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linux_ptrace.c revision 1.9
      1 /*	$NetBSD: linux_ptrace.c,v 1.9 2007/03/04 06:01:19 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Matthias Scheler.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 
     40 #include <sys/cdefs.h>
     41 __KERNEL_RCSID(0, "$NetBSD: linux_ptrace.c,v 1.9 2007/03/04 06:01:19 christos Exp $");
     42 
     43 #include <sys/param.h>
     44 #include <sys/malloc.h>
     45 #include <sys/mount.h>
     46 #include <sys/proc.h>
     47 #include <sys/ptrace.h>
     48 #include <sys/systm.h>
     49 #include <sys/syscallargs.h>
     50 #include <uvm/uvm_extern.h>
     51 
     52 #include <machine/reg.h>
     53 
     54 #include <compat/linux/common/linux_types.h>
     55 #include <compat/linux/common/linux_ptrace.h>
     56 #include <compat/linux/common/linux_signal.h>
     57 
     58 #include <compat/linux/common/linux_util.h>
     59 #include <compat/linux/common/linux_machdep.h>
     60 #include <compat/linux/common/linux_emuldata.h>
     61 #include <compat/linux/common/linux_exec.h>	/* for emul_linux */
     62 
     63 #include <compat/linux/linux_syscallargs.h>
     64 
     65 #include <lib/libkern/libkern.h>	/* for offsetof() */
     66 
     67 /*
     68  * On ARMv2, uregs contains R0--R15, orig_R0.
     69  * On ARMv3 and later, it's R0--R15, CPSR, orig_R0.
     70  * As far as I can see, Linux doesn't initialise orig_R0 on ARMv2, so we
     71  * just produce the ARMv3 version.
     72  */
     73 
     74 struct linux_reg {
     75 	long uregs[18];
     76 };
     77 
     78 #define LINUX_REG_R0	0
     79 #define LINUX_REG_R1	1
     80 #define LINUX_REG_R2	2
     81 #define LINUX_REG_R3	3
     82 #define LINUX_REG_R4	4
     83 #define LINUX_REG_R5	5
     84 #define LINUX_REG_R6	6
     85 #define LINUX_REG_R7	7
     86 #define LINUX_REG_R8	8
     87 #define LINUX_REG_R9	9
     88 #define LINUX_REG_R10	10
     89 #define LINUX_REG_FP	11
     90 #define LINUX_REG_IP	12
     91 #define LINUX_REG_SP	13
     92 #define LINUX_REG_LR	14
     93 #define LINUX_REG_PC	15
     94 #define LINUX_REG_CPSR	16
     95 #define LINUX_REG_ORIG_R0 17
     96 
     97 int
     98 linux_sys_ptrace_arch(l, v, retval)
     99 	struct lwp *l;
    100 	void *v;
    101 	register_t *retval;
    102 {
    103 	struct linux_sys_ptrace_args /* {
    104 		syscallarg(int) request;
    105 		syscallarg(int) pid;
    106 		syscallarg(int) addr;
    107 		syscallarg(int) data;
    108 	} */ *uap = v;
    109 	struct proc *p = l->l_proc;
    110 	int request, error;
    111 	struct proc *t;				/* target process */
    112 	struct lwp *lt;
    113 	struct reg *regs = NULL;
    114 	struct fpreg *fpregs = NULL;
    115 	struct linux_reg *linux_regs = NULL;
    116 	struct linux_fpreg *linux_fpregs = NULL;
    117 
    118 	request = SCARG(uap, request);
    119 
    120 	if ((request != LINUX_PTRACE_GETREGS) &&
    121 	    (request != LINUX_PTRACE_SETREGS))
    122 		return EIO;
    123 
    124 	/* Find the process we're supposed to be operating on. */
    125 	if ((t = pfind(SCARG(uap, pid))) == NULL)
    126 		return ESRCH;
    127 
    128 	/*
    129 	 * You can't do what you want to the process if:
    130 	 *	(1) It's not being traced at all,
    131 	 */
    132 	if (!ISSET(t->p_slflag, PSL_TRACED))
    133 		return EPERM;
    134 
    135 	/*
    136 	 *	(2) it's being traced by procfs (which has
    137 	 *	    different signal delivery semantics),
    138 	 */
    139 	if (ISSET(t->p_slflag, PSL_FSTRACE))
    140 		return EBUSY;
    141 
    142 	/*
    143 	 *	(3) it's not being traced by _you_, or
    144 	 */
    145 	if (t->p_pptr != p)
    146 		return EBUSY;
    147 
    148 	/*
    149 	 *	(4) it's not currently stopped.
