1 #ifndef _LINUX_PTRACE_H 2 #define _LINUX_PTRACE_H 3 /* ptrace.h */ 4 /* structs and defines to help the user use the ptrace system call. */ 5 6 /* has the defines to get at the registers. */ 7 8 #define PTRACE_TRACEME 0 9 #define PTRACE_PEEKTEXT 1 10 #define PTRACE_PEEKDATA 2 11 #define PTRACE_PEEKUSR 3 12 #define PTRACE_POKETEXT 4 13 #define PTRACE_POKEDATA 5 14 #define PTRACE_POKEUSR 6 15 #define PTRACE_CONT 7 16 #define PTRACE_KILL 8 17 #define PTRACE_SINGLESTEP 9 18 19 #define PTRACE_ATTACH 16 20 #define PTRACE_DETACH 17 21 22 #define PTRACE_SYSCALL 24 23 24 /* 0x4200-0x4300 are reserved for architecture-independent additions. */ 25 #define PTRACE_SETOPTIONS 0x4200 26 #define PTRACE_GETEVENTMSG 0x4201 27 #define PTRACE_GETSIGINFO 0x4202 28 #define PTRACE_SETSIGINFO 0x4203 29 30 /* 31 * Generic ptrace interface that exports the architecture specific regsets 32 * using the corresponding NT_* types (which are also used in the core dump). 33 * Please note that the NT_PRSTATUS note type in a core dump contains a full 34 * 'struct elf_prstatus'. But the user_regset for NT_PRSTATUS contains just the 35 * elf_gregset_t that is the pr_reg field of 'struct elf_prstatus'. For all the 36 * other user_regset flavors, the user_regset layout and the ELF core dump note 37 * payload are exactly the same layout. 38 * 39 * This interface usage is as follows: 40 * struct iovec iov = { buf, len}; 41 * 42 * ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov); 43 * 44 * On the successful completion, iov.len will be updated by the kernel, 45 * specifying how much the kernel has written/read to/from the user's iov.buf. 46 */ 47 #define PTRACE_GETREGSET 0x4204 48 #define PTRACE_SETREGSET 0x4205 49 50 #define PTRACE_SEIZE 0x4206 51 #define PTRACE_INTERRUPT 0x4207 52 #define PTRACE_LISTEN 0x4208 53 54 /* flags in @data for PTRACE_SEIZE */ 55 #define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */ 56 57 /* options set using PTRACE_SETOPTIONS */ 58 #define PTRACE_O_TRACESYSGOOD 0x00000001 59 #define PTRACE_O_TRACEFORK 0x00000002 60 #define PTRACE_O_TRACEVFORK 0x00000004 61 #define PTRACE_O_TRACECLONE 0x00000008 62 #define PTRACE_O_TRACEEXEC 0x00000010 63 #define PTRACE_O_TRACEVFORKDONE 0x00000020 64 #define PTRACE_O_TRACEEXIT 0x00000040 65 66 #define PTRACE_O_MASK 0x0000007f 67 68 /* Wait extended result codes for the above trace options. */ 69 #define PTRACE_EVENT_FORK 1 70 #define PTRACE_EVENT_VFORK 2 71 #define PTRACE_EVENT_CLONE 3 72 #define PTRACE_EVENT_EXEC 4 73 #define PTRACE_EVENT_VFORK_DONE 5 74 #define PTRACE_EVENT_EXIT 6 75 #define PTRACE_EVENT_STOP 7 76 77 #include <asm/ptrace.h> 78 79 #ifdef __KERNEL__ 80 /* 81 * Ptrace flags 82 * 83 * The owner ship rules for task->ptrace which holds the ptrace 84 * flags is simple. When a task is running it owns it's task->ptrace 85 * flags. When the a task is stopped the ptracer owns task->ptrace. 86 */ 87 88 #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ 89 #define PT_PTRACED 0x00000001 90 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ 91 #define PT_TRACESYSGOOD 0x00000004 92 #define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */ 93 94 /* PT_TRACE_* event enable flags */ 95 #define PT_EVENT_FLAG_SHIFT 4 96 #define PT_EVENT_FLAG(event) (1 << (PT_EVENT_FLAG_SHIFT + (event) - 1)) 97 98 #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK) 99 #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK) 100 #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE) 101 #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC) 102 #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE) 103 #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT) 104 105 #define PT_TRACE_MASK 0x000003f4 106 107 /* single stepping state bits (used on ARM and PA-RISC) */ 108 #define PT_SINGLESTEP_BIT 31 109 #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) 