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 #include "os.h" 22 23 static inline void set_singlestepping(struct task_struct *child, int on) 24 { 25 if (on) 26 child->ptrace |= PT_DTRACE; 27 else 28 child->ptrace &= ~PT_DTRACE; 29 child->thread.singlestep_syscall = 0; 30 31 #ifdef SUBARCH_SET_SINGLESTEPPING 32 SUBARCH_SET_SINGLESTEPPING(child, on); 33 #endif 34 } 35 36 /* 37 * Called by kernel/ptrace.c when detaching.. 38 */ 39 void ptrace_disable(struct task_struct *child) 40 { 41 set_singlestepping(child,0); 42 } 43 44 extern int peek_user(struct task_struct * child, long addr, long data); 45 extern int poke_user(struct task_struct * child, long addr, long data); 46 47 long arch_ptrace(struct task_struct *child, long request, long addr, long data) 48 { 49 int i, ret; 50 unsigned long __user *p = (void __user *)(unsigned long)data; 51 52 switch (request) { 53 /* when I and D space are separate, these will need to be fixed. */ 54 case PTRACE_PEEKTEXT: /* read word at location addr. */ 55 case PTRACE_PEEKDATA: { 56 unsigned long tmp; 57 int copied; 58 59 ret = -EIO; 60 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); 61 if (copied != sizeof(tmp)) 62 break; 63 ret = put_user(tmp, p); 64 break; 65 } 66 67 /* read the word at location addr in the USER area. */ 68 case PTRACE_PEEKUSR: 69 ret = peek_user(child, addr, data); 70 break; 71 72 /* when I and D space are separate, this will have to be fixed. */ 73 case PTRACE_POKETEXT: /* write the word at location addr. */ 74 case PTRACE_POKEDATA: 75 ret = -EIO; 76 if (access_process_vm(child, addr, &data, sizeof(data), 77 1) != sizeof(data)) 78 break; 79 ret = 0; 80 break; 81 82 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ 83 ret = poke_user(child, addr, data); 84 break; 85 86 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ 87 case PTRACE_CONT: { /* restart after signal. */ 88 ret = -EIO; 89 if (!valid_signal(data)) 90 break; 91 92 set_singlestepping(child, 0); 93 if (request == PTRACE_SYSCALL) { 94 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 95 } 96 else { 97 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 98 } 99 child->exit_code = data; 100 wake_up_process(child); 101 ret = 0; 102 break; 103 } 104 105 /* 106 * make the child exit. Best I can do is send it a sigkill. 107 * perhaps it should be put in the status that it wants to 108 * exit. 109 */ 110 case PTRACE_KILL: { 111 ret = 0; 112 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 113 break; 114 115 set_singlestepping(child, 0); 116 child->exit_code = SIGKILL; 117 wake_up_process(child); 118 break; 119 } 120 121 case PTRACE_SINGLESTEP: { /* set the trap flag. */ 122 ret = -EIO; 123 if (!valid_signal(data)) 124 break; 125 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 126 set_singlestepping(child, 1); 127 child->exit_code = data; 128 /* give it a chance to run. */ 129 wake_up_process(child); 130 ret = 0; 131 break; 132 } 133 134 case PTRACE_DETACH: 135 /* detach a process that was attached. */ 136 ret = ptrace_detach(child, data); 137 break; 138 139 #ifdef PTRACE_GETREGS 140 case PTRACE_GETREGS: { /* Get all gp regs from the child. */ 141 if (!access_ok(VERIFY_WRITE, p, MAX_REG_OFFSET)) { 142 ret = -EIO; 143 break; 144 } 145 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 146 __put_user(getreg(child, i), p); 147 p++; 148 } 149 ret = 0; 150 break; 151 } 152 #endif 153 #ifdef PTRACE_SETREGS 154 case PTRACE_SETREGS: { /* Set all gp regs in the child. */ 155 unsigned long tmp = 0; 156 if (!access_ok(VERIFY_READ, p, MAX_REG_OFFSET)) { 157 ret = -EIO; 158 break; 159 } 160 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 161 __get_user(tmp, p); 162 putreg(child, i, tmp); 163 p++; 164 } 165 ret = 0; 166 break; 167 } 168 #endif 169 #ifdef PTRACE_GETFPREGS 170 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 171 ret = get_fpregs(data, child); 172 break; 173 #endif 