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/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <linux/audit.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/tracehook.h>
#include <linux/uaccess.h>
#include <asm/ptrace-abi.h>
void user_enable_single_step(struct task_struct *child)
{
child->ptrace |= PT_DTRACE;
child->thread.singlestep_syscall = 0;
#ifdef SUBARCH_SET_SINGLESTEPPING
SUBARCH_SET_SINGLESTEPPING(child, 1);
#endif
}
void user_disable_single_step(struct task_struct *child)
{
child->ptrace &= ~PT_DTRACE;
child->thread.singlestep_syscall = 0;
#ifdef SUBARCH_SET_SINGLESTEPPING
SUBARCH_SET_SINGLESTEPPING(child, 0);
#endif
}
/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
{
user_disable_single_step(child);
}
extern int peek_user(struct task_struct * child, long addr, long data);
extern int poke_user(struct task_struct * child, long addr, long data);
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
int i, ret;
unsigned long __user *p = (void __user *)data;
void __user *vp = p;
switch (request) {
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR:
ret = peek_user(child, addr, data);
break;
/* write the word at location addr in the USER area */
case PTRACE_POKEUSR:
ret = poke_user(child, addr, data);
break;
case PTRACE_SYSEMU:
case PTRACE_SYSEMU_SINGLESTEP:
ret = -EIO;
break;
#ifdef PTRACE_GETREGS
case PTRACE_GETREGS: { /* Get all gp regs from the child. */
if (!access_ok(VERIFY_WRITE, p, MAX_REG_OFFSET)) {
ret = -EIO;
break;
}
for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
__put_user(getreg(child, i), p);
p++;
}
ret = 0;
break;
}
#endif
#ifdef PTRACE_SETREGS
case PTRACE_SETREGS: { /* Set all gp regs in the child. */
unsigned long tmp = 0;
if (!access_ok(VERIFY_READ, p, MAX_REG_OFFSET)) {
ret = -EIO;
break;
}
for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
__get_user(tmp, p);
putreg(child, i, tmp);
p++;
}
ret = 0;
break;
}
#endif
case PTRACE_GET_THREAD_AREA:
ret = ptrace_get_thread_area(child, addr, vp);
break;
case PTRACE_SET_THREAD_AREA:
ret = ptrace_set_thread_area(child, addr, vp);
break;
default:
ret = ptrace_request(child, request, addr, data);
if (ret == -EIO)
ret = subarch_ptrace(child, request, addr, data);
break;
}
return ret;
}
static void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs,
int error_code)
{
/* Send us the fake SIGTRAP */
force_sig_fault(SIGTRAP, TRAP_BRKPT,
/* User-mode eip? */
UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL, tsk);
}
/*
* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and
* PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
*/
int syscall_trace_enter(struct pt_regs *regs)
{
audit_syscall_entry(UPT_SYSCALL_NR(®s->regs),
UPT_SYSCALL_ARG1(®s->regs),
UPT_SYSCALL_ARG2(®s->regs),
UPT_SYSCALL_ARG3(®s->regs),
UPT_SYSCALL_ARG4(®s->regs));
if (!test_thread_flag(TIF_SYSCALL_TRACE))
return 0;
return tracehook_report_syscall_entry(regs);
}
void syscall_trace_leave(struct pt_regs *regs)
{
int ptraced = current->ptrace;
audit_syscall_exit(regs);
/* Fake a debug trap */
if (ptraced & PT_DTRACE)
send_sigtrap(current, ®s->regs, 0);
if (!test_thread_flag(TIF_SYSCALL_TRACE))
return;
tracehook_report_syscall_exit(regs, 0);
/* force do_signal() --> is_syscall() */
if (ptraced & PT_PTRACED)
set_thread_flag(TIF_SIGPENDING);
}
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