1 /* 2 * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) 3 * Licensed under the GPL 4 */ 5 6 #include "linux/sched.h" 7 #include "linux/mm.h" 8 #include "linux/errno.h" 9 #include "linux/smp_lock.h" 10 #include "linux/security.h" 11 #include "linux/ptrace.h" 12 #include "linux/audit.h" 13 #ifdef CONFIG_PROC_MM 14 #include "linux/proc_mm.h" 15 #endif 16 #include "asm/ptrace.h" 17 #include "asm/uaccess.h" 18 #include "kern_util.h" 19 #include "skas_ptrace.h" 20 #include "sysdep/ptrace.h" 21 22 /* 23 * Called by kernel/ptrace.c when detaching.. 24 */ 25 void ptrace_disable(struct task_struct *child) 26 { 27 child->ptrace &= ~PT_DTRACE; 28 child->thread.singlestep_syscall = 0; 29 } 30 31 long sys_ptrace(long request, long pid, long addr, long data) 32 { 33 struct task_struct *child; 34 int i, ret; 35 36 lock_kernel(); 37 ret = -EPERM; 38 if (request == PTRACE_TRACEME) { 39 /* are we already being traced? */ 40 if (current->ptrace & PT_PTRACED) 41 goto out; 42 43 ret = security_ptrace(current->parent, current); 44 if (ret) 45 goto out; 46 47 /* set the ptrace bit in the process flags. */ 48 current->ptrace |= PT_PTRACED; 49 ret = 0; 50 goto out; 51 } 52 ret = -ESRCH; 53 read_lock(&tasklist_lock); 54 child = find_task_by_pid(pid); 55 if (child) 56 get_task_struct(child); 57 read_unlock(&tasklist_lock); 58 if (!child) 59 goto out; 60 61 ret = -EPERM; 62 if (pid == 1) /* you may not mess with init */ 63 goto out_tsk; 64 65 if (request == PTRACE_ATTACH) { 66 ret = ptrace_attach(child); 67 goto out_tsk; 68 } 69 70 ret = ptrace_check_attach(child, request == PTRACE_KILL); 71 if (ret < 0) 72 goto out_tsk; 73 74 switch (request) { 75 /* when I and D space are separate, these will need to be fixed. */ 76 case PTRACE_PEEKTEXT: /* read word at location addr. */ 77 case PTRACE_PEEKDATA: { 78 unsigned long tmp; 79 int copied; 80 81 ret = -EIO; 82 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); 83 if (copied != sizeof(tmp)) 84 break; 85 ret = put_user(tmp, (unsigned long __user *) data); 86 break; 87 } 88 89 /* read the word at location addr in the USER area. */ 90 case PTRACE_PEEKUSR: { 91 unsigned long tmp; 92 93 ret = -EIO; 94 if ((addr & 3) || addr < 0) 95 break; 96 97 tmp = 0; /* Default return condition */ 98 if(addr < MAX_REG_OFFSET){ 99 tmp = getreg(child, addr); 100 } 101 #if defined(CONFIG_UML_X86) && !defined(CONFIG_64BIT) 102 else if((addr >= offsetof(struct user, u_debugreg[0])) && 103 (addr <= offsetof(struct user, u_debugreg[7]))){ 104 addr -= offsetof(struct user, u_debugreg[0]); 105 addr = addr >> 2; 106 tmp = child->thread.arch.debugregs[addr]; 107 } 108 #endif 109 ret = put_user(tmp, (unsigned long __user *) data); 110 break; 111 } 112 113 /* when I and D space are separate, this will have to be fixed. */ 114 case PTRACE_POKETEXT: /* write the word at location addr. */ 115 case PTRACE_POKEDATA: 116 ret = -EIO; 117 if (access_process_vm(child, addr, &data, sizeof(data), 118 1) != sizeof(data)) 119 break; 120 ret = 0; 121 break; 122 123 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ 124 ret = -EIO; 125 if ((addr & 3) || addr < 0) 126 break; 127 128 if (addr < MAX_REG_OFFSET) { 129 ret = putreg(child, addr, data); 130 break; 131 } 132 #if defined(CONFIG_UML_X86) && !defined(CONFIG_64BIT) 133 else if((addr >= offsetof(struct user, u_debugreg[0])) && 134 (addr <= offsetof(struct