signal.h 12 KB

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  1. #ifndef _LINUX_SIGNAL_H
  2. #define _LINUX_SIGNAL_H
  3. #include <linux/bug.h>
  4. #include <linux/signal_types.h>
  5. #include <linux/string.h>
  6. struct task_struct;
  7. /* for sysctl */
  8. extern int print_fatal_signals;
  9. static inline void copy_siginfo(struct siginfo *to, struct siginfo *from)
  10. {
  11. if (from->si_code < 0)
  12. memcpy(to, from, sizeof(*to));
  13. else
  14. /* _sigchld is currently the largest know union member */
  15. memcpy(to, from, __ARCH_SI_PREAMBLE_SIZE + sizeof(from->_sifields._sigchld));
  16. }
  17. int copy_siginfo_to_user(struct siginfo __user *to, const struct siginfo *from);
  18. enum siginfo_layout {
  19. SIL_KILL,
  20. SIL_TIMER,
  21. SIL_POLL,
  22. SIL_FAULT,
  23. SIL_CHLD,
  24. SIL_RT,
  25. #ifdef __ARCH_SIGSYS
  26. SIL_SYS,
  27. #endif
  28. };
  29. enum siginfo_layout siginfo_layout(int sig, int si_code);
  30. /*
  31. * Define some primitives to manipulate sigset_t.
  32. */
  33. #ifndef __HAVE_ARCH_SIG_BITOPS
  34. #include <linux/bitops.h>
  35. /* We don't use <linux/bitops.h> for these because there is no need to
  36. be atomic. */
  37. static inline void sigaddset(sigset_t *set, int _sig)
  38. {
  39. unsigned long sig = _sig - 1;
  40. if (_NSIG_WORDS == 1)
  41. set->sig[0] |= 1UL << sig;
  42. else
  43. set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW);
  44. }
  45. static inline void sigdelset(sigset_t *set, int _sig)
  46. {
  47. unsigned long sig = _sig - 1;
  48. if (_NSIG_WORDS == 1)
  49. set->sig[0] &= ~(1UL << sig);
  50. else
  51. set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW));
  52. }
  53. static inline int sigismember(sigset_t *set, int _sig)
  54. {
  55. unsigned long sig = _sig - 1;
  56. if (_NSIG_WORDS == 1)
  57. return 1 & (set->sig[0] >> sig);
  58. else
  59. return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
  60. }
  61. #endif /* __HAVE_ARCH_SIG_BITOPS */
  62. static inline int sigisemptyset(sigset_t *set)
  63. {
  64. switch (_NSIG_WORDS) {
  65. case 4:
  66. return (set->sig[3] | set->sig[2] |
  67. set->sig[1] | set->sig[0]) == 0;
  68. case 2:
  69. return (set->sig[1] | set->sig[0]) == 0;
  70. case 1:
  71. return set->sig[0] == 0;
  72. default:
  73. BUILD_BUG();
  74. return 0;
  75. }
  76. }
  77. static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2)
  78. {
  79. switch (_NSIG_WORDS) {
  80. case 4:
  81. return (set1->sig[3] == set2->sig[3]) &&
  82. (set1->sig[2] == set2->sig[2]) &&
  83. (set1->sig[1] == set2->sig[1]) &&
  84. (set1->sig[0] == set2->sig[0]);
  85. case 2:
  86. return (set1->sig[1] == set2->sig[1]) &&
  87. (set1->sig[0] == set2->sig[0]);
  88. case 1:
  89. return set1->sig[0] == set2->sig[0];
  90. }
  91. return 0;
  92. }
  93. #define sigmask(sig) (1UL << ((sig) - 1))
  94. #ifndef __HAVE_ARCH_SIG_SETOPS
  95. #include <linux/string.h>
  96. #define _SIG_SET_BINOP(name, op) \
  97. static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
  98. { \
  99. unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \
  100. \
  101. switch (_NSIG_WORDS) { \
  102. case 4: \
  103. a3 = a->sig[3]; a2 = a->sig[2]; \
  104. b3 = b->sig[3]; b2 = b->sig[2]; \
  105. r->sig[3] = op(a3, b3); \
  106. r->sig[2] = op(a2, b2); \
  107. case 2: \
  108. a1 = a->sig[1]; b1 = b->sig[1]; \
  109. r->sig[1] = op(a1, b1); \
  110. case 1: \
  111. a0 = a->sig[0]; b0 = b->sig[0]; \
  112. r->sig[0] = op(a0, b0); \
  113. break; \
  114. default: \
  115. BUILD_BUG(); \
  116. } \
  117. }
  118. #define _sig_or(x,y) ((x) | (y))
  119. _SIG_SET_BINOP(sigorsets, _sig_or)
  120. #define _sig_and(x,y) ((x) & (y))
  121. _SIG_SET_BINOP(sigandsets, _sig_and)
  122. #define _sig_andn(x,y) ((x) & ~(y))
  123. _SIG_SET_BINOP(sigandnsets, _sig_andn)
  124. #undef _SIG_SET_BINOP
  125. #undef _sig_or
  126. #undef _sig_and
  127. #undef _sig_andn
  128. #define _SIG_SET_OP(name, op) \
  129. static inline void name(sigset_t *set) \
  130. { \
  131. switch (_NSIG_WORDS) { \
  132. case 4: set->sig[3] = op(set->sig[3]); \
  133. set->sig[2] = op(set->sig[2]); \
  134. case 2: set->sig[1] = op(set->sig[1]); \
  135. case 1: set->sig[0] = op(set->sig[0]); \
  136. break; \
  137. default: \
  138. BUILD_BUG(); \
  139. } \
  140. }
  141. #define _sig_not(x) (~(x))
  142. _SIG_SET_OP(signotset, _sig_not)
  143. #undef _SIG_SET_OP
  144. #undef _sig_not
