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 /* Take the info from thread->arch->faultinfo, 256 * but transfer max. sizeof(struct ptrace_faultinfo). 257 * On i386, ptrace_faultinfo is smaller! 258 */ 259 ret = copy_to_user((unsigned long __user *) data, 260 &child->thread.arch.faultinfo, 261 sizeof(struct ptrace_faultinfo)); 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 #ifdef PTRACE_LDT 273 case PTRACE_LDT: { 274 struct ptrace_ldt ldt; 275 276 if(copy_from_user(&ldt, (unsigned long __user *) data, 277 sizeof(ldt))){ 278 ret = -EIO; 279 break; 280 } 281 282 /* This one is confusing, so just punt and return -EIO for 283 * now 284 */ 285 ret = -EIO; 286 break; 287 } 288 #endif 289 #ifdef CONFIG_PROC_MM 290 case PTRACE_SWITCH_MM: { 291 struct mm_struct *old = child->mm; 292 struct mm_struct *new = proc_mm_get_mm(data); 293 294 if(IS_ERR(new)){ 295 ret = PTR_ERR(new); 296 break; 297 } 298 299 atomic_inc(&new->mm_users); 300 child->mm = new; 301 child->active_mm = new; 302 mmput(old); 303 ret = 0; 304 break; 305 } 306 #endif 307 default: 308 ret = ptrace_request(child, request, addr, data); 309 break; 310 } 311 out_tsk: 312 put_task_struct(child); 313 out: 314 unlock_kernel(); 315 return ret; 316 } 317 318 void send_sigtrap(struct task_struct *tsk, union uml_pt_regs *regs, 319 int error_code) 320 { 321 struct siginfo info; 322 323 memset(&info, 0, sizeof(info)); 324 info.si_signo = SIGTRAP; 325 info.si_code = TRAP_BRKPT; 326 327 /* User-mode eip? */ 328 info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL; 329 330 /* Send us the fakey SIGTRAP */ 331 force_sig_info(SIGTRAP, &info, tsk); 332 } 333 334 /* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and 335 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check 336 */ 337 void syscall_trace(union uml_pt_regs *regs, int entryexit) 338 { 339 int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit; 340 int tracesysgood; 341 342 if (unlikely(current->audit_context)) { 343 if (!entryexit) 344 audit_syscall_entry(current, 345 HOST_AUDIT_ARCH, 346 UPT_SYSCALL_NR(regs), 347 UPT_SYSCALL_ARG1(regs), 348 UPT_SYSCALL_ARG2(regs), 349 UPT_SYSCALL_ARG3(regs), 350 UPT_SYSCALL_ARG4(regs)); 351 else { 352 int res = UPT_SYSCALL_RET(regs); 353 audit_syscall_exit(current, AUDITSC_RESULT(res), 354 res); 355 } 356 } 357 358 /* Fake a debug trap */ 359 if (is_singlestep) 360 send_sigtrap(current, regs, 0); 361 362 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 363 return; 364 365 if (!(current->ptrace & PT_PTRACED)) 366 return; 367 368 /* the 0x80 provides a way for the tracing parent to distinguish 369 between a syscall stop and SIGTRAP delivery */ 370 tracesysgood = (current->ptrace & PT_TRACESYSGOOD); 371 ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0)); 372 373 if (entryexit) /* force do_signal() --> is_syscall() */ 374 set_thread_flag(TIF_SIGPENDING); 375 376 /* this isn't the same as continuing with a signal, but it will do 377 * for normal use. strace only continues with a signal if the 378 * stopping signal is not SIGTRAP. -brl 379 */ 380 if (current->exit_code) { 381 send_sig(current->exit_code, current, 1); 382 current->exit_code = 0; 383 } 384 } 385 386 /* 387 * Overrides for Emacs so that we follow Linus's tabbing style. 388 * Emacs will notice this stuff at the end of the file and automatically 389 * adjust the settings for this buffer only. This must remain at the end 390 * of the file. 391 * --------------------------------------------------------------------------- 392 * Local variables: 393 * c-file-style: "linux" 394 * End: 395 */ 396