arch/m68k/kernel/ptrace.c - linux - Git at Google

 /*
  *  linux/arch/m68k/kernel/ptrace.c
  *
  *  Copyright (C) 1994 by Hamish Macdonald
  *  Taken from linux/kernel/ptrace.c and modified for M680x0.
  *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
  *
  * This file is subject to the terms and conditions of the GNU General
  * Public License.  See the file COPYING in the main directory of
  * this archive for more details.
  */

 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <linux/user.h>
 #include <linux/signal.h>
 #include <linux/tracehook.h>

 #include <linux/uaccess.h>
 #include <asm/page.h>
 #include <asm/processor.h>

 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.
  */

 /* determines which bits in the SR the user has access to. */
 /* 1 = access 0 = no access */
 #define SR_MASK 0x001f

 /* sets the trace bits. */
 #define TRACE_BITS 0xC000
 #define T1_BIT 0x8000
 #define T0_BIT 0x4000

 /* Find the stack offset for a register, relative to thread.esp0. */
 #define PT_REG(reg)	((long)&((struct pt_regs *)0)->reg)
 #define SW_REG(reg)	((long)&((struct switch_stack *)0)->reg \
 			 - sizeof(struct switch_stack))
 /* Mapping from PT_xxx to the stack offset at which the register is
    saved.  Notice that usp has no stack-slot and needs to be treated
    specially (see get_reg/put_reg below). */
 static const int regoff[] = {
 	[0]	= PT_REG(d1),
 	[1]	= PT_REG(d2),
 	[2]	= PT_REG(d3),
 	[3]	= PT_REG(d4),
 	[4]	= PT_REG(d5),
 	[5]	= SW_REG(d6),
 	[6]	= SW_REG(d7),
 	[7]	= PT_REG(a0),
 	[8]	= PT_REG(a1),
 	[9]	= PT_REG(a2),
 	[10]	= SW_REG(a3),
 	[11]	= SW_REG(a4),
 	[12]	= SW_REG(a5),
 	[13]	= SW_REG(a6),
 	[14]	= PT_REG(d0),
 	[15]	= -1,
 	[16]	= PT_REG(orig_d0),
 	[17]	= PT_REG(sr),
 	[18]	= PT_REG(pc),
 };

 /*
  * Get contents of register REGNO in task TASK.
  */
 static inline long get_reg(struct task_struct *task, int regno)
 {
 	unsigned long *addr;

 	if (regno == PT_USP)
 		addr = &task->thread.usp;
 	else if (regno < ARRAY_SIZE(regoff))
 		addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
 	else
 		return 0;
 	/* Need to take stkadj into account. */
 	if (regno == PT_SR || regno == PT_PC) {
 		long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));
 		addr = (unsigned long *) ((unsigned long)addr + stkadj);
 		/* The sr is actually a 16 bit register.  */
 		if (regno == PT_SR)
 			return *(unsigned short *)addr;
 	}
 	return *addr;
 }

 /*
  * Write contents of register REGNO in task TASK.
  */
 static inline int put_reg(struct task_struct *task, int regno,
 			  unsigned long data)
 {
 	unsigned long *addr;

 	if (regno == PT_USP)
 		addr = &task->thread.usp;
 	else if (regno < ARRAY_SIZE(regoff))
 		addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
 	else
 		return -1;
 	/* Need to take stkadj into account. */
 	if (regno == PT_SR || regno == PT_PC) {
 		long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));
 		addr = (unsigned long *) ((unsigned long)addr + stkadj);
 		/* The sr is actually a 16 bit register.  */
 		if (regno == PT_SR) {
 			*(unsigned short *)addr = data;
 			return 0;
 		}
 	}
 	*addr = data;
 	return 0;
 }

 /*
  * Make sure the single step bit is not set.
  */
 static inline void singlestep_disable(struct task_struct *child)
 {
 	unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
 	put_reg(child, PT_SR, tmp);
 	clear_tsk_thread_flag(child, TIF_DELAYED_TRACE);
 }

 /*
  * Called by kernel/ptrace.c when detaching..
  */
 void ptrace_disable(struct task_struct *child)
 {
 	singlestep_disable(child);
 }

 void user_enable_single_step(struct task_struct *child)
 {
 	unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
 	put_reg(child, PT_SR, tmp | T1_BIT);
 	set_tsk_thread_flag(child, TIF_DELAYED_TRACE);
 }

