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/*

 * Copyright (C) 2006 Ondrej Palkovsky

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include <arch/debugger.h>

#include <console/kconsole.h>

#include <console/cmd.h>

#include <symtab.h>

#include <print.h>

#include <panic.h>

#include <interrupt.h>

#include <arch/asm.h>

#include <arch/cpu.h>

#include <debug.h>

#include <func.h>

typedef struct  {

	__address address;      /**< Breakpoint address */

	int flags;              /**< Flags regarding breakpoint */

	int counter;            /**< How many times the exception occured */

} bpinfo_t;

static bpinfo_t breakpoints[BKPOINTS_MAX];

SPINLOCK_INITIALIZE(bkpoint_lock);

static int cmd_print_breakpoints(cmd_arg_t *argv);

static cmd_info_t bkpts_info = {

	.name = "bkpts",

	.description = "Print breakpoint table.",

	.func = cmd_print_breakpoints,

	.argc = 0,

};

static int cmd_del_breakpoint(cmd_arg_t *argv);

static cmd_arg_t del_argv = {

	.type = ARG_TYPE_INT

};

static cmd_info_t delbkpt_info = {

	.name = "delbkpt",

	.description = "delbkpt <number> - Delete breakpoint.",

	.func = cmd_del_breakpoint,

	.argc = 1,

	.argv = &del_argv

};

static int cmd_add_breakpoint(cmd_arg_t *argv);

static cmd_arg_t add_argv = {

	.type = ARG_TYPE_INT

};

static cmd_info_t addbkpt_info = {

	.name = "addbkpt",

	.description = "addbkpt <&symbol> - new breakpoint.",

	.func = cmd_add_breakpoint,

	.argc = 1,

	.argv = &add_argv

};

static cmd_arg_t addw_argv = {

	.type = ARG_TYPE_INT

};

static cmd_info_t addwatchp_info = {

	.name = "addwatchp",

	.description = "addbwatchp <&symbol> - new write watchpoint.",

	.func = cmd_add_breakpoint,

	.argc = 1,

	.argv = &addw_argv

};

/** Print table of active breakpoints */

int cmd_print_breakpoints(cmd_arg_t *argv)

{

	int i;

	char *symbol;

	printf("Breakpoint table.\n");

	for (i=0; i < BKPOINTS_MAX; i++)

		if (breakpoints[i].address) {

			symbol = get_symtab_entry(breakpoints[i].address);

			printf("%d. 0x%p in %s\n",i,

			       breakpoints[i].address, symbol);

			printf("     Count(%d) ", breakpoints[i].counter);

			printf("\n");

		}

	return 1;

}

/** Enable hardware breakpoint

 *

 *

 * @param where Address of HW breakpoint

 * @param flags Type of breakpoint (EXECUTE, WRITE)

 * @return Debug slot on success, -1 - no available HW breakpoint

 */

int breakpoint_add(void * where, int flags)

{

	bpinfo_t *cur = NULL;

	int curidx;

	ipl_t ipl;

	int i;

	__native dr7;

	ASSERT( flags & (BKPOINT_INSTR | BKPOINT_WRITE | BKPOINT_READ_WRITE));

	ipl = interrupts_disable();

	spinlock_lock(&bkpoint_lock);

	/* Find free space in slots */

	for (i=0; i<BKPOINTS_MAX; i++)

		if (!breakpoints[i].address) {

			cur = &breakpoints[i];

			curidx = i;

			break;

		}

	if (!cur) {

		/* Too many breakpoints */

		spinlock_unlock(&bkpoint_lock);

		interrupts_restore(ipl);

		return -1;

	}

	cur->address = (__address) where;

	cur->flags = flags;

	cur->counter = 0;

	/* Set breakpoint to debug registers */

	switch (curidx) {

	case 0:

		write_dr0(cur->address);

		break;

	case 1:

		write_dr1(cur->address);

		break;

	case 2:

		write_dr2(cur->address);

		break;

	case 3:

		write_dr3(cur->address);

		break;

	}

	dr7 = read_dr7();

	/* Set type to requested breakpoint & length*/

	dr7 &= ~ (0x3 << (16 + 4*curidx));

	dr7 &= ~ (0x3 << (18 + 4*curidx));

	if ((flags & BKPOINT_INSTR)) {

		printf("Instr breakpoint\n");

		;