  145. static inline void sigemptyset(sigset_t *set)
  146. {
  147. switch (_NSIG_WORDS) {
  148. default:
  149. memset(set, 0, sizeof(sigset_t));
  150. break;
  151. case 2: set->sig[1] = 0;
  152. case 1: set->sig[0] = 0;
  153. break;
  154. }
  155. }
  156. static inline void sigfillset(sigset_t *set)
  157. {
  158. switch (_NSIG_WORDS) {
  159. default:
  160. memset(set, -1, sizeof(sigset_t));
  161. break;
  162. case 2: set->sig[1] = -1;
  163. case 1: set->sig[0] = -1;
  164. break;
  165. }
  166. }
  167. /* Some extensions for manipulating the low 32 signals in particular. */
  168. static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
  169. {
  170. set->sig[0] |= mask;
  171. }
  172. static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
  173. {
  174. set->sig[0] &= ~mask;
  175. }
  176. static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
  177. {
  178. return (set->sig[0] & mask) != 0;
  179. }
  180. static inline void siginitset(sigset_t *set, unsigned long mask)
  181. {
  182. set->sig[0] = mask;
  183. switch (_NSIG_WORDS) {
  184. default:
  185. memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
  186. break;
  187. case 2: set->sig[1] = 0;
  188. case 1: ;
  189. }
  190. }
  191. static inline void siginitsetinv(sigset_t *set, unsigned long mask)
  192. {
  193. set->sig[0] = ~mask;
  194. switch (_NSIG_WORDS) {
  195. default:
  196. memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
  197. break;
  198. case 2: set->sig[1] = -1;
  199. case 1: ;
  200. }
  201. }
  202. #endif /* __HAVE_ARCH_SIG_SETOPS */
  203. static inline void init_sigpending(struct sigpending *sig)
  204. {
  205. sigemptyset(&sig->signal);
  206. INIT_LIST_HEAD(&sig->list);
  207. }
  208. extern void flush_sigqueue(struct sigpending *queue);
  209. /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
  210. static inline int valid_signal(unsigned long sig)
  211. {
  212. return sig <= _NSIG ? 1 : 0;
  213. }
  214. struct timespec;
  215. struct pt_regs;
  216. extern int next_signal(struct sigpending *pending, sigset_t *mask);
  217. extern int do_send_sig_info(int sig, struct siginfo *info,
  218. struct task_struct *p, bool group);
  219. extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
  220. extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
  221. extern int sigprocmask(int, sigset_t *, sigset_t *);
  222. extern void set_current_blocked(sigset_t *);
  223. extern void __set_current_blocked(const sigset_t *);
  224. extern int show_unhandled_signals;
  225. extern int get_signal(struct ksignal *ksig);
  226. extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
  227. extern void exit_signals(struct task_struct *tsk);
  228. extern void kernel_sigaction(int, __sighandler_t);
  229. static inline void allow_signal(int sig)
  230. {
  231. /*
  232. * Kernel threads handle their own signals. Let the signal code
  233. * know it'll be handled, so that they don't get converted to
  234. * SIGKILL or just silently dropped.
  235. */
  236. kernel_sigaction(sig, (__force __sighandler_t)2);
  237. }
  238. static inline void disallow_signal(int sig)
  239. {
  240. kernel_sigaction(sig, SIG_IGN);
  241. }
  242. extern struct kmem_cache *sighand_cachep;
  243. int unhandled_signal(struct task_struct *tsk, int sig);
  244. /*
  245. * In POSIX a signal is sent either to a specific thread (Linux task)
  246. * or to the process as a whole (Linux thread group). How the signal
  247. * is sent determines whether it's to one thread or the whole group,
  248. * which determines which signal mask(s) are involved in blocking it
  249. * from being delivered until later. When the signal is delivered,
  250. * either it's caught or ignored by a user handler or it has a default
  251. * effect that applies to the whole thread group (POSIX process).
  252. *
  253. * The possible effects an unblocked signal set to SIG_DFL can have are:
  254. * ignore - Nothing Happens
  255. * terminate - kill the process, i.e. all threads in the group,
  256. * similar to exit_group. The group leader (only) reports
  257. * WIFSIGNALED status to its parent.
  258. * coredump - write a core dump file describing all threads using
  259. * the same mm and then kill all those threads
  260. * stop - stop all the threads in the group, i.e. TASK_STOPPED state
  261. *
  262. * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
  263. * Other signals when not blocked and set to SIG_DFL behaves as follows.
