arch/arm64/kernel/kgdb.c - linux - Git at Google

 /*
  * AArch64 KGDB support
  *
  * Based on arch/arm/kernel/kgdb.c
  *
  * Copyright (C) 2013 Cavium Inc.
  * Author: Vijaya Kumar K <vijaya.kumar@caviumnetworks.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * 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.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include <linux/irq.h>
 #include <linux/kdebug.h>
 #include <linux/kgdb.h>
 #include <asm/traps.h>

 struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
 	{ "x0", 8, offsetof(struct pt_regs, regs[0])},
 	{ "x1", 8, offsetof(struct pt_regs, regs[1])},
 	{ "x2", 8, offsetof(struct pt_regs, regs[2])},
 	{ "x3", 8, offsetof(struct pt_regs, regs[3])},
 	{ "x4", 8, offsetof(struct pt_regs, regs[4])},
 	{ "x5", 8, offsetof(struct pt_regs, regs[5])},
 	{ "x6", 8, offsetof(struct pt_regs, regs[6])},
 	{ "x7", 8, offsetof(struct pt_regs, regs[7])},
 	{ "x8", 8, offsetof(struct pt_regs, regs[8])},
 	{ "x9", 8, offsetof(struct pt_regs, regs[9])},
 	{ "x10", 8, offsetof(struct pt_regs, regs[10])},
 	{ "x11", 8, offsetof(struct pt_regs, regs[11])},
 	{ "x12", 8, offsetof(struct pt_regs, regs[12])},
 	{ "x13", 8, offsetof(struct pt_regs, regs[13])},
 	{ "x14", 8, offsetof(struct pt_regs, regs[14])},
 	{ "x15", 8, offsetof(struct pt_regs, regs[15])},
 	{ "x16", 8, offsetof(struct pt_regs, regs[16])},
 	{ "x17", 8, offsetof(struct pt_regs, regs[17])},
 	{ "x18", 8, offsetof(struct pt_regs, regs[18])},
 	{ "x19", 8, offsetof(struct pt_regs, regs[19])},
 	{ "x20", 8, offsetof(struct pt_regs, regs[20])},
 	{ "x21", 8, offsetof(struct pt_regs, regs[21])},
 	{ "x22", 8, offsetof(struct pt_regs, regs[22])},
 	{ "x23", 8, offsetof(struct pt_regs, regs[23])},
 	{ "x24", 8, offsetof(struct pt_regs, regs[24])},
 	{ "x25", 8, offsetof(struct pt_regs, regs[25])},
 	{ "x26", 8, offsetof(struct pt_regs, regs[26])},
 	{ "x27", 8, offsetof(struct pt_regs, regs[27])},
 	{ "x28", 8, offsetof(struct pt_regs, regs[28])},
 	{ "x29", 8, offsetof(struct pt_regs, regs[29])},
 	{ "x30", 8, offsetof(struct pt_regs, regs[30])},
 	{ "sp", 8, offsetof(struct pt_regs, sp)},
 	{ "pc", 8, offsetof(struct pt_regs, pc)},
 	{ "pstate", 8, offsetof(struct pt_regs, pstate)},
 	{ "v0", 16, -1 },
 	{ "v1", 16, -1 },
 	{ "v2", 16, -1 },
 	{ "v3", 16, -1 },
 	{ "v4", 16, -1 },
 	{ "v5", 16, -1 },
 	{ "v6", 16, -1 },
 	{ "v7", 16, -1 },
 	{ "v8", 16, -1 },
 	{ "v9", 16, -1 },
 	{ "v10", 16, -1 },
 	{ "v11", 16, -1 },
 	{ "v12", 16, -1 },
 	{ "v13", 16, -1 },
 	{ "v14", 16, -1 },
 	{ "v15", 16, -1 },
 	{ "v16", 16, -1 },
 	{ "v17", 16, -1 },
 	{ "v18", 16, -1 },
 	{ "v19", 16, -1 },
 	{ "v20", 16, -1 },
 	{ "v21", 16, -1 },
 	{ "v22", 16, -1 },
 	{ "v23", 16, -1 },
 	{ "v24", 16, -1 },
 	{ "v25", 16, -1 },
 	{ "v26", 16, -1 },
 	{ "v27", 16, -1 },
 	{ "v28", 16, -1 },
 	{ "v29", 16, -1 },
 	{ "v30", 16, -1 },
 	{ "v31", 16, -1 },
 	{ "fpsr", 4, -1 },
 	{ "fpcr", 4, -1 },
 };

 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;
 }

 int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
 {
 	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
 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
 {
 	struct pt_regs *thread_regs;