 #ifdef CONFIG_MMU
 void user_enable_block_step(struct task_struct *child)
 {
 	unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
 	put_reg(child, PT_SR, tmp | T0_BIT);
 }
 #endif

 void user_disable_single_step(struct task_struct *child)
 {
 	singlestep_disable(child);
 }

 long arch_ptrace(struct task_struct *child, long request,
 		 unsigned long addr, unsigned long data)
 {
 	unsigned long tmp;
 	int i, ret = 0;
 	int regno = addr >> 2; /* temporary hack. */
 	unsigned long __user *datap = (unsigned long __user *) data;

 	switch (request) {
 	/* read the word at location addr in the USER area. */
 	case PTRACE_PEEKUSR:
 		if (addr & 3)
 			goto out_eio;

 		if (regno >= 0 && regno < 19) {
 			tmp = get_reg(child, regno);
 		} else if (regno >= 21 && regno < 49) {
 			tmp = child->thread.fp[regno - 21];
 			/* Convert internal fpu reg representation
 			 * into long double format
 			 */
 			if (FPU_IS_EMU && (regno < 45) && !(regno % 3))
 				tmp = ((tmp & 0xffff0000) << 15) |
 				      ((tmp & 0x0000ffff) << 16);
 #ifndef CONFIG_MMU
 		} else if (regno == 49) {
 			tmp = child->mm->start_code;
 		} else if (regno == 50) {
 			tmp = child->mm->start_data;
 		} else if (regno == 51) {
 			tmp = child->mm->end_code;
 #endif
 		} else
 			goto out_eio;
 		ret = put_user(tmp, datap);
 		break;

 	case PTRACE_POKEUSR:
 	/* write the word at location addr in the USER area */
 		if (addr & 3)
 			goto out_eio;

 		if (regno == PT_SR) {
 			data &= SR_MASK;
 			data |= get_reg(child, PT_SR) & ~SR_MASK;
 		}
 		if (regno >= 0 && regno < 19) {
 			if (put_reg(child, regno, data))
 				goto out_eio;
 		} else if (regno >= 21 && regno < 48) {
 			/* Convert long double format
 			 * into internal fpu reg representation
 			 */
 			if (FPU_IS_EMU && (regno < 45) && !(regno % 3)) {
 				data <<= 15;
 				data = (data & 0xffff0000) |
 				       ((data & 0x0000ffff) >> 1);
 			}
 			child->thread.fp[regno - 21] = data;
 		} else
 			goto out_eio;
 		break;

 	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
 		for (i = 0; i < 19; i++) {
 			tmp = get_reg(child, i);
 			ret = put_user(tmp, datap);
 			if (ret)
 				break;
 			datap++;
 		}
 		break;

 	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
 		for (i = 0; i < 19; i++) {
 			ret = get_user(tmp, datap);
 			if (ret)
 				break;
 			if (i == PT_SR) {
 				tmp &= SR_MASK;
 				tmp |= get_reg(child, PT_SR) & ~SR_MASK;
 			}
 			put_reg(child, i, tmp);
 			datap++;
 		}
 		break;

 	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
 		if (copy_to_user(datap, &child->thread.fp,
 				 sizeof(struct user_m68kfp_struct)))
 			ret = -EFAULT;
 		break;

 	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
 		if (copy_from_user(&child->thread.fp, datap,
 				   sizeof(struct user_m68kfp_struct)))
 			ret = -EFAULT;
 		break;

 	case PTRACE_GET_THREAD_AREA:
 		ret = put_user(task_thread_info(child)->tp_value, datap);
 		break;

 	default:
 		ret = ptrace_request(child, request, addr, data);
 		break;
 	}

 	return ret;
 out_eio:
 	return -EIO;
 }

 asmlinkage void syscall_trace(void)
 {
 	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 				 ? 0x80 : 0));
 	/*
 	 * this isn't the same as continuing with a signal, but it will do
 	 * for normal use.  strace only continues with a signal if the
 	 * stopping signal is not SIGTRAP.  -brl
 	 */
 	if (current->exit_code) {
 		send_sig(current->exit_code, current, 1);
 		current->exit_code = 0;
 	}
 }

 #if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
 asmlinkage int syscall_trace_enter(void)
 {
 	int ret = 0;

 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		ret = tracehook_report_syscall_entry(task_pt_regs(current));
 	return ret;
 }

 asmlinkage void syscall_trace_leave(void)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		tracehook_report_syscall_exit(task_pt_regs(current), 0);
 }
 #endif /* CONFIG_COLDFIRE */
	/*
	* linux/arch/m68k/kernel/ptrace.c
	*
	* Copyright (C) 1994 by Hamish Macdonald
	* Taken from linux/kernel/ptrace.c and modified for M680x0.
	* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
	*
	* This file is subject to the terms and conditions of the GNU General
	* Public License. See the file COPYING in the main directory of
	* this archive for more details.
	*/

