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 /* continue and stop at next (return from) syscall */ 68 case PTRACE_SYSCALL: 69 /* restart after signal. */ 70 case PTRACE_CONT: { 71 ret = -EIO; 72 if (!valid_signal(data)) 73 break; 74 75 set_singlestepping(child, 0); 76 if (request == PTRACE_SYSCALL) 77 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 78 else clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 79 child->exit_code = data; 80 wake_up_process(child); 81 ret = 0; 82 break; 83 } 84 85 /* 86 * make the child exit. Best I can do is send it a sigkill. 87 * perhaps it should be put in the status that it wants to 88 * exit. 89 */ 90 case PTRACE_KILL: { 91 ret = 0; 92 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 93 break; 94 95 set_singlestepping(child, 0); 96 child->exit_code = SIGKILL; 97 wake_up_process(child); 98 break; 99 } 100 101 case PTRACE_SINGLESTEP: { /* set the trap flag. */ 102 ret = -EIO; 103 if (!valid_signal(data)) 104 break; 105 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 106 set_singlestepping(child, 1); 107 child->exit_code = data; 108 /* give it a chance to run. */ 109 wake_up_process(child); 110 ret = 0; 111 break; 112 } 113 114 #ifdef PTRACE_GETREGS 115 case PTRACE_GETREGS: { /* Get all gp regs from the child. */ 116 if (!access_ok(VERIFY_WRITE, p, MAX_REG_OFFSET)) { 117 ret = -EIO; 118 break; 119 } 120 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 121 __put_user(getreg(child, i), p); 122 p++; 123 } 124 ret = 0; 125 break; 126 } 127 #endif 128 #ifdef PTRACE_SETREGS 129 case PTRACE_SETREGS: { /* Set all gp regs in the child. */ 130 unsigned long tmp = 0; 131 if (!access_ok(VERIFY_READ, p, MAX_REG_OFFSET)) { 132 ret = -EIO; 133 break; 134 } 135 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 136 __get_user(tmp, p); 137 putreg(child, i, tmp); 138 p++; 139 } 140 ret = 0; 141 break; 142 } 143 #endif 144 #ifdef PTRACE_GETFPREGS 145 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 146 ret = get_fpregs((struct user_i387_struct __user *) data, 147 child); 148 break; 149 #endif 150 #ifdef PTRACE_SETFPREGS 151 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 152 ret = set_fpregs((struct user_i387_struct __user *) data, 153 child); 154 break; 155 #endif 156 case PTRACE_GET_THREAD_AREA: 157 ret = ptrace_get_thread_area(child, addr, 158 (struct user_desc __user *) data); 159 break; 160 161 case PTRACE_SET_THREAD_AREA: 162 ret = ptrace_set_thread_area(child, addr, 163 (struct user_desc __user *) data); 164 break; 165 166 case PTRACE_FAULTINFO: { 167 /* 168 * Take the info from thread->arch->faultinfo, 169 * but transfer max. sizeof(struct ptrace_faultinfo). 170 * On i386, ptrace_faultinfo is smaller! 171 */ 172 ret = copy_to_user(p, &child->thread.arch.faultinfo, 173 sizeof(struct ptrace_faultinfo)); 174 break; 175 } 176 177 #ifdef PTRACE_LDT 178 case PTRACE_LDT: { 179 struct ptrace_ldt ldt; 180 181 if (copy_from_user(&ldt, p, sizeof(ldt))) { 182 ret = -EIO; 183 break; 184 } 185 186 /* 187 * This one is confusing, so just punt and return -EIO for 188 * now 189 */ 190 ret = -EIO; 191 break; 192 } 193 #endif 194 #ifdef CONFIG_PROC_MM 195 case PTRACE_SWITCH_MM: { 196 struct mm_struct *old = child->mm; 197 struct mm_struct *new = proc_mm_get_mm(data); 198 199 if (IS_ERR(new)) { 200 ret = PTR_ERR(new); 201 break; 202 } 203 204 atomic_inc(&new->mm_users); 205 child->mm = new; 206 child->active_mm = new; 207 mmput(old); 208 ret = 0; 209 break; 210 } 211 #endif 212 #ifdef PTRACE_ARCH_PRCTL 213 case PTRACE_ARCH_PRCTL: 214 /* XXX Calls ptrace on the host - needs some SMP thinking */ 215 ret = arch_prctl(child, data, (void *) addr); 216 break; 217 #endif 218 default: 219 ret = ptrace_request(child, request, addr, data); 220 if (ret == -EIO) 221 ret = subarch_ptrace(child, request, addr, data); 222 break; 223 } 224 225 return ret; 226 } 227 228 static void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs, 229 int error_code) 230 { 231 struct siginfo info; 232 233 memset(&info, 0, sizeof(info)); 234 info.si_signo = SIGTRAP; 235 info.si_code = TRAP_BRKPT; 236 237 /* User-mode eip? */ 238 info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL; 239 240 /* Send us the fake SIGTRAP */ 241 force_sig_info(SIGTRAP, &info, tsk); 242 } 243 244 /* 245 * XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and 246 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check 247 */ 248 void syscall_trace(struct uml_pt_regs *regs, int entryexit) 249 { 250 int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit; 251 int tracesysgood; 252 253 if (unlikely(current->audit_context)) { 254 if (!entryexit) 255 audit_syscall_entry(HOST_AUDIT_ARCH, 256 UPT_SYSCALL_NR(regs), 257 UPT_SYSCALL_ARG1(regs), 258 UPT_SYSCALL_ARG2(regs), 259 UPT_SYSCALL_ARG3(regs), 260 UPT_SYSCALL_ARG4(regs)); 261 else audit_syscall_exit(AUDITSC_RESULT(UPT_SYSCALL_RET(regs)), 262 UPT_SYSCALL_RET(regs)); 263 } 264 265 /* Fake a debug trap */ 266 if (is_singlestep) 267 send_sigtrap(current, regs, 0); 268 269 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 270 return; 271 272 if (!(current->ptrace & PT_PTRACED)) 273 return; 274 275 /* 276 * the 0x80 provides a way for the tracing parent to distinguish 277 * between a syscall stop and SIGTRAP delivery 278 */ 279 tracesysgood = (current->ptrace & PT_TRACESYSGOOD); 280 ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0)); 281 282 if (entryexit) /* force do_signal() --> is_syscall() */ 283 set_thread_flag(TIF_SIGPENDING); 284 285 /* 286 * this isn't the same as continuing with a signal, but it will do 287 * for normal use. strace only continues with a signal if the 288 * stopping signal is not SIGTRAP. -brl 289 */ 290 if (current->exit_code) { 291 send_sig(current->exit_code, current, 1); 292 current->exit_code = 0; 293 } 294 } 295