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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 "asm/uaccess.h"
#include "skas_ptrace.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;
case PTRACE_FAULTINFO: {
/*
* Take the info from thread->arch->faultinfo,
* but transfer max. sizeof(struct ptrace_faultinfo).
* On i386, ptrace_faultinfo is smaller!
*/
ret = copy_to_user(p, &child->thread.arch.faultinfo,
sizeof(struct ptrace_faultinfo)) ?
-EIO : 0;
break;
}
#ifdef PTRACE_LDT
case PTRACE_LDT: {
struct ptrace_ldt ldt;
if (copy_from_user(&ldt, p, sizeof(ldt))) {
ret = -EIO;
break;
}
/*
* This one is confusing, so just punt and return -EIO for
* now
*/
ret = -EIO;
break;
}
#endif
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)
{
struct siginfo info;
memset(&info, 0, sizeof(info));
info.si_signo = SIGTRAP;
info.si_code = TRAP_BRKPT;
/* User-mode eip? */
info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL;
/* Send us the fake SIGTRAP */
force_sig_info(SIGTRAP, &info, tsk);
}
/*
* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and
* PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
*/
void syscall_trace(struct uml_pt_regs *regs, int entryexit)
{
int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit;
int tracesysgood;
if (!entryexit)
audit_syscall_entry(HOST_AUDIT_ARCH,
UPT_SYSCALL_NR(regs),
UPT_SYSCALL_ARG1(regs),
UPT_SYSCALL_ARG2(regs),
UPT_SYSCALL_ARG3(regs),
UPT_SYSCALL_ARG4(regs));
else
audit_syscall_exit(regs);
/* Fake a debug trap */
if (is_singlestep)
send_sigtrap(current, regs, 0);
if (!test_thread_flag(TIF_SYSCALL_TRACE))
return;
if (!(current->ptrace & PT_PTRACED))
return;
/*
* the 0x80 provides a way for the tracing parent to distinguish
* between a syscall stop and SIGTRAP delivery
*/
tracesysgood = (current->ptrace & PT_TRACESYSGOOD);
ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0));
if (entryexit) /* force do_signal() --> is_syscall() */
set_thread_flag(TIF_SIGPENDING);
/*
* 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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