signal_32.c 19 KB

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  1. /*
  2. * Copyright (C) 1991, 1992 Linus Torvalds
  3. *
  4. * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
  5. * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
  6. */
  7. #include <linux/list.h>
  8. #include <linux/personality.h>
  9. #include <linux/binfmts.h>
  10. #include <linux/suspend.h>
  11. #include <linux/kernel.h>
  12. #include <linux/ptrace.h>
  13. #include <linux/signal.h>
  14. #include <linux/stddef.h>
  15. #include <linux/unistd.h>
  16. #include <linux/errno.h>
  17. #include <linux/sched.h>
  18. #include <linux/wait.h>
  19. #include <linux/tracehook.h>
  20. #include <linux/elf.h>
  21. #include <linux/smp.h>
  22. #include <linux/mm.h>
  23. #include <asm/processor.h>
  24. #include <asm/ucontext.h>
  25. #include <asm/uaccess.h>
  26. #include <asm/i387.h>
  27. #include <asm/vdso.h>
  28. #include <asm/syscall.h>
  29. #include <asm/syscalls.h>
  30. #include "sigframe.h"
  31. #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  32. #define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \
  33. X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
  34. X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
  35. X86_EFLAGS_CF)
  36. #ifdef CONFIG_X86_32
  37. # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
  38. #else
  39. # define FIX_EFLAGS __FIX_EFLAGS
  40. #endif
  41. /*
  42. * Atomically swap in the new signal mask, and wait for a signal.
  43. */
  44. asmlinkage int
  45. sys_sigsuspend(int history0, int history1, old_sigset_t mask)
  46. {
  47. mask &= _BLOCKABLE;
  48. spin_lock_irq(&current->sighand->siglock);
  49. current->saved_sigmask = current->blocked;
  50. siginitset(&current->blocked, mask);
  51. recalc_sigpending();
  52. spin_unlock_irq(&current->sighand->siglock);
  53. current->state = TASK_INTERRUPTIBLE;
  54. schedule();
  55. set_restore_sigmask();
  56. return -ERESTARTNOHAND;
  57. }
  58. asmlinkage int
  59. sys_sigaction(int sig, const struct old_sigaction __user *act,
  60. struct old_sigaction __user *oact)
  61. {
  62. struct k_sigaction new_ka, old_ka;
  63. int ret;
  64. if (act) {
  65. old_sigset_t mask;
  66. if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
  67. __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
  68. __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
  69. return -EFAULT;
  70. __get_user(new_ka.sa.sa_flags, &act->sa_flags);
  71. __get_user(mask, &act->sa_mask);
  72. siginitset(&new_ka.sa.sa_mask, mask);
  73. }
  74. ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
  75. if (!ret && oact) {
  76. if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
  77. __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
  78. __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
  79. return -EFAULT;
  80. __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
  81. __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
  82. }
  83. return ret;
  84. }
  85. asmlinkage int sys_sigaltstack(unsigned long bx)
  86. {
  87. /*
  88. * This is needed to make gcc realize it doesn't own the
  89. * "struct pt_regs"
  90. */
  91. struct pt_regs *regs = (struct pt_regs *)&bx;
  92. const stack_t __user *uss = (const stack_t __user *)bx;
  93. stack_t __user *uoss = (stack_t __user *)regs->cx;
  94. return do_sigaltstack(uss, uoss, regs->sp);
  95. }
  96. #define COPY(x) { \
  97. err |= __get_user(regs->x, &sc->x); \
  98. }
  99. #define COPY_SEG(seg) { \
  100. unsigned short tmp; \
  101. err |= __get_user(tmp, &sc->seg); \
  102. regs->seg = tmp; \
  103. }
  104. #define COPY_SEG_STRICT(seg) { \
  105. unsigned short tmp; \
  106. err |= __get_user(tmp, &sc->seg); \
  107. regs->seg = tmp | 3; \
  108. }
  109. #define GET_SEG(seg) { \
  110. unsigned short tmp; \
  111. err |= __get_user(tmp, &sc->seg); \
  112. loadsegment(seg, tmp); \
  113. }
  114. /*
  115. * Do a signal return; undo the signal stack.
