1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1992 Ross Biro 7 * Copyright (C) Linus Torvalds 8 * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle 9 * Copyright (C) 1996 David S. Miller 10 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com 11 * Copyright (C) 1999 MIPS Technologies, Inc. 12 * Copyright (C) 2000 Ulf Carlsson 13 * 14 * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit 15 * binaries. 16 */ 17 #include <linux/compiler.h> 18 #include <linux/kernel.h> 19 #include <linux/sched.h> 20 #include <linux/mm.h> 21 #include <linux/errno.h> 22 #include <linux/ptrace.h> 23 #include <linux/smp.h> 24 #include <linux/smp_lock.h> 25 #include <linux/user.h> 26 #include <linux/security.h> 27 #include <linux/signal.h> 28 29 #include <asm/cpu.h> 30 #include <asm/fpu.h> 31 #include <asm/mipsregs.h> 32 #include <asm/pgtable.h> 33 #include <asm/page.h> 34 #include <asm/system.h> 35 #include <asm/uaccess.h> 36 #include <asm/bootinfo.h> 37 38 /* 39 * Tracing a 32-bit process with a 64-bit strace and vice versa will not 40 * work. I don't know how to fix this. 41 */ 42 asmlinkage int sys32_ptrace(int request, int pid, int addr, int data) 43 { 44 struct task_struct *child; 45 int ret; 46 47 #if 0 48 printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n", 49 (int) request, (int) pid, (unsigned long) addr, 50 (unsigned long) data); 51 #endif 52 lock_kernel(); 53 ret = -EPERM; 54 if (request == PTRACE_TRACEME) { 55 /* are we already being traced? */ 56 if (current->ptrace & PT_PTRACED) 57 goto out; 58 if ((ret = security_ptrace(current->parent, current))) 59 goto out; 60 /* set the ptrace bit in the process flags. */ 61 current->ptrace |= PT_PTRACED; 62 ret = 0; 63 goto out; 64 } 65 ret = -ESRCH; 66 read_lock(&tasklist_lock); 67 child = find_task_by_pid(pid); 68 if (child) 69 get_task_struct(child); 70 read_unlock(&tasklist_lock); 71 if (!child) 72 goto out; 73 74 ret = -EPERM; 75 if (pid == 1) /* you may not mess with init */ 76 goto out_tsk; 77 78 if (request == PTRACE_ATTACH) { 79 ret = ptrace_attach(child); 80 goto out_tsk; 81 } 82 83 ret = ptrace_check_attach(child, request == PTRACE_KILL); 84 if (ret < 0) 85 goto out_tsk; 86 87 switch (request) { 88 /* when I and D space are separate, these will need to be fixed. */ 89 case PTRACE_PEEKTEXT: /* read word at location addr. */ 90 case PTRACE_PEEKDATA: { 91 unsigned int tmp; 92 int copied; 93 94 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); 95 ret = -EIO; 96 if (copied != sizeof(tmp)) 97 break; 98 ret = put_user(tmp, (unsigned int *) (unsigned long) data); 99 break; 100 } 101 102 /* Read the word at location addr in the USER area. */ 103 case PTRACE_PEEKUSR: { 104 struct pt_regs *regs; 105 unsigned int tmp; 106 107 regs = (struct pt_regs *) ((unsigned long) child->thread_info + 108 THREAD_SIZE - 32 - sizeof(struct pt_regs)); 109 ret = 0; /* Default return value. */ 110 111 switch (addr) { 112 case 0 ... 31: 113 tmp = regs->regs[addr]; 114 break; 115 case FPR_BASE ... FPR_BASE + 31: 116 if (tsk_used_math(child)) { 117 fpureg_t *fregs = get_fpu_regs(child); 118 119 /* 120 * The odd registers are actually the high 121 * order bits of the values stored in the even 122 * registers - unless we're using r2k_switch.S. 123 */ 124 if (addr & 1) 125 tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32); 126 else 127 tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff); 128 } else { 129 tmp = -1; /* FP not yet used */ 130 } 131 break; 132 case PC: 133 tmp = regs->cp0_epc; 134 break; 135 case CAUSE: 136 