ptrace.h 12 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. /* options set using PTRACE_SETOPTIONS */
  25. #define PTRACE_O_TRACESYSGOOD 0x00000001
  26. #define PTRACE_O_TRACEFORK 0x00000002
  27. #define PTRACE_O_TRACEVFORK 0x00000004
  28. #define PTRACE_O_TRACECLONE 0x00000008
  29. #define PTRACE_O_TRACEEXEC 0x00000010
  30. #define PTRACE_O_TRACEVFORKDONE 0x00000020
  31. #define PTRACE_O_TRACEEXIT 0x00000040
  32. #define PTRACE_O_MASK 0x0000007f
  33. /* Wait extended result codes for the above trace options. */
  34. #define PTRACE_EVENT_FORK 1
  35. #define PTRACE_EVENT_VFORK 2
  36. #define PTRACE_EVENT_CLONE 3
  37. #define PTRACE_EVENT_EXEC 4
  38. #define PTRACE_EVENT_VFORK_DONE 5
  39. #define PTRACE_EVENT_EXIT 6
  40. #include <asm/ptrace.h>
  41. #ifdef __KERNEL__
  42. /*
  43. * Ptrace flags
  44. *
  45. * The owner ship rules for task->ptrace which holds the ptrace
  46. * flags is simple. When a task is running it owns it's task->ptrace
  47. * flags. When the a task is stopped the ptracer owns task->ptrace.
  48. */
  49. #define PT_PTRACED 0x00000001
  50. #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
  51. #define PT_TRACESYSGOOD 0x00000004
  52. #define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
  53. #define PT_TRACE_FORK 0x00000010
  54. #define PT_TRACE_VFORK 0x00000020
  55. #define PT_TRACE_CLONE 0x00000040
  56. #define PT_TRACE_EXEC 0x00000080
  57. #define PT_TRACE_VFORK_DONE 0x00000100
  58. #define PT_TRACE_EXIT 0x00000200
  59. #define PT_TRACE_MASK 0x000003f4
  60. /* single stepping state bits (used on ARM and PA-RISC) */
  61. #define PT_SINGLESTEP_BIT 31
  62. #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
  63. #define PT_BLOCKSTEP_BIT 30
  64. #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
  65. #include <linux/compiler.h> /* For unlikely. */
  66. #include <linux/sched.h> /* For struct task_struct. */
  67. extern long arch_ptrace(struct task_struct *child, long request, long addr, long data);
  68. extern struct task_struct *ptrace_get_task_struct(pid_t pid);
  69. extern int ptrace_traceme(void);
  70. extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
  71. extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
  72. extern int ptrace_attach(struct task_struct *tsk);
  73. extern int ptrace_detach(struct task_struct *, unsigned int);
  74. extern void ptrace_disable(struct task_struct *);
  75. extern int ptrace_check_attach(struct task_struct *task, int kill);
  76. extern int ptrace_request(struct task_struct *child, long request, long addr, long data);
  77. extern void ptrace_notify(int exit_code);
  78. extern void __ptrace_link(struct task_struct *child,
  79. struct task_struct *new_parent);
  80. extern void __ptrace_unlink(struct task_struct *child);
  81. extern void ptrace_fork(struct task_struct *task, unsigned long clone_flags);
  82. #define PTRACE_MODE_READ 1
  83. #define PTRACE_MODE_ATTACH 2
  84. /* Returns 0 on success, -errno on denial. */
  85. extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
  86. /* Returns true on success, false on denial. */
  87. extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
  88. static inline int ptrace_reparented(struct task_struct *child)
  89. {
  90. return child->real_parent != child->parent;
  91. }
  92. static inline void ptrace_link(struct task_struct *child,
  93. struct task_struct *new_parent)
  94. {
  95. if (unlikely(child->ptrace))
  96. __ptrace_link(child, new_parent);
  97. }
  98. static inline void ptrace_unlink(struct task_struct *child)
  99. {
  100. if (unlikely(child->ptrace))
  101. __ptrace_unlink(child);
  102. }
  103. int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data);
  104. int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data);
  105. /**
  106. * task_ptrace - return %PT_* flags that apply to a task
  107. * @task: pointer to &task_struct in question
  108. *
  109. * Returns the %PT_* flags that apply to @task.
