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 /* Wait extended result codes for the above trace options. */ 55 #define PTRACE_EVENT_FORK 1 56 #define PTRACE_EVENT_VFORK 2 57 #define PTRACE_EVENT_CLONE 3 58 #define PTRACE_EVENT_EXEC 4 59 #define PTRACE_EVENT_VFORK_DONE 5 60 #define PTRACE_EVENT_EXIT 6 61 /* Extended result codes which enabled by means other than options. */ 62 #define PTRACE_EVENT_STOP 128 63 64 /* Options set using PTRACE_SETOPTIONS or using PTRACE_SEIZE @data param */ 65 #define PTRACE_O_TRACESYSGOOD 1 66 #define PTRACE_O_TRACEFORK (1 << PTRACE_EVENT_FORK) 67 #define PTRACE_O_TRACEVFORK (1 << PTRACE_EVENT_VFORK) 68 #define PTRACE_O_TRACECLONE (1 << PTRACE_EVENT_CLONE) 69 #define PTRACE_O_TRACEEXEC (1 << PTRACE_EVENT_EXEC) 70 #define PTRACE_O_TRACEVFORKDONE (1 << PTRACE_EVENT_VFORK_DONE) 71 #define PTRACE_O_TRACEEXIT (1 << PTRACE_EVENT_EXIT) 72 73 #define PTRACE_O_MASK 0x0000007f 74 75 #include <asm/ptrace.h> 76 77 #ifdef __KERNEL__ 78 /* 79 * Ptrace flags 80 * 81 * The owner ship rules for task->ptrace which holds the ptrace 82 * flags is simple. When a task is running it owns it's task->ptrace 83 * flags. When the a task is stopped the ptracer owns task->ptrace. 84 */ 85 86 #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ 87 #define PT_PTRACED 0x00000001 88 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ 89 #define PT_PTRACE_CAP 0x00000004 /* ptracer can follow suid-exec */ 90 91 #define PT_OPT_FLAG_SHIFT 3 92 /* PT_TRACE_* event enable flags */ 93 #define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event))) 94 #define PT_TRACESYSGOOD PT_EVENT_FLAG(0) 95 #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK) 96 #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK) 97 #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE) 98 #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC) 99 #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE) 100 #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT) 101 102 /* single stepping state bits (used on ARM and PA-RISC) */ 103 #define PT_SINGLESTEP_BIT 31 104 #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) 105 #define PT_BLOCKSTEP_BIT 30 106 #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) 107 108 #include <linux/compiler.h> /* For unlikely. */ 109 #include <linux/sched.h> /* For struct task_struct. */ 110 #include <linux/err.h> /* for IS_ERR_VALUE */ 111 #include <linux/bug.h> /* For BUG_ON. */ 112 113 114 extern long arch_ptrace(struct task_struct *child, long request, 115 unsigned long addr, unsigned long data); 116 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len); 117 extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len); 118 extern void ptrace_disable(struct task_struct *); 119 extern int ptrace_check_attach(struct task_struct *task, bool ignore_state); 120 extern int ptrace_request(struct task_struct *child, long request, 121 unsigned long addr, unsigned long data); 122 extern void ptrace_notify(int exit_code); 123 extern void __ptrace_link(struct task_struct *child, 124 struct task_struct *new_parent); 125 extern void __ptrace_unlink(struct task_struct *child); 126 extern void exit_ptrace(struct task_struct *tracer); 127 #define PTRACE_MODE_READ 0x01 128 #define PTRACE_MODE_ATTACH 0x02 129 #define PTRACE_MODE_NOAUDIT 0x04 130 /* Returns 0 on success, -errno on denial. */ 131 extern int __ptrace_may_access(struct task_struct *task, unsigned int mode); 132 /* Returns true on success, false on denial. */ 133 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); 134 135 static inline int ptrace_reparented(struct task_struct *child) 136 { 137 return !same_thread_group(child->real_parent, child->parent); 138 } 139 140 static inline void ptrace_unlink(struct task_struct *child) 141 { 142 if (unlikely(child->ptrace)) 143 __ptrace_unlink(child); 144 } 145 146 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 147 unsigned long data); 148 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 149 unsigned long data); 150 151 /** 152 * ptrace_parent - return the task that is tracing the given task 153 * @task: task to consider 154 * 155 * Returns %NULL if no one is tracing @task, or the &struct task_struct 156 * pointer to its tracer. 157 * 158 * Must called under rcu_read_lock(). The pointer returned might be kept 159 * live only by RCU. During exec, this may be called with task_lock() held 160 * on @task, still held from when check_unsafe_exec() was called. 161 */ 162 static inline struct task_struct *ptrace_parent(struct task_struct *task) 163 { 164 if (unlikely(task->ptrace)) 165 return rcu_dereference(task->parent); 166 return NULL; 167 } 168 169 /** 170 * ptrace_event_enabled - test whether a ptrace event is enabled 171 * @task: ptracee of interest 172 * @event: %PTRACE_EVENT_* to test 173 * 174 * Test whether @event is enabled for ptracee @task. 175 * 176 * Returns %true if @event is enabled, %false otherwise. 