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