  110. */
  111. static inline int task_ptrace(struct task_struct *task)
  112. {
  113. return task->ptrace;
  114. }
  115. /**
  116. * ptrace_event - possibly stop for a ptrace event notification
  117. * @mask: %PT_* bit to check in @current->ptrace
  118. * @event: %PTRACE_EVENT_* value to report if @mask is set
  119. * @message: value for %PTRACE_GETEVENTMSG to return
  120. *
  121. * This checks the @mask bit to see if ptrace wants stops for this event.
  122. * If so we stop, reporting @event and @message to the ptrace parent.
  123. *
  124. * Returns nonzero if we did a ptrace notification, zero if not.
  125. *
  126. * Called without locks.
  127. */
  128. static inline int ptrace_event(int mask, int event, unsigned long message)
  129. {
  130. if (mask && likely(!(current->ptrace & mask)))
  131. return 0;
  132. current->ptrace_message = message;
  133. ptrace_notify((event << 8) | SIGTRAP);
  134. return 1;
  135. }
  136. /**
  137. * ptrace_init_task - initialize ptrace state for a new child
  138. * @child: new child task
  139. * @ptrace: true if child should be ptrace'd by parent's tracer
  140. *
  141. * This is called immediately after adding @child to its parent's children
  142. * list. @ptrace is false in the normal case, and true to ptrace @child.
  143. *
  144. * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
  145. */
  146. static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
  147. {
  148. INIT_LIST_HEAD(&child->ptrace_entry);
  149. INIT_LIST_HEAD(&child->ptraced);
  150. child->parent = child->real_parent;
  151. child->ptrace = 0;
  152. if (unlikely(ptrace)) {
  153. child->ptrace = current->ptrace;
  154. ptrace_link(child, current->parent);
  155. }
  156. }
  157. /**
  158. * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
  159. * @task: task in %EXIT_DEAD state
  160. *
  161. * Called with write_lock(&tasklist_lock) held.
  162. */
  163. static inline void ptrace_release_task(struct task_struct *task)
  164. {
  165. BUG_ON(!list_empty(&task->ptraced));
  166. ptrace_unlink(task);
  167. BUG_ON(!list_empty(&task->ptrace_entry));
  168. }
  169. #ifndef force_successful_syscall_return
  170. /*
  171. * System call handlers that, upon successful completion, need to return a
  172. * negative value should call force_successful_syscall_return() right before
  173. * returning. On architectures where the syscall convention provides for a
  174. * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
  175. * others), this macro can be used to ensure that the error flag will not get
  176. * set. On architectures which do not support a separate error flag, the macro
  177. * is a no-op and the spurious error condition needs to be filtered out by some
  178. * other means (e.g., in user-level, by passing an extra argument to the
  179. * syscall handler, or something along those lines).
  180. */
  181. #define force_successful_syscall_return() do { } while (0)
  182. #endif
  183. /*
  184. * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
  185. *
  186. * These do-nothing inlines are used when the arch does not
  187. * implement single-step. The kerneldoc comments are here
  188. * to document the interface for all arch definitions.
  189. */
  190. #ifndef arch_has_single_step
  191. /**
  192. * arch_has_single_step - does this CPU support user-mode single-step?
  193. *
  194. * If this is defined, then there must be function declarations or
  195. * inlines for user_enable_single_step() and user_disable_single_step().
  196. * arch_has_single_step() should evaluate to nonzero iff the machine
  197. * supports instruction single-step for user mode.
  198. * It can be a constant or it can test a CPU feature bit.
  199. */
  200. #define arch_has_single_step() (0)
  201. /**
  202. * user_enable_single_step - single-step in user-mode task
  203. * @task: either current or a task stopped in %TASK_TRACED
  204. *
  205. * This can only be called when arch_has_single_step() has returned nonzero.
  206. * Set @task so that when it returns to user mode, it will trap after the
  207. * next single instruction executes. If arch_has_block_step() is defined,
  208. * this must clear the effects of user_enable_block_step() too.
