ptrace.h 13 KB

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