x86: kgdb support

	select HAVE_KPROBES

	select HAVE_KRETPROBES

	select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)

	select HAVE_ARCH_KGDB

config GENERIC_LOCKBREAK

obj-$(CONFIG_ACPI_SRAT) 	+= srat_32.o

obj-$(CONFIG_EFI) 		+= efi.o efi_$(BITS).o efi_stub_$(BITS).o

obj-$(CONFIG_DOUBLEFAULT) 	+= doublefault_32.o

obj-$(CONFIG_KGDB)		+= kgdb.o

obj-$(CONFIG_VM86)		+= vm86_32.o

obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o

/*

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the

 * Free Software Foundation; either version 2, or (at your option) any

 * later version.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 *

 */

/*

 * Copyright (C) 2004 Amit S. Kale <amitkale@linsyssoft.com>

 * Copyright (C) 2000-2001 VERITAS Software Corporation.

 * Copyright (C) 2002 Andi Kleen, SuSE Labs

 * Copyright (C) 2004 LinSysSoft Technologies Pvt. Ltd.

 * Copyright (C) 2007 MontaVista Software, Inc.

 * Copyright (C) 2007-2008 Jason Wessel, Wind River Systems, Inc.

 */

/****************************************************************************

 *  Contributor:     Lake Stevens Instrument Division$

 *  Written by:      Glenn Engel $

 *  Updated by:	     Amit Kale<akale@veritas.com>

 *  Updated by:	     Tom Rini <trini@kernel.crashing.org>

 *  Updated by:	     Jason Wessel <jason.wessel@windriver.com>

 *  Modified for 386 by Jim Kingdon, Cygnus Support.

 *  Origianl kgdb, compatibility with 2.1.xx kernel by

 *  David Grothe <dave@gcom.com>

 *  Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com>

 *  X86_64 changes from Andi Kleen's patch merged by Jim Houston

 */

#include <linux/spinlock.h>

#include <linux/kdebug.h>

#include <linux/string.h>

#include <linux/kernel.h>

#include <linux/ptrace.h>

#include <linux/sched.h>

#include <linux/delay.h>

#include <linux/kgdb.h>

#include <linux/init.h>

#include <linux/smp.h>

#include <asm/apicdef.h>

#include <asm/system.h>

#ifdef CONFIG_X86_32

# include <mach_ipi.h>

#else

# include <asm/mach_apic.h>

#endif

/*

 * Put the error code here just in case the user cares:

 */

static int gdb_x86errcode;

/*

 * Likewise, the vector number here (since GDB only gets the signal

 * number through the usual means, and that's not very specific):

 */

static int gdb_x86vector = -1;

/**

 *	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)

{

	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_PS]	= regs->flags;

	gdb_regs[GDB_PC]	= regs->ip;

#ifdef CONFIG_X86_32

	gdb_regs[GDB_DS]	= regs->ds;

	gdb_regs[GDB_ES]	= regs->es;

	gdb_regs[GDB_CS]	= regs->cs;

	gdb_regs[GDB_SS]	= __KERNEL_DS;

	gdb_regs[GDB_FS]	= 0xFFFF;

	gdb_regs[GDB_GS]	= 0xFFFF;

#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;

#endif

	gdb_regs[GDB_SP]	= regs->sp;

}

/**

 *	sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs

 *	@gdb_regs: A pointer to hold the registers in the order GDB wants.

 *	@p: The &struct task_struct of the desired process.

 *

 *	Convert the register values of the sleeping process in @p to

 *	the format that GDB expects.

 *	This function is called when kgdb does not have access to the

 *	&struct pt_regs and therefore it should fill the gdb registers

 *	@gdb_regs with what has	been saved in &struct thread_struct

 *	thread field during switch_to.

 */

void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)

{

	gdb_regs[GDB_AX]	= 0;

	gdb_regs[GDB_BX]	= 0;

	gdb_regs[GDB_CX]	= 0;

	gdb_regs[GDB_DX]	= 0;

	gdb_regs[GDB_SI]	= 0;

	gdb_regs[GDB_DI]	= 0;

	gdb_regs[GDB_BP]	= *(unsigned long *)p->thread.sp;

#ifdef CONFIG_X86_32

	gdb_regs[GDB_DS]	= __KERNEL_DS;

	gdb_regs[GDB_ES]	= __KERNEL_DS;

	gdb_regs[GDB_PS]	= 0;

	gdb_regs[GDB_CS]	= __KERNEL_CS;

	gdb_regs[GDB_PC]	= p->thread.ip;

	gdb_regs[GDB_SS]	= __KERNEL_DS;

	gdb_regs[GDB_FS]	= 0xFFFF;

	gdb_regs[GDB_GS]	= 0xFFFF;

#else

	gdb_regs[GDB_PS]	= *(unsigned long *)(p->thread.sp + 8);

	gdb_regs[GDB_PC]	= 0;

	gdb_regs[GDB_R8]	= 0;

	gdb_regs[GDB_R9]	= 0;

	gdb_regs[GDB_R10]	= 0;

	gdb_regs[GDB_R11]	= 0;

	gdb_regs[GDB_R12]	= 0;

	gdb_regs[GDB_R13]	= 0;

	gdb_regs[GDB_R14]	= 0;

	gdb_regs[GDB_R15]	= 0;

#endif

	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)

{

	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->flags		= gdb_regs[GDB_PS];

	regs->ip		= gdb_regs[GDB_PC];

#ifdef CONFIG_X86_32

	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];

#endif

}

/**

 *	kgdb_post_primary_code - Save error vector/code numbers.

