1 /* $NetBSD: linux_ptrace.c,v 1.15 2010/07/01 02:38:28 rmind 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: linux_ptrace.c,v 1.15 2010/07/01 02:38:28 rmind Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/malloc.h> 38 #include <sys/mount.h> 39 #include <sys/proc.h> 40 #include <sys/ptrace.h> 41 #include <sys/systm.h> 42 #include <sys/syscallargs.h> 43 #include <uvm/uvm_extern.h> 44 45 #include <machine/reg.h> 46 47 #include <compat/linux/common/linux_types.h> 48 #include <compat/linux/common/linux_ptrace.h> 49 #include <compat/linux/common/linux_signal.h> 50 51 #include <compat/linux/common/linux_util.h> 52 #include <compat/linux/common/linux_machdep.h> 53 #include <compat/linux/common/linux_emuldata.h> 54 #include <compat/linux/common/linux_exec.h> /* for emul_linux */ 55 56 #include <compat/linux/linux_syscallargs.h> 57 58 #include <lib/libkern/libkern.h> /* for offsetof() */ 59 60 /* 61 * On ARMv2, uregs contains R0--R15, orig_R0. 62 * On ARMv3 and later, it's R0--R15, CPSR, orig_R0. 63 * As far as I can see, Linux doesn't initialise orig_R0 on ARMv2, so we 64 * just produce the ARMv3 version. 65 */ 66 67 struct linux_reg { 68 long uregs[18]; 69 }; 70 71 #define LINUX_REG_R0 0 72 #define LINUX_REG_R1 1 73 #define LINUX_REG_R2 2 74 #define LINUX_REG_R3 3 75 #define LINUX_REG_R4 4 76 #define LINUX_REG_R5 5 77 #define LINUX_REG_R6 6 78 #define LINUX_REG_R7 7 79 #define LINUX_REG_R8 8 80 #define LINUX_REG_R9 9 81 #define LINUX_REG_R10 10 82 #define LINUX_REG_FP 11 83 #define LINUX_REG_IP 12 84 #define LINUX_REG_SP 13 85 #define LINUX_REG_LR 14 86 #define LINUX_REG_PC 15 87 #define LINUX_REG_CPSR 16 88 #define LINUX_REG_ORIG_R0 17 89 90 int linux_ptrace_disabled = 1; /* bitrotted */ 91 92 int 93 linux_sys_ptrace_arch(struct lwp *l, const struct linux_sys_ptrace_args *uap, 94 register_t *retval) 95 { 96 /* { 97 syscallarg(int) request; 98 syscallarg(int) pid; 99 syscallarg(int) addr; 100 syscallarg(int) data; 101 } */ 102 struct proc *p = l->l_proc, *t; 103 struct lwp *lt; 104 struct reg *regs = NULL; 105 struct linux_reg *linux_regs = NULL; 106 int request, error; 107 108 if (linux_ptrace_disabled) 109 return ENOSYS; 110 111 error = 0; 112 request = SCARG(uap, request); 113 regs = kmem_alloc(sizeof(struct reg), KM_SLEEP); 114 linux_regs = kmem_alloc(sizeof(struct linux_reg), KM_SLEEP); 115 116 switch (request) { 117 case LINUX_PTRACE_GETREGS: 118 break; 119 case LINUX_PTRACE_SETREGS: 120 error = copyin((void *)SCARG(uap, data), linux_regs, 121 sizeof(struct linux_reg)); 122 if (error) { 123 goto out; 124 } 125 break; 126 default: 127 error = EIO; 128 goto out; 129 } 130 131 /* Find the process we are supposed to be operating on. */ 132 mutex_enter(proc_lock); 133 if ((t = proc_find(SCARG(uap, pid))) == NULL) { 134 mutex_exit(proc_lock); 135 error = ESRCH; 136 goto out; 137 } 138 mutex_enter(t->p_lock); 139 mutex_exit(proc_lock); 140 141 /* 142 * You cannot do what you want to the process if: 143 * 1. It is not being traced at all, 144 */ 145 if (!ISSET(t->p_slflag, PSL_TRACED)) { 146 mutex_exit(t->p_lock); 147 error = EPERM; 148 goto out; 149 } 150 /* 151 * 2. It is being traced by procfs (which has different signal 152 * delivery semantics), 153 * 3. It is not being traced by _you_, or 154 * 4. It is not currently stopped. 155 */ 156 if (ISSET(t->p_slflag, PSL_FSTRACE) || t->p_pptr != p || 157 t->p_stat != SSTOP || !t->p_waited) { 158 mutex_exit(t->p_lock); 159 error = EBUSY; 160 goto out; 161 } 162 /* XXX: ptrace needs revamp for multi-threading support. */ 163 if (t->p_nlwps > 1) { 164 mutex_exit(t->p_lock); 165 error = ENOSYS; 166 goto out; 167 } 168 lt = LIST_FIRST(&t->p_lwps); 169 *retval = 0; 170 171 switch (request) { 172 case LINUX_PTRACE_GETREGS: 173 error = process_read_regs(lt, regs); 174 mutex_exit(t->p_lock); 175 if (error) { 176 break; 177 } 178 memcpy(linux_regs->uregs, regs->r, 13 * sizeof(register_t)); 179 linux_regs->uregs[LINUX_REG_SP] = regs->r_sp; 180 linux_regs->uregs[LINUX_REG_LR] = regs->r_lr; 181 linux_regs->uregs[LINUX_REG_PC] = regs->r_pc; 182 linux_regs->uregs[LINUX_REG_CPSR] = regs->r_cpsr; 183 linux_regs->uregs[LINUX_REG_ORIG_R0] = regs->r[0]; 184 185 error = copyout(linux_regs, (void *)SCARG(uap, data), 186 sizeof(struct linux_reg)); 187 break; 188 189 case LINUX_PTRACE_SETREGS: 190 memcpy(regs->r, linux_regs->uregs, 13 * sizeof(register_t)); 191 regs->r_sp = linux_regs->uregs[LINUX_REG_SP]; 192 regs->r_lr = linux_regs->uregs[LINUX_REG_LR]; 193 regs->r_pc = linux_regs->uregs[LINUX_REG_PC]; 194 regs->r_cpsr = linux_regs->uregs[LINUX_REG_CPSR]; 195 error = process_write_regs(lt, regs); 196 /* FALLTHROUGH */ 197 default: 198 mutex_exit(t->p_lock); 199 } 200 out: 201 if (regs) 202 kmem_free(regs, sizeof(*regs)); 203 if (linux_regs) 204 kmem_free(linux_regs, sizeof(*linux_regs)); 205 return error; 206 207 } 208