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. #define PTRACE_EVENT_SECCOMP 7
  54. /* Extended result codes which enabled by means other than options. */
  55. #define PTRACE_EVENT_STOP 128
  56. /* Options set using PTRACE_SETOPTIONS or using PTRACE_SEIZE @data param */
  57. #define PTRACE_O_TRACESYSGOOD 1
  58. #define PTRACE_O_TRACEFORK (1 << PTRACE_EVENT_FORK)
  59. #define PTRACE_O_TRACEVFORK (1 << PTRACE_EVENT_VFORK)
  60. #define PTRACE_O_TRACECLONE (1 << PTRACE_EVENT_CLONE)
  61. #define PTRACE_O_TRACEEXEC (1 << PTRACE_EVENT_EXEC)
  62. #define PTRACE_O_TRACEVFORKDONE (1 << PTRACE_EVENT_VFORK_DONE)
  63. #define PTRACE_O_TRACEEXIT (1 << PTRACE_EVENT_EXIT)
  64. #define PTRACE_O_TRACESECCOMP (1 << PTRACE_EVENT_SECCOMP)
  65. #define PTRACE_O_MASK 0x000000ff
  66. #include <asm/ptrace.h>
  67. #ifdef __KERNEL__
  68. /*
  69. * Ptrace flags
  70. *
  71. * The owner ship rules for task->ptrace which holds the ptrace
  72. * flags is simple. When a task is running it owns it's task->ptrace
  73. * flags. When the a task is stopped the ptracer owns task->ptrace.
  74. */
  75. #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */
  76. #define PT_PTRACED 0x00000001
  77. #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
  78. #define PT_PTRACE_CAP 0x00000004 /* ptracer can follow suid-exec */
  79. #define PT_OPT_FLAG_SHIFT 3
  80. /* PT_TRACE_* event enable flags */
  81. #define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event)))
  82. #define PT_TRACESYSGOOD PT_EVENT_FLAG(0)
  83. #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK)
  84. #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK)
  85. #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE)
  86. #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC)
  87. #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE)
  88. #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT)
  89. #define PT_TRACE_SECCOMP PT_EVENT_FLAG(PTRACE_EVENT_SECCOMP)
  90. /* single stepping state bits (used on ARM and PA-RISC) */
  91. #define PT_SINGLESTEP_BIT 31
  92. #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
  93. #define PT_BLOCKSTEP_BIT 30
  94. #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
  95. #include <linux/compiler.h> /* For unlikely. */
  96. #include <linux/sched.h> /* For struct task_struct. */
  97. #include <linux/err.h> /* for IS_ERR_VALUE */
  98. #include <linux/bug.h> /* For BUG_ON. */
  99. extern long arch_ptrace(struct task_struct *child, long request,
  100. unsigned long addr, unsigned long data);
  101. extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
  102. extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
  103. extern void ptrace_disable(struct task_struct *);
  104. extern int ptrace_check_attach(struct task_struct *task, bool ignore_state);
  105. extern int ptrace_request(struct task_struct *child, long request,
  106. unsigned long addr, unsigned long data);
  107. extern void ptrace_notify(int exit_code);
  108. extern void __ptrace_link(struct task_struct *child,
  109. struct task_struct *new_parent);
  110. extern void __ptrace_unlink(struct task_struct *child);
  111. extern void exit_ptrace(struct task_struct *tracer);
  112. #define PTRACE_MODE_READ 0x01
  113. #define PTRACE_MODE_ATTACH 0x02
  114. #define PTRACE_MODE_NOAUDIT 0x04
  115. /* Returns 0 on success, -errno on denial. */
  116. extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
  117. /* Returns true on success, false on denial. */
  118. extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
  119. static inline int ptrace_reparented(struct task_struct *child)
  120. {
  121. return !same_thread_group(child->real_parent, child->parent);
  122. }
  123. static inline void ptrace_unlink(struct task_struct *child)
  124. {
  125. if (unlikely(child->ptrace))
  126. __ptrace_unlink(child);
  127. }
  128. int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
  129. unsigned long data);
  130. int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
  131. unsigned long data);
  132. /**
  133. * ptrace_parent - return the task that is tracing the given task
  134. * @task: task to consider
  135. *
  136. * Returns %NULL if no one is tracing @task, or the &struct task_struct
  137. * pointer to its tracer.
  138. *
  139. * Must called under rcu_read_lock(). The pointer returned might be kept
  140. * live only by RCU. During exec, this may be called with task_lock() held
  141. * on @task, still held from when check_unsafe_exec() was called.
  142. */
  143. static inline struct task_struct *ptrace_parent(struct task_struct *task)
  144. {
  145. if (unlikely(task->ptrace))
  146. return rcu_dereference(task->parent);
  147. return NULL;
  148. }
  149. /**
  150. * ptrace_event_enabled - test whether a ptrace event is enabled
  151. * @task: ptracee of interest
  152. * @event: %PTRACE_EVENT_* to test
  153. *
  154. * Test whether @event is enabled for ptracee @task.
