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freebsd_ptrace.c revision 1.17
      1 /*	$NetBSD: freebsd_ptrace.c,v 1.17 2007/12/20 23:02:47 dsl Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1982, 1986, 1989, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  * (c) UNIX System Laboratories, Inc.
      7  * All or some portions of this file are derived from material licensed
      8  * to the University of California by American Telephone and Telegraph
      9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     10  * the permission of UNIX System Laboratories, Inc.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  *
     36  *	from: @(#)sys_process.c	8.1 (Berkeley) 6/10/93
     37  */
     38 
     39 /*-
     40  * Copyright (c) 1994 Christopher G. Demetriou.  All rights reserved.
     41  *
     42  * Redistribution and use in source and binary forms, with or without
     43  * modification, are permitted provided that the following conditions
     44  * are met:
     45  * 1. Redistributions of source code must retain the above copyright
     46  *    notice, this list of conditions and the following disclaimer.
     47  * 2. Redistributions in binary form must reproduce the above copyright
     48  *    notice, this list of conditions and the following disclaimer in the
     49  *    documentation and/or other materials provided with the distribution.
     50  * 3. All advertising materials mentioning features or use of this software
     51  *    must display the following acknowledgement:
     52  *	This product includes software developed by the University of
     53  *	California, Berkeley and its contributors.
     54  * 4. Neither the name of the University nor the names of its contributors
     55  *    may be used to endorse or promote products derived from this software
     56  *    without specific prior written permission.
     57  *
     58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68  * SUCH DAMAGE.
     69  *
     70  *	from: @(#)sys_process.c	8.1 (Berkeley) 6/10/93
     71  */
     72 
     73 #include <sys/cdefs.h>
     74 __KERNEL_RCSID(0, "$NetBSD: freebsd_ptrace.c,v 1.17 2007/12/20 23:02:47 dsl Exp $");
     75 
     76 #if defined(_KERNEL_OPT)
     77 #include "opt_ptrace.h"
     78 #endif
     79 
     80 #include <sys/param.h>
     81 #include <sys/systm.h>
     82 #include <sys/proc.h>
     83 #include <sys/errno.h>
     84 #include <sys/ptrace.h>
     85 #include <sys/uio.h>
     86 #include <sys/user.h>
     87 #include <sys/mount.h>
     88 #include <sys/syscallargs.h>
     89 
     90 #include <compat/sys/signal.h>
     91 #include <compat/sys/signalvar.h>
     92 
     93 #include <machine/reg.h>
     94 #include <machine/freebsd_machdep.h>
     95 
     96 #include <compat/common/compat_util.h>
     97 #include <compat/freebsd/freebsd_syscallargs.h>
     98 #include <compat/freebsd/freebsd_ptrace.h>
     99 
    100 /*
    101  * Process debugging system call.
    102  */
    103 int
    104 freebsd_sys_ptrace(struct lwp *l, const struct freebsd_sys_ptrace_args *uap, register_t *retval)
    105 {
    106 #if defined(PTRACE) || defined(_LKM)
    107 	/* {
    108 		syscallarg(int) req;
    109 		syscallarg(pid_t) pid;
    110 		syscallarg(void *) addr;
    111 		syscallarg(int) data;
    112 	} */
    113 	struct sys_ptrace_args npa;
    114 #ifdef _LKM
    115 	sy_call_t sys_ptrace = sysent[SYS_ptrace].sy_call;
    116 #endif
    117 
    118 	switch (SCARG(uap, req)) {
    119 #ifdef PT_STEP
    120 	case FREEBSD_PT_STEP:
    121 		SCARG(&npa, req) = PT_STEP;
    122 		SCARG(&npa, pid) = SCARG(uap, pid);
    123 		SCARG(&npa, addr) = SCARG(uap, addr);
    124 		SCARG(&npa, data) = SCARG(uap, data);
    125 		return sys_ptrace(l, &npa, retval);
    126 #endif
    127 	case FREEBSD_PT_TRACE_ME:
    128 	case FREEBSD_PT_READ_I:
    129 	case FREEBSD_PT_READ_D:
    130 	case FREEBSD_PT_WRITE_I:
    131 	case FREEBSD_PT_WRITE_D:
    132 	case FREEBSD_PT_CONTINUE:
    133 	case FREEBSD_PT_KILL:
    134 		/* These requests are compatible with NetBSD */
    135 		return sys_ptrace(l, (const void *)uap, retval);
    136 
    137 #if 0
    138 /*
    139  * XXX: I've commented out this code, it is broken on too many fronts to fix.