 	/* Initialize to zero */
 	memset((char *)gdb_regs, 0, NUMREGBYTES);
 	thread_regs = task_pt_regs(task);
 	memcpy((void *)gdb_regs, (void *)thread_regs->regs, GP_REG_BYTES);
 }

 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
 {
 	regs->pc = pc;
 }

 static int compiled_break;

 static void kgdb_arch_update_addr(struct pt_regs *regs,
 				char *remcom_in_buffer)
 {
 	unsigned long addr;
 	char *ptr;

 	ptr = &remcom_in_buffer[1];
 	if (kgdb_hex2long(&ptr, &addr))
 		kgdb_arch_set_pc(regs, addr);
 	else if (compiled_break == 1)
 		kgdb_arch_set_pc(regs, regs->pc + 4);

 	compiled_break = 0;
 }

 int kgdb_arch_handle_exception(int exception_vector, int signo,
 			       int err_code, char *remcom_in_buffer,
 			       char *remcom_out_buffer,
 			       struct pt_regs *linux_regs)
 {
 	int err;

 	switch (remcom_in_buffer[0]) {
 	case 'D':
 	case 'k':
 		/*
 		 * Packet D (Detach), k (kill). No special handling
 		 * is required here. Handle same as c packet.
 		 */
 	case 'c':
 		/*
 		 * Packet c (Continue) to continue executing.
 		 * Set pc to required address.
 		 * Try to read optional parameter and set pc.
 		 * If this was a compiled breakpoint, we need to move
 		 * to the next instruction else we will just breakpoint
 		 * over and over again.
 		 */
 		kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
 		atomic_set(&kgdb_cpu_doing_single_step, -1);
 		kgdb_single_step =  0;

 		/*
 		 * Received continue command, disable single step
 		 */
 		if (kernel_active_single_step())
 			kernel_disable_single_step();

 		err = 0;
 		break;
 	case 's':
 		/*
 		 * Update step address value with address passed
 		 * with step packet.
 		 * On debug exception return PC is copied to ELR
 		 * So just update PC.
 		 * If no step address is passed, resume from the address
 		 * pointed by PC. Do not update PC
 		 */
 		kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
 		atomic_set(&kgdb_cpu_doing_single_step, raw_smp_processor_id());
 		kgdb_single_step =  1;

 		/*
 		 * Enable single step handling
 		 */
 		if (!kernel_active_single_step())
 			kernel_enable_single_step(linux_regs);
 		err = 0;
 		break;
 	default:
 		err = -1;
 	}
 	return err;
 }

 static int kgdb_brk_fn(struct pt_regs *regs, unsigned int esr)
 {
 	kgdb_handle_exception(1, SIGTRAP, 0, regs);
 	return 0;
 }

 static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr)
 {
 	compiled_break = 1;
 	kgdb_handle_exception(1, SIGTRAP, 0, regs);

 	return 0;
 }

 static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned int esr)
 {
 	kgdb_handle_exception(1, SIGTRAP, 0, regs);
 	return 0;
 }

 static struct break_hook kgdb_brkpt_hook = {
 	.esr_mask	= 0xffffffff,
 	.esr_val	= DBG_ESR_VAL_BRK(KGDB_DYN_DBG_BRK_IMM),
 	.fn		= kgdb_brk_fn
 };

 static struct break_hook kgdb_compiled_brkpt_hook = {
 	.esr_mask	= 0xffffffff,
 	.esr_val	= DBG_ESR_VAL_BRK(KGDB_COMPILED_DBG_BRK_IMM),
 	.fn		= kgdb_compiled_brk_fn
 };

 static struct step_hook kgdb_step_hook = {
 	.fn		= kgdb_step_brk_fn
 };

 static void kgdb_call_nmi_hook(void *ignored)
 {
 	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
 }

 void kgdb_roundup_cpus(unsigned long flags)
 {
 	local_irq_enable();
 	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
 	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,
 	/*
 	 * Want to be lowest priority
 	 */
 	.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)
 {
 	int ret = register_die_notifier(&kgdb_notifier);

 	if (ret != 0)
 		return ret;

 	register_break_hook(&kgdb_brkpt_hook);
 	register_break_hook(&kgdb_compiled_brkpt_hook);
 	register_step_hook(&kgdb_step_hook);
 	return 0;
 }

 /*
  * 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_break_hook(&kgdb_brkpt_hook);
 	unregister_break_hook(&kgdb_compiled_brkpt_hook);
 	unregister_step_hook(&kgdb_step_hook);
 	unregister_die_notifier(&kgdb_notifier);
 }