  209. */
  210. static inline void user_enable_single_step(struct task_struct *task)
  211. {
  212. BUG(); /* This can never be called. */
  213. }
  214. /**
  215. * user_disable_single_step - cancel user-mode single-step
  216. * @task: either current or a task stopped in %TASK_TRACED
  217. *
  218. * Clear @task of the effects of user_enable_single_step() and
  219. * user_enable_block_step(). This can be called whether or not either
  220. * of those was ever called on @task, and even if arch_has_single_step()
  221. * returned zero.
  222. */
  223. static inline void user_disable_single_step(struct task_struct *task)
  224. {
  225. }
  226. #endif /* arch_has_single_step */
  227. #ifndef arch_has_block_step
  228. /**
  229. * arch_has_block_step - does this CPU support user-mode block-step?
  230. *
  231. * If this is defined, then there must be a function declaration or inline
  232. * for user_enable_block_step(), and arch_has_single_step() must be defined
  233. * too. arch_has_block_step() should evaluate to nonzero iff the machine
  234. * supports step-until-branch for user mode. It can be a constant or it
  235. * can test a CPU feature bit.
  236. */
  237. #define arch_has_block_step() (0)
  238. /**
  239. * user_enable_block_step - step until branch in user-mode task
  240. * @task: either current or a task stopped in %TASK_TRACED
  241. *
  242. * This can only be called when arch_has_block_step() has returned nonzero,
  243. * and will never be called when single-instruction stepping is being used.
  244. * Set @task so that when it returns to user mode, it will trap after the
  245. * next branch or trap taken.
  246. */
  247. static inline void user_enable_block_step(struct task_struct *task)
  248. {
  249. BUG(); /* This can never be called. */
  250. }
  251. #endif /* arch_has_block_step */
  252. #ifndef arch_ptrace_stop_needed
  253. /**
  254. * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
  255. * @code: current->exit_code value ptrace will stop with
  256. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  257. *
  258. * This is called with the siglock held, to decide whether or not it's
  259. * necessary to release the siglock and call arch_ptrace_stop() with the
  260. * same @code and @info arguments. It can be defined to a constant if
  261. * arch_ptrace_stop() is never required, or always is. On machines where
  262. * this makes sense, it should be defined to a quick test to optimize out
  263. * calling arch_ptrace_stop() when it would be superfluous. For example,
  264. * if the thread has not been back to user mode since the last stop, the
  265. * thread state might indicate that nothing needs to be done.
  266. */
  267. #define arch_ptrace_stop_needed(code, info) (0)
  268. #endif
  269. #ifndef arch_ptrace_stop
  270. /**
  271. * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
  272. * @code: current->exit_code value ptrace will stop with
  273. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  274. *
  275. * This is called with no locks held when arch_ptrace_stop_needed() has
  276. * just returned nonzero. It is allowed to block, e.g. for user memory
  277. * access. The arch can have machine-specific work to be done before
  278. * ptrace stops. On ia64, register backing store gets written back to user
  279. * memory here. Since this can be costly (requires dropping the siglock),
  280. * we only do it when the arch requires it for this particular stop, as
  281. * indicated by arch_ptrace_stop_needed().
  282. */
  283. #define arch_ptrace_stop(code, info) do { } while (0)
  284. #endif
  285. #ifndef arch_ptrace_untrace
  286. /*
  287. * Do machine-specific work before untracing child.
  288. *
  289. * This is called for a normal detach as well as from ptrace_exit()
  290. * when the tracing task dies.
  291. *
  292. * Called with write_lock(&tasklist_lock) held.
  293. */
  294. #define arch_ptrace_untrace(task) do { } while (0)
  295. #endif
  296. #ifndef arch_ptrace_fork
  297. /*
  298. * Do machine-specific work to initialize a new task.
  299. *
  300. * This is called from copy_process().
  301. */
  302. #define arch_ptrace_fork(child, clone_flags) do { } while (0)
  303. #endif
  304. extern int task_current_syscall(struct task_struct *target, long *callno,
  305. unsigned long args[6], unsigned int maxargs,
  306. unsigned long *sp, unsigned long *pc);
  307. #endif
  308. #endif