  116. */
  117. static int
  118. restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
  119. unsigned long *pax)
  120. {
  121. void __user *buf;
  122. unsigned int tmpflags;
  123. unsigned int err = 0;
  124. /* Always make any pending restarted system calls return -EINTR */
  125. current_thread_info()->restart_block.fn = do_no_restart_syscall;
  126. #ifdef CONFIG_X86_32
  127. GET_SEG(gs);
  128. COPY_SEG(fs);
  129. COPY_SEG(es);
  130. COPY_SEG(ds);
  131. #endif /* CONFIG_X86_32 */
  132. COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
  133. COPY(dx); COPY(cx); COPY(ip);
  134. #ifdef CONFIG_X86_64
  135. COPY(r8);
  136. COPY(r9);
  137. COPY(r10);
  138. COPY(r11);
  139. COPY(r12);
  140. COPY(r13);
  141. COPY(r14);
  142. COPY(r15);
  143. #endif /* CONFIG_X86_64 */
  144. #ifdef CONFIG_X86_32
  145. COPY_SEG_STRICT(cs);
  146. COPY_SEG_STRICT(ss);
  147. #else /* !CONFIG_X86_32 */
  148. /* Kernel saves and restores only the CS segment register on signals,
  149. * which is the bare minimum needed to allow mixed 32/64-bit code.
  150. * App's signal handler can save/restore other segments if needed. */
  151. COPY_SEG_STRICT(cs);
  152. #endif /* CONFIG_X86_32 */
  153. err |= __get_user(tmpflags, &sc->flags);
  154. regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
  155. regs->orig_ax = -1; /* disable syscall checks */
  156. err |= __get_user(buf, &sc->fpstate);
  157. err |= restore_i387_xstate(buf);
  158. err |= __get_user(*pax, &sc->ax);
  159. return err;
  160. }
  161. asmlinkage unsigned long sys_sigreturn(unsigned long __unused)
  162. {
  163. struct sigframe __user *frame;
  164. struct pt_regs *regs;
  165. unsigned long ax;
  166. sigset_t set;
  167. regs = (struct pt_regs *) &__unused;
  168. frame = (struct sigframe __user *)(regs->sp - 8);
  169. if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
  170. goto badframe;
  171. if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
  172. && __copy_from_user(&set.sig[1], &frame->extramask,
  173. sizeof(frame->extramask))))
  174. goto badframe;
  175. sigdelsetmask(&set, ~_BLOCKABLE);
  176. spin_lock_irq(&current->sighand->siglock);
  177. current->blocked = set;
  178. recalc_sigpending();
  179. spin_unlock_irq(&current->sighand->siglock);
  180. if (restore_sigcontext(regs, &frame->sc, &ax))
  181. goto badframe;
  182. return ax;
  183. badframe:
  184. if (show_unhandled_signals && printk_ratelimit()) {
  185. printk("%s%s[%d] bad frame in sigreturn frame:"
  186. "%p ip:%lx sp:%lx oeax:%lx",
  187. task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
  188. current->comm, task_pid_nr(current), frame, regs->ip,
  189. regs->sp, regs->orig_ax);
  190. print_vma_addr(" in ", regs->ip);
  191. printk(KERN_CONT "\n");
  192. }
  193. force_sig(SIGSEGV, current);
  194. return 0;
  195. }
  196. static long do_rt_sigreturn(struct pt_regs *regs)
  197. {
  198. struct rt_sigframe __user *frame;
  199. unsigned long ax;
  200. sigset_t set;
  201. frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
  202. if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
  203. goto badframe;
  204. if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
  205. goto badframe;
  206. sigdelsetmask(&set, ~_BLOCKABLE);
  207. spin_lock_irq(&current->sighand->siglock);
  208. current->blocked = set;
  209. recalc_sigpending();
  210. spin_unlock_irq(&current->sighand->siglock);
  211. if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
  212. goto badframe;
  213. if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
  214. goto badframe;
  215. return ax;
  216. badframe:
  217. signal_fault(regs, frame, "rt_sigreturn");
  218. return 0;
  219. }
  220. asmlinkage int sys_rt_sigreturn(unsigned long __unused)
  221. {
  222. struct pt_regs *regs = (struct pt_regs *)&__unused;
  223. return do_rt_sigreturn(regs);
  224. }
  225. /*
  226. * Set up a signal frame.