177 */ 178 static inline bool ptrace_event_enabled(struct task_struct *task, int event) 179 { 180 return task->ptrace & PT_EVENT_FLAG(event); 181 } 182 183 /** 184 * ptrace_event - possibly stop for a ptrace event notification 185 * @event: %PTRACE_EVENT_* value to report 186 * @message: value for %PTRACE_GETEVENTMSG to return 187 * 188 * Check whether @event is enabled and, if so, report @event and @message 189 * to the ptrace parent. 190 * 191 * Called without locks. 192 */ 193 static inline void ptrace_event(int event, unsigned long message) 194 { 195 if (unlikely(ptrace_event_enabled(current, event))) { 196 current->ptrace_message = message; 197 ptrace_notify((event << 8) | SIGTRAP); 198 } else if (event == PTRACE_EVENT_EXEC) { 199 /* legacy EXEC report via SIGTRAP */ 200 if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED) 201 send_sig(SIGTRAP, current, 0); 202 } 203 } 204 205 /** 206 * ptrace_init_task - initialize ptrace state for a new child 207 * @child: new child task 208 * @ptrace: true if child should be ptrace'd by parent's tracer 209 * 210 * This is called immediately after adding @child to its parent's children 211 * list. @ptrace is false in the normal case, and true to ptrace @child. 212 * 213 * Called with current's siglock and write_lock_irq(&tasklist_lock) held. 214 */ 215 static inline void ptrace_init_task(struct task_struct *child, bool ptrace) 216 { 217 INIT_LIST_HEAD(&child->ptrace_entry); 218 INIT_LIST_HEAD(&child->ptraced); 219 #ifdef CONFIG_HAVE_HW_BREAKPOINT 220 atomic_set(&child->ptrace_bp_refcnt, 1); 221 #endif 222 child->jobctl = 0; 223 child->ptrace = 0; 224 child->parent = child->real_parent; 225 226 if (unlikely(ptrace) && current->ptrace) { 227 child->ptrace = current->ptrace; 228 __ptrace_link(child, current->parent); 229 230 if (child->ptrace & PT_SEIZED) 231 task_set_jobctl_pending(child, JOBCTL_TRAP_STOP); 232 else 233 sigaddset(&child->pending.signal, SIGSTOP); 234 235 set_tsk_thread_flag(child, TIF_SIGPENDING); 236 } 237 } 238 239 /** 240 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped 241 * @task: task in %EXIT_DEAD state 242 * 243 * Called with write_lock(&tasklist_lock) held. 244 */ 245 static inline void ptrace_release_task(struct task_struct *task) 246 { 247 BUG_ON(!list_empty(&task->ptraced)); 248 ptrace_unlink(task); 249 BUG_ON(!list_empty(&task->ptrace_entry)); 250 } 251 252 #ifndef force_successful_syscall_return 253 /* 254 * System call handlers that, upon successful completion, need to return a 255 * negative value should call force_successful_syscall_return() right before 256 * returning. On architectures where the syscall convention provides for a 257 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly 258 * others), this macro can be used to ensure that the error flag will not get 259 * set. On architectures which do not support a separate error flag, the macro 260 * is a no-op and the spurious error condition needs to be filtered out by some 261 * other means (e.g., in user-level, by passing an extra argument to the 262 * syscall handler, or something along those lines). 263 */ 264 #define force_successful_syscall_return() do { } while (0) 265 #endif 266 267 #ifndef is_syscall_success 268 /* 269 * On most systems we can tell if a syscall is a success based on if the retval 270 * is an error value. On some systems like ia64 and powerpc they have different 271 * indicators of success/failure and must define their own. 272 */ 273 #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs)))) 274 #endif 275 276 /* 277 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. 278 * 279 * These do-nothing inlines are used when the arch does not 280 * implement single-step. The kerneldoc comments are here 281 * to document the interface for all arch definitions. 282 */ 283 284 #ifndef arch_has_single_step 285 /** 286 * arch_has_single_step - does this CPU support user-mode single-step? 287 * 288 * If this is defined, then there must be function declarations or 289 * inlines for user_enable_single_step() and user_disable_single_step(). 290 * arch_has_single_step() should evaluate to nonzero iff the machine 291 * supports instruction single-step for user mode. 292 * It can be a constant or it can test a CPU feature bit. 293 */ 294 #define arch_has_single_step() (0) 295 296 /** 297 * user_enable_single_step - single-step in user-mode task 298 * @task: either current or a task stopped in %TASK_TRACED 299 * 300 * This can only be called when arch_has_single_step() has returned nonzero. 