1/* $NetBSD: linux_ptrace.c,v 1.23 2021/09/07 11:43:04 riastradh 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 1.23 2021/09/07 11:43:04 riastradh Exp $"); 35 36#include <sys/param.h> 37#include <sys/mount.h> 38#include <sys/proc.h> 39#include <sys/ptrace.h> 40#include <sys/systm.h> 41#include <sys/syscallargs.h> 42#include <uvm/uvm_extern.h> 43 44#include <machine/reg.h> 45#include <machine/pcb.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 67struct 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 90int linux_ptrace_disabled = 1; /* bitrotted */ 91 92int 93linux_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#ifdef _ARM_ARCH_6 105 struct pcb *pcb; 106 void *val; 107#endif 108 struct reg *regs = NULL; 109 struct linux_reg *linux_regs = NULL; 110 int request, error; 111 112 if (linux_ptrace_disabled) 113 return ENOSYS; 114 115 error = 0; 116 request = SCARG(uap, request); 117 regs = kmem_alloc(sizeof(struct reg), KM_SLEEP); 118 linux_regs = kmem_alloc(sizeof(struct linux_reg), KM_SLEEP); 119 120 switch (request) { 121 case LINUX_PTRACE_GETREGS: 122 break; 123 case LINUX_PTRACE_SETREGS: 124 error = copyin((void *)SCARG(uap, data), linux_regs, 125 sizeof(struct linux_reg)); 126 if (error) { 127 goto out; 128 } 129 break; 130 default: 131 error = EIO; 132 goto out; 133 } 134 135 /* Find the process we are supposed to be operating on. */ 136 mutex_enter(&proc_lock); 137 if ((t = proc_find(SCARG(uap, pid))) == NULL) { 138 mutex_exit(&proc_lock); 139 error = ESRCH; 140 goto out; 141 } 142 mutex_enter(t->p_lock); 143 144 /* 145 * You cannot do what you want to the process if: 146 * 1. It is not being traced at all, 147 */ 148 if (!ISSET(t->p_slflag, PSL_TRACED)) { 149 mutex_exit(t->p_lock); 150 mutex_exit(&proc_lock); 151 error = EPERM; 152 goto out; 153 } 154 /* 155 * 2. It is being traced by procfs (which has different signal 156 * delivery semantics), 157 * 3. It is not being traced by _you_, or 158 * 4. It is not currently stopped. 159 */ 160 if (t->p_pptr != p || t->p_stat != SSTOP || !t->p_waited) { 161 mutex_exit(t->p_lock); 162 mutex_exit(&proc_lock); 163 error = EBUSY; 164 goto out; 165 } 166 mutex_exit(&proc_lock); 167 /* XXX: ptrace needs revamp for multi-threading support. */ 168 if (t->p_nlwps > 1) { 169 mutex_exit(t->p_lock); 170 error = ENOSYS; 171 goto out; 172 } 173 lt = LIST_FIRST(&t->p_lwps); 174 *retval = 0; 175 176 switch (request) { 177 case LINUX_PTRACE_GETREGS: 178 error = process_read_regs(lt, regs); 179 mutex_exit(t->p_lock); 180 if (error) { 181 break; 182 } 183 memset(linux_regs, 0, sizeof(*linux_regs)); 184 memcpy(linux_regs->uregs, regs->r, 13 * sizeof(register_t)); 185 linux_regs->uregs[LINUX_REG_SP] = regs->r_sp; 186 linux_regs->uregs[LINUX_REG_LR] = regs->r_lr; 187 linux_regs->uregs[LINUX_REG_PC] = regs->r_pc; 188 linux_regs->uregs[LINUX_REG_CPSR] = regs->r_cpsr; 189 linux_regs->uregs[LINUX_REG_ORIG_R0] = regs->r[0]; 190 191 error = copyout(linux_regs, (void *)SCARG(uap, data), 192 sizeof(struct linux_reg)); 193 break; 194 195 case LINUX_PTRACE_SETREGS: 196 memcpy(regs->r, linux_regs->uregs, 13 * sizeof(register_t)); 197 regs->r_sp = linux_regs->uregs[LINUX_REG_SP]; 198 regs->r_lr = linux_regs->uregs[LINUX_REG_LR]; 199 regs->r_pc = linux_regs->uregs[LINUX_REG_PC]; 200 regs->r_cpsr = linux_regs->uregs[LINUX_REG_CPSR]; 201 error = process_write_regs(lt, regs); 202 mutex_exit(t->p_lock); 203 break; 204 205#ifdef _ARM_ARCH_6 206#define LINUX_PTRACE_GET_THREAD_AREA 22 207 case LINUX_PTRACE_GET_THREAD_AREA: 208 mutex_exit(t->p_lock); 209 pcb = lwp_getpcb(l); 210 val = (void *)pcb->pcb_user_pid_ro; 211 error = copyout(&val, (void *)SCARG(uap, data), sizeof(val)); 212 break; 213#endif 214 215 default: 216 mutex_exit(t->p_lock); 217 } 218out: 219 if (regs) 220 kmem_free(regs, sizeof(*regs)); 221 if (linux_regs) 222 kmem_free(linux_regs, sizeof(*linux_regs)); 223 return error; 224 225} 226