xref: /src/sys/kern/sys_ptrace.c

/*	$NetBSD: sys_ptrace.c,v 1.1 2016/11/02 00:11:59 pgoyette Exp $	*/

/*-
 * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Andrew Doran.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*-
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * This code is derived from software contributed to Berkeley by
 * Jan-Simon Pendry.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)sys_process.c	8.1 (Berkeley) 6/10/93
 */

/*-
 * Copyright (c) 1993 Jan-Simon Pendry.
 * Copyright (c) 1994 Christopher G. Demetriou.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Jan-Simon Pendry.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)sys_process.c	8.1 (Berkeley) 6/10/93
 */

/*
 * References:
 *	(1) Bach's "The Design of the UNIX Operating System",
 *	(2) sys/miscfs/procfs from UCB's 4.4BSD-Lite distribution,
 *	(3) the "4.4BSD Programmer's Reference Manual" published
 *		by USENIX and O'Reilly & Associates.
 * The 4.4BSD PRM does a reasonably good job of documenting what the various
 * ptrace() requests should actually do, and its text is quoted several times
 * in this file.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sys_ptrace.c,v 1.1 2016/11/02 00:11:59 pgoyette Exp $");

#ifdef _KERNEL_OPT
#include "opt_ptrace.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/exec.h>
#include <sys/pax.h>
#include <sys/ptrace.h>
#include <sys/uio.h>
#include <sys/ras.h>
#include <sys/kmem.h>
#include <sys/kauth.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#include <sys/syscallvar.h>
#include <sys/syscall.h>
#include <sys/module.h>

#include <uvm/uvm_extern.h>

#include <machine/reg.h>

/*
 * PTRACE methods
 */

static int ptrace_copyinpiod(struct ptrace_io_desc *, const void *);
static void ptrace_copyoutpiod(const struct ptrace_io_desc *, void *);
static int ptrace_doregs(struct lwp *, struct lwp *, struct uio *);
static int ptrace_dofpregs(struct lwp *, struct lwp *, struct uio *);

static int
ptrace_copyinpiod(struct ptrace_io_desc *piod, const void *addr)
{
	return copyin(addr, piod, sizeof(*piod));
}

static void
ptrace_copyoutpiod(const struct ptrace_io_desc *piod, void *addr)
{
	(void) copyout(piod, addr, sizeof(*piod));
}

int
ptrace_doregs(struct lwp *curl /*tracer*/,
    struct lwp *l /*traced*/,
    struct uio *uio)
{
#if defined(PT_GETREGS) || defined(PT_SETREGS)
	int error;
	struct reg r;
	char *kv;
	int kl;

	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)sizeof(r))
		return EINVAL;

	kl = sizeof(r);
	kv = (char *)&r;

	kv += uio->uio_offset;
	kl -= uio->uio_offset;
	if ((size_t)kl > uio->uio_resid)
		kl = uio->uio_resid;

	error = process_read_regs(l, &r);
	if (error == 0)
		error = uiomove(kv, kl, uio);
	if (error == 0 && uio->uio_rw == UIO_WRITE) {
		if (l->l_stat != LSSTOP)
			error = EBUSY;
		else
			error = process_write_regs(l, &r);
	}

	uio->uio_offset = 0;
	return error;
#else
	return EINVAL;
#endif
}

int
ptrace_dofpregs(struct lwp *curl /*tracer*/,
    struct lwp *l /*traced*/,
    struct uio *uio)
{
#if defined(PT_GETFPREGS) || defined(PT_SETFPREGS)
	int error;
	struct fpreg r;
	char *kv;
	size_t kl;

	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)sizeof(r))
		return EINVAL;

	kl = sizeof(r);
	kv = (char *)&r;

	kv += uio->uio_offset;
	kl -= uio->uio_offset;
	if (kl > uio->uio_resid)
		kl = uio->uio_resid;

	error = process_read_fpregs(l, &r, &kl);
	if (error == 0)
		error = uiomove(kv, kl, uio);
	if (error == 0 && uio->uio_rw == UIO_WRITE) {
		if (l->l_stat != LSSTOP)
			error = EBUSY;
		else
			error = process_write_fpregs(l, &r, kl);
	}
	uio->uio_offset = 0;
	return error;
#else
	return EINVAL;
#endif
}

static struct ptrace_methods native_ptm = {
	.ptm_copyinpiod = ptrace_copyinpiod,
	.ptm_copyoutpiod = ptrace_copyoutpiod,
	.ptm_doregs = ptrace_doregs,
	.ptm_dofpregs = ptrace_dofpregs,
};

static const struct syscall_package ptrace_syscalls[] = {
	{ SYS_ptrace, 0, (sy_call_t *)sys_ptrace },
	{ 0, 0, NULL },
};

/*
 * Process debugging system call.
 */
int
sys_ptrace(struct lwp *l, const struct sys_ptrace_args *uap, register_t *retval)
{
	/* {
		syscallarg(int) req;
		syscallarg(pid_t) pid;
		syscallarg(void *) addr;
		syscallarg(int) data;
	} */

        return do_ptrace(&native_ptm, l, SCARG(uap, req), SCARG(uap, pid),
            SCARG(uap, addr), SCARG(uap, data), retval);
}

#define	DEPS	"ptrace_common"

MODULE(MODULE_CLASS_EXEC, ptrace, DEPS);

static int
ptrace_modcmd(modcmd_t cmd, void *arg)
{
	int error;

	switch (cmd) {
	case MODULE_CMD_INIT:
		error = syscall_establish(&emul_netbsd, ptrace_syscalls);
		break;
	case MODULE_CMD_FINI:
		error = syscall_disestablish(&emul_netbsd, ptrace_syscalls);
		break;
	default:
		error = ENOTTY;
		break;
	}
	return error;
}