110 #define PT_BLOCKSTEP_BIT 30 111 #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) 112 113 #include <linux/compiler.h> /* For unlikely. */ 114 #include <linux/sched.h> /* For struct task_struct. */ 115 116 117 extern long arch_ptrace(struct task_struct *child, long request, 118 unsigned long addr, unsigned long data); 119 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len); 120 extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len); 121 extern void ptrace_disable(struct task_struct *); 122 extern int ptrace_check_attach(struct task_struct *task, bool ignore_state); 123 extern int ptrace_request(struct task_struct *child, long request, 124 unsigned long addr, unsigned long data); 125 extern void ptrace_notify(int exit_code); 126 extern void __ptrace_link(struct task_struct *child, 127 struct task_struct *new_parent); 128 extern void __ptrace_unlink(struct task_struct *child); 129 extern void exit_ptrace(struct task_struct *tracer); 130 #define PTRACE_MODE_READ 1 131 #define PTRACE_MODE_ATTACH 2 132 /* Returns 0 on success, -errno on denial. */ 133 extern int __ptrace_may_access(struct task_struct *task, unsigned int mode); 134 /* Returns true on success, false on denial. */ 135 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); 136 137 static inline int ptrace_reparented(struct task_struct *child) 138 { 139 return !same_thread_group(child->real_parent, child->parent); 140 } 141 142 static inline void ptrace_unlink(struct task_struct *child) 143 { 144 if (unlikely(child->ptrace)) 145 __ptrace_unlink(child); 146 } 147 148 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 149 unsigned long data); 150 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 151 unsigned long data); 152 153 /** 154 * ptrace_parent - return the task that is tracing the given task 155 * @task: task to consider 156 * 157 * Returns %NULL if no one is tracing @task, or the &struct task_struct 158 * pointer to its tracer. 159 * 160 * Must called under rcu_read_lock(). The pointer returned might be kept 161 * live only by RCU. During exec, this may be called with task_lock() held 162 * on @task, still held from when check_unsafe_exec() was called. 163 */ 164 static inline struct task_struct *ptrace_parent(struct task_struct *task) 165 { 166 if (unlikely(task->ptrace)) 167 return rcu_dereference(task->parent); 168 return NULL; 169 } 170 171 /** 172 * ptrace_event_enabled - test whether a ptrace event is enabled 173 * @task: ptracee of interest 174 * @event: %PTRACE_EVENT_* to test 175 * 176 * Test whether @event is enabled for ptracee @task. 177 * 178 * Returns %true if @event is enabled, %false otherwise. 179 */ 180 static inline bool ptrace_event_enabled(struct task_struct *task, int event) 181 { 182 return task->ptrace & PT_EVENT_FLAG(event); 183 } 184 185 /** 186 * ptrace_event - possibly stop for a ptrace event notification 187 * @event: %PTRACE_EVENT_* value to report 188 * @message: value for %PTRACE_GETEVENTMSG to return 189 * 190 * Check whether @event is enabled and, if so, report @event and @message 191 * to the ptrace parent. 192 * 193 * Called without locks. 194 */ 195 static inline void ptrace_event(int event, unsigned long message) 196 { 197 if (unlikely(ptrace_event_enabled(current, event))) { 198 current->ptrace_message = message; 199 ptrace_notify((event << 8) | SIGTRAP); 200 } else if (event == PTRACE_EVENT_EXEC && unlikely(current->ptrace)) { 201 /* legacy EXEC report via SIGTRAP */ 202 send_sig(SIGTRAP, current, 0); 203 } 204 } 205 206 /** 207 * ptrace_init_task - initialize ptrace state for a new child 208 * @child: new child task 209 * @ptrace: true if child should be ptrace'd by parent's tracer 210 * 211 * This is called immediately after adding @child to its parent's children 212 * list. @ptrace is false in the normal case, and true to ptrace @child. 