    150 	 */
    151 	if (t->p_stat != SSTOP || !t->p_waited)
    152 		return EBUSY;
    153 
    154 	/* XXX NJWLWP
    155 	 * The entire ptrace interface needs work to be useful to
    156 	 * a process with multiple LWPs. For the moment, we'll
    157 	 * just kluge this and fail on others.
    158 	 */
    159 
    160 	if (p->p_nlwps > 1)
    161 		return (ENOSYS);
    162 
    163 	lt = LIST_FIRST(&t->p_lwps);
    164 
    165 	*retval = 0;
    166 
    167 	switch (request) {
    168 	case  LINUX_PTRACE_GETREGS:
    169 		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
    170 		MALLOC(linux_regs, struct linux_reg*, sizeof(struct linux_reg),
    171 			M_TEMP, M_WAITOK);
    172 
    173 		error = process_read_regs(lt, regs);
    174 		if (error != 0)
    175 			goto out;
    176 
    177 		memcpy(linux_regs->uregs, regs->r, 13 * sizeof(register_t));
    178 		linux_regs->uregs[LINUX_REG_SP] = regs->r_sp;
    179 		linux_regs->uregs[LINUX_REG_LR] = regs->r_lr;
    180 		linux_regs->uregs[LINUX_REG_PC] = regs->r_pc;
    181 		linux_regs->uregs[LINUX_REG_CPSR] = regs->r_cpsr;
    182 		linux_regs->uregs[LINUX_REG_ORIG_R0] = regs->r[0];
    183 
    184 		error = copyout(linux_regs, (void *)SCARG(uap, data),
    185 		    sizeof(struct linux_reg));
    186 		goto out;
    187 
    188 	case  LINUX_PTRACE_SETREGS:
    189 		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
    190 		MALLOC(linux_regs, struct linux_reg *, sizeof(struct linux_reg),
    191 			M_TEMP, M_WAITOK);
    192 
    193 		error = copyin((void *)SCARG(uap, data), linux_regs,
    194 		    sizeof(struct linux_reg));
    195 		if (error != 0)
    196 			goto out;
    197 
    198 		memcpy(regs->r, linux_regs->uregs, 13 * sizeof(register_t));
    199 		regs->r_sp = linux_regs->uregs[LINUX_REG_SP];
    200 		regs->r_lr = linux_regs->uregs[LINUX_REG_LR];
    201 		regs->r_pc = linux_regs->uregs[LINUX_REG_PC];
    202 		regs->r_cpsr = linux_regs->uregs[LINUX_REG_CPSR];
    203 
    204 		error = process_write_regs(lt, regs);
    205 		goto out;
    206 
    207 	default:
    208 		/* never reached */
    209 		break;
    210 	}
    211 
    212 	return EIO;
    213 
    214     out:
    215 	if (regs)
    216 		FREE(regs, M_TEMP);
    217 	if (fpregs)
    218 		FREE(fpregs, M_TEMP);
    219 	if (linux_regs)
    220 		FREE(linux_regs, M_TEMP);
    221 	if (linux_fpregs)
    222 		FREE(linux_fpregs, M_TEMP);
    223 	return (error);
    224 
    225 }
    226