ptrace.h 14 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404
  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 !same_thread_group(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_parent - return the task that is tracing the given task
  130. * @task: task to consider
  131. *
  132. * Returns %NULL if no one is tracing @task, or the &struct task_struct
  133. * pointer to its tracer.
  134. *
  135. * Must called under rcu_read_lock(). The pointer returned might be kept
  136. * live only by RCU. During exec, this may be called with task_lock() held
  137. * on @task, still held from when check_unsafe_exec() was called.
  138. */
  139. static inline struct task_struct *ptrace_parent(struct task_struct *task)
  140. {
  141. if (unlikely(task->ptrace))
  142. return rcu_dereference(task->parent);
  143. return NULL;
  144. }
  145. /**
  146. * ptrace_event_enabled - test whether a ptrace event is enabled
  147. * @task: ptracee of interest
  148. * @event: %PTRACE_EVENT_* to test
  149. *
  150. * Test whether @event is enabled for ptracee @task.
  151. *
  152. * Returns %true if @event is enabled, %false otherwise.
  153. */
  154. static inline bool ptrace_event_enabled(struct task_struct *task, int event)
  155. {
  156. return task->ptrace & PT_EVENT_FLAG(event);
  157. }
  158. /**
  159. * ptrace_event - possibly stop for a ptrace event notification
  160. * @event: %PTRACE_EVENT_* value to report
  161. * @message: value for %PTRACE_GETEVENTMSG to return
  162. *
  163. * Check whether @event is enabled and, if so, report @event and @message
  164. * to the ptrace parent.
  165. *
  166. * Called without locks.
  167. */
  168. static inline void ptrace_event(int event, unsigned long message)
  169. {
  170. if (unlikely(ptrace_event_enabled(current, event))) {
  171. current->ptrace_message = message;
  172. ptrace_notify((event << 8) | SIGTRAP);
  173. } else if (event == PTRACE_EVENT_EXEC && unlikely(current->ptrace)) {
  174. /* legacy EXEC report via SIGTRAP */
  175. send_sig(SIGTRAP, current, 0);
  176. }
  177. }
  178. /**
  179. * ptrace_init_task - initialize ptrace state for a new child
  180. * @child: new child task
  181. * @ptrace: true if child should be ptrace'd by parent's tracer
  182. *
  183. * This is called immediately after adding @child to its parent's children
  184. * list. @ptrace is false in the normal case, and true to ptrace @child.
  185. *
  186. * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
  187. */
  188. static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
  189. {
  190. INIT_LIST_HEAD(&child->ptrace_entry);
  191. INIT_LIST_HEAD(&child->ptraced);
  192. #ifdef CONFIG_HAVE_HW_BREAKPOINT
  193. atomic_set(&child->ptrace_bp_refcnt, 1);
  194. #endif
  195. child->jobctl = 0;
  196. child->ptrace = 0;
  197. child->parent = child->real_parent;
  198. if (unlikely(ptrace) && current->ptrace) {
  199. child->ptrace = current->ptrace;
  200. __ptrace_link(child, current->parent);
  201. sigaddset(&child->pending.signal, SIGSTOP);
  202. set_tsk_thread_flag(child, TIF_SIGPENDING);
  203. }
  204. }
  205. /**
  206. * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
  207. * @task: task in %EXIT_DEAD state
  208. *
  209. * Called with write_lock(&tasklist_lock) held.
  210. */
  211. static inline void ptrace_release_task(struct task_struct *task)
  212. {
  213. BUG_ON(!list_empty(&task->ptraced));
  214. ptrace_unlink(task);
  215. BUG_ON(!list_empty(&task->ptrace_entry));
  216. }
  217. #ifndef force_successful_syscall_return
  218. /*
  219. * System call handlers that, upon successful completion, need to return a
  220. * negative value should call force_successful_syscall_return() right before
  221. * returning. On architectures where the syscall convention provides for a
  222. * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
  223. * others), this macro can be used to ensure that the error flag will not get
  224. * set. On architectures which do not support a separate error flag, the macro
  225. * is a no-op and the spurious error condition needs to be filtered out by some
  226. * other means (e.g., in user-level, by passing an extra argument to the
  227. * syscall handler, or something along those lines).
  228. */
  229. #define force_successful_syscall_return() do { } while (0)
  230. #endif
  231. /*
  232. * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
  233. *
  234. * These do-nothing inlines are used when the arch does not
  235. * implement single-step. The kerneldoc comments are here
  236. * to document the interface for all arch definitions.
  237. */
  238. #ifndef arch_has_single_step
  239. /**
  240. * arch_has_single_step - does this CPU support user-mode single-step?
  241. *
  242. * If this is defined, then there must be function declarations or
  243. * inlines for user_enable_single_step() and user_disable_single_step().
  244. * arch_has_single_step() should evaluate to nonzero iff the machine
  245. * supports instruction single-step for user mode.
  246. * It can be a constant or it can test a CPU feature bit.