  227. */
  228. static int
  229. setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
  230. struct pt_regs *regs, unsigned long mask)
  231. {
  232. int tmp, err = 0;
  233. err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs);
  234. savesegment(gs, tmp);
  235. err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
  236. err |= __put_user(regs->es, (unsigned int __user *)&sc->es);
  237. err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds);
  238. err |= __put_user(regs->di, &sc->di);
  239. err |= __put_user(regs->si, &sc->si);
  240. err |= __put_user(regs->bp, &sc->bp);
  241. err |= __put_user(regs->sp, &sc->sp);
  242. err |= __put_user(regs->bx, &sc->bx);
  243. err |= __put_user(regs->dx, &sc->dx);
  244. err |= __put_user(regs->cx, &sc->cx);
  245. err |= __put_user(regs->ax, &sc->ax);
  246. err |= __put_user(current->thread.trap_no, &sc->trapno);
  247. err |= __put_user(current->thread.error_code, &sc->err);
  248. err |= __put_user(regs->ip, &sc->ip);
  249. err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs);
  250. err |= __put_user(regs->flags, &sc->flags);
  251. err |= __put_user(regs->sp, &sc->sp_at_signal);
  252. err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
  253. tmp = save_i387_xstate(fpstate);
  254. if (tmp < 0)
  255. err = 1;
  256. else
  257. err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate);
  258. /* non-iBCS2 extensions.. */
  259. err |= __put_user(mask, &sc->oldmask);
  260. err |= __put_user(current->thread.cr2, &sc->cr2);
  261. return err;
  262. }
  263. /*
  264. * Determine which stack to use..
  265. */
  266. static inline void __user *
  267. get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
  268. void **fpstate)
  269. {
  270. unsigned long sp;
  271. /* Default to using normal stack */
  272. sp = regs->sp;
  273. /*
  274. * If we are on the alternate signal stack and would overflow it, don't.
  275. * Return an always-bogus address instead so we will die with SIGSEGV.
  276. */
  277. if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
  278. return (void __user *) -1L;
  279. /* This is the X/Open sanctioned signal stack switching. */
  280. if (ka->sa.sa_flags & SA_ONSTACK) {
  281. if (sas_ss_flags(sp) == 0)
  282. sp = current->sas_ss_sp + current->sas_ss_size;
  283. } else {
  284. /* This is the legacy signal stack switching. */
  285. if ((regs->ss & 0xffff) != __USER_DS &&
  286. !(ka->sa.sa_flags & SA_RESTORER) &&
  287. ka->sa.sa_restorer)
  288. sp = (unsigned long) ka->sa.sa_restorer;
  289. }
  290. if (used_math()) {
  291. sp = sp - sig_xstate_size;
  292. *fpstate = (struct _fpstate *) sp;
  293. }
  294. sp -= frame_size;
  295. /*
  296. * Align the stack pointer according to the i386 ABI,
  297. * i.e. so that on function entry ((sp + 4) & 15) == 0.
  298. */
  299. sp = ((sp + 4) & -16ul) - 4;
  300. return (void __user *) sp;
  301. }
  302. static int
  303. __setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
  304. struct pt_regs *regs)
  305. {
  306. struct sigframe __user *frame;
  307. void __user *restorer;
  308. int err = 0;
  309. void __user *fpstate = NULL;
  310. frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
  311. if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
  312. return -EFAULT;
  313. if (__put_user(sig, &frame->sig))
  314. return -EFAULT;
  315. if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
  316. return -EFAULT;
  317. if (_NSIG_WORDS > 1) {
  318. if (__copy_to_user(&frame->extramask, &set->sig[1],
  319. sizeof(frame->extramask)))
  320. return -EFAULT;
  321. }
  322. if (current->mm->context.vdso)
  323. restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
  324. else
  325. restorer = &frame->retcode;
  326. if (ka->sa.sa_flags & SA_RESTORER)
  327. restorer = ka->sa.sa_restorer;
  328. /* Set up to return from userspace. */
  329. err |= __put_user(restorer, &frame->pretcode);
  330. /*
  331. * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
  332. *
  333. * WE DO NOT USE IT ANY MORE! It's only left here for historical
  334. * reasons and because gdb uses it as a signature to notice
  335. * signal handler stack frames.
