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/*
* 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/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/config.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.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 0x8000
/* 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 int regoff[] = {
PT_REG(d1), PT_REG(d2), PT_REG(d3), PT_REG(d4),
PT_REG(d5), SW_REG(d6), SW_REG(d7), PT_REG(a0),
PT_REG(a1), PT_REG(a2), SW_REG(a3), SW_REG(a4),
SW_REG(a5), SW_REG(a6), PT_REG(d0), -1,
PT_REG(orig_d0), PT_REG(sr), 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 < sizeof(regoff)/sizeof(regoff[0]))
addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
else
return 0;
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 < sizeof(regoff)/sizeof(regoff[0]))
addr = (unsigned long *) (task->thread.esp0 + regoff[regno]);
else
return -1;
*addr = data;
return 0;
}
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure the single step bit is not set.
*/
void ptrace_disable(struct task_struct *child)
{
unsigned long tmp;
/* make sure the single step bit is not set. */
tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
put_reg(child, PT_SR, tmp);
}
asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
{
struct task_struct *child;
unsigned long flags;
int ret;
lock_kernel();
ret = -EPERM;
if (request == PTRACE_TRACEME) {
/* are we already being traced? */
if (current->ptrace & PT_PTRACED)
goto out;
/* set the ptrace bit in the process flags. */
current->ptrace |= PT_PTRACED;
ret = 0;
goto out;
}
ret = -ESRCH;
read_lock(&tasklist_lock);
child = find_task_by_pid(pid);
if (child)
get_task_struct(child);
read_unlock(&tasklist_lock);
if (!child)
goto out;
ret = -EPERM;
if (pid == 1) /* you may not mess with init */
goto out_tsk;
if (request == PTRACE_ATTACH) {
ret = ptrace_attach(child);
goto out_tsk;
}
ret = -ESRCH;
if (!(child->ptrace & PT_PTRACED))
goto out_tsk;
if (child->state != TASK_STOPPED) {
if (request != PTRACE_KILL)
goto out_tsk;
}
if (child->p_pptr != current)
goto out_tsk;
switch (request) {
/* when I and D space are separate, these will need to be fixed. */
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA: {
unsigned long tmp;
int copied;
copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
ret = -EIO;
if (copied != sizeof(tmp))
break;
ret = put_user(tmp,(unsigned long *) data);
break;
}
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
unsigned long tmp;
ret = -EIO;
if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
tmp = 0; /* Default return condition */
addr = addr >> 2; /* temporary hack. */
ret = -EIO;
if (addr < 19) {
tmp = get_reg(child, addr);
if (addr == PT_SR)
tmp >>= 16;
} else if (addr >= 21 && addr < 49) {
tmp = child->thread.fp[addr - 21];
#ifdef CONFIG_M68KFPU_EMU
/* Convert internal fpu reg representation
* into long double format
*/
if (FPU_IS_EMU && (addr < 45) && !(addr % 3))
tmp = ((tmp & 0xffff0000) << 15) |
((tmp & 0x0000ffff) << 16);
#endif
} else
break;
ret = put_user(tmp,(unsigned long *) data);
break;
}
/* when I and D space are separate, this will have to be fixed. */
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA:
ret = 0;
if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
break;
ret = -EIO;
break;
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
ret = -EIO;
if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
addr = addr >> 2; /* temporary hack. */
if (addr == PT_SR) {
data &= SR_MASK;
data <<= 16;
data |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
}
if (addr < 19) {
if (put_reg(child, addr, data))
break;
ret = 0;
break;
}
if (addr >= 21 && addr < 48)
{
#ifdef CONFIG_M68KFPU_EMU
/* Convert long double format
* into internal fpu reg representation
*/
if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) {
data = (unsigned long)data << 15;
data = (data & 0xffff0000) |
((data & 0x0000ffff) >> 1);
}
#endif
child->thread.fp[addr - 21] = data;
ret = 0;
}
break;
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
case PTRACE_CONT: { /* restart after signal. */
long tmp;
ret = -EIO;
if ((unsigned long) data > _NSIG)
break;
if (request == PTRACE_SYSCALL)
child->ptrace |= PT_TRACESYS;
else
child->ptrace &= ~PT_TRACESYS;
child->exit_code = data;
/* make sure the single step bit is not set. */
tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
put_reg(child, PT_SR, tmp);
wake_up_process(child);
ret = 0;
break;
}
/*
* make the child exit. Best I can do is send it a sigkill.
* perhaps it should be put in the status that it wants to
* exit.
*/
case PTRACE_KILL: {
long tmp;
ret = 0;
if (child->state == TASK_ZOMBIE) /* already dead */
break;
child->exit_code = SIGKILL;
/* make sure the single step bit is not set. */
tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
put_reg(child, PT_SR, tmp);
wake_up_process(child);
break;
}
case PTRACE_SINGLESTEP: { /* set the trap flag. */
long tmp;
ret = -EIO;
if ((unsigned long) data > _NSIG)
break;
child->ptrace &= ~PT_TRACESYS;
tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16);
put_reg(child, PT_SR, tmp);
child->exit_code = data;
/* give it a chance to run. */
wake_up_process(child);
ret = 0;
break;
}
case PTRACE_DETACH: /* detach a process that was attached. */
ret = ptrace_detach(child, data);
break;
case PTRACE_GETREGS: { /* Get all gp regs from the child. */
int i;
unsigned long tmp;
for (i = 0; i < 19; i++) {
tmp = get_reg(child, i);
if (i == PT_SR)
tmp >>= 16;
if (put_user(tmp, (unsigned long *) data)) {
ret = -EFAULT;
break;
}
data += sizeof(long);
}
ret = 0;
break;
}
case PTRACE_SETREGS: { /* Set all gp regs in the child. */
int i;
unsigned long tmp;
for (i = 0; i < 19; i++) {
if (get_user(tmp, (unsigned long *) data)) {
ret = -EFAULT;
break;
}
if (i == PT_SR) {
tmp &= SR_MASK;
tmp <<= 16;
tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
}
put_reg(child, i, tmp);
data += sizeof(long);
}
ret = 0;
break;
}
case PTRACE_GETFPREGS: { /* Get the child FPU state. */
ret = 0;
if (copy_to_user((void *)data, &child->thread.fp,
sizeof(struct user_m68kfp_struct)))
ret = -EFAULT;
break;
}
case PTRACE_SETFPREGS: { /* Set the child FPU state. */
ret = 0;
if (copy_from_user(&child->thread.fp, (void *)data,
sizeof(struct user_m68kfp_struct)))
ret = -EFAULT;
break;
}
default:
ret = -EIO;
break;
}
out_tsk:
free_task_struct(child);
out:
unlock_kernel();
return ret;
}
asmlinkage void syscall_trace(void)
{
if ((current->ptrace & (PT_PTRACED|PT_TRACESYS))
!= (PT_PTRACED|PT_TRACESYS))
return;
current->exit_code = SIGTRAP;
current->state = TASK_STOPPED;
notify_parent(current, SIGCHLD);
schedule();
/*
* 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;
}
}
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