    140  *	1) It is doing an unlocked read-modify-write cycle on process that
    141  *	   I assume might be running!
    142  *	   and in code that might sleep (due to a pagefault), never mind
    143  *	   what happens on an SMP system
    144  *      2) It accesses data in userspace without using copyin/out.
    145  *	3) It all looks like a nasty hack that isn't likely to work.
    146  *	4) It uses the stackgap.
    147  * dsl June 2007
    148  */
    149 	case FREEBSD_PT_READ_U:
    150 	case FREEBSD_PT_WRITE_U:
    151     {
    152 	int error;
    153 	struct {
    154 		struct reg regs;
    155 		struct fpreg fpregs;
    156 	} *nrp;
    157 	struct freebsd_ptrace_reg fr;
    158 		sg = stackgap_init(p, 0);
    159 		nrp = stackgap_alloc(p, &sg, sizeof(*nrp));
    160 #ifdef PT_GETREGS
    161 		SCARG(&npa, req) = PT_GETREGS;
    162 		SCARG(&npa, pid) = SCARG(uap, pid);
    163 		SCARG(&npa, addr) = (void *)&nrp->regs;
    164 		if ((error = sys_ptrace(l, &npa, retval)) != 0)
    165 			return error;
    166 #endif
    167 #ifdef PT_GETFPREGS
    168 		SCARG(&npa, req) = PT_GETFPREGS;
    169 		SCARG(&npa, pid) = SCARG(uap, pid);
    170 		SCARG(&npa, addr) = (void *)&nrp->fpregs;
    171 		if ((error = sys_ptrace(l, &npa, retval)) != 0)
    172 			return error;
    173 #endif
    174 		netbsd_to_freebsd_ptrace_regs(&nrp->regs, &nrp->fpregs, &fr);
    175 		switch (SCARG(uap, req)) {
    176 		case FREEBSD_PT_READ_U:
    177 			return freebsd_ptrace_getregs(&fr, SCARG(uap, addr),
    178 						      retval);
    179 
    180 		case FREEBSD_PT_WRITE_U:
    181 			error = freebsd_ptrace_setregs(&fr,
    182 			    SCARG(uap, addr), SCARG(uap, data));
    183 			if (error)
    184 				return error;
    185 			freebsd_to_netbsd_ptrace_regs(&fr,
    186 						&nrp->regs, &nrp->fpregs);
    187 #ifdef PT_SETREGS
    188 			SCARG(&npa, req) = PT_SETREGS;
    189 			SCARG(&npa, pid) = SCARG(uap, pid);
    190 			SCARG(&npa, addr) = (void *)&nrp->regs;
    191 			if ((error = sys_ptrace(l, &npa, retval)) != 0)
    192 				return error;
    193 #endif
    194 #ifdef PT_SETFPREGS
    195 			SCARG(&npa, req) = PT_SETFPREGS;
    196 			SCARG(&npa, pid) = SCARG(uap, pid);
    197 			SCARG(&npa, addr) = (void *)&nrp->fpregs;
    198 			if ((error = sys_ptrace(l, &npa, retval)) != 0)
    199 				return error;
    200 #endif
    201 			return 0;
    202 		}
    203     }
    204 #endif
    205 
    206 	default:			/* It was not a legal request. */
    207 		return (EINVAL);
    208 	}
    209 
    210 #ifdef DIAGNOSTIC
    211 	panic("freebsd_ptrace: impossible");
    212 #endif
    213 #else
    214 	return (ENOSYS);
    215 #endif /* PTRACE || _LKM */
    216 }
    217