ptrace.h 14 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 0x01
  110. #define PTRACE_MODE_ATTACH 0x02
  111. #define PTRACE_MODE_NOAUDIT 0x04
  112. /* Returns 0 on success, -errno on denial. */
  113. extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
  114. /* Returns true on success, false on denial. */
  115. extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
  116. static inline int ptrace_reparented(struct task_struct *child)
  117. {
  118. return !same_thread_group(child->real_parent, child->parent);
  119. }
  120. static inline void ptrace_unlink(struct task_struct *child)
  121. {
  122. if (unlikely(child->ptrace))
  123. __ptrace_unlink(child);
  124. }
  125. int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
  126. unsigned long data);
  127. int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
  128. unsigned long data);
  129. /**
  130. * ptrace_parent - return the task that is tracing the given task
  131. * @task: task to consider
  132. *
  133. * Returns %NULL if no one is tracing @task, or the &struct task_struct
  134. * pointer to its tracer.
  135. *
  136. * Must called under rcu_read_lock(). The pointer returned might be kept
  137. * live only by RCU. During exec, this may be called with task_lock() held
  138. * on @task, still held from when check_unsafe_exec() was called.
  139. */
  140. static inline struct task_struct *ptrace_parent(struct task_struct *task)
  141. {
  142. if (unlikely(task->ptrace))
  143. return rcu_dereference(task->parent);
  144. return NULL;
  145. }
  146. /**
  147. * ptrace_event_enabled - test whether a ptrace event is enabled
  148. * @task: ptracee of interest
  149. * @event: %PTRACE_EVENT_* to test
  150. *
  151. * Test whether @event is enabled for ptracee @task.
  152. *
  153. * Returns %true if @event is enabled, %false otherwise.
  154. */
  155. static inline bool ptrace_event_enabled(struct task_struct *task, int event)
  156. {
  157. return task->ptrace & PT_EVENT_FLAG(event);
  158. }
  159. /**
  160. * ptrace_event - possibly stop for a ptrace event notification
  161. * @event: %PTRACE_EVENT_* value to report
  162. * @message: value for %PTRACE_GETEVENTMSG to return
  163. *
  164. * Check whether @event is enabled and, if so, report @event and @message
  165. * to the ptrace parent.
  166. *
  167. * Called without locks.
  168. */
  169. static inline void ptrace_event(int event, unsigned long message)
  170. {
  171. if (unlikely(ptrace_event_enabled(current, event))) {
  172. current->ptrace_message = message;
  173. ptrace_notify((event << 8) | SIGTRAP);
  174. } else if (event == PTRACE_EVENT_EXEC && unlikely(current->ptrace)) {
  175. /* legacy EXEC report via SIGTRAP */
  176. send_sig(SIGTRAP, current, 0);
  177. }
  178. }
  179. /**
  180. * ptrace_init_task - initialize ptrace state for a new child
  181. * @child: new child task
  182. * @ptrace: true if child should be ptrace'd by parent's tracer
  183. *
  184. * This is called immediately after adding @child to its parent's children
  185. * list. @ptrace is false in the normal case, and true to ptrace @child.
  186. *
  187. * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
  188. */
  189. static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
  190. {
  191. INIT_LIST_HEAD(&child->ptrace_entry);
  192. INIT_LIST_HEAD(&child->ptraced);
  193. #ifdef CONFIG_HAVE_HW_BREAKPOINT
  194. atomic_set(&child->ptrace_bp_refcnt, 1);
  195. #endif
  196. child->jobctl = 0;
  197. child->ptrace = 0;
  198. child->parent = child->real_parent;
  199. if (unlikely(ptrace) && current->ptrace) {
  200. child->ptrace = current->ptrace;
  201. __ptrace_link(child, current->parent);
  202. if (child->ptrace & PT_SEIZED)
  203. task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
  204. else
  205. sigaddset(&child->pending.signal, SIGSTOP);
  206. set_tsk_thread_flag(child, TIF_SIGPENDING);
  207. }
  208. }
  209. /**
  210. * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
  211. * @task: task in %EXIT_DEAD state
  212. *
  213. * Called with write_lock(&tasklist_lock) held.
  214. */
  215. static inline void ptrace_release_task(struct task_struct *task)
  216. {
  217. BUG_ON(!list_empty(&task->ptraced));
  218. ptrace_unlink(task);
  219. BUG_ON(!list_empty(&task->ptrace_entry));
  220. }
  221. #ifndef force_successful_syscall_return
  222. /*
  223. * System call handlers that, upon successful completion, need to return a
  224. * negative value should call force_successful_syscall_return() right before
  225. * returning. On architectures where the syscall convention provides for a
  226. * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
  227. * others), this macro can be used to ensure that the error flag will not get
  228. * set. On architectures which do not support a separate error flag, the macro
  229. * is a no-op and the spurious error condition needs to be filtered out by some
  230. * other means (e.g., in user-level, by passing an extra argument to the
  231. * syscall handler, or something along those lines).
  232. */
  233. #define force_successful_syscall_return() do { } while (0)
  234. #endif
  235. /*
  236. * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
  237. *
  238. * These do-nothing inlines are used when the arch does not
  239. * implement single-step. The kerneldoc comments are here
  240. * to document the interface for all arch definitions.