  155. *
  156. * Returns %true if @event is enabled, %false otherwise.
  157. */
  158. static inline bool ptrace_event_enabled(struct task_struct *task, int event)
  159. {
  160. return task->ptrace & PT_EVENT_FLAG(event);
  161. }
  162. /**
  163. * ptrace_event - possibly stop for a ptrace event notification
  164. * @event: %PTRACE_EVENT_* value to report
  165. * @message: value for %PTRACE_GETEVENTMSG to return
  166. *
  167. * Check whether @event is enabled and, if so, report @event and @message
  168. * to the ptrace parent.
  169. *
  170. * Called without locks.
  171. */
  172. static inline void ptrace_event(int event, unsigned long message)
  173. {
  174. if (unlikely(ptrace_event_enabled(current, event))) {
  175. current->ptrace_message = message;
  176. ptrace_notify((event << 8) | SIGTRAP);
  177. } else if (event == PTRACE_EVENT_EXEC) {
  178. /* legacy EXEC report via SIGTRAP */
  179. if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED)
  180. send_sig(SIGTRAP, current, 0);
  181. }
  182. }
  183. /**
  184. * ptrace_init_task - initialize ptrace state for a new child
  185. * @child: new child task
  186. * @ptrace: true if child should be ptrace'd by parent's tracer
  187. *
  188. * This is called immediately after adding @child to its parent's children
  189. * list. @ptrace is false in the normal case, and true to ptrace @child.
  190. *
  191. * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
  192. */
  193. static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
  194. {
  195. INIT_LIST_HEAD(&child->ptrace_entry);
  196. INIT_LIST_HEAD(&child->ptraced);
  197. #ifdef CONFIG_HAVE_HW_BREAKPOINT
  198. atomic_set(&child->ptrace_bp_refcnt, 1);
  199. #endif
  200. child->jobctl = 0;
  201. child->ptrace = 0;
  202. child->parent = child->real_parent;
  203. if (unlikely(ptrace) && current->ptrace) {
  204. child->ptrace = current->ptrace;
  205. __ptrace_link(child, current->parent);
  206. if (child->ptrace & PT_SEIZED)
  207. task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
  208. else
  209. sigaddset(&child->pending.signal, SIGSTOP);
  210. set_tsk_thread_flag(child, TIF_SIGPENDING);
  211. }
  212. }
  213. /**
  214. * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
  215. * @task: task in %EXIT_DEAD state
  216. *
  217. * Called with write_lock(&tasklist_lock) held.
  218. */
  219. static inline void ptrace_release_task(struct task_struct *task)
  220. {
  221. BUG_ON(!list_empty(&task->ptraced));
  222. ptrace_unlink(task);
  223. BUG_ON(!list_empty(&task->ptrace_entry));
  224. }
  225. #ifndef force_successful_syscall_return
  226. /*
  227. * System call handlers that, upon successful completion, need to return a
  228. * negative value should call force_successful_syscall_return() right before
  229. * returning. On architectures where the syscall convention provides for a
  230. * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
  231. * others), this macro can be used to ensure that the error flag will not get
  232. * set. On architectures which do not support a separate error flag, the macro
  233. * is a no-op and the spurious error condition needs to be filtered out by some
  234. * other means (e.g., in user-level, by passing an extra argument to the
  235. * syscall handler, or something along those lines).
  236. */
  237. #define force_successful_syscall_return() do { } while (0)
  238. #endif
  239. #ifndef is_syscall_success
  240. /*
  241. * On most systems we can tell if a syscall is a success based on if the retval
  242. * is an error value. On some systems like ia64 and powerpc they have different
  243. * indicators of success/failure and must define their own.
  244. */
  245. #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs))))
  246. #endif
  247. /*
  248. * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
  249. *
  250. * These do-nothing inlines are used when the arch does not
  251. * implement single-step. The kerneldoc comments are here
  252. * to document the interface for all arch definitions.
  253. */
  254. #ifndef arch_has_single_step
  255. /**
  256. * arch_has_single_step - does this CPU support user-mode single-step?
  257. *
  258. * If this is defined, then there must be function declarations or
  259. * inlines for user_enable_single_step() and user_disable_single_step().
  260. * arch_has_single_step() should evaluate to nonzero iff the machine
  261. * supports instruction single-step for user mode.
  262. * It can be a constant or it can test a CPU feature bit.
  263. */
  264. #define arch_has_single_step() (0)
  265. /**
  266. * user_enable_single_step - single-step in user-mode task
  267. * @task: either current or a task stopped in %TASK_TRACED
  268. *
  269. * This can only be called when arch_has_single_step() has returned nonzero.