tmp = regs->cp0_cause; 137 break; 138 case BADVADDR: 139 tmp = regs->cp0_badvaddr; 140 break; 141 case MMHI: 142 tmp = regs->hi; 143 break; 144 case MMLO: 145 tmp = regs->lo; 146 break; 147 case FPC_CSR: 148 if (cpu_has_fpu) 149 tmp = child->thread.fpu.hard.fcr31; 150 else 151 tmp = child->thread.fpu.soft.fcr31; 152 break; 153 case FPC_EIR: { /* implementation / version register */ 154 unsigned int flags; 155 156 if (!cpu_has_fpu) 157 break; 158 159 flags = read_c0_status(); 160 __enable_fpu(); 161 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp)); 162 write_c0_status(flags); 163 break; 164 } 165 default: 166 tmp = 0; 167 ret = -EIO; 168 goto out_tsk; 169 } 170 ret = put_user(tmp, (unsigned *) (unsigned long) data); 171 break; 172 } 173 174 /* when I and D space are separate, this will have to be fixed. */ 175 case PTRACE_POKETEXT: /* write the word at location addr. */ 176 case PTRACE_POKEDATA: 177 ret = 0; 178 if (access_process_vm(child, addr, &data, sizeof(data), 1) 179 == sizeof(data)) 180 break; 181 ret = -EIO; 182 break; 183 184 case PTRACE_POKEUSR: { 185 struct pt_regs *regs; 186 ret = 0; 187 regs = (struct pt_regs *) ((unsigned long) child->thread_info + 188 THREAD_SIZE - 32 - sizeof(struct pt_regs)); 189 190 switch (addr) { 191 case 0 ... 31: 192 regs->regs[addr] = data; 193 break; 194 case FPR_BASE ... FPR_BASE + 31: { 195 fpureg_t *fregs = get_fpu_regs(child); 196 197 if (!tsk_used_math(child)) { 198 /* FP not yet used */ 199 memset(&child->thread.fpu.hard, ~0, 200 sizeof(child->thread.fpu.hard)); 201 child->thread.fpu.hard.fcr31 = 0; 202 } 203 /* 204 * The odd registers are actually the high order bits 205 * of the values stored in the even registers - unless 206 * we're using r2k_switch.S. 207 */ 208 if (addr & 1) { 209 fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff; 210 fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32; 211 } else { 212 fregs[addr - FPR_BASE] &= ~0xffffffffLL; 213 /* Must cast, lest sign extension fill upper 214 bits! */ 215 fregs[addr - FPR_BASE] |= (unsigned int)data; 216 } 217 break; 218 } 219 case PC: 220 regs->cp0_epc = data; 221 break; 222 case MMHI: 223 regs->hi = data; 224 break; 225 case MMLO: 226 regs->lo = data; 227 break; 228 case FPC_CSR: 229 if (cpu_has_fpu) 230 child->thread.fpu.hard.fcr31 = data; 231 else 232 child->thread.fpu.soft.fcr31 = data; 233 break; 234 default: 235 /* The rest are not allowed. */ 236 ret = -EIO; 237 break; 238 } 239 break; 240 } 241 242 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ 243 case PTRACE_CONT: { /* restart after signal. */ 244 ret = -EIO; 245 if (!valid_signal(data)) 246 break; 247 if (request == PTRACE_SYSCALL) { 248 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 249 } 250 else { 251 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 252 } 253 child->exit_code = data; 254 wake_up_process(child); 255 ret = 0; 256 break; 257 } 258 259 /* 260 * make the child exit. Best I can do is send it a sigkill. 261 * perhaps it should be put in the status that it wants to 262 * exit. 263 */ 264 case PTRACE_KILL: 265 ret = 0; 266 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 267 break; 268 child->exit_code = SIGKILL; 269 wake_up_process(child); 270 break; 271 272 case PTRACE_DETACH: /* detach a process that was attached. */ 273 ret = ptrace_detach(child, data); 274 break; 275 276 default: 277 ret = ptrace_request(child, request, addr, data); 278 break; 279 } 280 281 out_tsk: 282 put_task_struct(child); 283 out: 284 unlock_kernel(); 285 return ret; 286 } 287