB regs in @gdb_regs into the pt_regs, and store them
- *	in @regs.
- */
-void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
-{
-#ifndef CONFIG_X86_32
-	u32 *gdb_regs32 = (u32 *)gdb_regs;
-#endif
-	regs->ax		= gdb_regs[GDB_AX];
-	regs->bx		= gdb_regs[GDB_BX];
-	regs->cx		= gdb_regs[GDB_CX];
-	regs->dx		= gdb_regs[GDB_DX];
-	regs->si		= gdb_regs[GDB_SI];
-	regs->di		= gdb_regs[GDB_DI];
-	regs->bp		= gdb_regs[GDB_BP];
-	regs->ip		= gdb_regs[GDB_PC];
-#ifdef CONFIG_X86_32
-	regs->flags		= gdb_regs[GDB_PS];
-	regs->ds		= gdb_regs[GDB_DS];
-	regs->es		= gdb_regs[GDB_ES];
-	regs->cs		= gdb_regs[GDB_CS];
-#else
-	regs->r8		= gdb_regs[GDB_R8];
-	regs->r9		= gdb_regs[GDB_R9];
-	regs->r10		= gdb_regs[GDB_R10];
-	regs->r11		= gdb_regs[GDB_R11];
-	regs->r12		= gdb_regs[GDB_R12];
-	regs->r13		= gdb_regs[GDB_R13];
-	regs->r14		= gdb_regs[GDB_R14];
-	regs->r15		= gdb_regs[GDB_R15];
-	regs->flags		= gdb_regs32[GDB_PS];
-	regs->cs		= gdb_regs32[GDB_CS];
-	regs->ss		= gdb_regs32[GDB_SS];
-#endif
-}
-
 static struct hw_breakpoint {
 	unsigned		enabled;
 	unsigned long		addr;
 	int			len;
 	int			type;
 	struct perf_event	**pev;
-} breakinfo[4];
+} breakinfo[HBP_NUM];
 
 static unsigned long early_dr7;
 
@@ -205,7 +203,7 @@ static void kgdb_correct_hw_break(void)
 {
 	int breakno;
 
-	for (breakno = 0; breakno < 4; breakno++) {
+	for (breakno = 0; breakno < HBP_NUM; breakno++) {
 		struct perf_event *bp;
 		struct arch_hw_breakpoint *info;
 		int val;
@@ -292,10 +290,10 @@ kgdb_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype)
 {
 	int i;
 
-	for (i = 0; i < 4; i++)
+	for (i = 0; i < HBP_NUM; i++)
 		if (breakinfo[i].addr == addr && breakinfo[i].enabled)
 			break;
-	if (i == 4)
+	if (i == HBP_NUM)
 		return -1;
 
 	if (hw_break_release_slot(i)) {
@@ -313,7 +311,7 @@ static void kgdb_remove_all_hw_break(void)
 	int cpu = raw_smp_processor_id();
 	struct perf_event *bp;
 
-	for (i = 0; i < 4; i++) {
+	for (i = 0; i < HBP_NUM; i++) {
 		if (!breakinfo[i].enabled)
 			continue;
 		bp = *per_cpu_ptr(breakinfo[i].pev, cpu);
@@ -333,10 +331,10 @@ kgdb_set_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype)
 {
 	int i;
 
-	for (i = 0; i < 4; i++)
+	for (i = 0; i < HBP_NUM; i++)
 		if (!breakinfo[i].enabled)
 			break;
-	if (i == 4)
+	if (i == HBP_NUM)
 		return -1;
 
 	switch (bptype) {
@@ -397,7 +395,7 @@ void kgdb_disable_hw_debug(struct pt_regs *regs)
 
 	/* Disable hardware debugging while we are in kgdb: */
 	set_debugreg(0UL, 7);
-	for (i = 0; i < 4; i++) {
+	for (i = 0; i < HBP_NUM; i++) {
 		if (!breakinfo[i].enabled)
 			continue;
 		if (dbg_is_early) {
@@ -458,7 +456,6 @@ int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 {
 	unsigned long addr;
 	char *ptr;
-	int newPC;
 
 	switch (remcomInBuffer[0]) {
 	case 'c':
@@ -469,8 +466,6 @@ int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 			linux_regs->ip = addr;
 	case 'D':
 	case 'k':
-		newPC = linux_regs->ip;
-
 		/* clear the trace bit */
 		linux_regs->flags &= ~X86_EFLAGS_TF;
 		atomic_set(&kgdb_cpu_doing_single_step, -1);
@@ -645,7 +640,7 @@ void kgdb_arch_late(void)
 	attr.bp_len = HW_BREAKPOINT_LEN_1;
 	attr.bp_type = HW_BREAKPOINT_W;
 	attr.disabled = 1;
-	for (i = 0; i < 4; i++) {
+	for (i = 0; i < HBP_NUM; i++) {
 		if (breakinfo[i].pev)
 			continue;
 		breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL);