signal.h 12 KB

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  1. #ifndef _LINUX_SIGNAL_H
  2. #define _LINUX_SIGNAL_H
  3. #include <linux/list.h>
  4. #include <linux/bug.h>
  5. #include <uapi/linux/signal.h>
  6. struct task_struct;
  7. /* for sysctl */
  8. extern int print_fatal_signals;
  9. /*
  10. * Real Time signals may be queued.
  11. */
  12. struct sigqueue {
  13. struct list_head list;
  14. int flags;
  15. siginfo_t info;
  16. struct user_struct *user;
  17. };
  18. /* flags values. */
  19. #define SIGQUEUE_PREALLOC 1
  20. struct sigpending {
  21. struct list_head list;
  22. sigset_t signal;
  23. };
  24. /*
  25. * Define some primitives to manipulate sigset_t.
  26. */
  27. #ifndef __HAVE_ARCH_SIG_BITOPS
  28. #include <linux/bitops.h>
  29. /* We don't use <linux/bitops.h> for these because there is no need to
  30. be atomic. */
  31. static inline void sigaddset(sigset_t *set, int _sig)
  32. {
  33. unsigned long sig = _sig - 1;
  34. if (_NSIG_WORDS == 1)
  35. set->sig[0] |= 1UL << sig;
  36. else
  37. set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW);
  38. }
  39. static inline void sigdelset(sigset_t *set, int _sig)
  40. {
  41. unsigned long sig = _sig - 1;
  42. if (_NSIG_WORDS == 1)
  43. set->sig[0] &= ~(1UL << sig);
  44. else
  45. set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW));
  46. }
  47. static inline int sigismember(sigset_t *set, int _sig)
  48. {
  49. unsigned long sig = _sig - 1;
  50. if (_NSIG_WORDS == 1)
  51. return 1 & (set->sig[0] >> sig);
  52. else
  53. return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
  54. }
  55. #endif /* __HAVE_ARCH_SIG_BITOPS */
  56. static inline int sigisemptyset(sigset_t *set)
  57. {
  58. switch (_NSIG_WORDS) {
  59. case 4:
  60. return (set->sig[3] | set->sig[2] |
  61. set->sig[1] | set->sig[0]) == 0;
  62. case 2:
  63. return (set->sig[1] | set->sig[0]) == 0;
  64. case 1:
  65. return set->sig[0] == 0;
  66. default:
  67. BUILD_BUG();
  68. return 0;
  69. }
  70. }
  71. #define sigmask(sig) (1UL << ((sig) - 1))
  72. #ifndef __HAVE_ARCH_SIG_SETOPS
  73. #include <linux/string.h>
  74. #define _SIG_SET_BINOP(name, op) \
  75. static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
  76. { \
  77. unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \
  78. \
  79. switch (_NSIG_WORDS) { \
  80. case 4: \
  81. a3 = a->sig[3]; a2 = a->sig[2]; \
  82. b3 = b->sig[3]; b2 = b->sig[2]; \
  83. r->sig[3] = op(a3, b3); \
  84. r->sig[2] = op(a2, b2); \
  85. case 2: \
  86. a1 = a->sig[1]; b1 = b->sig[1]; \
  87. r->sig[1] = op(a1, b1); \
  88. case 1: \
  89. a0 = a->sig[0]; b0 = b->sig[0]; \
  90. r->sig[0] = op(a0, b0); \
  91. break; \
  92. default: \
  93. BUILD_BUG(); \
  94. } \
  95. }
  96. #define _sig_or(x,y) ((x) | (y))
  97. _SIG_SET_BINOP(sigorsets, _sig_or)
  98. #define _sig_and(x,y) ((x) & (y))
  99. _SIG_SET_BINOP(sigandsets, _sig_and)
  100. #define _sig_andn(x,y) ((x) & ~(y))
  101. _SIG_SET_BINOP(sigandnsets, _sig_andn)
  102. #undef _SIG_SET_BINOP
  103. #undef _sig_or
  104. #undef _sig_and
  105. #undef _sig_andn
  106. #define _SIG_SET_OP(name, op) \
  107. static inline void name(sigset_t *set) \
  108. { \
  109. switch (_NSIG_WORDS) { \
  110. case 4: set->sig[3] = op(set->sig[3]); \
  111. set->sig[2] = op(set->sig[2]); \
  112. case 2: set->sig[1] = op(set->sig[1]); \
  113. case 1: set->sig[0] = op(set->sig[0]); \
  114. break; \
  115. default: \
  116. BUILD_BUG(); \
  117. } \
  118. }
  119. #define _sig_not(x) (~(x))
  120. _SIG_SET_OP(signotset, _sig_not)
  121. #undef _SIG_SET_OP
  122. #undef _sig_not
  123. static inline void sigemptyset(sigset_t *set)
  124. {
  125. switch (_NSIG_WORDS) {
  126. default:
  127. memset(set, 0, sizeof(sigset_t));
  128. break;
  129. case 2: set->sig[1] = 0;
  130. case 1: set->sig[0] = 0;
  131. break;
  132. }
  133. }
  134. static inline void sigfillset(sigset_t *set)
  135. {
  136. switch (_NSIG_WORDS) {
  137. default:
  138. memset(set, -1, sizeof(sigset_t));
  139. break;
  140. case 2: set->sig[1] = -1;
  141. case 1: set->sig[0] = -1;
  142. break;
  143. }
  144. }
  145. /* Some extensions for manipulating the low 32 signals in particular. */
