/*
* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/sched.h"
#include "linux/mm.h"
#include "linux/errno.h"
#include "linux/smp_lock.h"
#include "linux/security.h"
#include "linux/ptrace.h"
#include "linux/audit.h"
#ifdef CONFIG_PROC_MM
#include "linux/proc_mm.h"
#endif
#include "asm/ptrace.h"
#include "asm/uaccess.h"
#include "kern_util.h"
#include "skas_ptrace.h"
#include "sysdep/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 sys_ptrace(long request, long pid, long addr, long data)
{
struct task_struct *child;
int i, ret;
lock_kernel();
ret = -EPERM;
if (request == PTRACE_TRACEME) {
/* are we already being traced? */
if (current->ptrace & PT_PTRACED)
goto out;
ret = security_ptrace(current->parent, current);
if (ret)
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;
}
#ifdef SUBACH_PTRACE_SPECIAL
SUBARCH_PTRACE_SPECIAL(child,request,addr,data);
#endif
ret = ptrace_check_attach(child, request == PTRACE_KILL);
if (ret < 0)
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;
ret = -EIO;
copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
if (copied != sizeof(tmp))
break;
ret = put_user(tmp, (unsigned long __user *) data);
break;
}
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR:
ret = peek_user(child, addr, 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 = -EIO;
if (access_process_vm(child, addr, &data, sizeof(data),
1) != sizeof(data))
break;
ret = 0;
break;
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
ret = poke_user(child, addr, data);
break;
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
case PTRACE_CONT: { /* restart after signal. */
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;
}
case PTRACE_DETACH:
/* detach a process that was attached. */
ret = ptrace_detach(child, data);
break;
#ifdef PTRACE_GETREGS
case PTRACE_GETREGS: { /* Get all gp regs from the child. */
if (!access_ok(VERIFY_WRITE, (unsigned long *)data,
MAX_REG_OFFSET)) {
ret = -EIO;
break;
}
for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
__put_user(getreg(child, i),
(unsigned long __user *) data);
data += sizeof(long);
}
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, (unsigned *)data,
MAX_REG_OFFSET)) {
ret = -EIO;
break;
}
for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
__get_user(tmp, (unsigned long __user *) data);
putreg(child, i, tmp);
data += sizeof(long);
}
ret = 0;
break;
}
#endif
#ifdef PTRACE_GETFPREGS
case PTRACE_GETFPREGS: /* Get the child FPU state. */
ret = get_fpregs(data, child);
break;
#endif
#ifdef PTRACE_SETFPREGS
case PTRACE_SETFPREGS: /* Set the child FPU state. */
ret = set_fpregs(data, child);
break;
#endif
#ifdef PTRACE_GETFPXREGS
case PTRACE_GETFPXREGS: /* Get the child FPU state. */
ret = get_fpxregs(data, child);
break;
#endif
#ifdef PTRACE_SETFPXREGS
case PTRACE_SETFPXREGS: /* Set the child FPU state. */
ret = set_fpxregs(data, child);
break;
#endif
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((unsigned long __user *) data,
&child->thread.arch.faultinfo,
sizeof(struct ptrace_faultinfo));
if(ret)
break;
break;
}
#ifdef PTRACE_LDT
case PTRACE_LDT: {
struct ptrace_ldt ldt;
if(copy_from_user(&ldt, (unsigned long __user *) data,
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
default:
ret = ptrace_request(child, request, addr, data);
break;
}
out_tsk:
put_task_struct(child);
out:
unlock_kernel();
return ret;
}
void send_sigtrap(struct task_struct *tsk, union 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 fakey 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(union 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(current,
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(current,
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;
}
}
