1 /* 2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3 * Licensed under the GPL 4 */ 5 6 #include "linux/audit.h" 7 #include "linux/ptrace.h" 8 #include "linux/sched.h" 9 #include "asm/uaccess.h" 10 #ifdef CONFIG_PROC_MM 11 #include "proc_mm.h" 12 #endif 13 #include "skas_ptrace.h" 14 15 static inline void set_singlestepping(struct task_struct *child, int on) 16 { 17 if (on) 18 child->ptrace |= PT_DTRACE; 19 else 20 child->ptrace &= ~PT_DTRACE; 21 child->thread.singlestep_syscall = 0; 22 23 #ifdef SUBARCH_SET_SINGLESTEPPING 24 SUBARCH_SET_SINGLESTEPPING(child, on); 25 #endif 26 } 27 28 /* 29 * Called by kernel/ptrace.c when detaching.. 30 */ 31 void ptrace_disable(struct task_struct *child) 32 { 33 set_singlestepping(child,0); 34 } 35 36 extern int peek_user(struct task_struct * child, long addr, long data); 37 extern int poke_user(struct task_struct * child, long addr, long data); 38 39 long arch_ptrace(struct task_struct *child, long request, long addr, long data) 40 { 41 int i, ret; 42 unsigned long __user *p = (void __user *)(unsigned long)data; 43 44 switch (request) { 45 /* read word at location addr. */ 46 case PTRACE_PEEKTEXT: 47 case PTRACE_PEEKDATA: 48 ret = generic_ptrace_peekdata(child, addr, data); 49 break; 50 51 /* read the word at location addr in the USER area. */ 52 case PTRACE_PEEKUSR: 53 ret = peek_user(child, addr, data); 54 break; 55 56 /* write the word at location addr. */ 57 case PTRACE_POKETEXT: 58 case PTRACE_POKEDATA: 59 ret = generic_ptrace_pokedata(child, addr, data); 60 break; 61 62 /* write the word at location addr in the USER area */ 63 case PTRACE_POKEUSR: 64 ret = poke_user(child, addr, data); 65 break; 66 67 case PTRACE_SYSEMU: 68 case PTRACE_SYSEMU_SINGLESTEP: 69 ret = -EIO; 70 break; 71 72 /* continue and stop at next (return from) syscall */ 73 case PTRACE_SYSCALL: 74 /* restart after signal. */ 75 case PTRACE_CONT: { 76 ret = -EIO; 77 if (!valid_signal(data)) 78 break; 79 80 set_singlestepping(child, 0); 81 if (request == PTRACE_SYSCALL) 82 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 83 else clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 84 child->exit_code = data; 85 wake_up_process(child); 86 ret = 0; 87 break; 88 } 89 90 /* 91 * make the child exit. Best I can do is send it a sigkill. 92 * perhaps it should be put in the status that it wants to 93 * exit. 94 */ 95 case PTRACE_KILL: { 96 ret = 0; 97 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 98 break; 99 100 set_singlestepping(child, 0); 101 child->exit_code = SIGKILL; 102 wake_up_process(child); 103 break; 104 } 105 106 case PTRACE_SINGLESTEP: { /* set the trap flag. */ 107 ret = -EIO; 108 if (!valid_signal(data)) 109 break; 110 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 111 set_singlestepping(child, 1); 112 child->exit_code = data; 113 /* give it a chance to run. */ 114 wake_up_process(child); 115 ret = 0; 116 break; 117 } 118 119 #ifdef PTRACE_GETREGS 120 case PTRACE_GETREGS: { /* Get all gp regs from the child. */ 121 if (!access_ok(VERIFY_WRITE, p, MAX_REG_OFFSET)) { 122 ret = -EIO; 123 break; 124 } 125 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 126 __put_user(getreg(child, i), p); 127 p++; 128 } 129 ret = 0; 130 break; 131 } 132 #endif 133 #ifdef PTRACE_SETREGS 134 case PTRACE_SETREGS: { /* Set all gp regs in the child. */ 135 unsigned long tmp = 0; 136 if (!access_ok(VERIFY_READ, p, MAX_REG_OFFSET)) { 137 ret = -EIO; 138 break; 139 } 140 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 141 __get_user(tmp, p); 142 putreg(child, i, tmp); 143 p++; 144 } 145 ret = 0; 146 break; 147 } 148 #endif 149 #ifdef PTRACE_GETFPREGS 150 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 151 ret = get_fpregs((struct user_i387_struct __user *) data, 