301 * Set @task so that when it returns to user mode, it will trap after the 302 * next single instruction executes. If arch_has_block_step() is defined, 303 * this must clear the effects of user_enable_block_step() too. 304 */ 305 static inline void user_enable_single_step(struct task_struct *task) 306 { 307 BUG(); /* This can never be called. */ 308 } 309 310 /** 311 * user_disable_single_step - cancel user-mode single-step 312 * @task: either current or a task stopped in %TASK_TRACED 313 * 314 * Clear @task of the effects of user_enable_single_step() and 315 * user_enable_block_step(). This can be called whether or not either 316 * of those was ever called on @task, and even if arch_has_single_step() 317 * returned zero. 318 */ 319 static inline void user_disable_single_step(struct task_struct *task) 320 { 321 } 322 #else 323 extern void user_enable_single_step(struct task_struct *); 324 extern void user_disable_single_step(struct task_struct *); 325 #endif /* arch_has_single_step */ 326 327 #ifndef arch_has_block_step 328 /** 329 * arch_has_block_step - does this CPU support user-mode block-step? 330 * 331 * If this is defined, then there must be a function declaration or inline 332 * for user_enable_block_step(), and arch_has_single_step() must be defined 333 * too. arch_has_block_step() should evaluate to nonzero iff the machine 334 * supports step-until-branch for user mode. It can be a constant or it 335 * can test a CPU feature bit. 336 */ 337 #define arch_has_block_step() (0) 338 339 /** 340 * user_enable_block_step - step until branch in user-mode task 341 * @task: either current or a task stopped in %TASK_TRACED 342 * 343 * This can only be called when arch_has_block_step() has returned nonzero, 344 * and will never be called when single-instruction stepping is being used. 345 * Set @task so that when it returns to user mode, it will trap after the 346 * next branch or trap taken. 347 */ 348 static inline void user_enable_block_step(struct task_struct *task) 349 { 350 BUG(); /* This can never be called. */ 351 } 352 #else 353 extern void user_enable_block_step(struct task_struct *); 354 #endif /* arch_has_block_step */ 355 356 #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO 357 extern void user_single_step_siginfo(struct task_struct *tsk, 358 struct pt_regs *regs, siginfo_t *info); 359 #else 360 static inline void user_single_step_siginfo(struct task_struct *tsk, 361 struct pt_regs *regs, siginfo_t *info) 362 { 363 memset(info, 0, sizeof(*info)); 364 info->si_signo = SIGTRAP; 365 } 366 #endif 367 368 #ifndef arch_ptrace_stop_needed 369 /** 370 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called 371 * @code: current->exit_code value ptrace will stop with 372 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 373 * 374 * This is called with the siglock held, to decide whether or not it's 375 * necessary to release the siglock and call arch_ptrace_stop() with the 376 * same @code and @info arguments. It can be defined to a constant if 377 * arch_ptrace_stop() is never required, or always is. On machines where 378 * this makes sense, it should be defined to a quick test to optimize out 379 * calling arch_ptrace_stop() when it would be superfluous. For example, 380 * if the thread has not been back to user mode since the last stop, the 381 * thread state might indicate that nothing needs to be done. 382 */ 383 #define arch_ptrace_stop_needed(code, info) (0) 384 #endif 385 386 #ifndef arch_ptrace_stop 387 /** 388 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace 389 * @code: current->exit_code value ptrace will stop with 390 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 391 * 392 * This is called with no locks held when arch_ptrace_stop_needed() has 393 * just returned nonzero. It is allowed to block, e.g. for user memory 394 * access. The arch can have machine-specific work to be done before 395 * ptrace stops. On ia64, register backing store gets written back to user 396 * memory here. Since this can be costly (requires dropping the siglock), 397 * we only do it when the arch requires it for this particular stop, as 398 * indicated by arch_ptrace_stop_needed(). 399 */ 400 #define arch_ptrace_stop(code, info) do { } while (0) 401 #endif 402 403 extern int task_current_syscall(struct task_struct *target, long *callno, 404 unsigned long args[6], unsigned int maxargs, 405 unsigned long *sp, unsigned long *pc); 406 407 #ifdef CONFIG_HAVE_HW_BREAKPOINT 408 extern int ptrace_get_breakpoints(struct task_struct *tsk); 409 extern void ptrace_put_breakpoints(struct task_struct *tsk); 410 #else 411 static inline void ptrace_put_breakpoints(struct task_struct *tsk) { } 412 #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 413 414 #endif /* __KERNEL */ 415 416 #endif 417