 /*
  * ARM instructions are always in LE.
  * Break instruction is encoded in LE format
  */
 struct kgdb_arch arch_kgdb_ops = {
 	.gdb_bpt_instr = {
 		KGDB_DYN_BRK_INS_BYTE0,
 		KGDB_DYN_BRK_INS_BYTE1,
 		KGDB_DYN_BRK_INS_BYTE2,
 		KGDB_DYN_BRK_INS_BYTE3,
 	}
 };
	/*
	* AArch64 KGDB support
	*
	* Based on arch/arm/kernel/kgdb.c
	*
	* Copyright (C) 2013 Cavium Inc.
	* Author: Vijaya Kumar K <vijaya.kumar@caviumnetworks.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include <linux/irq.h>
	#include <linux/kdebug.h>
	#include <linux/kgdb.h>
	#include <asm/traps.h>

	struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
	{ "x0", 8, offsetof(struct pt_regs, regs[0])},
	{ "x1", 8, offsetof(struct pt_regs, regs[1])},
	{ "x2", 8, offsetof(struct pt_regs, regs[2])},
	{ "x3", 8, offsetof(struct pt_regs, regs[3])},
	{ "x4", 8, offsetof(struct pt_regs, regs[4])},
	{ "x5", 8, offsetof(struct pt_regs, regs[5])},
	{ "x6", 8, offsetof(struct pt_regs, regs[6])},
	{ "x7", 8, offsetof(struct pt_regs, regs[7])},
	{ "x8", 8, offsetof(struct pt_regs, regs[8])},
	{ "x9", 8, offsetof(struct pt_regs, regs[9])},
	{ "x10", 8, offsetof(struct pt_regs, regs[10])},
	{ "x11", 8, offsetof(struct pt_regs, regs[11])},
	{ "x12", 8, offsetof(struct pt_regs, regs[12])},
	{ "x13", 8, offsetof(struct pt_regs, regs[13])},
	{ "x14", 8, offsetof(struct pt_regs, regs[14])},
	{ "x15", 8, offsetof(struct pt_regs, regs[15])},
	{ "x16", 8, offsetof(struct pt_regs, regs[16])},
	{ "x17", 8, offsetof(struct pt_regs, regs[17])},
	{ "x18", 8, offsetof(struct pt_regs, regs[18])},
	{ "x19", 8, offsetof(struct pt_regs, regs[19])},
	{ "x20", 8, offsetof(struct pt_regs, regs[20])},
	{ "x21", 8, offsetof(struct pt_regs, regs[21])},
	{ "x22", 8, offsetof(struct pt_regs, regs[22])},
	{ "x23", 8, offsetof(struct pt_regs, regs[23])},
	{ "x24", 8, offsetof(struct pt_regs, regs[24])},
	{ "x25", 8, offsetof(struct pt_regs, regs[25])},
	{ "x26", 8, offsetof(struct pt_regs, regs[26])},
	{ "x27", 8, offsetof(struct pt_regs, regs[27])},
	{ "x28", 8, offsetof(struct pt_regs, regs[28])},
	{ "x29", 8, offsetof(struct pt_regs, regs[29])},
	{ "x30", 8, offsetof(struct pt_regs, regs[30])},
	{ "sp", 8, offsetof(struct pt_regs, sp)},
	{ "pc", 8, offsetof(struct pt_regs, pc)},
	{ "pstate", 8, offsetof(struct pt_regs, pstate)},
	{ "v0", 16, -1 },
	{ "v1", 16, -1 },
	{ "v2", 16, -1 },
	{ "v3", 16, -1 },
	{ "v4", 16, -1 },
	{ "v5", 16, -1 },
	{ "v6", 16, -1 },
	{ "v7", 16, -1 },
	{ "v8", 16, -1 },
	{ "v9", 16, -1 },
	{ "v10", 16, -1 },
	{ "v11", 16, -1 },
	{ "v12", 16, -1 },
	{ "v13", 16, -1 },
	{ "v14", 16, -1 },
	{ "v15", 16, -1 },
	{ "v16", 16, -1 },
	{ "v17", 16, -1 },
	{ "v18", 16, -1 },
	{ "v19", 16, -1 },
	{ "v20", 16, -1 },
	{ "v21", 16, -1 },
	{ "v22", 16, -1 },
	{ "v23", 16, -1 },
	{ "v24", 16, -1 },
	{ "v25", 16, -1 },
	{ "v26", 16, -1 },
	{ "v27", 16, -1 },
	{ "v28", 16, -1 },
	{ "v29", 16, -1 },
	{ "v30", 16, -1 },
	{ "v31", 16, -1 },
	{ "fpsr", 4, -1 },
	{ "fpcr", 4, -1 },
	};

	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;
	}

	int dbg_set_reg(int regno, void mem, struct pt_regs regs)
	{
	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
	sleeping_thread_to_gdb_regs(unsigned long gdb_regs, struct task_struct task)
	{
	struct pt_regs *thread_regs;

