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(data, child); 147 break; 148 #endif 149 #ifdef PTRACE_SETFPREGS 150 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 151 ret = set_fpregs(data, child); 152 break; 153 #endif 154 #ifdef PTRACE_GETFPXREGS 155 case PTRACE_GETFPXREGS: /* Get the child FPU state. */ 156 ret = get_fpxregs(data, child); 157 break; 158 #endif 159 #ifdef PTRACE_SETFPXREGS 160 case PTRACE_SETFPXREGS: /* Set the child FPU state. */ 161 ret = set_fpxregs(data, child); 162 break; 163 #endif 164 case PTRACE_GET_THREAD_AREA: 165 ret = ptrace_get_thread_area(child, addr, 166 (struct user_desc __user *) data); 167 break; 168 169 case PTRACE_SET_THREAD_AREA: 170 ret = ptrace_set_thread_area(child, addr, 171 (struct user_desc __user *) data); 172 break; 173 174 case PTRACE_FAULTINFO: { 175 /* 176 * Take the info from thread->arch->faultinfo, 177 * but transfer max. sizeof(struct ptrace_faultinfo). 178 * On i386, ptrace_faultinfo is smaller! 179 */ 180 ret = copy_to_user(p, &child->thread.arch.faultinfo, 181 sizeof(struct ptrace_faultinfo)); 182 if (ret) 183 break; 184 break; 185 } 186 187 #ifdef PTRACE_LDT 188 case PTRACE_LDT: { 189 struct ptrace_ldt ldt; 190 191 if (copy_from_user(&ldt, p, sizeof(ldt))) { 192 ret = -EIO; 193 break; 194 } 195 196 /* 197 * This one is confusing, so just punt and return -EIO for 198 * now 199 */ 200 ret = -EIO; 201 break; 202 } 203 #endif 204 #ifdef CONFIG_PROC_MM 205 case PTRACE_SWITCH_MM: { 206 struct mm_struct *old = child->mm; 207 struct mm_struct *new = proc_mm_get_mm(data); 208 209 if (IS_ERR(new)) { 210 ret = PTR_ERR(new); 211 break; 212 } 213 214 atomic_inc(&new->mm_users); 215 child->mm = new; 216 child->active_mm = new; 217 mmput(old); 218 ret = 0; 219 break; 220 } 221 #endif 222 #ifdef PTRACE_ARCH_PRCTL 223 case PTRACE_ARCH_PRCTL: 224 /* XXX Calls ptrace on the host - needs some SMP thinking */ 225 ret = arch_prctl(child, data, (void *) addr); 226 break; 227 #endif 228 default: 229 ret = ptrace_request(child, request, addr, data); 230 break; 231 } 232 233 return ret; 234 } 235 236 void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs, 237 int error_code) 238 { 239 struct siginfo info; 240 241 memset(&info, 0, sizeof(info)); 242 info.si_signo = SIGTRAP; 243 info.si_code = TRAP_BRKPT; 244 245 /* User-mode eip? */ 246 info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL; 247 248 /* Send us the fakey SIGTRAP */ 249 force_sig_info(SIGTRAP, &info, tsk); 250 } 251 252 /* 253 * XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and 254 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check 255 */ 256 void syscall_trace(struct uml_pt_regs *regs, int entryexit) 257 { 258 int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit; 259 int tracesysgood; 260 261 if (unlikely(current->audit_context)) { 262 if (!entryexit) 263 audit_syscall_entry(HOST_AUDIT_ARCH, 264 UPT_SYSCALL_NR(regs), 265 UPT_SYSCALL_ARG1(regs), 266 UPT_SYSCALL_ARG2(regs), 267 UPT_SYSCALL_ARG3(regs), 268 UPT_SYSCALL_ARG4(regs)); 269 else audit_syscall_exit(AUDITSC_RESULT(UPT_SYSCALL_RET(regs)), 270 UPT_SYSCALL_RET(regs)); 271 } 272 273 /* Fake a debug trap */ 274 if (is_singlestep) 275 send_sigtrap(current, regs, 0); 276 277 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 278 return; 279 280 if (!(current->ptrace & PT_PTRACED)) 281 return; 282 283 /* 284 * the 0x80 provides a way for the tracing parent to distinguish 285 * between a syscall stop and SIGTRAP delivery 286 */ 287 tracesysgood = (current->ptrace & PT_TRACESYSGOOD); 288 ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0)); 289 290 if (entryexit) /* force do_signal() --> is_syscall() */ 291 set_thread_flag(TIF_SIGPENDING); 292 293 /* 294 * this isn't the same as continuing with a signal, but it will do 295 * for normal use. strace only continues with a signal if the 296 * stopping signal is not SIGTRAP. -brl 297 */ 298 if (current->exit_code) { 299 send_sig(current->exit_code, current, 1); 300 current->exit_code = 0; 301 } 302 } 303