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