  270. * Set @task so that when it returns to user mode, it will trap after the
  271. * next single instruction executes. If arch_has_block_step() is defined,
  272. * this must clear the effects of user_enable_block_step() too.
  273. */
  274. static inline void user_enable_single_step(struct task_struct *task)
  275. {
  276. BUG(); /* This can never be called. */
  277. }
  278. /**
  279. * user_disable_single_step - cancel user-mode single-step
  280. * @task: either current or a task stopped in %TASK_TRACED
  281. *
  282. * Clear @task of the effects of user_enable_single_step() and
  283. * user_enable_block_step(). This can be called whether or not either
  284. * of those was ever called on @task, and even if arch_has_single_step()
  285. * returned zero.
  286. */
  287. static inline void user_disable_single_step(struct task_struct *task)
  288. {
  289. }
  290. #else
  291. extern void user_enable_single_step(struct task_struct *);
  292. extern void user_disable_single_step(struct task_struct *);
  293. #endif /* arch_has_single_step */
  294. #ifndef arch_has_block_step
  295. /**
  296. * arch_has_block_step - does this CPU support user-mode block-step?
  297. *
  298. * If this is defined, then there must be a function declaration or inline
  299. * for user_enable_block_step(), and arch_has_single_step() must be defined
  300. * too. arch_has_block_step() should evaluate to nonzero iff the machine
  301. * supports step-until-branch for user mode. It can be a constant or it
  302. * can test a CPU feature bit.
  303. */
  304. #define arch_has_block_step() (0)
  305. /**
  306. * user_enable_block_step - step until branch in user-mode task
  307. * @task: either current or a task stopped in %TASK_TRACED
  308. *
  309. * This can only be called when arch_has_block_step() has returned nonzero,
  310. * and will never be called when single-instruction stepping is being used.
  311. * Set @task so that when it returns to user mode, it will trap after the
  312. * next branch or trap taken.
  313. */
  314. static inline void user_enable_block_step(struct task_struct *task)
  315. {
  316. BUG(); /* This can never be called. */
  317. }
  318. #else
  319. extern void user_enable_block_step(struct task_struct *);
  320. #endif /* arch_has_block_step */
  321. #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
  322. extern void user_single_step_siginfo(struct task_struct *tsk,
  323. struct pt_regs *regs, siginfo_t *info);
  324. #else
  325. static inline void user_single_step_siginfo(struct task_struct *tsk,
  326. struct pt_regs *regs, siginfo_t *info)
  327. {
  328. memset(info, 0, sizeof(*info));
  329. info->si_signo = SIGTRAP;
  330. }
  331. #endif
  332. #ifndef arch_ptrace_stop_needed
  333. /**
  334. * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
  335. * @code: current->exit_code value ptrace will stop with
  336. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  337. *
  338. * This is called with the siglock held, to decide whether or not it's
  339. * necessary to release the siglock and call arch_ptrace_stop() with the
  340. * same @code and @info arguments. It can be defined to a constant if
  341. * arch_ptrace_stop() is never required, or always is. On machines where
  342. * this makes sense, it should be defined to a quick test to optimize out
  343. * calling arch_ptrace_stop() when it would be superfluous. For example,
  344. * if the thread has not been back to user mode since the last stop, the
  345. * thread state might indicate that nothing needs to be done.
  346. *
  347. * This is guaranteed to be invoked once before a task stops for ptrace and
  348. * may include arch-specific operations necessary prior to a ptrace stop.
  349. */
  350. #define arch_ptrace_stop_needed(code, info) (0)
  351. #endif
  352. #ifndef arch_ptrace_stop
  353. /**
  354. * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
  355. * @code: current->exit_code value ptrace will stop with
  356. * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
  357. *
  358. * This is called with no locks held when arch_ptrace_stop_needed() has
  359. * just returned nonzero. It is allowed to block, e.g. for user memory
  360. * access. The arch can have machine-specific work to be done before
  361. * ptrace stops. On ia64, register backing store gets written back to user
  362. * memory here. Since this can be costly (requires dropping the siglock),
  363. * we only do it when the arch requires it for this particular stop, as
  364. * indicated by arch_ptrace_stop_needed().
  365. */
  366. #define arch_ptrace_stop(code, info) do { } while (0)
  367. #endif
  368. extern int task_current_syscall(struct task_struct *target, long *callno,
  369. unsigned long args[6], unsigned int maxargs,
  370. unsigned long *sp, unsigned long *pc);
  371. #ifdef CONFIG_HAVE_HW_BREAKPOINT
  372. extern int ptrace_get_breakpoints(struct task_struct *tsk);
  373. extern void ptrace_put_breakpoints(struct task_struct *tsk);
  374. #else
  375. static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
  376. #endif /* CONFIG_HAVE_HW_BREAKPOINT */
  377. #endif /* __KERNEL */
  378. #endif