174 #ifdef PTRACE_SETFPREGS 175 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 176 ret = set_fpregs(data, child); 177 break; 178 #endif 179 #ifdef PTRACE_GETFPXREGS 180 case PTRACE_GETFPXREGS: /* Get the child FPU state. */ 181 ret = get_fpxregs(data, child); 182 break; 183 #endif 184 #ifdef PTRACE_SETFPXREGS 185 case PTRACE_SETFPXREGS: /* Set the child FPU state. */ 186 ret = set_fpxregs(data, child); 187 break; 188 #endif 189 case PTRACE_GET_THREAD_AREA: 190 ret = ptrace_get_thread_area(child, addr, 191 (struct user_desc __user *) data); 192 break; 193 194 case PTRACE_SET_THREAD_AREA: 195 ret = ptrace_set_thread_area(child, addr, 196 (struct user_desc __user *) data); 197 break; 198 199 case PTRACE_FAULTINFO: { 200 /* Take the info from thread->arch->faultinfo, 201 * but transfer max. sizeof(struct ptrace_faultinfo). 202 * On i386, ptrace_faultinfo is smaller! 203 */ 204 ret = copy_to_user(p, &child->thread.arch.faultinfo, 205 sizeof(struct ptrace_faultinfo)); 206 if(ret) 207 break; 208 break; 209 } 210 211 #ifdef PTRACE_LDT 212 case PTRACE_LDT: { 213 struct ptrace_ldt ldt; 214 215 if(copy_from_user(&ldt, p, sizeof(ldt))){ 216 ret = -EIO; 217 break; 218 } 219 220 /* This one is confusing, so just punt and return -EIO for 221 * now 222 */ 223 ret = -EIO; 224 break; 225 } 226 #endif 227 #ifdef CONFIG_PROC_MM 228 case PTRACE_SWITCH_MM: { 229 struct mm_struct *old = child->mm; 230 struct mm_struct *new = proc_mm_get_mm(data); 231 232 if(IS_ERR(new)){ 233 ret = PTR_ERR(new); 234 break; 235 } 236 237 atomic_inc(&new->mm_users); 238 child->mm = new; 239 child->active_mm = new; 240 mmput(old); 241 ret = 0; 242 break; 243 } 244 #endif 245 #ifdef PTRACE_ARCH_PRCTL 246 case PTRACE_ARCH_PRCTL: 247 /* XXX Calls ptrace on the host - needs some SMP thinking */ 248 ret = arch_prctl_skas(child, data, (void *) addr); 249 break; 250 #endif 251 default: 252 ret = ptrace_request(child, request, addr, data); 253 break; 254 } 255 256 return ret; 257 } 258 259 void send_sigtrap(struct task_struct *tsk, union uml_pt_regs *regs, 260 int error_code) 261 { 262 struct siginfo info; 263 264 memset(&info, 0, sizeof(info)); 265 info.si_signo = SIGTRAP; 266 info.si_code = TRAP_BRKPT; 267 268 /* User-mode eip? */ 269 info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL; 270 271 /* Send us the fakey SIGTRAP */ 272 force_sig_info(SIGTRAP, &info, tsk); 273 } 274 275 /* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and 276 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check 277 */ 278 void syscall_trace(union uml_pt_regs *regs, int entryexit) 279 { 280 int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit; 281 int tracesysgood; 282 283 if (unlikely(current->audit_context)) { 284 if (!entryexit) 285 audit_syscall_entry(HOST_AUDIT_ARCH, 286 UPT_SYSCALL_NR(regs), 287 UPT_SYSCALL_ARG1(regs), 288 UPT_SYSCALL_ARG2(regs), 289 UPT_SYSCALL_ARG3(regs), 290 UPT_SYSCALL_ARG4(regs)); 291 else audit_syscall_exit(AUDITSC_RESULT(UPT_SYSCALL_RET(regs)), 292 UPT_SYSCALL_RET(regs)); 293 } 294 295 /* Fake a debug trap */ 296 if (is_singlestep) 297 send_sigtrap(current, regs, 0); 298 299 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 300 return; 301 302 if (!(current->ptrace & PT_PTRACED)) 303 return; 304 305 /* the 0x80 provides a way for the tracing parent to distinguish 306 between a syscall stop and SIGTRAP delivery */ 307 tracesysgood = (current->ptrace & PT_TRACESYSGOOD); 308 ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0)); 309 310 if (entryexit) /* force do_signal() --> is_syscall() */ 311 set_thread_flag(TIF_SIGPENDING); 312 313 /* this isn't the same as continuing with a signal, but it will do 314 * for normal use. strace only continues with a signal if the 315 * stopping signal is not SIGTRAP. -brl 316 */ 317 if (current->exit_code) { 318 send_sig(current->exit_code, current, 1); 319 current->exit_code = 0; 320 } 321 } 322