user, u_debugreg[7]))){ 135 addr -= offsetof(struct user, u_debugreg[0]); 136 addr = addr >> 2; 137 if((addr == 4) || (addr == 5)) break; 138 child->thread.arch.debugregs[addr] = data; 139 ret = 0; 140 } 141 #endif 142 143 break; 144 145 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ 146 case PTRACE_CONT: { /* restart after signal. */ 147 ret = -EIO; 148 if (!valid_signal(data)) 149 break; 150 151 child->ptrace &= ~PT_DTRACE; 152 child->thread.singlestep_syscall = 0; 153 if (request == PTRACE_SYSCALL) { 154 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 155 } 156 else { 157 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 158 } 159 child->exit_code = data; 160 wake_up_process(child); 161 ret = 0; 162 break; 163 } 164 165 /* 166 * make the child exit. Best I can do is send it a sigkill. 167 * perhaps it should be put in the status that it wants to 168 * exit. 169 */ 170 case PTRACE_KILL: { 171 ret = 0; 172 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 173 break; 174 175 child->ptrace &= ~PT_DTRACE; 176 child->thread.singlestep_syscall = 0; 177 child->exit_code = SIGKILL; 178 wake_up_process(child); 179 break; 180 } 181 182 case PTRACE_SINGLESTEP: { /* set the trap flag. */ 183 ret = -EIO; 184 if (!valid_signal(data)) 185 break; 186 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 187 child->ptrace |= PT_DTRACE; 188 child->thread.singlestep_syscall = 0; 189 child->exit_code = data; 190 /* give it a chance to run. */ 191 wake_up_process(child); 192 ret = 0; 193 break; 194 } 195 196 case PTRACE_DETACH: 197 /* detach a process that was attached. */ 198 ret = ptrace_detach(child, data); 199 break; 200 201 #ifdef PTRACE_GETREGS 202 case PTRACE_GETREGS: { /* Get all gp regs from the child. */ 203 if (!access_ok(VERIFY_WRITE, (unsigned long *)data, 204 MAX_REG_OFFSET)) { 205 ret = -EIO; 206 break; 207 } 208 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 209 __put_user(getreg(child, i), 210 (unsigned long __user *) data); 211 data += sizeof(long); 212 } 213 ret = 0; 214 break; 215 } 216 #endif 217 #ifdef PTRACE_SETREGS 218 case PTRACE_SETREGS: { /* Set all gp regs in the child. */ 219 unsigned long tmp = 0; 220 if (!access_ok(VERIFY_READ, (unsigned *)data, 221 MAX_REG_OFFSET)) { 222 ret = -EIO; 223 break; 224 } 225 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 226 __get_user(tmp, (unsigned long __user *) data); 227 putreg(child, i, tmp); 228 data += sizeof(long); 229 } 230 ret = 0; 231 break; 232 } 233 #endif 234 #ifdef PTRACE_GETFPREGS 235 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 236 ret = get_fpregs(data, child); 237 break; 238 #endif 239 #ifdef PTRACE_SETFPREGS 240 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 241 ret = set_fpregs(data, child); 242 break; 243 #endif 244 #ifdef PTRACE_GETFPXREGS 245 case PTRACE_GETFPXREGS: /* Get the child FPU state. */ 246 ret = get_fpxregs(data, child); 247 break; 248 #endif 249 #ifdef PTRACE_SETFPXREGS 250 case PTRACE_SETFPXREGS: /* Set the child FPU state. */ 251 ret = set_fpxregs(data, child); 252 break; 253 #endif 254 case PTRACE_FAULTINFO: { 255 struct ptrace_faultinfo fault; 256 257 fault = ((struct ptrace_faultinfo) 258 { .is_write = child->thread.err, 259 .addr = child->thread.cr2 }); 260 ret = copy_to_user((unsigned long __user *) data, &fault, 261 sizeof(fault)); 262 if(ret) 263 