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/*
* debug.c
* pdb debug functionality for processes.
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <asm-xen/asm-i386/ptrace.h>
#include <asm-xen/xen-public/xen.h>
#include "pdb_module.h"
EXPORT_SYMBOL(pdb_attach);
EXPORT_SYMBOL(pdb_detach);
int
pdb_attach (int pid)
{
struct task_struct *target;
u32 rc = 0;
printk ("pdb attach: 0x%x\n", pid);
read_lock(&tasklist_lock);
target = find_task_by_pid(pid);
if (target)
get_task_struct(target);
read_unlock(&tasklist_lock);
force_sig(SIGSTOP, target); /* force_sig_specific ??? */
return rc;
}
int
pdb_detach (int pid)
{
int rc = 0;
struct task_struct *target;
printk ("pdb detach: 0x%x\n", pid);
read_lock(&tasklist_lock);
target = find_task_by_pid(pid);
if (target)
get_task_struct(target);
read_unlock(&tasklist_lock);
wake_up_process(target);
return rc;
}
/*
* from linux-2.6.11/arch/i386/kernel/ptrace.c::getreg()
*/
int
pdb_read_register (int pid, pdb_op_rd_reg_p op, unsigned long *dest)
{
int rc = 0;
struct task_struct *target;
unsigned long offset;
unsigned char *stack = 0L;
*dest = ~0UL;
read_lock(&tasklist_lock);
target = find_task_by_pid(pid);
if (target)
get_task_struct(target);
read_unlock(&tasklist_lock);
switch (op->reg)
{
case FS:
*dest = target->thread.fs;
break;
case GS:
*dest = target->thread.gs;
break;
case DS:
case ES:
case SS:
case CS:
*dest = 0xffff;
/* fall through */
default:
if (op->reg > GS)
op->reg -= 2;
offset = op->reg * sizeof(long);
offset -= sizeof(struct pt_regs);
stack = (unsigned char *)target->thread.esp0;
stack += offset;
*dest &= *((int *)stack);
}
/*
printk ("pdb read register: 0x%x %2d 0x%p 0x%lx\n",
pid, op->reg, stack, *dest);
*/
return rc;
}
/*
* from linux-2.6.11/arch/i386/kernel/ptrace.c::putreg()
*/
int
pdb_write_register (int pid, pdb_op_wr_reg_p op)
{
int rc = 0;
struct task_struct *target;
unsigned long offset;
unsigned char *stack;
unsigned long value = op->value;
/*
printk ("pdb write register: 0x%x %2d 0x%lx\n", pid, op->reg, value);
*/
read_lock(&tasklist_lock);
target = find_task_by_pid(pid);
if (target)
get_task_struct(target);
read_unlock(&tasklist_lock);
switch (op->reg)
{
case FS:
target->thread.fs = value;
return rc;
case GS:
target->thread.gs = value;
return rc;
case DS:
case ES:
value &= 0xffff;
break;
case SS:
case CS:
value &= 0xffff;
break;
case EFL:
break;
}
if (op->reg > GS)
op->reg -= 2;
offset = op->reg * sizeof(long);
offset -= sizeof(struct pt_regs);
stack = (unsigned char *)target->thread.esp0;
stack += offset;
*(unsigned long *) stack = op->value;
return rc;
}
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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