ptrace.c

linux-2.6.15.6

	char nat = 0;
	int i;

	if (!access_ok(VERIFY_WRITE, ppr, sizeof(struct pt_all_user_regs)))
		return -EIO;

	pt = ia64_task_regs(child);
	sw = (struct switch_stack *) (child->thread.ksp + 16);
	unw_init_from_blocked_task(&info, child);
	if (unw_unwind_to_user(&info) < 0) {
		return -EIO;
	}

	if (((unsigned long) ppr & 0x7) != 0) {
		dprintk("ptrace:unaligned register address %p\n", ppr);
		return -EIO;
	}

	if (access_uarea(child, PT_CR_IPSR, &psr, 0) < 0
	    || access_uarea(child, PT_AR_EC, &ec, 0) < 0
	    || access_uarea(child, PT_AR_LC, &lc, 0) < 0
	    || access_uarea(child, PT_AR_RNAT, &rnat, 0) < 0
	    || access_uarea(child, PT_AR_BSP, &bsp, 0) < 0
	    || access_uarea(child, PT_CFM, &cfm, 0)
	    || access_uarea(child, PT_NAT_BITS, &nat_bits, 0))
		return -EIO;

	/* control regs */

	retval |= __put_user(pt->cr_iip, &ppr->cr_iip);
	retval |= __put_user(psr, &ppr->cr_ipsr);

	/* app regs */

	retval |= __put_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
	retval |= __put_user(pt->ar_rsc, &ppr->ar[PT_AUR_RSC]);
	retval |= __put_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
	retval |= __put_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
	retval |= __put_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
	retval |= __put_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);

	retval |= __put_user(ec, &ppr->ar[PT_AUR_EC]);
	retval |= __put_user(lc, &ppr->ar[PT_AUR_LC]);
	retval |= __put_user(rnat, &ppr->ar[PT_AUR_RNAT]);
	retval |= __put_user(bsp, &ppr->ar[PT_AUR_BSP]);
	retval |= __put_user(cfm, &ppr->cfm);

	/* gr1-gr3 */

	retval |= __copy_to_user(&ppr->gr[1], &pt->r1, sizeof(long));
	retval |= __copy_to_user(&ppr->gr[2], &pt->r2, sizeof(long) *2);

	/* gr4-gr7 */

	for (i = 4; i < 8; i++) {
		if (unw_access_gr(&info, i, &val, &nat, 0) < 0)
			return -EIO;
		retval |= __put_user(val, &ppr->gr[i]);
	}

	/* gr8-gr11 */

	retval |= __copy_to_user(&ppr->gr[8], &pt->r8, sizeof(long) * 4);

	/* gr12-gr15 */

	retval |= __copy_to_user(&ppr->gr[12], &pt->r12, sizeof(long) * 2);
	retval |= __copy_to_user(&ppr->gr[14], &pt->r14, sizeof(long));
	retval |= __copy_to_user(&ppr->gr[15], &pt->r15, sizeof(long));

	/* gr16-gr31 */

	retval |= __copy_to_user(&ppr->gr[16], &pt->r16, sizeof(long) * 16);

	/* b0 */

	retval |= __put_user(pt->b0, &ppr->br[0]);

	/* b1-b5 */

	for (i = 1; i < 6; i++) {
		if (unw_access_br(&info, i, &val, 0) < 0)
			return -EIO;
		__put_user(val, &ppr->br[i]);
	}

	/* b6-b7 */

	retval |= __put_user(pt->b6, &ppr->br[6]);
	retval |= __put_user(pt->b7, &ppr->br[7]);

	/* fr2-fr5 */

	for (i = 2; i < 6; i++) {
		if (unw_get_fr(&info, i, &fpval) < 0)
			return -EIO;
		retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
	}

	/* fr6-fr11 */

	retval |= __copy_to_user(&ppr->fr[6], &pt->f6,
				 sizeof(struct ia64_fpreg) * 6);

	/* fp scratch regs(12-15) */

	retval |= __copy_to_user(&ppr->fr[12], &sw->f12,
				 sizeof(struct ia64_fpreg) * 4);

	/* fr16-fr31 */

	for (i = 16; i < 32; i++) {
		if (unw_get_fr(&info, i, &fpval) < 0)
			return -EIO;
		retval |= __copy_to_user(&ppr->fr[i], &fpval, sizeof (fpval));
	}

