ptrace.h 15 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. /* Wait extended result codes for the above trace options. */
  47. #define PTRACE_EVENT_FORK 1
  48. #define PTRACE_EVENT_VFORK 2
  49. #define PTRACE_EVENT_CLONE 3
  50. #define PTRACE_EVENT_EXEC 4
  51. #define PTRACE_EVENT_VFORK_DONE 5
  52. #define PTRACE_EVENT_EXIT 6
  53. /* Extended result codes which enabled by means other than options. */
  54. #define PTRACE_EVENT_STOP 128
  55. /* Options set using PTRACE_SETOPTIONS or using PTRACE_SEIZE @data param */
  56. #define PTRACE_O_TRACESYSGOOD 1
  57. #define PTRACE_O_TRACEFORK (1 << PTRACE_EVENT_FORK)
  58. #define PTRACE_O_TRACEVFORK (1 << PTRACE_EVENT_VFORK)
  59. #define PTRACE_O_TRACECLONE (1 << PTRACE_EVENT_CLONE)
  60. #define PTRACE_O_TRACEEXEC (1 << PTRACE_EVENT_EXEC)
  61. #define PTRACE_O_TRACEVFORKDONE (1 << PTRACE_EVENT_VFORK_DONE)
  62. #define PTRACE_O_TRACEEXIT (1 << PTRACE_EVENT_EXIT)
  63. #define PTRACE_O_MASK 0x0000007f
  64. #include <asm/ptrace.h>
  65. #ifdef __KERNEL__
  66. /*
  67. * Ptrace flags
  68. *
  69. * The owner ship rules for task->ptrace which holds the ptrace
  70. * flags is simple. When a task is running it owns it's task->ptrace
  71. * flags. When the a task is stopped the ptracer owns task->ptrace.
  72. */
  73. #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */
  74. #define PT_PTRACED 0x00000001
  75. #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
  76. #define PT_PTRACE_CAP 0x00000004 /* ptracer can follow suid-exec */
  77. #define PT_OPT_FLAG_SHIFT 3
  78. /* PT_TRACE_* event enable flags */
  79. #define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event)))
  80. #define PT_TRACESYSGOOD PT_EVENT_FLAG(0)
  81. #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK)
  82. #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK)
  83. #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE)
  84. #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC)
  85. #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE)
  86. #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT)
  87. /* single stepping state bits (used on ARM and PA-RISC) */
  88. #define PT_SINGLESTEP_BIT 31
  89. #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
  90. #define PT_BLOCKSTEP_BIT 30
  91. #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
  92. #include <linux/compiler.h> /* For unlikely. */
  93. #include <linux/sched.h> /* For struct task_struct. */
  94. #include <linux/err.h> /* for IS_ERR_VALUE */
  95. #include <linux/bug.h> /* For BUG_ON. */
  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) {
  175. /* legacy EXEC report via SIGTRAP */
  176. if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED)
  177. send_sig(SIGTRAP, current, 0);
  178. }
  179. }
  180. /**
  181. * ptrace_init_task - initialize ptrace state for a new child
  182. * @child: new child task
  183. * @ptrace: true if child should be ptrace'd by parent's tracer
  184. *
  185. * This is called immediately after adding @child to its parent's children
  186. * list. @ptrace is false in the normal case, and true to ptrace @child.
  187. *
  188. * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
  189. */
  190. static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
  191. {
  192. INIT_LIST_HEAD(&child->ptrace_entry);
  193. INIT_LIST_HEAD(&child->ptraced);
  194. #ifdef CONFIG_HAVE_HW_BREAKPOINT
  195. atomic_set(&child->ptrace_bp_refcnt, 1);
  196. #endif
  197. child->jobctl = 0;
  198. child->ptrace = 0;
  199. child->parent = child->real_parent;
  200. if (unlikely(ptrace) && current->ptrace) {
  201. child->ptrace = current->ptrace;
  202. __ptrace_link(child, current->parent);
  203. if (child->ptrace & PT_SEIZED)
  204. task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
  205. else
  206. sigaddset(&child->pending.signal, SIGSTOP);
  207. set_tsk_thread_flag(child, TIF_SIGPENDING);
  208. }
  209. }
  210. /**
  211. * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
  212. * @task: task in %EXIT_DEAD state
  213. *
  214. * Called with write_lock(&tasklist_lock) held.
  215. */
  216. static inline void ptrace_release_task(struct task_struct *task)
  217. {
  218. BUG_ON(!list_empty(&task->ptraced));
  219. ptrace_unlink(task);
  220. BUG_ON(!list_empty(&task->ptrace_entry));
  221. }
  222. #ifndef force_successful_syscall_return
  223. /*
  224. * System call handlers that, upon successful completion, need to return a
  225. * negative value should call force_successful_syscall_return() right before
  226. * returning. On architectures where the syscall convention provides for a
  227. * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
  228. * others), this macro can be used to ensure that the error flag will not get
  229. * set. On architectures which do not support a separate error flag, the macro
  230. * is a no-op and the spurious error condition needs to be filtered out by some
  231. * other means (e.g., in user-level, by passing an extra argument to the
  232. * syscall handler, or something along those lines).
  233. */
  234. #define force_successful_syscall_return() do { } while (0)
  235. #endif
  236. #ifndef is_syscall_success
  237. /*
  238. * On most systems we can tell if a syscall is a success based on if the retval
  239. * is an error value. On some systems like ia64 and powerpc they have different
  240. * indicators of success/failure and must define their own.