152 child); 153 break; 154 #endif 155 #ifdef PTRACE_SETFPREGS 156 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 157 ret = set_fpregs((struct user_i387_struct __user *) data, 158 child); 159 break; 160 #endif 161 case PTRACE_GET_THREAD_AREA: 162 ret = ptrace_get_thread_area(child, addr, 163 (struct user_desc __user *) data); 164 break; 165 166 case PTRACE_SET_THREAD_AREA: 167 ret = ptrace_set_thread_area(child, addr, 168 (struct user_desc __user *) data); 169 break; 170 171 case PTRACE_FAULTINFO: { 172 /* 173 * Take the info from thread->arch->faultinfo, 174 * but transfer max. sizeof(struct ptrace_faultinfo). 175 * On i386, ptrace_faultinfo is smaller! 176 */ 177 ret = copy_to_user(p, &child->thread.arch.faultinfo, 178 sizeof(struct ptrace_faultinfo)); 179 break; 180 } 181 182 #ifdef PTRACE_LDT 183 case PTRACE_LDT: { 184 struct ptrace_ldt ldt; 185 186 if (copy_from_user(&ldt, p, sizeof(ldt))) { 187 ret = -EIO; 188 break; 189 } 190 191 /* 192 * This one is confusing, so just punt and return -EIO for 193 * now 194 */ 195 ret = -EIO; 196 break; 197 } 198 #endif 199 #ifdef CONFIG_PROC_MM 200 case PTRACE_SWITCH_MM: { 201 struct mm_struct *old = child->mm; 202 struct mm_struct *new = proc_mm_get_mm(data); 203 204 if (IS_ERR(new)) { 205 ret = PTR_ERR(new); 206 break; 207 } 208 209 atomic_inc(&new->mm_users); 210 child->mm = new; 211 child->active_mm = new; 212 mmput(old); 213 ret = 0; 214 break; 215 } 216 #endif 217 #ifdef PTRACE_ARCH_PRCTL 218 case PTRACE_ARCH_PRCTL: 219 /* XXX Calls ptrace on the host - needs some SMP thinking */ 220 ret = arch_prctl(child, data, (void *) addr); 221 break; 222 #endif 223 default: 224 ret = ptrace_request(child, request, addr, data); 225 if (ret == -EIO) 226 ret = subarch_ptrace(child, request, addr, data); 227 break; 228 } 229 230 return ret; 231 } 232 233 static void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs, 234 int error_code) 235 { 236 struct siginfo info; 237 238 memset(&info, 0, sizeof(info)); 239 info.si_signo = SIGTRAP; 240 info.si_code = TRAP_BRKPT; 241 242 /* User-mode eip? */ 243 info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL; 244 245 /* Send us the fake SIGTRAP */ 246 force_sig_info(SIGTRAP, &info, tsk); 247 } 248 249 /* 250 * XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and 251 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check 252 */ 253 void syscall_trace(struct uml_pt_regs *regs, int entryexit) 254 { 255 int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit; 256 int tracesysgood; 257 258 if (unlikely(current->audit_context)) { 259 if (!entryexit) 260 audit_syscall_entry(HOST_AUDIT_ARCH, 261 UPT_SYSCALL_NR(regs), 262 UPT_SYSCALL_ARG1(regs), 263 UPT_SYSCALL_ARG2(regs), 264 UPT_SYSCALL_ARG3(regs), 265 UPT_SYSCALL_ARG4(regs)); 266 else audit_syscall_exit(AUDITSC_RESULT(UPT_SYSCALL_RET(regs)), 267 UPT_SYSCALL_RET(regs)); 268 } 269 270 /* Fake a debug trap */ 271 if (is_singlestep) 272 send_sigtrap(current, regs, 0); 273 274 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 275 return; 276 277 if (!(current->ptrace & PT_PTRACED)) 278 return; 279 280 /* 281 * the 0x80 provides a way for the tracing parent to distinguish 282 * between a syscall stop and SIGTRAP delivery 283 */ 284 tracesysgood = (current->ptrace & PT_TRACESYSGOOD); 285 ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0)); 286 287 if (entryexit) /* force do_signal() --> is_syscall() */ 288 set_thread_flag(TIF_SIGPENDING); 289 290 /* 291 * this isn't the same as continuing with a signal, but it will do 292 * for normal use. strace only continues with a signal if the 293 * stopping signal is not SIGTRAP. -brl 294 */ 295 if (current->exit_code) { 296 send_sig(current->exit_code, current, 1); 297 current->exit_code = 0; 298 } 299 } 300