	/* Initialize to zero */
	memset((char *)gdb_regs, 0, NUMREGBYTES);
	thread_regs = task_pt_regs(task);
	memcpy((void )gdb_regs, (void )thread_regs->regs, GP_REG_BYTES);
	}

	void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
	{
	regs->pc = pc;
	}

	static int compiled_break;

	static void kgdb_arch_update_addr(struct pt_regs *regs,
	char *remcom_in_buffer)
	{
	unsigned long addr;
	char *ptr;

	ptr = &remcom_in_buffer[1];
	if (kgdb_hex2long(&ptr, &addr))
	kgdb_arch_set_pc(regs, addr);
	else if (compiled_break == 1)
	kgdb_arch_set_pc(regs, regs->pc + 4);

	compiled_break = 0;
	}

	int kgdb_arch_handle_exception(int exception_vector, int signo,
	int err_code, char *remcom_in_buffer,
	char *remcom_out_buffer,
	struct pt_regs *linux_regs)
	{
	int err;

	switch (remcom_in_buffer[0]) {
	case 'D':
	case 'k':
	/*
	* Packet D (Detach), k (kill). No special handling
	* is required here. Handle same as c packet.
	*/
	case 'c':
	/*
	* Packet c (Continue) to continue executing.
	* Set pc to required address.
	* Try to read optional parameter and set pc.
	* If this was a compiled breakpoint, we need to move
	* to the next instruction else we will just breakpoint
	* over and over again.
	*/
	kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
	atomic_set(&kgdb_cpu_doing_single_step, -1);
	kgdb_single_step = 0;

	/*
	* Received continue command, disable single step
	*/
	if (kernel_active_single_step())
	kernel_disable_single_step();

	err = 0;
	break;
	case 's':
	/*
	* Update step address value with address passed
	* with step packet.
	* On debug exception return PC is copied to ELR
	* So just update PC.
	* If no step address is passed, resume from the address
	* pointed by PC. Do not update PC
	*/
	kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
	atomic_set(&kgdb_cpu_doing_single_step, raw_smp_processor_id());
	kgdb_single_step = 1;

	/*
	* Enable single step handling
	*/
	if (!kernel_active_single_step())
	kernel_enable_single_step(linux_regs);
	err = 0;
	break;
	default:
	err = -1;
	}
	return err;
	}

	static int kgdb_brk_fn(struct pt_regs *regs, unsigned int esr)
	{
	kgdb_handle_exception(1, SIGTRAP, 0, regs);
	return 0;
	}

	static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr)
	{
	compiled_break = 1;
	kgdb_handle_exception(1, SIGTRAP, 0, regs);

	return 0;
	}

	static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned int esr)
	{
	kgdb_handle_exception(1, SIGTRAP, 0, regs);
	return 0;
	}

	static struct break_hook kgdb_brkpt_hook = {
	.esr_mask = 0xffffffff,
	.esr_val = DBG_ESR_VAL_BRK(KGDB_DYN_DBG_BRK_IMM),
	.fn = kgdb_brk_fn
	};

	static struct break_hook kgdb_compiled_brkpt_hook = {
	.esr_mask = 0xffffffff,
	.esr_val = DBG_ESR_VAL_BRK(KGDB_COMPILED_DBG_BRK_IMM),
	.fn = kgdb_compiled_brk_fn
	};

	static struct step_hook kgdb_step_hook = {
	.fn = kgdb_step_brk_fn
	};

	static void kgdb_call_nmi_hook(void *ignored)
	{
	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
	}

	void kgdb_roundup_cpus(unsigned long flags)
	{
	local_irq_enable();
	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
	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,
	/*
	* Want to be lowest priority
	*/
	.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)
	{
	int ret = register_die_notifier(&kgdb_notifier);

	if (ret != 0)
	return ret;

	register_break_hook(&kgdb_brkpt_hook);
	register_break_hook(&kgdb_compiled_brkpt_hook);
	register_step_hook(&kgdb_step_hook);
	return 0;
	}

	/*
	* 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_break_hook(&kgdb_brkpt_hook);
	unregister_break_hook(&kgdb_compiled_brkpt_hook);
	unregister_step_hook(&kgdb_step_hook);
	unregister_die_notifier(&kgdb_notifier);
	}

	/*
	* ARM instructions are always in LE.
	* Break instruction is encoded in LE format
	*/
	struct kgdb_arch arch_kgdb_ops = {
	.gdb_bpt_instr = {
	KGDB_DYN_BRK_INS_BYTE0,
	KGDB_DYN_BRK_INS_BYTE1,
	KGDB_DYN_BRK_INS_BYTE2,
	KGDB_DYN_BRK_INS_BYTE3,
	}
	};