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 #include "os.h" 22 23 static inline void set_singlestepping(struct task_struct *child, int on) 24 { 25 if (on) 26 child->ptrace |= PT_DTRACE; 27 else 28 child->ptrace &= ~PT_DTRACE; 29 child->thread.singlestep_syscall = 0; 30 31 #ifdef SUBARCH_SET_SINGLESTEPPING 32 SUBARCH_SET_SINGLESTEPPING(child, on); 33 #endif 34 } 35 36 /* 37 * Called by kernel/ptrace.c when detaching.. 38 */ 39 void ptrace_disable(struct task_struct *child) 40 { 41 set_singlestepping(child,0); 42 } 43 44 extern int peek_user(struct task_struct * child, long addr, long data); 45 extern int poke_user(struct task_struct * child, long addr, long data); 46 47 long arch_ptrace(struct task_struct *child, long request, long addr, long data) 48 { 49 int i, ret; 50 unsigned long __user *p = (void __user *)(unsigned long)data; 51 52 switch (request) { 53 /* when I and D space are separate, these will need to be fixed. */ 54 case PTRACE_PEEKTEXT: /* read word at location addr. */ 55 case PTRACE_PEEKDATA: 56 ret = generic_ptrace_peekdata(child, addr, data); 57 break; 58 59 /* read the word at location addr in the USER area. */ 60 case PTRACE_PEEKUSR: 61 ret = peek_user(child, addr, data); 62 break; 63 64 /* when I and D space are separate, this will have to be fixed. */ 65 case PTRACE_POKETEXT: /* write the word at location addr. */ 66 case PTRACE_POKEDATA: 67 ret = generic_ptrace_pokedata(child, addr, data); 68 break; 69 70 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ 71 ret = poke_user(child, addr, data); 72 break; 73 74 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ 75 case PTRACE_CONT: { /* restart after signal. */ 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 } 84 else { 85 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 86 } 87 child->exit_code = data; 88 wake_up_process(child); 89 ret = 0; 90 break; 91 } 92 93 /* 94 * make the child exit. Best I can do is send it a sigkill. 95 * perhaps it should be put in the status that it wants to 96 * exit. 97 */ 98 case PTRACE_KILL: { 99 ret = 0; 100 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 101 break; 102 103 set_singlestepping(child, 0); 104 child->exit_code = SIGKILL; 105 wake_up_process(child); 106 break; 107 } 108 109 case PTRACE_SINGLESTEP: { /* set the trap flag. */ 110 ret = -EIO; 111 if (!valid_signal(data)) 112 break; 113 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 114 set_singlestepping(child, 1); 115 child->exit_code = data; 116 /* give it a chance to run. */ 117 wake_up_process(child); 118 ret = 0; 119 break; 120 } 121 122 #ifdef PTRACE_GETREGS 123 case PTRACE_GETREGS: { /* Get all gp regs from the child. */ 124 if (!access_ok(VERIFY_WRITE, p, MAX_REG_OFFSET)) { 125 ret = -EIO; 126 break; 127 } 128 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 129 __put_user(getreg(child, i), p); 130 p++; 131 } 132 ret = 0; 133 break; 134 } 135 #endif 136 #ifdef PTRACE_SETREGS 137 case PTRACE_SETREGS: { /* Set all gp regs in the child. */ 138 unsigned long tmp = 0; 139 if (!access_ok(VERIFY_READ, p, MAX_REG_OFFSET)) { 140 ret = -EIO; 141 break; 142 } 143 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 144 __get_user(tmp, p); 145 putreg(child, i, tmp); 146 p++; 147 } 148 ret = 0; 149 break; 150 } 151 #endif 152 #ifdef PTRACE_GETFPREGS 153 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 154 ret = get_fpregs(data, child); 155 break; 156 #endif 157 #ifdef PTRACE_SETFPREGS 158 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 159 ret = set_fpregs(data, child); 160 break; 161 #endif 162 #ifdef PTRACE_GETFPXREGS 163 case PTRACE_GETFPXREGS: /* Get the child FPU state. */ 