break; 264 break; 265 } 266 case PTRACE_SIGPENDING: 267 ret = copy_to_user((unsigned long __user *) data, 268 &child->pending.signal, 269 sizeof(child->pending.signal)); 270 break; 271 272 case PTRACE_LDT: { 273 struct ptrace_ldt ldt; 274 275 if(copy_from_user(&ldt, (unsigned long __user *) data, 276 sizeof(ldt))){ 277 ret = -EIO; 278 break; 279 } 280 281 /* This one is confusing, so just punt and return -EIO for 282 * now 283 */ 284 ret = -EIO; 285 break; 286 } 287 #ifdef CONFIG_PROC_MM 288 case PTRACE_SWITCH_MM: { 289 struct mm_struct *old = child->mm; 290 struct mm_struct *new = proc_mm_get_mm(data); 291 292 if(IS_ERR(new)){ 293 ret = PTR_ERR(new); 294 break; 295 } 296 297 atomic_inc(&new->mm_users); 298 child->mm = new; 299 child->active_mm = new; 300 mmput(old); 301 ret = 0; 302 break; 303 } 304 #endif 305 default: 306 ret = ptrace_request(child, request, addr, data); 307 break; 308 } 309 out_tsk: 310 put_task_struct(child); 311 out: 312 unlock_kernel(); 313 return ret; 314 } 315 316 void send_sigtrap(struct task_struct *tsk, union uml_pt_regs *regs, 317 int error_code) 318 { 319 struct siginfo info; 320 321 memset(&info, 0, sizeof(info)); 322 info.si_signo = SIGTRAP; 323 info.si_code = TRAP_BRKPT; 324 325 /* User-mode eip? */ 326 info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL; 327 328 /* Send us the fakey SIGTRAP */ 329 force_sig_info(SIGTRAP, &info, tsk); 330 } 331 332 /* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and 333 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check 334 */ 335 void syscall_trace(union uml_pt_regs *regs, int entryexit) 336 { 337 int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit; 338 int tracesysgood; 339 340 if (unlikely(current->audit_context)) { 341 if (!entryexit) 342 audit_syscall_entry(current, 343 HOST_AUDIT_ARCH, 344 UPT_SYSCALL_NR(regs), 345 UPT_SYSCALL_ARG1(regs), 346 UPT_SYSCALL_ARG2(regs), 347 UPT_SYSCALL_ARG3(regs), 348 UPT_SYSCALL_ARG4(regs)); 349 else { 350 int res = UPT_SYSCALL_RET(regs); 351 audit_syscall_exit(current, AUDITSC_RESULT(res), 352 res); 353 } 354 } 355 356 /* Fake a debug trap */ 357 if (is_singlestep) 358 send_sigtrap(current, regs, 0); 359 360 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 361 return; 362 363 if (!(current->ptrace & PT_PTRACED)) 364 return; 365 366 /* the 0x80 provides a way for the tracing parent to distinguish 367 between a syscall stop and SIGTRAP delivery */ 368 tracesysgood = (current->ptrace & PT_TRACESYSGOOD); 369 ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0)); 370 371 if (entryexit) /* force do_signal() --> is_syscall() */ 372 set_thread_flag(TIF_SIGPENDING); 373 374 /* this isn't the same as continuing with a signal, but it will do 375 * for normal use. strace only continues with a signal if the 376 * stopping signal is not SIGTRAP. -brl 377 */ 378 if (current->exit_code) { 379 send_sig(current->exit_code, current, 1); 380 current->exit_code = 0; 381 } 382 } 383 384 /* 385 * Overrides for Emacs so that we follow Linus's tabbing style. 386 * Emacs will notice this stuff at the end of the file and automatically 387 * adjust the settings for this buffer only. This must remain at the end 388 * of the file. 389 * --------------------------------------------------------------------------- 390 * Local variables: 391 * c-file-style: "linux" 392 * End: 393 */ 394