	/* fph */

	ia64_flush_fph(child);
	retval |= __copy_to_user(&ppr->fr[32], &child->thread.fph,
				 sizeof(ppr->fr[32]) * 96);

	/*  preds */

	retval |= __put_user(pt->pr, &ppr->pr);

	/* nat bits */

	retval |= __put_user(nat_bits, &ppr->nat);

	ret = retval ? -EIO : 0;
	return ret;
}

static long
ptrace_setregs (struct task_struct *child, struct pt_all_user_regs __user *ppr)
{
	unsigned long psr, rsc, ec, lc, rnat, bsp, cfm, nat_bits, val = 0;
	struct unw_frame_info info;
	struct switch_stack *sw;
	struct ia64_fpreg fpval;
	struct pt_regs *pt;
	long ret, retval = 0;
	int i;

	memset(&fpval, 0, sizeof(fpval));

	if (!access_ok(VERIFY_READ, ppr, sizeof(struct pt_all_user_regs)))
		return -EIO;

	pt = ia64_task_regs(child);
	sw = (struct switch_stack *) (child->thread.ksp + 16);
	unw_init_from_blocked_task(&info, child);
	if (unw_unwind_to_user(&info) < 0) {
		return -EIO;
	}

	if (((unsigned long) ppr & 0x7) != 0) {
		dprintk("ptrace:unaligned register address %p\n", ppr);
		return -EIO;
	}

	/* control regs */

	retval |= __get_user(pt->cr_iip, &ppr->cr_iip);
	retval |= __get_user(psr, &ppr->cr_ipsr);

	/* app regs */

	retval |= __get_user(pt->ar_pfs, &ppr->ar[PT_AUR_PFS]);
	retval |= __get_user(rsc, &ppr->ar[PT_AUR_RSC]);
	retval |= __get_user(pt->ar_bspstore, &ppr->ar[PT_AUR_BSPSTORE]);
	retval |= __get_user(pt->ar_unat, &ppr->ar[PT_AUR_UNAT]);
	retval |= __get_user(pt->ar_ccv, &ppr->ar[PT_AUR_CCV]);
	retval |= __get_user(pt->ar_fpsr, &ppr->ar[PT_AUR_FPSR]);

	retval |= __get_user(ec, &ppr->ar[PT_AUR_EC]);
	retval |= __get_user(lc, &ppr->ar[PT_AUR_LC]);
	retval |= __get_user(rnat, &ppr->ar[PT_AUR_RNAT]);
	retval |= __get_user(bsp, &ppr->ar[PT_AUR_BSP]);
	retval |= __get_user(cfm, &ppr->cfm);

	/* gr1-gr3 */

	retval |= __copy_from_user(&pt->r1, &ppr->gr[1], sizeof(long));
	retval |= __copy_from_user(&pt->r2, &ppr->gr[2], sizeof(long) * 2);

	/* gr4-gr7 */

	for (i = 4; i < 8; i++) {
		retval |= __get_user(val, &ppr->gr[i]);
		/* NaT bit will be set via PT_NAT_BITS: */
		if (unw_set_gr(&info, i, val, 0) < 0)
			return -EIO;
	}

	/* gr8-gr11 */

	retval |= __copy_from_user(&pt->r8, &ppr->gr[8], sizeof(long) * 4);

	/* gr12-gr15 */

	retval |= __copy_from_user(&pt->r12, &ppr->gr[12], sizeof(long) * 2);
	retval |= __copy_from_user(&pt->r14, &ppr->gr[14], sizeof(long));
	retval |= __copy_from_user(&pt->r15, &ppr->gr[15], sizeof(long));

	/* gr16-gr31 */

	retval |= __copy_from_user(&pt->r16, &ppr->gr[16], sizeof(long) * 16);

	/* b0 */

	retval |= __get_user(pt->b0, &ppr->br[0]);

	/* b1-b5 */

	for (i = 1; i < 6; i++) {
		retval |= __get_user(val, &ppr->br[i]);
		unw_set_br(&info, i, val);
	}

	/* b6-b7 */

	retval |= __get_user(pt->b6, &ppr->br[6]);
	retval |= __get_user(pt->b7, &ppr->br[7]);