  146. static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
  147. {
  148. set->sig[0] |= mask;
  149. }
  150. static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
  151. {
  152. set->sig[0] &= ~mask;
  153. }
  154. static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
  155. {
  156. return (set->sig[0] & mask) != 0;
  157. }
  158. static inline void siginitset(sigset_t *set, unsigned long mask)
  159. {
  160. set->sig[0] = mask;
  161. switch (_NSIG_WORDS) {
  162. default:
  163. memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
  164. break;
  165. case 2: set->sig[1] = 0;
  166. case 1: ;
  167. }
  168. }
  169. static inline void siginitsetinv(sigset_t *set, unsigned long mask)
  170. {
  171. set->sig[0] = ~mask;
  172. switch (_NSIG_WORDS) {
  173. default:
  174. memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
  175. break;
  176. case 2: set->sig[1] = -1;
  177. case 1: ;
  178. }
  179. }
  180. #endif /* __HAVE_ARCH_SIG_SETOPS */
  181. static inline void init_sigpending(struct sigpending *sig)
  182. {
  183. sigemptyset(&sig->signal);
  184. INIT_LIST_HEAD(&sig->list);
  185. }
  186. extern void flush_sigqueue(struct sigpending *queue);
  187. /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
  188. static inline int valid_signal(unsigned long sig)
  189. {
  190. return sig <= _NSIG ? 1 : 0;
  191. }
  192. struct timespec;
  193. struct pt_regs;
  194. extern int next_signal(struct sigpending *pending, sigset_t *mask);
  195. extern int do_send_sig_info(int sig, struct siginfo *info,
  196. struct task_struct *p, bool group);
  197. extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
  198. extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
  199. extern int do_sigtimedwait(const sigset_t *, siginfo_t *,
  200. const struct timespec *);
  201. extern int sigprocmask(int, sigset_t *, sigset_t *);
  202. extern void set_current_blocked(sigset_t *);
  203. extern void __set_current_blocked(const sigset_t *);
  204. extern int show_unhandled_signals;
  205. extern int sigsuspend(sigset_t *);
  206. struct sigaction {
  207. #ifndef __ARCH_HAS_IRIX_SIGACTION
  208. __sighandler_t sa_handler;
  209. unsigned long sa_flags;
  210. #else
  211. unsigned int sa_flags;
  212. __sighandler_t sa_handler;
  213. #endif
  214. #ifdef __ARCH_HAS_SA_RESTORER
  215. __sigrestore_t sa_restorer;
  216. #endif
  217. sigset_t sa_mask; /* mask last for extensibility */
  218. };
  219. struct k_sigaction {
  220. struct sigaction sa;
  221. #ifdef __ARCH_HAS_KA_RESTORER
  222. __sigrestore_t ka_restorer;
  223. #endif
  224. };
  225. #ifdef CONFIG_OLD_SIGACTION
  226. struct old_sigaction {
  227. __sighandler_t sa_handler;
  228. old_sigset_t sa_mask;
  229. unsigned long sa_flags;
  230. __sigrestore_t sa_restorer;
  231. };
  232. #endif
  233. struct ksignal {
  234. struct k_sigaction ka;
  235. siginfo_t info;
  236. int sig;
  237. };
  238. extern int get_signal(struct ksignal *ksig);
  239. extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
  240. extern void exit_signals(struct task_struct *tsk);
  241. extern void kernel_sigaction(int, __sighandler_t);
  242. static inline void allow_signal(int sig)
  243. {
  244. /*
  245. * Kernel threads handle their own signals. Let the signal code
  246. * know it'll be handled, so that they don't get converted to
  247. * SIGKILL or just silently dropped.
  248. */
  249. kernel_sigaction(sig, (__force __sighandler_t)2);
  250. }
  251. static inline void disallow_signal(int sig)
  252. {
  253. kernel_sigaction(sig, SIG_IGN);
  254. }
  255. extern struct kmem_cache *sighand_cachep;
  256. int unhandled_signal(struct task_struct *tsk, int sig);
  257. /*
  258. * In POSIX a signal is sent either to a specific thread (Linux task)
  259. * or to the process as a whole (Linux thread group). How the signal
  260. * is sent determines whether it's to one thread or the whole group,
  261. * which determines which signal mask(s) are involved in blocking it
  262. * from being delivered until later. When the signal is delivered,
  263. * either it's caught or ignored by a user handler or it has a default
  264. * effect that applies to the whole thread group (POSIX process).
