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. /*
  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. /* options set using PTRACE_SETOPTIONS */
  44. #define PTRACE_O_TRACESYSGOOD 0x00000001
  45. #define PTRACE_O_TRACEFORK 0x00000002
  46. #define PTRACE_O_TRACEVFORK 0x00000004
  47. #define PTRACE_O_TRACECLONE 0x00000008
  48. #define PTRACE_O_TRACEEXEC 0x00000010
  49. #define PTRACE_O_TRACEVFORKDONE 0x00000020
  50. #define PTRACE_O_TRACEEXIT 0x00000040
  51. #define PTRACE_O_MASK 0x0000007f
  52. /* Wait extended result codes for the above trace options. */
  53. #define PTRACE_EVENT_FORK 1
  54. #define PTRACE_EVENT_VFORK 2
  55. #define PTRACE_EVENT_CLONE 3
  56. #define PTRACE_EVENT_EXEC 4
  57. #define PTRACE_EVENT_VFORK_DONE 5
  58. #define PTRACE_EVENT_EXIT 6
  59. #include <asm/ptrace.h>
  60. #ifdef __KERNEL__
  61. /*
  62. * Ptrace flags
  63. *
  64. * The owner ship rules for task->ptrace which holds the ptrace
  65. * flags is simple. When a task is running it owns it's task->ptrace
  66. * flags. When the a task is stopped the ptracer owns task->ptrace.
  67. */
  68. #define PT_PTRACED 0x00000001
  69. #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
  70. #define PT_TRACESYSGOOD 0x00000004
  71. #define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
  72. #define PT_TRACE_FORK 0x00000010
  73. #define PT_TRACE_VFORK 0x00000020
  74. #define PT_TRACE_CLONE 0x00000040
  75. #define PT_TRACE_EXEC 0x00000080
  76. #define PT_TRACE_VFORK_DONE 0x00000100
  77. #define PT_TRACE_EXIT 0x00000200
  78. #define PT_TRACE_MASK 0x000003f4
  79. /* single stepping state bits (used on ARM and PA-RISC) */
  80. #define PT_SINGLESTEP_BIT 31
  81. #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
  82. #define PT_BLOCKSTEP_BIT 30
  83. #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
  84. #include <linux/compiler.h> /* For unlikely. */
  85. #include <linux/sched.h> /* For struct task_struct. */
  86. extern long arch_ptrace(struct task_struct *child, long request, long addr, long data);
  87. extern int ptrace_traceme(void);
  88. extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
  89. extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
  90. extern int ptrace_attach(struct task_struct *tsk);
  91. extern int ptrace_detach(struct task_struct *, unsigned int);
  92. extern void ptrace_disable(struct task_struct *);
  93. extern int ptrace_check_attach(struct task_struct *task, int kill);
  94. extern int ptrace_request(struct task_struct *child, long request, long addr, long data);
  95. extern void ptrace_notify(int exit_code);
  96. extern void __ptrace_link(struct task_struct *child,
  97. struct task_struct *new_parent);
  98. extern void __ptrace_unlink(struct task_struct *child);
  99. extern void exit_ptrace(struct task_struct *tracer);
  100. #define PTRACE_MODE_READ 1
  101. #define PTRACE_MODE_ATTACH 2
  102. /* Returns 0 on success, -errno on denial. */
  103. extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
  104. /* Returns true on success, false on denial. */
  105. extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
  106. static inline int ptrace_reparented(struct task_struct *child)
  107. {
  108. return child->real_parent != child->parent;
  109. }
  110. static inline void ptrace_unlink(struct task_struct *child)
  111. {
  112. if (unlikely(child->ptrace))
  113. __ptrace_unlink(child);
  114. }
  115. int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data);
  116. int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data);
  117. /**
  118. * task_ptrace - return %PT_* flags that apply to a task
  119. * @task: pointer to &task_struct in question
  120. *
  121. * Returns the %PT_* flags that apply to @task.