164 ret = get_fpxregs(data, child); 165 break; 166 #endif 167 #ifdef PTRACE_SETFPXREGS 168 case PTRACE_SETFPXREGS: /* Set the child FPU state. */ 169 ret = set_fpxregs(data, child); 170 break; 171 #endif 172 case PTRACE_GET_THREAD_AREA: 173 ret = ptrace_get_thread_area(child, addr, 174 (struct user_desc __user *) data); 175 break; 176 177 case PTRACE_SET_THREAD_AREA: 178 ret = ptrace_set_thread_area(child, addr, 179 (struct user_desc __user *) data); 180 break; 181 182 case PTRACE_FAULTINFO: { 183 /* Take the info from thread->arch->faultinfo, 184 * but transfer max. sizeof(struct ptrace_faultinfo). 185 * On i386, ptrace_faultinfo is smaller! 186 */ 187 ret = copy_to_user(p, &child->thread.arch.faultinfo, 188 sizeof(struct ptrace_faultinfo)); 189 if(ret) 190 break; 191 break; 192 } 193 194 #ifdef PTRACE_LDT 195 case PTRACE_LDT: { 196 struct ptrace_ldt ldt; 197 198 if(copy_from_user(&ldt, p, sizeof(ldt))){ 199 ret = -EIO; 200 break; 201 } 202 203 /* This one is confusing, so just punt and return -EIO for 204 * now 205 */ 206 ret = -EIO; 207 break; 208 } 209 #endif 210 #ifdef CONFIG_PROC_MM 211 case PTRACE_SWITCH_MM: { 212 struct mm_struct *old = child->mm; 213 struct mm_struct *new = proc_mm_get_mm(data); 214 215 if(IS_ERR(new)){ 216 ret = PTR_ERR(new); 217 break; 218 } 219 220 atomic_inc(&new->mm_users); 221 child->mm = new; 222 child->active_mm = new; 223 mmput(old); 224 ret = 0; 225 break; 226 } 227 #endif 228 #ifdef PTRACE_ARCH_PRCTL 229 case PTRACE_ARCH_PRCTL: 230 /* XXX Calls ptrace on the host - needs some SMP thinking */ 231 ret = arch_prctl_skas(child, data, (void *) addr); 232 break; 233 #endif 234 default: 235 ret = ptrace_request(child, request, addr, data); 236 break; 237 } 238 239 return ret; 240 } 241 242 void send_sigtrap(struct task_struct *tsk, union uml_pt_regs *regs, 243 int error_code) 244 { 245 struct siginfo info; 246 247 memset(&info, 0, sizeof(info)); 248 info.si_signo = SIGTRAP; 249 info.si_code = TRAP_BRKPT; 250 251 /* User-mode eip? */ 252 info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL; 253 254 /* Send us the fakey SIGTRAP */ 255 force_sig_info(SIGTRAP, &info, tsk); 256 } 257 258 /* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and 259 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check 260 */ 261 void syscall_trace(union uml_pt_regs *regs, int entryexit) 262 { 263 int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit; 264 int tracesysgood; 265 266 if (unlikely(current->audit_context)) { 267 if (!entryexit) 268 audit_syscall_entry(HOST_AUDIT_ARCH, 269 UPT_SYSCALL_NR(regs), 270 UPT_SYSCALL_ARG1(regs), 271 UPT_SYSCALL_ARG2(regs), 272 UPT_SYSCALL_ARG3(regs), 273 UPT_SYSCALL_ARG4(regs)); 274 else audit_syscall_exit(AUDITSC_RESULT(UPT_SYSCALL_RET(regs)), 275 UPT_SYSCALL_RET(regs)); 276 } 277 278 /* Fake a debug trap */ 279 if (is_singlestep) 280 send_sigtrap(current, regs, 0); 281 282 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 283 return; 284 285 if (!(current->ptrace & PT_PTRACED)) 286 return; 287 288 /* the 0x80 provides a way for the tracing parent to distinguish 289 between a syscall stop and SIGTRAP delivery */ 290 tracesysgood = (current->ptrace & PT_TRACESYSGOOD); 291 ptrace_notify(SIGTRAP | (tracesysgood ? 0x80 : 0)); 292 293 if (entryexit) /* force do_signal() --> is_syscall() */ 294 set_thread_flag(TIF_SIGPENDING); 295 296 /* this isn't the same as continuing with a signal, but it will do 297 * for normal use. strace only continues with a signal if the 298 * stopping signal is not SIGTRAP. -brl 299 */ 300 if (current->exit_code) { 301 send_sig(current->exit_code, current, 1); 302 current->exit_code = 0; 303 } 304 } 305