  265. *
  266. * The possible effects an unblocked signal set to SIG_DFL can have are:
  267. * ignore - Nothing Happens
  268. * terminate - kill the process, i.e. all threads in the group,
  269. * similar to exit_group. The group leader (only) reports
  270. * WIFSIGNALED status to its parent.
  271. * coredump - write a core dump file describing all threads using
  272. * the same mm and then kill all those threads
  273. * stop - stop all the threads in the group, i.e. TASK_STOPPED state
  274. *
  275. * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
  276. * Other signals when not blocked and set to SIG_DFL behaves as follows.
  277. * The job control signals also have other special effects.
  278. *
  279. * +--------------------+------------------+
  280. * | POSIX signal | default action |
  281. * +--------------------+------------------+
  282. * | SIGHUP | terminate |
  283. * | SIGINT | terminate |
  284. * | SIGQUIT | coredump |
  285. * | SIGILL | coredump |
  286. * | SIGTRAP | coredump |
  287. * | SIGABRT/SIGIOT | coredump |
  288. * | SIGBUS | coredump |
  289. * | SIGFPE | coredump |
  290. * | SIGKILL | terminate(+) |
  291. * | SIGUSR1 | terminate |
  292. * | SIGSEGV | coredump |
  293. * | SIGUSR2 | terminate |
  294. * | SIGPIPE | terminate |
  295. * | SIGALRM | terminate |
  296. * | SIGTERM | terminate |
  297. * | SIGCHLD | ignore |
  298. * | SIGCONT | ignore(*) |
  299. * | SIGSTOP | stop(*)(+) |
  300. * | SIGTSTP | stop(*) |
  301. * | SIGTTIN | stop(*) |
  302. * | SIGTTOU | stop(*) |
  303. * | SIGURG | ignore |
  304. * | SIGXCPU | coredump |
  305. * | SIGXFSZ | coredump |
  306. * | SIGVTALRM | terminate |
  307. * | SIGPROF | terminate |
  308. * | SIGPOLL/SIGIO | terminate |
  309. * | SIGSYS/SIGUNUSED | coredump |
  310. * | SIGSTKFLT | terminate |
  311. * | SIGWINCH | ignore |
  312. * | SIGPWR | terminate |
  313. * | SIGRTMIN-SIGRTMAX | terminate |
  314. * +--------------------+------------------+
  315. * | non-POSIX signal | default action |
  316. * +--------------------+------------------+
  317. * | SIGEMT | coredump |
  318. * +--------------------+------------------+
  319. *
  320. * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
  321. * (*) Special job control effects:
  322. * When SIGCONT is sent, it resumes the process (all threads in the group)
  323. * from TASK_STOPPED state and also clears any pending/queued stop signals
  324. * (any of those marked with "stop(*)"). This happens regardless of blocking,
  325. * catching, or ignoring SIGCONT. When any stop signal is sent, it clears
  326. * any pending/queued SIGCONT signals; this happens regardless of blocking,
  327. * catching, or ignored the stop signal, though (except for SIGSTOP) the
  328. * default action of stopping the process may happen later or never.
  329. */
  330. #ifdef SIGEMT
  331. #define SIGEMT_MASK rt_sigmask(SIGEMT)
  332. #else
  333. #define SIGEMT_MASK 0
  334. #endif
  335. #if SIGRTMIN > BITS_PER_LONG
  336. #define rt_sigmask(sig) (1ULL << ((sig)-1))
  337. #else
  338. #define rt_sigmask(sig) sigmask(sig)
  339. #endif
  340. #define siginmask(sig, mask) (rt_sigmask(sig) & (mask))
  341. #define SIG_KERNEL_ONLY_MASK (\
  342. rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP))
  343. #define SIG_KERNEL_STOP_MASK (\
  344. rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \
  345. rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) )
  346. #define SIG_KERNEL_COREDUMP_MASK (\
  347. rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \
  348. rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \
  349. rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \
  350. rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \
  351. rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \
  352. SIGEMT_MASK )
  353. #define SIG_KERNEL_IGNORE_MASK (\
  354. rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \
  355. rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) )
  356. #define sig_kernel_only(sig) \
  357. (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
  358. #define sig_kernel_coredump(sig) \
  359. (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
  360. #define sig_kernel_ignore(sig) \
  361. (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
  362. #define sig_kernel_stop(sig) \
  363. (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))
  364. #define sig_user_defined(t, signr) \
  365. (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \
  366. ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
  367. #define sig_fatal(t, signr) \
  368. (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
  369. (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
  370. void signals_init(void);
  371. int restore_altstack(const stack_t __user *);
  372. int __save_altstack(stack_t __user *, unsigned long);
  373. #define save_altstack_ex(uss, sp) do { \
  374. stack_t __user *__uss = uss; \
  375. struct task_struct *t = current; \
  376. put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \
  377. put_user_ex(sas_ss_flags(sp), &__uss->ss_flags); \
  378. put_user_ex(t->sas_ss_size, &__uss->ss_size); \
  379. } while (0);
  380. #ifdef CONFIG_PROC_FS
  381. struct seq_file;
  382. extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
  383. #endif
  384. #endif /* _LINUX_SIGNAL_H */