 *	@regs: Original pt_regs.

 *	@e_vector: Original error vector.

 *	@err_code: Original error code.

 *

 *	This is needed on architectures which support SMP and KGDB.

 *	This function is called after all the slave cpus have been put

 *	to a know spin state and the primary CPU has control over KGDB.

 */

void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code)

{

	/* primary processor is completely in the debugger */

	gdb_x86vector = e_vector;

	gdb_x86errcode = err_code;

}

#ifdef CONFIG_SMP

/**

 *	kgdb_roundup_cpus - Get other CPUs into a holding pattern

 *	@flags: Current IRQ state

 *

 *	On SMP systems, we need to get the attention of the other CPUs

 *	and get them be in a known state.  This should do what is needed

 *	to get the other CPUs to call kgdb_wait(). Note that on some arches,

 *	the NMI approach is not used for rounding up all the CPUs. For example,

 *	in case of MIPS, smp_call_function() is used to roundup CPUs. In

 *	this case, we have to make sure that interrupts are enabled before

 *	calling smp_call_function(). The argument to this function is

 *	the flags that will be used when restoring the interrupts. There is

 *	local_irq_save() call before kgdb_roundup_cpus().

 *

 *	On non-SMP systems, this is not called.

 */

void kgdb_roundup_cpus(unsigned long flags)

{

	send_IPI_allbutself(APIC_DM_NMI);

}

#endif

/**

 *	kgdb_arch_handle_exception - Handle architecture specific GDB packets.

 *	@vector: The error vector of the exception that happened.

 *	@signo: The signal number of the exception that happened.

 *	@err_code: The error code of the exception that happened.

 *	@remcom_in_buffer: The buffer of the packet we have read.

 *	@remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.

 *	@regs: The &struct pt_regs of the current process.

 *

 *	This function MUST handle the 'c' and 's' command packets,

 *	as well packets to set / remove a hardware breakpoint, if used.

 *	If there are additional packets which the hardware needs to handle,

 *	they are handled here.  The code should return -1 if it wants to

 *	process more packets, and a %0 or %1 if it wants to exit from the

 *	kgdb callback.

 */

int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,

			       char *remcomInBuffer, char *remcomOutBuffer,

			       struct pt_regs *linux_regs)

{

	unsigned long addr;

	char *ptr;

	int newPC;

	switch (remcomInBuffer[0]) {

	case 'c':

	case 's':

		/* try to read optional parameter, pc unchanged if no parm */

		ptr = &remcomInBuffer[1];

		if (kgdb_hex2long(&ptr, &addr))

			linux_regs->ip = addr;

		newPC = linux_regs->ip;

		/* clear the trace bit */

		linux_regs->flags &= ~TF_MASK;

		atomic_set(&kgdb_cpu_doing_single_step, -1);

		/* set the trace bit if we're stepping */

		if (remcomInBuffer[0] == 's') {

			linux_regs->flags |= TF_MASK;

			kgdb_single_step = 1;

			if (kgdb_contthread) {

				atomic_set(&kgdb_cpu_doing_single_step,

					   raw_smp_processor_id());

			}

		}

		return 0;

	}

	/* this means that we do not want to exit from the handler: */

	return -1;

}

static inline int

single_step_cont(struct pt_regs *regs, struct die_args *args)

{

	/*

	 * Single step exception from kernel space to user space so

	 * eat the exception and continue the process:

	 */

	printk(KERN_ERR "KGDB: trap/step from kernel to user space, "

			"resuming...\n");

	kgdb_arch_handle_exception(args->trapnr, args->signr,

				   args->err, "c", "", regs);

	return NOTIFY_STOP;

}

static int __kgdb_notify(struct die_args *args, unsigned long cmd)

{

	struct pt_regs *regs = args->regs;

	switch (cmd) {

	case DIE_NMI:

		if (atomic_read(&kgdb_active) != -1) {

			/* KGDB CPU roundup */

			kgdb_nmicallback(raw_smp_processor_id(), regs);

			return NOTIFY_STOP;

		}

		return NOTIFY_DONE;

	case DIE_NMI_IPI:

		if (atomic_read(&kgdb_active) != -1) {

			/* KGDB CPU roundup: */

			if (kgdb_nmicallback(raw_smp_processor_id(), regs))

				return NOTIFY_DONE;

			return NOTIFY_STOP;