  241. */
  242. #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs))))
  243. #endif
  244. /*
  245. * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
  246. *
  247. * These do-nothing inlines are used when the arch does not
  248. * implement single-step. The kerneldoc comments are here
  249. * to document the interface for all arch definitions.
  250. */
  251. #ifndef arch_has_single_step
  252. /**
  253. * arch_has_single_step - does this CPU support user-mode single-step?
  254. *
  255. * If this is defined, then there must be function declarations or
  256. * inlines for user_enable_single_step() and user_disable_single_step().
  257. * arch_has_single_step() should evaluate to nonzero iff the machine
  258. * supports instruction single-step for user mode.
  259. * It can be a constant or it can test a CPU feature bit.
  260. */
  261. #define arch_has_single_step() (0)
  262. /**
  263. * user_enable_single_step - single-step in user-mode task
  264. * @task: either current or a task stopped in %TASK_TRACED
  265. *
  266. * This can only be called when arch_has_single_step() has returned nonzero.
  267. * Set @task so that when it returns to user mode, it will trap after the
  268. * next single instruction executes. If arch_has_block_step() is defined,
  269. * this must clear the effects of user_enable_block_step() too.
  270. */
  271. static inline void user_enable_single_step(struct task_struct *task)
  272. {
  273. BUG(); /* This can never be called. */
  274. }
  275. /**
  276. * user_disable_single_step - cancel user-mode single-step
  277. * @task: either current or a task stopped in %TASK_TRACED
  278. *
  279. * Clear @task of the effects of user_enable_single_step() and
  280. * user_enable_block_step(). This can be called whether or not either
  281. * of those was ever called on @task, and even if arch_has_single_step()
  282. * returned zero.
  283. */
  284. static inline void user_disable_single_step(struct task_struct *task)
  285. {
  286. }
  287. #else
  288. extern void user_enable_single_step(struct task_struct *);
  289. extern void user_disable_single_step(struct task_struct *);
  290. #endif /* arch_has_single_step */
  291. #ifndef arch_has_block_step
  292. /**
  293. * arch_has_block_step - does this CPU support user-mode block-step?
  294. *
  295. * If this is defined, then there must be a function declaration or inline
  296. * for user_enable_block_step(), and arch_has_single_step() must be defined
  297. * too. arch_has_block_step() should evaluate to nonzero iff the machine
  298. * supports step-until-branch for user mode. It can be a constant or it
  299. * can test a CPU feature bit.
  300. */
  301. #define arch_has_block_step() (0)
  302. /**
  303. * user_enable_block_step - step until branch in user-mode task
  304. * @task: either current or a task stopped in %TASK_TRACED
  305. *
  306. * This can only be called when arch_has_block_step() has returned nonzero,
  307. * and will never be called when single-instruction stepping is being used.
  308. * Set @task so that when it returns to user mode, it will trap after the
  309. * next branch or trap taken.
  310. */
  311. static inline void user_enable_block_step(struct task_struct *task)
  312. {
  313. BUG(); /* This can never be called. */
  314. }
  315. #else
  316. extern void user_enable_block_step(struct task_struct *);
  317. #endif /* arch_has_block_step */
  318. #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
  319. extern void user_single_step_siginfo(struct task_struct *tsk,
  320. struct pt_regs *regs, siginfo_t *info);
  321. #else
  322. static inline void user_single_step_siginfo(struct task_struct *tsk,
  323. struct pt_regs *regs, siginfo_t *info)
  324. {
  325. memset(info, 0, sizeof(*info));
  326. info->si_signo = SIGTRAP;
  327. }
  328. #endif
  329. #ifndef arch_ptrace_stop_needed
  330. /**
  331. * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
  332. * @code: current->exit_code value ptrace will stop with
  333. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  334. *
  335. * This is called with the siglock held, to decide whether or not it's
  336. * necessary to release the siglock and call arch_ptrace_stop() with the
  337. * same @code and @info arguments. It can be defined to a constant if
  338. * arch_ptrace_stop() is never required, or always is. On machines where
  339. * this makes sense, it should be defined to a quick test to optimize out
  340. * calling arch_ptrace_stop() when it would be superfluous. For example,
  341. * if the thread has not been back to user mode since the last stop, the
  342. * thread state might indicate that nothing needs to be done.
  343. */
  344. #define arch_ptrace_stop_needed(code, info) (0)
  345. #endif
  346. #ifndef arch_ptrace_stop
  347. /**
  348. * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
  349. * @code: current->exit_code value ptrace will stop with
  350. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  351. *
  352. * This is called with no locks held when arch_ptrace_stop_needed() has
  353. * just returned nonzero. It is allowed to block, e.g. for user memory
  354. * access. The arch can have machine-specific work to be done before
  355. * ptrace stops. On ia64, register backing store gets written back to user
  356. * memory here. Since this can be costly (requires dropping the siglock),
  357. * we only do it when the arch requires it for this particular stop, as
  358. * indicated by arch_ptrace_stop_needed().
  359. */
  360. #define arch_ptrace_stop(code, info) do { } while (0)
  361. #endif
  362. extern int task_current_syscall(struct task_struct *target, long *callno,
  363. unsigned long args[6], unsigned int maxargs,
  364. unsigned long *sp, unsigned long *pc);
  365. #ifdef CONFIG_HAVE_HW_BREAKPOINT
  366. extern int ptrace_get_breakpoints(struct task_struct *tsk);
  367. extern void ptrace_put_breakpoints(struct task_struct *tsk);
  368. #else
  369. static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
  370. #endif /* CONFIG_HAVE_HW_BREAKPOINT */
  371. #endif /* __KERNEL */
  372. #endif