	/* fr2-fr5 */

	for (i = 2; i < 6; i++) {
		retval |= __copy_from_user(&fpval, &ppr->fr[i], sizeof(fpval));
		if (unw_set_fr(&info, i, fpval) < 0)
			return -EIO;
	}

	/* fr6-fr11 */

	retval |= __copy_from_user(&pt->f6, &ppr->fr[6],
				   sizeof(ppr->fr[6]) * 6);

	/* fp scratch regs(12-15) */

	retval |= __copy_from_user(&sw->f12, &ppr->fr[12],
				   sizeof(ppr->fr[12]) * 4);

	/* fr16-fr31 */

	for (i = 16; i < 32; i++) {
		retval |= __copy_from_user(&fpval, &ppr->fr[i],
					   sizeof(fpval));
		if (unw_set_fr(&info, i, fpval) < 0)
			return -EIO;
	}

	/* fph */

	ia64_sync_fph(child);
	retval |= __copy_from_user(&child->thread.fph, &ppr->fr[32],
				   sizeof(ppr->fr[32]) * 96);

	/* preds */

	retval |= __get_user(pt->pr, &ppr->pr);

	/* nat bits */

	retval |= __get_user(nat_bits, &ppr->nat);

	retval |= access_uarea(child, PT_CR_IPSR, &psr, 1);
	retval |= access_uarea(child, PT_AR_RSC, &rsc, 1);
	retval |= access_uarea(child, PT_AR_EC, &ec, 1);
	retval |= access_uarea(child, PT_AR_LC, &lc, 1);
	retval |= access_uarea(child, PT_AR_RNAT, &rnat, 1);
	retval |= access_uarea(child, PT_AR_BSP, &bsp, 1);
	retval |= access_uarea(child, PT_CFM, &cfm, 1);
	retval |= access_uarea(child, PT_NAT_BITS, &nat_bits, 1);

	ret = retval ? -EIO : 0;
	return ret;
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure the single step bit is not set.
 */
void
ptrace_disable (struct task_struct *child)
{
	struct ia64_psr *child_psr = ia64_psr(ia64_task_regs(child));

	/* make sure the single step/taken-branch trap bits are not set: */
	child_psr->ss = 0;
	child_psr->tb = 0;
}

asmlinkage long
sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
{
	struct pt_regs *pt;
	unsigned long urbs_end, peek_or_poke;
	struct task_struct *child;
	struct switch_stack *sw;
	long 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;
		current->ptrace |= PT_PTRACED;
		ret = 0;
		goto out;
	}

	peek_or_poke = (request == PTRACE_PEEKTEXT
			|| request == PTRACE_PEEKDATA
			|| request == PTRACE_POKETEXT
			|| request == PTRACE_POKEDATA);
	ret = -ESRCH;
	read_lock(&tasklist_lock);
	{
		child = find_task_by_pid(pid);
		if (child) {
			if (peek_or_poke)
				child = find_thread_for_addr(child, addr);
			get_task_struct(child);
		}
	}
	read_unlock(&tasklist_lock);
	if (!child)
		goto out;
	ret = -EPERM;
	if (pid == 1)		/* no messing around with init! */
		goto out_tsk;

	if (request == PTRACE_ATTACH) {
		ret = ptrace_attach(child);
		goto out_tsk;
	}

	ret = ptrace_check_attach(child, request == PTRACE_KILL);
	if (ret < 0)
		goto out_tsk;

	pt = ia64_task_regs(child);
	sw = (struct switch_stack *) (child->thread.ksp + 16);

	switch (request) {
	      case PTRACE_PEEKTEXT:
	      case PTRACE_PEEKDATA:
		/* read word at location addr */
		urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
		ret = ia64_peek(child, sw, urbs_end, addr, &data);
		if (ret == 0) {
			ret = data;
			/* ensure "ret" is not mistaken as an error code: */
			force_successful_syscall_return();
		}
		goto out_tsk;

	      case PTRACE_POKETEXT:
	      case PTRACE_POKEDATA:
		/* write the word at location addr */
		urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
		ret = ia64_poke(child, sw, urbs_end, addr, data);
		goto out_tsk;

	      case PTRACE_PEEKUSR:
		/* read the word at addr in the USER area */
		if (access_uarea(child, addr, &data, 0) < 0) {
			ret = -EIO;
			goto out_tsk;
		}
		ret = data;
		/* ensure "ret" is not mistaken as an error code */
		force_successful_syscall_return();
		goto out_tsk;