  247. */
  248. #define arch_has_single_step() (0)
  249. /**
  250. * user_enable_single_step - single-step in user-mode task
  251. * @task: either current or a task stopped in %TASK_TRACED
  252. *
  253. * This can only be called when arch_has_single_step() has returned nonzero.
  254. * Set @task so that when it returns to user mode, it will trap after the
  255. * next single instruction executes. If arch_has_block_step() is defined,
  256. * this must clear the effects of user_enable_block_step() too.
  257. */
  258. static inline void user_enable_single_step(struct task_struct *task)
  259. {
  260. BUG(); /* This can never be called. */
  261. }
  262. /**
  263. * user_disable_single_step - cancel user-mode single-step
  264. * @task: either current or a task stopped in %TASK_TRACED
  265. *
  266. * Clear @task of the effects of user_enable_single_step() and
  267. * user_enable_block_step(). This can be called whether or not either
  268. * of those was ever called on @task, and even if arch_has_single_step()
  269. * returned zero.
  270. */
  271. static inline void user_disable_single_step(struct task_struct *task)
  272. {
  273. }
  274. #else
  275. extern void user_enable_single_step(struct task_struct *);
  276. extern void user_disable_single_step(struct task_struct *);
  277. #endif /* arch_has_single_step */
  278. #ifndef arch_has_block_step
  279. /**
  280. * arch_has_block_step - does this CPU support user-mode block-step?
  281. *
  282. * If this is defined, then there must be a function declaration or inline
  283. * for user_enable_block_step(), and arch_has_single_step() must be defined
  284. * too. arch_has_block_step() should evaluate to nonzero iff the machine
  285. * supports step-until-branch for user mode. It can be a constant or it
  286. * can test a CPU feature bit.
  287. */
  288. #define arch_has_block_step() (0)
  289. /**
  290. * user_enable_block_step - step until branch in user-mode task
  291. * @task: either current or a task stopped in %TASK_TRACED
  292. *
  293. * This can only be called when arch_has_block_step() has returned nonzero,
  294. * and will never be called when single-instruction stepping is being used.
  295. * Set @task so that when it returns to user mode, it will trap after the
  296. * next branch or trap taken.
  297. */
  298. static inline void user_enable_block_step(struct task_struct *task)
  299. {
  300. BUG(); /* This can never be called. */
  301. }
  302. #else
  303. extern void user_enable_block_step(struct task_struct *);
  304. #endif /* arch_has_block_step */
  305. #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
  306. extern void user_single_step_siginfo(struct task_struct *tsk,
  307. struct pt_regs *regs, siginfo_t *info);
  308. #else
  309. static inline void user_single_step_siginfo(struct task_struct *tsk,
  310. struct pt_regs *regs, siginfo_t *info)
  311. {
  312. memset(info, 0, sizeof(*info));
  313. info->si_signo = SIGTRAP;
  314. }
  315. #endif
  316. #ifndef arch_ptrace_stop_needed
  317. /**
  318. * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
  319. * @code: current->exit_code value ptrace will stop with
  320. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  321. *
  322. * This is called with the siglock held, to decide whether or not it's
  323. * necessary to release the siglock and call arch_ptrace_stop() with the
  324. * same @code and @info arguments. It can be defined to a constant if
  325. * arch_ptrace_stop() is never required, or always is. On machines where
  326. * this makes sense, it should be defined to a quick test to optimize out
  327. * calling arch_ptrace_stop() when it would be superfluous. For example,
  328. * if the thread has not been back to user mode since the last stop, the
  329. * thread state might indicate that nothing needs to be done.
  330. */
  331. #define arch_ptrace_stop_needed(code, info) (0)
  332. #endif
  333. #ifndef arch_ptrace_stop
  334. /**
  335. * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
  336. * @code: current->exit_code value ptrace will stop with
  337. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  338. *
  339. * This is called with no locks held when arch_ptrace_stop_needed() has
  340. * just returned nonzero. It is allowed to block, e.g. for user memory
  341. * access. The arch can have machine-specific work to be done before
  342. * ptrace stops. On ia64, register backing store gets written back to user
  343. * memory here. Since this can be costly (requires dropping the siglock),
  344. * we only do it when the arch requires it for this particular stop, as
  345. * indicated by arch_ptrace_stop_needed().
  346. */
  347. #define arch_ptrace_stop(code, info) do { } while (0)
  348. #endif
  349. extern int task_current_syscall(struct task_struct *target, long *callno,
  350. unsigned long args[6], unsigned int maxargs,
  351. unsigned long *sp, unsigned long *pc);
  352. #ifdef CONFIG_HAVE_HW_BREAKPOINT
  353. extern int ptrace_get_breakpoints(struct task_struct *tsk);
  354. extern void ptrace_put_breakpoints(struct task_struct *tsk);
  355. #else
  356. static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
  357. #endif /* CONFIG_HAVE_HW_BREAKPOINT */
  358. #endif /* __KERNEL */
  359. #endif