		}

		return NOTIFY_DONE;

	case DIE_NMIWATCHDOG:

		if (atomic_read(&kgdb_active) != -1) {

			/* KGDB CPU roundup: */

			kgdb_nmicallback(raw_smp_processor_id(), regs);

			return NOTIFY_STOP;

		}

		/* Enter debugger: */

		break;

	case DIE_DEBUG:

		if (atomic_read(&kgdb_cpu_doing_single_step) ==

			raw_smp_processor_id() &&

			user_mode(regs))

			return single_step_cont(regs, args);

		/* fall through */

	default:

		if (user_mode(regs))

			return NOTIFY_DONE;

	}

	if (kgdb_handle_exception(args->trapnr, args->signr, args->err, 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,

	/*

	 * Lowest-prio notifier priority, we want to be notified last:

	 */

	.priority	= -INT_MAX,

};

/**

 *	kgdb_arch_init - Perform any architecture specific initalization.

 *

 *	This function will handle the initalization of any architecture

 *	specific callbacks.

 */

int kgdb_arch_init(void)

{

	return register_die_notifier(&kgdb_notifier);

}

/**

 *	kgdb_arch_exit - Perform any architecture specific uninitalization.

 *

 *	This function will handle the uninitalization of any architecture

 *	specific callbacks, for dynamic registration and unregistration.

 */

void kgdb_arch_exit(void)

{

	unregister_die_notifier(&kgdb_notifier);

}

/**

 *

 *	kgdb_skipexception - Bail out of KGDB when we've been triggered.

 *	@exception: Exception vector number

 *	@regs: Current &struct pt_regs.

 *

 *	On some architectures we need to skip a breakpoint exception when

 *	it occurs after a breakpoint has been removed.

 *

 * Skip an int3 exception when it occurs after a breakpoint has been

 * removed. Backtrack eip by 1 since the int3 would have caused it to

 * increment by 1.

 */

int kgdb_skipexception(int exception, struct pt_regs *regs)

{

	if (exception == 3 && kgdb_isremovedbreak(regs->ip - 1)) {

		regs->ip -= 1;

		return 1;

	}

	return 0;

}

unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs)

{

	if (exception == 3)

		return instruction_pointer(regs) - 1;

	return instruction_pointer(regs);

}

struct kgdb_arch arch_kgdb_ops = {

	/* Breakpoint instruction: */

	.gdb_bpt_instr		= { 0xcc },

};

#ifndef _ASM_KGDB_H_

#define _ASM_KGDB_H_

/*

 * Copyright (C) 2001-2004 Amit S. Kale

 * Copyright (C) 2008 Wind River Systems, Inc.

 */

/*

 * BUFMAX defines the maximum number of characters in inbound/outbound

 * buffers at least NUMREGBYTES*2 are needed for register packets

 * Longer buffer is needed to list all threads

 */

#define BUFMAX			1024

/*

 *  Note that this register image is in a different order than

 *  the register image that Linux produces at interrupt time.

 *

 *  Linux's register image is defined by struct pt_regs in ptrace.h.

 *  Just why GDB uses a different order is a historical mystery.

 */

#ifdef CONFIG_X86_32

enum regnames {

	GDB_AX,			/* 0 */

	GDB_CX,			/* 1 */

	GDB_DX,			/* 2 */

	GDB_BX,			/* 3 */

	GDB_SP,			/* 4 */

	GDB_BP,			/* 5 */

	GDB_SI,			/* 6 */

	GDB_DI,			/* 7 */

	GDB_PC,			/* 8 also known as eip */

	GDB_PS,			/* 9 also known as eflags */

	GDB_CS,			/* 10 */

	GDB_SS,			/* 11 */

	GDB_DS,			/* 12 */

	GDB_ES,			/* 13 */

	GDB_FS,			/* 14 */

	GDB_GS,			/* 15 */

};

#else /* ! CONFIG_X86_32 */

enum regnames {

	GDB_AX,			/* 0 */

	GDB_DX,			/* 1 */

	GDB_CX,			/* 2 */

	GDB_BX,			/* 3 */

	GDB_SI,			/* 4 */

	GDB_DI,			/* 5 */

	GDB_BP,			/* 6 */

	GDB_SP,			/* 7 */

	GDB_R8,			/* 8 */

	GDB_R9,			/* 9 */

	GDB_R10,		/* 10 */

	GDB_R11,		/* 11 */

	GDB_R12,		/* 12 */

	GDB_R13,		/* 13 */

	GDB_R14,		/* 14 */

	GDB_R15,		/* 15 */

	GDB_PC,			/* 16 */

	GDB_PS,			/* 17 */

};

#endif /* CONFIG_X86_32 */

/*

 * Number of bytes of registers:

 */

#ifdef CONFIG_X86_32

# define NUMREGBYTES		64

#else

# define NUMREGBYTES		((GDB_PS+1)*8)

#endif

static inline void arch_kgdb_breakpoint(void)

{

	asm("   int $3");

}

#define BREAK_INSTR_SIZE	1

#define CACHE_FLUSH_IS_SAFE	1

#endif				/* _ASM_KGDB_H_ */