  336. */
  337. err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
  338. err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
  339. err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
  340. if (err)
  341. return -EFAULT;
  342. /* Set up registers for signal handler */
  343. regs->sp = (unsigned long)frame;
  344. regs->ip = (unsigned long)ka->sa.sa_handler;
  345. regs->ax = (unsigned long)sig;
  346. regs->dx = 0;
  347. regs->cx = 0;
  348. regs->ds = __USER_DS;
  349. regs->es = __USER_DS;
  350. regs->ss = __USER_DS;
  351. regs->cs = __USER_CS;
  352. return 0;
  353. }
  354. static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
  355. sigset_t *set, struct pt_regs *regs)
  356. {
  357. struct rt_sigframe __user *frame;
  358. void __user *restorer;
  359. int err = 0;
  360. void __user *fpstate = NULL;
  361. frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
  362. if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
  363. return -EFAULT;
  364. err |= __put_user(sig, &frame->sig);
  365. err |= __put_user(&frame->info, &frame->pinfo);
  366. err |= __put_user(&frame->uc, &frame->puc);
  367. err |= copy_siginfo_to_user(&frame->info, info);
  368. if (err)
  369. return -EFAULT;
  370. /* Create the ucontext. */
  371. if (cpu_has_xsave)
  372. err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
  373. else
  374. err |= __put_user(0, &frame->uc.uc_flags);
  375. err |= __put_user(0, &frame->uc.uc_link);
  376. err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
  377. err |= __put_user(sas_ss_flags(regs->sp),
  378. &frame->uc.uc_stack.ss_flags);
  379. err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
  380. err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
  381. regs, set->sig[0]);
  382. err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
  383. if (err)
  384. return -EFAULT;
  385. /* Set up to return from userspace. */
  386. restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
  387. if (ka->sa.sa_flags & SA_RESTORER)
  388. restorer = ka->sa.sa_restorer;
  389. err |= __put_user(restorer, &frame->pretcode);
  390. /*
  391. * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
  392. *
  393. * WE DO NOT USE IT ANY MORE! It's only left here for historical
  394. * reasons and because gdb uses it as a signature to notice
  395. * signal handler stack frames.
  396. */
  397. err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
  398. err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
  399. err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
  400. if (err)
  401. return -EFAULT;
  402. /* Set up registers for signal handler */
  403. regs->sp = (unsigned long)frame;
  404. regs->ip = (unsigned long)ka->sa.sa_handler;
  405. regs->ax = (unsigned long)sig;
  406. regs->dx = (unsigned long)&frame->info;
  407. regs->cx = (unsigned long)&frame->uc;
  408. regs->ds = __USER_DS;
  409. regs->es = __USER_DS;
  410. regs->ss = __USER_DS;
  411. regs->cs = __USER_CS;
  412. return 0;
  413. }
  414. /*
  415. * OK, we're invoking a handler:
  416. */
  417. static int signr_convert(int sig)
  418. {
  419. #ifdef CONFIG_X86_32
  420. struct thread_info *info = current_thread_info();
  421. if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32)
  422. return info->exec_domain->signal_invmap[sig];
  423. #endif /* CONFIG_X86_32 */
  424. return sig;
  425. }
  426. #ifdef CONFIG_X86_32
  427. #define is_ia32 1
  428. #define ia32_setup_frame __setup_frame
  429. #define ia32_setup_rt_frame __setup_rt_frame
  430. #else /* !CONFIG_X86_32 */
  431. #ifdef CONFIG_IA32_EMULATION