  122. */
  123. static inline int task_ptrace(struct task_struct *task)
  124. {
  125. return task->ptrace;
  126. }
  127. /**
  128. * ptrace_event - possibly stop for a ptrace event notification
  129. * @mask: %PT_* bit to check in @current->ptrace
  130. * @event: %PTRACE_EVENT_* value to report if @mask is set
  131. * @message: value for %PTRACE_GETEVENTMSG to return
  132. *
  133. * This checks the @mask bit to see if ptrace wants stops for this event.
  134. * If so we stop, reporting @event and @message to the ptrace parent.
  135. *
  136. * Returns nonzero if we did a ptrace notification, zero if not.
  137. *
  138. * Called without locks.
  139. */
  140. static inline int ptrace_event(int mask, int event, unsigned long message)
  141. {
  142. if (mask && likely(!(current->ptrace & mask)))
  143. return 0;
  144. current->ptrace_message = message;
  145. ptrace_notify((event << 8) | SIGTRAP);
  146. return 1;
  147. }
  148. /**
  149. * ptrace_init_task - initialize ptrace state for a new child
  150. * @child: new child task
  151. * @ptrace: true if child should be ptrace'd by parent's tracer
  152. *
  153. * This is called immediately after adding @child to its parent's children
  154. * list. @ptrace is false in the normal case, and true to ptrace @child.
  155. *
  156. * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
  157. */
  158. static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
  159. {
  160. INIT_LIST_HEAD(&child->ptrace_entry);
  161. INIT_LIST_HEAD(&child->ptraced);
  162. child->parent = child->real_parent;
  163. child->ptrace = 0;
  164. if (unlikely(ptrace) && (current->ptrace & PT_PTRACED)) {
  165. child->ptrace = current->ptrace;
  166. __ptrace_link(child, current->parent);
  167. }
  168. }
  169. /**
  170. * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
  171. * @task: task in %EXIT_DEAD state
  172. *
  173. * Called with write_lock(&tasklist_lock) held.
  174. */
  175. static inline void ptrace_release_task(struct task_struct *task)
  176. {
  177. BUG_ON(!list_empty(&task->ptraced));
  178. ptrace_unlink(task);
  179. BUG_ON(!list_empty(&task->ptrace_entry));
  180. }
  181. #ifndef force_successful_syscall_return
  182. /*
  183. * System call handlers that, upon successful completion, need to return a
  184. * negative value should call force_successful_syscall_return() right before
  185. * returning. On architectures where the syscall convention provides for a
  186. * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
  187. * others), this macro can be used to ensure that the error flag will not get
  188. * set. On architectures which do not support a separate error flag, the macro
  189. * is a no-op and the spurious error condition needs to be filtered out by some
  190. * other means (e.g., in user-level, by passing an extra argument to the
  191. * syscall handler, or something along those lines).
  192. */
  193. #define force_successful_syscall_return() do { } while (0)
  194. #endif
  195. /*
  196. * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
  197. *
  198. * These do-nothing inlines are used when the arch does not
  199. * implement single-step. The kerneldoc comments are here
  200. * to document the interface for all arch definitions.
  201. */
  202. #ifndef arch_has_single_step
  203. /**
  204. * arch_has_single_step - does this CPU support user-mode single-step?
  205. *
  206. * If this is defined, then there must be function declarations or
  207. * inlines for user_enable_single_step() and user_disable_single_step().
  208. * arch_has_single_step() should evaluate to nonzero iff the machine
  209. * supports instruction single-step for user mode.
  210. * It can be a constant or it can test a CPU feature bit.
  211. */
  212. #define arch_has_single_step() (0)
  213. /**
  214. * user_enable_single_step - single-step in user-mode task
  215. * @task: either current or a task stopped in %TASK_TRACED
  216. *
  217. * This can only be called when arch_has_single_step() has returned nonzero.
  218. * Set @task so that when it returns to user mode, it will trap after the
  219. * next single instruction executes. If arch_has_block_step() is defined,
  220. * this must clear the effects of user_enable_block_step() too.