	      case PTRACE_POKEUSR:
		/* write the word at addr in the USER area */
		if (access_uarea(child, addr, &data, 1) < 0) {
			ret = -EIO;
			goto out_tsk;
		}
		ret = 0;
		goto out_tsk;

	      case PTRACE_OLD_GETSIGINFO:
		/* for backwards-compatibility */
		ret = ptrace_request(child, PTRACE_GETSIGINFO, addr, data);
		goto out_tsk;

	      case PTRACE_OLD_SETSIGINFO:
		/* for backwards-compatibility */
		ret = ptrace_request(child, PTRACE_SETSIGINFO, addr, data);
		goto out_tsk;

	      case PTRACE_SYSCALL:
		/* continue and stop at next (return from) syscall */
	      case PTRACE_CONT:
		/* restart after signal. */
		ret = -EIO;
		if (!valid_signal(data))
			goto out_tsk;
		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;

		/*
		 * Make sure the single step/taken-branch trap bits
		 * are not set:
		 */
		ia64_psr(pt)->ss = 0;
		ia64_psr(pt)->tb = 0;

		wake_up_process(child);
		ret = 0;
		goto out_tsk;

	      case PTRACE_KILL:
		/*
		 * 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.
		 */
		if (child->exit_state == EXIT_ZOMBIE)
			/* already dead */
			goto out_tsk;
		child->exit_code = SIGKILL;

		ptrace_disable(child);
		wake_up_process(child);
		ret = 0;
		goto out_tsk;

	      case PTRACE_SINGLESTEP:
		/* let child execute for one instruction */
	      case PTRACE_SINGLEBLOCK:
		ret = -EIO;
		if (!valid_signal(data))
			goto out_tsk;

		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		if (request == PTRACE_SINGLESTEP) {
			ia64_psr(pt)->ss = 1;
		} else {
			ia64_psr(pt)->tb = 1;
		}
		child->exit_code = data;

		/* give it a chance to run. */
		wake_up_process(child);
		ret = 0;
		goto out_tsk;

	      case PTRACE_DETACH:
		/* detach a process that was attached. */
		ret = ptrace_detach(child, data);
		goto out_tsk;

	      case PTRACE_GETREGS:
		ret = ptrace_getregs(child,
				     (struct pt_all_user_regs __user *) data);
		goto out_tsk;

	      case PTRACE_SETREGS:
		ret = ptrace_setregs(child,
				     (struct pt_all_user_regs __user *) data);
		goto out_tsk;

	      default:
		ret = ptrace_request(child, request, addr, data);
		goto out_tsk;
	}
  out_tsk:
	put_task_struct(child);
  out:
	unlock_kernel();
	return ret;
}


void
syscall_trace (void)
{
	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.
	 */
	ptrace_notify(SIGTRAP
		      | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));

	/*
	 * 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;
	}
}

/* "asmlinkage" so the input arguments are preserved... */

asmlinkage void
syscall_trace_enter (long arg0, long arg1, long arg2, long arg3,
		     long arg4, long arg5, long arg6, long arg7,
		     struct pt_regs regs)
{
	if (test_thread_flag(TIF_SYSCALL_TRACE) 
	    && (current->ptrace & PT_PTRACED))
		syscall_trace();

	if (unlikely(current->audit_context)) {
		long syscall;
		int arch;

		if (IS_IA32_PROCESS(&regs)) {
			syscall = regs.r1;
			arch = AUDIT_ARCH_I386;
		} else {
			syscall = regs.r15;
			arch = AUDIT_ARCH_IA64;
		}

		audit_syscall_entry(current, arch, syscall, arg0, arg1, arg2, arg3);
	}

}

/* "asmlinkage" so the input arguments are preserved... */

asmlinkage void
syscall_trace_leave (long arg0, long arg1, long arg2, long arg3,
		     long arg4, long arg5, long arg6, long arg7,
		     struct pt_regs regs)
{
	if (unlikely(current->audit_context))
		audit_syscall_exit(current, AUDITSC_RESULT(regs.r10), regs.r8);

	if (test_thread_flag(TIF_SYSCALL_TRACE)
	    && (current->ptrace & PT_PTRACED))
		syscall_trace();
}