/*
* 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"
#ifdef CONFIG_PROC_MM
#include "proc_mm.h"
#endif
#include "skas_ptrace.h"
static inline void set_singlestepping(struct task_struct *child, int on)
{
if (on)
child->ptrace |= PT_DTRACE;
else
child->ptrace &= ~PT_DTRACE;
child->thread.singlestep_syscall = 0;
#ifdef SUBARCH_SET_SINGLESTEPPING
SUBARCH_SET_SINGLESTEPPING(child, on);
#endif
}
/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
{
set_singlestepping(child,0);
}
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, long addr, long data)
{
int i, ret;
unsigned long __user *p = (void __user *)(unsigned long)data;
switch (request) {
/* read word at location addr. */
case PTRACE_PEEKTEXT:
case PTRACE_PEEKDATA:
ret = generic_ptrace_peekdata(child, addr, data);
break;
/* 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. */
case PTRACE_POKETEXT:
case PTRACE_POKEDATA:
ret = generic_ptrace_pokedata(child, addr, data);
break;
/* write the word at location addr in the USER area */
case PTRACE_POKEUSR:
ret = poke_user(child, addr, data);
break;
/* continue and stop at next (return from) syscall */
case PTRACE_SYSCALL:
/* restart after signal. */
case PTRACE_CONT: {
ret = -EIO;
if (!valid_signal(data))
break;
set_singlestepping(child, 0);
if (request == PTRACE_SYSCALL)
set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
else clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
child->exit_code = data;
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: {
ret = 0;
if (child->exit_state == EXIT_ZOMBIE) /* already dead */
break;
set_singlestepping(child, 0);
child->exit_code = SIGKILL;
wake_up_process(child);
break;
}
case PTRACE_SINGLESTEP: { /* set the trap flag. */
ret = -EIO;
if (!valid_signal(data))
break;
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
set_singlestepping(child, 1);
child->exit_code = data;
/* give it a chance to run. */
wake_up_process(child);
ret = 0;
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
#ifdef PTRACE_GETFPREGS
case PTRACE_GETFPREGS: /* Get the child FPU state. */
ret = get_fpregs((struct user_i387_struct __user *) data,
child);
break;
#endif
#ifdef PTRACE_SETFPREGS
case PTRACE_SETFPREGS: /* Set the child FPU state. */
ret = set_fpregs((struct user_i387_struct __user *) data,
child);
break;
#endif
case PTRACE_GET_THREAD_AREA:
ret = ptrace_get_thread_area(child, addr,
(struct user_desc __user *) data);
break;
case PTRACE_SET_THREAD_AREA:
ret = ptrace_set_thread_area(child, addr,
(struct user_desc __user *) data);
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));
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
#ifdef CONFIG_PROC_MM
case PTRACE_SWITCH_MM: {
struct mm_struct *old = child->mm;
struct mm_struct *new = proc_mm_get_mm(data);
if (IS_ERR(new)) {
ret = PTR_ERR(new);
break;
}
atomic_inc(&new->mm_users);
child->mm = new;
child->active_mm = new;
mmput(old);
ret = 0;
break;
}
#endif
#ifdef PTRACE_ARCH_PRCTL
case PTRACE_ARCH_PRCTL:
/* XXX Calls ptrace on the host - needs some SMP thinking */
ret = arch_prctl(child, data, (void *) addr);
break;
#endif
default:
ret = ptrace_request(child, request, addr, data);
if (ret == -EIO)
ret = subarch_ptrace(child, request, addr, data);
break;
}
return ret;
}
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 (unlikely(current->audit_context)) {
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(AUDITSC_RESULT(UPT_SYSCALL_RET(regs)),
UPT_SYSCALL_RET(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;
}
}