  221. */
  222. static inline void user_enable_single_step(struct task_struct *task)
  223. {
  224. BUG(); /* This can never be called. */
  225. }
  226. /**
  227. * user_disable_single_step - cancel user-mode single-step
  228. * @task: either current or a task stopped in %TASK_TRACED
  229. *
  230. * Clear @task of the effects of user_enable_single_step() and
  231. * user_enable_block_step(). This can be called whether or not either
  232. * of those was ever called on @task, and even if arch_has_single_step()
  233. * returned zero.
  234. */
  235. static inline void user_disable_single_step(struct task_struct *task)
  236. {
  237. }
  238. #else
  239. extern void user_enable_single_step(struct task_struct *);
  240. extern void user_disable_single_step(struct task_struct *);
  241. #endif /* arch_has_single_step */
  242. #ifndef arch_has_block_step
  243. /**
  244. * arch_has_block_step - does this CPU support user-mode block-step?
  245. *
  246. * If this is defined, then there must be a function declaration or inline
  247. * for user_enable_block_step(), and arch_has_single_step() must be defined
  248. * too. arch_has_block_step() should evaluate to nonzero iff the machine
  249. * supports step-until-branch for user mode. It can be a constant or it
  250. * can test a CPU feature bit.
  251. */
  252. #define arch_has_block_step() (0)
  253. /**
  254. * user_enable_block_step - step until branch in user-mode task
  255. * @task: either current or a task stopped in %TASK_TRACED
  256. *
  257. * This can only be called when arch_has_block_step() has returned nonzero,
  258. * and will never be called when single-instruction stepping is being used.
  259. * Set @task so that when it returns to user mode, it will trap after the
  260. * next branch or trap taken.
  261. */
  262. static inline void user_enable_block_step(struct task_struct *task)
  263. {
  264. BUG(); /* This can never be called. */
  265. }
  266. #else
  267. extern void user_enable_block_step(struct task_struct *);
  268. #endif /* arch_has_block_step */
  269. #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
  270. extern void user_single_step_siginfo(struct task_struct *tsk,
  271. struct pt_regs *regs, siginfo_t *info);
  272. #else
  273. static inline void user_single_step_siginfo(struct task_struct *tsk,
  274. struct pt_regs *regs, siginfo_t *info)
  275. {
  276. memset(info, 0, sizeof(*info));
  277. info->si_signo = SIGTRAP;
  278. }
  279. #endif
  280. #ifndef arch_ptrace_stop_needed
  281. /**
  282. * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
  283. * @code: current->exit_code value ptrace will stop with
  284. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  285. *
  286. * This is called with the siglock held, to decide whether or not it's
  287. * necessary to release the siglock and call arch_ptrace_stop() with the
  288. * same @code and @info arguments. It can be defined to a constant if
  289. * arch_ptrace_stop() is never required, or always is. On machines where
  290. * this makes sense, it should be defined to a quick test to optimize out
  291. * calling arch_ptrace_stop() when it would be superfluous. For example,
  292. * if the thread has not been back to user mode since the last stop, the
  293. * thread state might indicate that nothing needs to be done.
  294. */
  295. #define arch_ptrace_stop_needed(code, info) (0)
  296. #endif
  297. #ifndef arch_ptrace_stop
  298. /**
  299. * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
  300. * @code: current->exit_code value ptrace will stop with
  301. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  302. *
  303. * This is called with no locks held when arch_ptrace_stop_needed() has
  304. * just returned nonzero. It is allowed to block, e.g. for user memory
  305. * access. The arch can have machine-specific work to be done before
  306. * ptrace stops. On ia64, register backing store gets written back to user
  307. * memory here. Since this can be costly (requires dropping the siglock),
  308. * we only do it when the arch requires it for this particular stop, as
  309. * indicated by arch_ptrace_stop_needed().
  310. */
  311. #define arch_ptrace_stop(code, info) do { } while (0)
  312. #endif
  313. extern int task_current_syscall(struct task_struct *target, long *callno,
  314. unsigned long args[6], unsigned int maxargs,
  315. unsigned long *sp, unsigned long *pc);
  316. #endif
  317. #endif