  264. * The job control signals also have other special effects.
  265. *
  266. * +--------------------+------------------+
  267. * | POSIX signal | default action |
  268. * +--------------------+------------------+
  269. * | SIGHUP | terminate |
  270. * | SIGINT | terminate |
  271. * | SIGQUIT | coredump |
  272. * | SIGILL | coredump |
  273. * | SIGTRAP | coredump |
  274. * | SIGABRT/SIGIOT | coredump |
  275. * | SIGBUS | coredump |
  276. * | SIGFPE | coredump |
  277. * | SIGKILL | terminate(+) |
  278. * | SIGUSR1 | terminate |
  279. * | SIGSEGV | coredump |
  280. * | SIGUSR2 | terminate |
  281. * | SIGPIPE | terminate |
  282. * | SIGALRM | terminate |
  283. * | SIGTERM | terminate |
  284. * | SIGCHLD | ignore |
  285. * | SIGCONT | ignore(*) |
  286. * | SIGSTOP | stop(*)(+) |
  287. * | SIGTSTP | stop(*) |
  288. * | SIGTTIN | stop(*) |
  289. * | SIGTTOU | stop(*) |
  290. * | SIGURG | ignore |
  291. * | SIGXCPU | coredump |
  292. * | SIGXFSZ | coredump |
  293. * | SIGVTALRM | terminate |
  294. * | SIGPROF | terminate |
  295. * | SIGPOLL/SIGIO | terminate |
  296. * | SIGSYS/SIGUNUSED | coredump |
  297. * | SIGSTKFLT | terminate |
  298. * | SIGWINCH | ignore |
  299. * | SIGPWR | terminate |
  300. * | SIGRTMIN-SIGRTMAX | terminate |
  301. * +--------------------+------------------+
  302. * | non-POSIX signal | default action |
  303. * +--------------------+------------------+
  304. * | SIGEMT | coredump |
  305. * +--------------------+------------------+
  306. *
  307. * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
  308. * (*) Special job control effects:
  309. * When SIGCONT is sent, it resumes the process (all threads in the group)
  310. * from TASK_STOPPED state and also clears any pending/queued stop signals
  311. * (any of those marked with "stop(*)"). This happens regardless of blocking,
  312. * catching, or ignoring SIGCONT. When any stop signal is sent, it clears
  313. * any pending/queued SIGCONT signals; this happens regardless of blocking,
  314. * catching, or ignored the stop signal, though (except for SIGSTOP) the
  315. * default action of stopping the process may happen later or never.
  316. */
  317. #ifdef SIGEMT
  318. #define SIGEMT_MASK rt_sigmask(SIGEMT)
  319. #else
  320. #define SIGEMT_MASK 0
  321. #endif
  322. #if SIGRTMIN > BITS_PER_LONG
  323. #define rt_sigmask(sig) (1ULL << ((sig)-1))
  324. #else
  325. #define rt_sigmask(sig) sigmask(sig)
  326. #endif
  327. #define siginmask(sig, mask) \
  328. ((sig) < SIGRTMIN && (rt_sigmask(sig) & (mask)))
  329. #define SIG_KERNEL_ONLY_MASK (\
  330. rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP))
  331. #define SIG_KERNEL_STOP_MASK (\
  332. rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \
  333. rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) )
  334. #define SIG_KERNEL_COREDUMP_MASK (\
  335. rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \
  336. rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \
  337. rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \
  338. rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \
  339. rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \
  340. SIGEMT_MASK )
  341. #define SIG_KERNEL_IGNORE_MASK (\
  342. rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \
  343. rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) )
  344. #define SIG_SPECIFIC_SICODES_MASK (\
  345. rt_sigmask(SIGILL) | rt_sigmask(SIGFPE) | \
  346. rt_sigmask(SIGSEGV) | rt_sigmask(SIGBUS) | \
  347. rt_sigmask(SIGTRAP) | rt_sigmask(SIGCHLD) | \
  348. rt_sigmask(SIGPOLL) | rt_sigmask(SIGSYS) | \
  349. SIGEMT_MASK )
  350. #define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK)
  351. #define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK)
  352. #define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK)
  353. #define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK)
  354. #define sig_specific_sicodes(sig) siginmask(sig, SIG_SPECIFIC_SICODES_MASK)
  355. #define sig_fatal(t, signr) \
  356. (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
  357. (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
  358. void signals_init(void);
  359. int restore_altstack(const stack_t __user *);
  360. int __save_altstack(stack_t __user *, unsigned long);
  361. #define save_altstack_ex(uss, sp) do { \
  362. stack_t __user *__uss = uss; \
  363. struct task_struct *t = current; \
  364. put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \
  365. put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \
  366. put_user_ex(t->sas_ss_size, &__uss->ss_size); \
  367. if (t->sas_ss_flags & SS_AUTODISARM) \
  368. sas_ss_reset(t); \
  369. } while (0);
  370. #ifdef CONFIG_PROC_FS
  371. struct seq_file;
  372. extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
  373. #endif
  374. #endif /* _LINUX_SIGNAL_H */