	#include <linux/kernel.h>
	#include <linux/sched.h>
	#include <linux/sched/task_stack.h>
	#include <linux/mm.h>
	#include <linux/smp.h>
	#include <linux/errno.h>
	#include <linux/ptrace.h>
	#include <linux/user.h>
	#include <linux/signal.h>
	#include <linux/tracehook.h>

	#include <linux/uaccess.h>
	#include <asm/page.h>
	#include <asm/processor.h>

	/*
	* does not yet catch signals sent when the child dies.
	* in exit.c or in signal.c.
	*/

	/* determines which bits in the SR the user has access to. */
	/* 1 = access 0 = no access */
	#define SR_MASK 0x001f

	/* sets the trace bits. */
	#define TRACE_BITS 0xC000
	#define T1_BIT 0x8000
	#define T0_BIT 0x4000

	/* Find the stack offset for a register, relative to thread.esp0. */
	#define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
	#define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \
	- sizeof(struct switch_stack))
	/* Mapping from PT_xxx to the stack offset at which the register is
	saved. Notice that usp has no stack-slot and needs to be treated
	specially (see get_reg/put_reg below). */
	static const int regoff[] = {
	[0] = PT_REG(d1),
	[1] = PT_REG(d2),
	[2] = PT_REG(d3),
	[3] = PT_REG(d4),
	[4] = PT_REG(d5),
	[5] = SW_REG(d6),
	[6] = SW_REG(d7),
	[7] = PT_REG(a0),
	[8] = PT_REG(a1),
	[9] = PT_REG(a2),
	[10] = SW_REG(a3),
	[11] = SW_REG(a4),
	[12] = SW_REG(a5),
	[13] = SW_REG(a6),
	[14] = PT_REG(d0),
	[15] = -1,
	[16] = PT_REG(orig_d0),
	[17] = PT_REG(sr),
	[18] = PT_REG(pc),
	};

	/*
	* Get contents of register REGNO in task TASK.
	*/
	static inline long get_reg(struct task_struct *task, int regno)
	{
	unsigned long *addr;

	if (regno == PT_USP)
	addr = &task->thread.usp;
	else if (regno < ARRAY_SIZE(regoff))
	addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
	else
	return 0;
	/* Need to take stkadj into account. */
	if (regno == PT_SR \|\| regno == PT_PC) {
	long stkadj = (long )(task->thread.esp0 + PT_REG(stkadj));
	addr = (unsigned long *) ((unsigned long)addr + stkadj);
	/* The sr is actually a 16 bit register. */
	if (regno == PT_SR)
	return (unsigned short )addr;
	}
	return *addr;
	}

	/*
	* Write contents of register REGNO in task TASK.
	*/
	static inline int put_reg(struct task_struct *task, int regno,
	unsigned long data)
	{
	unsigned long *addr;

	if (regno == PT_USP)
	addr = &task->thread.usp;
	else if (regno < ARRAY_SIZE(regoff))
	addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
	else
	return -1;
	/* Need to take stkadj into account. */
	if (regno == PT_SR \|\| regno == PT_PC) {
	long stkadj = (long )(task->thread.esp0 + PT_REG(stkadj));
	addr = (unsigned long *) ((unsigned long)addr + stkadj);
	/* The sr is actually a 16 bit register. */
	if (regno == PT_SR) {
	(unsigned short )addr = data;
	return 0;
	}
	}
	*addr = data;
	return 0;
	}

	/*
	* Make sure the single step bit is not set.
	*/
	static inline void singlestep_disable(struct task_struct *child)
	{
	unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
	put_reg(child, PT_SR, tmp);
	clear_tsk_thread_flag(child, TIF_DELAYED_TRACE);
	}

	/*
	* Called by kernel/ptrace.c when detaching..
	*/
	void ptrace_disable(struct task_struct *child)
	{
	singlestep_disable(child);
	}

	void user_enable_single_step(struct task_struct *child)
	{
	unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
	put_reg(child, PT_SR, tmp \| T1_BIT);
	set_tsk_thread_flag(child, TIF_DELAYED_TRACE);
	}