  241. */
  242. #ifndef arch_has_single_step
  243. /**
  244. * arch_has_single_step - does this CPU support user-mode single-step?
  245. *
  246. * If this is defined, then there must be function declarations or
  247. * inlines for user_enable_single_step() and user_disable_single_step().
  248. * arch_has_single_step() should evaluate to nonzero iff the machine
  249. * supports instruction single-step for user mode.
  250. * It can be a constant or it can test a CPU feature bit.
  251. */
  252. #define arch_has_single_step() (0)
  253. /**
  254. * user_enable_single_step - single-step 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_single_step() has returned nonzero.
  258. * Set @task so that when it returns to user mode, it will trap after the
  259. * next single instruction executes. If arch_has_block_step() is defined,
  260. * this must clear the effects of user_enable_block_step() too.
  261. */
  262. static inline void user_enable_single_step(struct task_struct *task)
  263. {
  264. BUG(); /* This can never be called. */
  265. }
  266. /**
  267. * user_disable_single_step - cancel user-mode single-step
  268. * @task: either current or a task stopped in %TASK_TRACED
  269. *
  270. * Clear @task of the effects of user_enable_single_step() and
  271. * user_enable_block_step(). This can be called whether or not either
  272. * of those was ever called on @task, and even if arch_has_single_step()
  273. * returned zero.
  274. */
  275. static inline void user_disable_single_step(struct task_struct *task)
  276. {
  277. }
  278. #else
  279. extern void user_enable_single_step(struct task_struct *);
  280. extern void user_disable_single_step(struct task_struct *);
  281. #endif /* arch_has_single_step */
  282. #ifndef arch_has_block_step
  283. /**
  284. * arch_has_block_step - does this CPU support user-mode block-step?
  285. *
  286. * If this is defined, then there must be a function declaration or inline
  287. * for user_enable_block_step(), and arch_has_single_step() must be defined
  288. * too. arch_has_block_step() should evaluate to nonzero iff the machine
  289. * supports step-until-branch for user mode. It can be a constant or it
  290. * can test a CPU feature bit.
  291. */
  292. #define arch_has_block_step() (0)
  293. /**
  294. * user_enable_block_step - step until branch in user-mode task
  295. * @task: either current or a task stopped in %TASK_TRACED
  296. *
  297. * This can only be called when arch_has_block_step() has returned nonzero,
  298. * and will never be called when single-instruction stepping is being used.
  299. * Set @task so that when it returns to user mode, it will trap after the
  300. * next branch or trap taken.
  301. */
  302. static inline void user_enable_block_step(struct task_struct *task)
  303. {
  304. BUG(); /* This can never be called. */
  305. }
  306. #else
  307. extern void user_enable_block_step(struct task_struct *);
  308. #endif /* arch_has_block_step */
  309. #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
  310. extern void user_single_step_siginfo(struct task_struct *tsk,
  311. struct pt_regs *regs, siginfo_t *info);
  312. #else
  313. static inline void user_single_step_siginfo(struct task_struct *tsk,
  314. struct pt_regs *regs, siginfo_t *info)
  315. {
  316. memset(info, 0, sizeof(*info));
  317. info->si_signo = SIGTRAP;
  318. }
  319. #endif
  320. #ifndef arch_ptrace_stop_needed
  321. /**
  322. * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
  323. * @code: current->exit_code value ptrace will stop with
  324. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  325. *
  326. * This is called with the siglock held, to decide whether or not it's
  327. * necessary to release the siglock and call arch_ptrace_stop() with the
  328. * same @code and @info arguments. It can be defined to a constant if
  329. * arch_ptrace_stop() is never required, or always is. On machines where
  330. * this makes sense, it should be defined to a quick test to optimize out
  331. * calling arch_ptrace_stop() when it would be superfluous. For example,
  332. * if the thread has not been back to user mode since the last stop, the
  333. * thread state might indicate that nothing needs to be done.
  334. */
  335. #define arch_ptrace_stop_needed(code, info) (0)
  336. #endif
  337. #ifndef arch_ptrace_stop
  338. /**
  339. * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
  340. * @code: current->exit_code value ptrace will stop with
  341. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  342. *
  343. * This is called with no locks held when arch_ptrace_stop_needed() has
  344. * just returned nonzero. It is allowed to block, e.g. for user memory
  345. * access. The arch can have machine-specific work to be done before
  346. * ptrace stops. On ia64, register backing store gets written back to user
  347. * memory here. Since this can be costly (requires dropping the siglock),
  348. * we only do it when the arch requires it for this particular stop, as
  349. * indicated by arch_ptrace_stop_needed().
  350. */
  351. #define arch_ptrace_stop(code, info) do { } while (0)
  352. #endif
  353. extern int task_current_syscall(struct task_struct *target, long *callno,
  354. unsigned long args[6], unsigned int maxargs,
  355. unsigned long *sp, unsigned long *pc);
  356. #ifdef CONFIG_HAVE_HW_BREAKPOINT
  357. extern int ptrace_get_breakpoints(struct task_struct *tsk);
  358. extern void ptrace_put_breakpoints(struct task_struct *tsk);
  359. #else
  360. static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
  361. #endif /* CONFIG_HAVE_HW_BREAKPOINT */
  362. #endif /* __KERNEL */
  363. #endif