	} else {

		if (sizeof(int) == 4)

			dr7 |= 0x3 << (18 + 4*curidx);

		else /* 8 */

			dr7 |= 0x2 << (18 + 4*curidx);

		if ((flags & BKPOINT_WRITE))

			dr7 |= 0x1 << (16 + 4*curidx);

		else if ((flags & BKPOINT_READ_WRITE))

			dr7 |= 0x3 << (16 + 4*curidx);

	}

	/* Enable global breakpoint */

	dr7 |= 0x2 << (curidx*2);

	write_dr7(dr7);

	spinlock_unlock(&bkpoint_lock);

	interrupts_restore(ipl);

	return curidx;

}

static void handle_exception(int slot, istate_t *istate)

{

	ASSERT(breakpoints[slot].address);

	/* Handle zero checker */

	if (! (breakpoints[slot].flags & BKPOINT_INSTR)) {

		if ((breakpoints[slot].flags & BKPOINT_CHECK_ZERO)) {

			if (*((__native *) breakpoints[slot].address) != 0)

				return;

			printf("**** Found ZERO on address %P ****\n",

			       slot, breakpoints[slot].address);

		} else {

			printf("Data watchpoint - new data: %P\n",

			       *((__native *) breakpoints[slot].address));

		}

	}

	printf("Reached breakpoint %d:%P(%s)\n", slot, istate->rip,

	       get_symtab_entry(istate->rip));

	printf("***Type 'exit' to exit kconsole.\n");

	atomic_set(&haltstate,1);

	kconsole("debug");

	atomic_set(&haltstate,0);

}

static void debug_exception(int n, istate_t *istate)

{

	__native dr6;

	int i;

	/* Set RF to restart the instruction  */

	istate->rflags |= RFLAGS_RF;

	dr6 = read_dr6();

	for (i=0; i < BKPOINTS_MAX; i++) {

		if (dr6 & (1 << i)) {

			dr6 &= ~ (1 << i);

			write_dr6(dr6);

			handle_exception(i, istate);

		}

	}

}

void breakpoint_del(int slot)

{

	bpinfo_t *cur;

	ipl_t ipl;

	__native dr7;

	ipl = interrupts_disable();

	spinlock_lock(&bkpoint_lock);

	cur = &breakpoints[slot];

	if (!cur->address) {

		spinlock_unlock(&bkpoint_lock);

		interrupts_restore(ipl);

		return;

	}

	cur->address = NULL;

	/* Disable breakpoint in DR7 */

	dr7 = read_dr7();

	dr7 &= ~(0x2 << (slot*2));

	write_dr7(dr7);

	spinlock_unlock(&bkpoint_lock);

	interrupts_restore(ipl);

}

/** Remove breakpoint from table */

int cmd_del_breakpoint(cmd_arg_t *argv)

{

	if (argv->intval < 0 || argv->intval > BKPOINTS_MAX) {

		printf("Invalid breakpoint number.\n");

		return 0;

	}

	breakpoint_del(argv->intval);

	return 1;

}

/** Add new breakpoint to table */

static int cmd_add_breakpoint(cmd_arg_t *argv)

{

	int flags;

	if (argv == &add_argv) {

		flags = BKPOINT_INSTR;

	} else { /* addwatchp */

		flags = BKPOINT_WRITE;

	}

	printf("Adding breakpoint on address: %p\n", argv->intval);

	if (breakpoint_add((void *)argv->intval, flags))

		printf("Add breakpoint failed.\n");

	return 1;

}

/** Initialize debugger */

void debugger_init()

{

	int i;

	for (i=0; i<BKPOINTS_MAX; i++)

		breakpoints[i].address = NULL;

	cmd_initialize(&bkpts_info);

	if (!cmd_register(&bkpts_info))

		panic("could not register command %s\n", bkpts_info.name);

	cmd_initialize(&delbkpt_info);

	if (!cmd_register(&delbkpt_info))

		panic("could not register command %s\n", delbkpt_info.name);

	cmd_initialize(&addbkpt_info);

	if (!cmd_register(&addbkpt_info))

		panic("could not register command %s\n", addbkpt_info.name);

	cmd_initialize(&addwatchp_info);

	if (!cmd_register(&addwatchp_info))

		panic("could not register command %s\n", addwatchp_info.name);

	exc_register(VECTOR_DEBUG, "debugger",

		     debug_exception);

}