	#ifdef CONFIG_MMU
	void user_enable_block_step(struct task_struct *child)
	{
	unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
	put_reg(child, PT_SR, tmp \| T0_BIT);
	}
	#endif

	void user_disable_single_step(struct task_struct *child)
	{
	singlestep_disable(child);
	}

	long arch_ptrace(struct task_struct *child, long request,
	unsigned long addr, unsigned long data)
	{
	unsigned long tmp;
	int i, ret = 0;
	int regno = addr >> 2; /* temporary hack. */
	unsigned long __user datap = (unsigned long __user ) data;

	switch (request) {
	/* read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR:
	if (addr & 3)
	goto out_eio;

	if (regno >= 0 && regno < 19) {
	tmp = get_reg(child, regno);
	} else if (regno >= 21 && regno < 49) {
	tmp = child->thread.fp[regno - 21];
	/* Convert internal fpu reg representation
	* into long double format
	*/
	if (FPU_IS_EMU && (regno < 45) && !(regno % 3))
	tmp = ((tmp & 0xffff0000) << 15) \|
	((tmp & 0x0000ffff) << 16);
	#ifndef CONFIG_MMU
	} else if (regno == 49) {
	tmp = child->mm->start_code;
	} else if (regno == 50) {
	tmp = child->mm->start_data;
	} else if (regno == 51) {
	tmp = child->mm->end_code;
	#endif
	} else
	goto out_eio;
	ret = put_user(tmp, datap);
	break;

	case PTRACE_POKEUSR:
	/* write the word at location addr in the USER area */
	if (addr & 3)
	goto out_eio;

	if (regno == PT_SR) {
	data &= SR_MASK;
	data \|= get_reg(child, PT_SR) & ~SR_MASK;
	}
	if (regno >= 0 && regno < 19) {
	if (put_reg(child, regno, data))
	goto out_eio;
	} else if (regno >= 21 && regno < 48) {
	/* Convert long double format
	* into internal fpu reg representation
	*/
	if (FPU_IS_EMU && (regno < 45) && !(regno % 3)) {
	data <<= 15;
	data = (data & 0xffff0000) \|
	((data & 0x0000ffff) >> 1);
	}
	child->thread.fp[regno - 21] = data;
	} else
	goto out_eio;
	break;

	case PTRACE_GETREGS: /* Get all gp regs from the child. */
	for (i = 0; i < 19; i++) {
	tmp = get_reg(child, i);
	ret = put_user(tmp, datap);
	if (ret)
	break;
	datap++;
	}
	break;

	case PTRACE_SETREGS: /* Set all gp regs in the child. */
	for (i = 0; i < 19; i++) {
	ret = get_user(tmp, datap);
	if (ret)
	break;
	if (i == PT_SR) {
	tmp &= SR_MASK;
	tmp \|= get_reg(child, PT_SR) & ~SR_MASK;
	}
	put_reg(child, i, tmp);
	datap++;
	}
	break;

	case PTRACE_GETFPREGS: /* Get the child FPU state. */
	if (copy_to_user(datap, &child->thread.fp,
	sizeof(struct user_m68kfp_struct)))
	ret = -EFAULT;
	break;

	case PTRACE_SETFPREGS: /* Set the child FPU state. */
	if (copy_from_user(&child->thread.fp, datap,
	sizeof(struct user_m68kfp_struct)))
	ret = -EFAULT;
	break;

	case PTRACE_GET_THREAD_AREA:
	ret = put_user(task_thread_info(child)->tp_value, datap);
	break;

	default:
	ret = ptrace_request(child, request, addr, data);
	break;
	}

	return ret;
	out_eio:
	return -EIO;
	}

	asmlinkage void syscall_trace(void)
	{
	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD)
	? 0x80 : 0));
	/*
	* this isn't the same as continuing with a signal, but it will do
	* for normal use. strace only continues with a signal if the
	* stopping signal is not SIGTRAP. -brl
	*/
	if (current->exit_code) {
	send_sig(current->exit_code, current, 1);
	current->exit_code = 0;
	}
	}

	#if defined(CONFIG_COLDFIRE) \|\| !defined(CONFIG_MMU)
	asmlinkage int syscall_trace_enter(void)
	{
	int ret = 0;

	if (test_thread_flag(TIF_SYSCALL_TRACE))
	ret = tracehook_report_syscall_entry(task_pt_regs(current));
	return ret;
	}

	asmlinkage void syscall_trace_leave(void)
	{
	if (test_thread_flag(TIF_SYSCALL_TRACE))
	tracehook_report_syscall_exit(task_pt_regs(current), 0);
	}
	#endif /* CONFIG_COLDFIRE */