213 * 214 * Called with current's siglock and write_lock_irq(&tasklist_lock) held. 215 */ 216 static inline void ptrace_init_task(struct task_struct *child, bool ptrace) 217 { 218 INIT_LIST_HEAD(&child->ptrace_entry); 219 INIT_LIST_HEAD(&child->ptraced); 220 #ifdef CONFIG_HAVE_HW_BREAKPOINT 221 atomic_set(&child->ptrace_bp_refcnt, 1); 222 #endif 223 child->jobctl = 0; 224 child->ptrace = 0; 225 child->parent = child->real_parent; 226 227 if (unlikely(ptrace) && current->ptrace) { 228 child->ptrace = current->ptrace; 229 __ptrace_link(child, current->parent); 230 231 if (child->ptrace & PT_SEIZED) 232 task_set_jobctl_pending(child, JOBCTL_TRAP_STOP); 233 else 234 sigaddset(&child->pending.signal, SIGSTOP); 235 236 set_tsk_thread_flag(child, TIF_SIGPENDING); 237 } 238 } 239 240 /** 241 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped 242 * @task: task in %EXIT_DEAD state 243 * 244 * Called with write_lock(&tasklist_lock) held. 245 */ 246 static inline void ptrace_release_task(struct task_struct *task) 247 { 248 BUG_ON(!list_empty(&task->ptraced)); 249 ptrace_unlink(task); 250 BUG_ON(!list_empty(&task->ptrace_entry)); 251 } 252 253 #ifndef force_successful_syscall_return 254 /* 255 * System call handlers that, upon successful completion, need to return a 256 * negative value should call force_successful_syscall_return() right before 257 * returning. On architectures where the syscall convention provides for a 258 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly 259 * others), this macro can be used to ensure that the error flag will not get 260 * set. On architectures which do not support a separate error flag, the macro 261 * is a no-op and the spurious error condition needs to be filtered out by some 262 * other means (e.g., in user-level, by passing an extra argument to the 263 * syscall handler, or something along those lines). 264 */ 265 #define force_successful_syscall_return() do { } while (0) 266 #endif 267 268 /* 269 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. 270 * 271 * These do-nothing inlines are used when the arch does not 272 * implement single-step. The kerneldoc comments are here 273 * to document the interface for all arch definitions. 274 */ 275 276 #ifndef arch_has_single_step 277 /** 278 * arch_has_single_step - does this CPU support user-mode single-step? 279 * 280 * If this is defined, then there must be function declarations or 281 * inlines for user_enable_single_step() and user_disable_single_step(). 282 * arch_has_single_step() should evaluate to nonzero iff the machine 283 * supports instruction single-step for user mode. 284 * It can be a constant or it can test a CPU feature bit. 285 */ 286 #define arch_has_single_step() (0) 287 288 /** 289 * user_enable_single_step - single-step in user-mode task 290 * @task: either current or a task stopped in %TASK_TRACED 291 * 292 * This can only be called when arch_has_single_step() has returned nonzero. 293 * Set @task so that when it returns to user mode, it will trap after the 294 * next single instruction executes. If arch_has_block_step() is defined, 295 * this must clear the effects of user_enable_block_step() too. 296 */ 297 static inline void user_enable_single_step(struct task_struct *task) 298 { 299 BUG(); /* This can never be called. */ 300 } 301 302 /** 303 * user_disable_single_step - cancel user-mode single-step 304 * @task: either current or a task stopped in %TASK_TRACED 305 * 306 * Clear @task of the effects of user_enable_single_step() and 307 * user_enable_block_step(). This can be called whether or not either 308 * of those was ever called on @task, and even if arch_has_single_step() 309 * returned zero. 310 */ 311 static inline void user_disable_single_step(struct task_struct *task) 312 { 313 } 314 #else 315 extern void user_enable_single_step(struct task_struct *); 316 extern void