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linux_ptrace.c revision 1.9.24.1
      1 /*	$NetBSD: linux_ptrace.c,v 1.9.24.1 2007/12/26 19:49:06 ad 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 1.9.24.1 2007/12/26 19:49:06 ad 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(struct lwp *l, const struct linux_sys_ptrace_args *uap, register_t *retval)
     99 {
    100 	/* {
    101 		syscallarg(int) request;
    102 		syscallarg(int) pid;
    103 		syscallarg(int) addr;
    104 		syscallarg(int) data;
    105 	} */
    106 	struct proc *p = l->l_proc;
    107 	int request, error;
    108 	struct proc *t;				/* target process */
    109 	struct lwp *lt;
    110 	struct reg *regs = NULL;
    111 	struct fpreg *fpregs = NULL;
    112 	struct linux_reg *linux_regs = NULL;
    113 	struct linux_fpreg *linux_fpregs = NULL;
    114 
    115 	request = SCARG(uap, request);
    116 
    117 	if ((request != LINUX_PTRACE_GETREGS) &&
    118 	    (request != LINUX_PTRACE_SETREGS))
    119 		return EIO;
    120 
    121 	/* Find the process we're supposed to be operating on. */
    122 	if ((t = pfind(SCARG(uap, pid))) == NULL)
    123 		return ESRCH;
    124 
    125 	/*
    126 	 * You can't do what you want to the process if:
    127 	 *	(1) It's not being traced at all,
    128 	 */
    129 	if (!ISSET(t->p_slflag, PSL_TRACED))
    130 		return EPERM;
    131 
    132 	/*
    133 	 *	(2) it's being traced by procfs (which has
    134 	 *	    different signal delivery semantics),
    135 	 */
    136 	if (ISSET(t->p_slflag, PSL_FSTRACE))
    137 		return EBUSY;
    138 
    139 	/*
    140 	 *	(3) it's not being traced by _you_, or
    141 	 */
    142 	if (t->p_pptr != p)
    143 		return EBUSY;
    144 
    145 	/*
    146 	 *	(4) it's not currently stopped.
    147 	 */
    148 	if (t->p_stat != SSTOP || !t->p_waited)
    149 		return EBUSY;
    150 
    151 	/* XXX NJWLWP
    152 	 * The entire ptrace interface needs work to be useful to
    153 	 * a process with multiple LWPs. For the moment, we'll
    154 	 * just kluge this and fail on others.
    155 	 */
    156 
    157 	if (p->p_nlwps > 1)
    158 		return (ENOSYS);
    159 
    160 	lt = LIST_FIRST(&t->p_lwps);
    161 
    162 	*retval = 0;
    163 
    164 	switch (request) {
    165 	case  LINUX_PTRACE_GETREGS:
    166 		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
    167 		MALLOC(linux_regs, struct linux_reg*, sizeof(struct linux_reg),
    168 			M_TEMP, M_WAITOK);
    169 
    170 		error = process_read_regs(lt, regs);
    171 		if (error != 0)
    172 			goto out;
    173 
    174 		memcpy(linux_regs->uregs, regs->r, 13 * sizeof(register_t));
    175 		linux_regs->uregs[LINUX_REG_SP] = regs->r_sp;
    176 		linux_regs->uregs[LINUX_REG_LR] = regs->r_lr;
    177 		linux_regs->uregs[LINUX_REG_PC] = regs->r_pc;
    178 		linux_regs->uregs[LINUX_REG_CPSR] = regs->r_cpsr;
    179 		linux_regs->uregs[LINUX_REG_ORIG_R0] = regs->r[0];
    180 
    181 		error = copyout(linux_regs, (void *)SCARG(uap, data),
    182 		    sizeof(struct linux_reg));
    183 		goto out;
    184 
    185 	case  LINUX_PTRACE_SETREGS:
    186 		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
    187 		MALLOC(linux_regs, struct linux_reg *, sizeof(struct linux_reg),
    188 			M_TEMP, M_WAITOK);
    189 
    190 		error = copyin((void *)SCARG(uap, data), linux_regs,
    191 		    sizeof(struct linux_reg));
    192 		if (error != 0)
    193 			goto out;
    194 
    195 		memcpy(regs->r, linux_regs->uregs, 13 * sizeof(register_t));
    196 		regs->r_sp = linux_regs->uregs[LINUX_REG_SP];
    197 		regs->r_lr = linux_regs->uregs[LINUX_REG_LR];
    198 		regs->r_pc = linux_regs->uregs[LINUX_REG_PC];
    199 		regs->r_cpsr = linux_regs->uregs[LINUX_REG_CPSR];
    200 
    201 		error = process_write_regs(lt, regs);
    202 		goto out;
    203 
    204 	default:
    205 		/* never reached */
    206 		break;
    207 	}
    208 
    209 	return EIO;
    210 
    211     out:
    212 	if (regs)
    213 		FREE(regs, M_TEMP);
    214 	if (fpregs)
    215 		FREE(fpregs, M_TEMP);
    216 	if (linux_regs)
    217 		FREE(linux_regs, M_TEMP);
    218 	if (linux_fpregs)
    219 		FREE(linux_fpregs, M_TEMP);
    220 	return (error);
    221 
    222 }
    223