user_disable_single_step(struct task_struct *); 317 #endif /* arch_has_single_step */ 318 319 #ifndef arch_has_block_step 320 /** 321 * arch_has_block_step - does this CPU support user-mode block-step? 322 * 323 * If this is defined, then there must be a function declaration or inline 324 * for user_enable_block_step(), and arch_has_single_step() must be defined 325 * too. arch_has_block_step() should evaluate to nonzero iff the machine 326 * supports step-until-branch for user mode. It can be a constant or it 327 * can test a CPU feature bit. 328 */ 329 #define arch_has_block_step() (0) 330 331 /** 332 * user_enable_block_step - step until branch in user-mode task 333 * @task: either current or a task stopped in %TASK_TRACED 334 * 335 * This can only be called when arch_has_block_step() has returned nonzero, 336 * and will never be called when single-instruction stepping is being used. 337 * Set @task so that when it returns to user mode, it will trap after the 338 * next branch or trap taken. 339 */ 340 static inline void user_enable_block_step(struct task_struct *task) 341 { 342 BUG(); /* This can never be called. */ 343 } 344 #else 345 extern void user_enable_block_step(struct task_struct *); 346 #endif /* arch_has_block_step */ 347 348 #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO 349 extern void user_single_step_siginfo(struct task_struct *tsk, 350 struct pt_regs *regs, siginfo_t *info); 351 #else 352 static inline void user_single_step_siginfo(struct task_struct *tsk, 353 struct pt_regs *regs, siginfo_t *info) 354 { 355 memset(info, 0, sizeof(*info)); 356 info->si_signo = SIGTRAP; 357 } 358 #endif 359 360 #ifndef arch_ptrace_stop_needed 361 /** 362 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called 363 * @code: current->exit_code value ptrace will stop with 364 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 365 * 366 * This is called with the siglock held, to decide whether or not it's 367 * necessary to release the siglock and call arch_ptrace_stop() with the 368 * same @code and @info arguments. It can be defined to a constant if 369 * arch_ptrace_stop() is never required, or always is. On machines where 370 * this makes sense, it should be defined to a quick test to optimize out 371 * calling arch_ptrace_stop() when it would be superfluous. For example, 372 * if the thread has not been back to user mode since the last stop, the 373 * thread state might indicate that nothing needs to be done. 374 */ 375 #define arch_ptrace_stop_needed(code, info) (0) 376 #endif 377 378 #ifndef arch_ptrace_stop 379 /** 380 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace 381 * @code: current->exit_code value ptrace will stop with 382 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 383 * 384 * This is called with no locks held when arch_ptrace_stop_needed() has 385 * just returned nonzero. It is allowed to block, e.g. for user memory 386 * access. The arch can have machine-specific work to be done before 387 * ptrace stops. On ia64, register backing store gets written back to user 388 * memory here. Since this can be costly (requires dropping the siglock), 389 * we only do it when the arch requires it for this particular stop, as 390 * indicated by arch_ptrace_stop_needed(). 391 */ 392 #define arch_ptrace_stop(code, info) do { } while (0) 393 #endif 394 395 extern int task_current_syscall(struct task_struct *target, long *callno, 396 unsigned long args[6], unsigned int maxargs, 397 unsigned long *sp, unsigned long *pc); 398 399 #ifdef CONFIG_HAVE_HW_BREAKPOINT 400 extern int ptrace_get_breakpoints(struct task_struct *tsk); 401 extern void ptrace_put_breakpoints(struct task_struct *tsk); 402 #else 403 static inline void ptrace_put_breakpoints(struct task_struct *tsk) { } 404 #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 405 406 #endif /* __KERNEL */ 407 408 #endif 409