  432. #define is_ia32 test_thread_flag(TIF_IA32)
  433. #else /* !CONFIG_IA32_EMULATION */
  434. #define is_ia32 0
  435. #endif /* CONFIG_IA32_EMULATION */
  436. #endif /* CONFIG_X86_32 */
  437. static int
  438. setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
  439. sigset_t *set, struct pt_regs *regs)
  440. {
  441. int usig = signr_convert(sig);
  442. int ret;
  443. /* Set up the stack frame */
  444. if (is_ia32) {
  445. if (ka->sa.sa_flags & SA_SIGINFO)
  446. ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
  447. else
  448. ret = ia32_setup_frame(usig, ka, set, regs);
  449. } else
  450. ret = __setup_rt_frame(sig, ka, info, set, regs);
  451. if (ret) {
  452. force_sigsegv(sig, current);
  453. return -EFAULT;
  454. }
  455. return ret;
  456. }
  457. static int
  458. handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
  459. sigset_t *oldset, struct pt_regs *regs)
  460. {
  461. int ret;
  462. /* Are we from a system call? */
  463. if (syscall_get_nr(current, regs) >= 0) {
  464. /* If so, check system call restarting.. */
  465. switch (syscall_get_error(current, regs)) {
  466. case -ERESTART_RESTARTBLOCK:
  467. case -ERESTARTNOHAND:
  468. regs->ax = -EINTR;
  469. break;
  470. case -ERESTARTSYS:
  471. if (!(ka->sa.sa_flags & SA_RESTART)) {
  472. regs->ax = -EINTR;
  473. break;
  474. }
  475. /* fallthrough */
  476. case -ERESTARTNOINTR:
  477. regs->ax = regs->orig_ax;
  478. regs->ip -= 2;
  479. break;
  480. }
  481. }
  482. /*
  483. * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
  484. * flag so that register information in the sigcontext is correct.
  485. */
  486. if (unlikely(regs->flags & X86_EFLAGS_TF) &&
  487. likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
  488. regs->flags &= ~X86_EFLAGS_TF;
  489. ret = setup_rt_frame(sig, ka, info, oldset, regs);
  490. if (ret)
  491. return ret;
  492. #ifdef CONFIG_X86_64
  493. /*
  494. * This has nothing to do with segment registers,
  495. * despite the name. This magic affects uaccess.h
  496. * macros' behavior. Reset it to the normal setting.
  497. */
  498. set_fs(USER_DS);
  499. #endif
  500. /*
  501. * Clear the direction flag as per the ABI for function entry.
  502. */
  503. regs->flags &= ~X86_EFLAGS_DF;
  504. /*
  505. * Clear TF when entering the signal handler, but
  506. * notify any tracer that was single-stepping it.
  507. * The tracer may want to single-step inside the
  508. * handler too.
  509. */
  510. regs->flags &= ~X86_EFLAGS_TF;
  511. spin_lock_irq(&current->sighand->siglock);
  512. sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
  513. if (!(ka->sa.sa_flags & SA_NODEFER))
  514. sigaddset(&current->blocked, sig);
  515. recalc_sigpending();
  516. spin_unlock_irq(&current->sighand->siglock);
  517. tracehook_signal_handler(sig, info, ka, regs,
  518. test_thread_flag(TIF_SINGLESTEP));
  519. return 0;
  520. }
  521. #define NR_restart_syscall __NR_restart_syscall
  522. /*
  523. * Note that 'init' is a special process: it doesn't get signals it doesn't
  524. * want to handle. Thus you cannot kill init even with a SIGKILL even by
  525. * mistake.
  526. */
  527. static void do_signal(struct pt_regs *regs)
  528. {
  529. struct k_sigaction ka;
  530. siginfo_t info;
  531. int signr;
  532. sigset_t *oldset;
  533. /*
  534. * We want the common case to go fast, which is why we may in certain
  535. * cases get here from kernel mode. Just return without doing anything
  536. * if so.
  537. * X86_32: vm86 regs switched out by assembly code before reaching
  538. * here, so testing against kernel CS suffices.
  539. */
  540. if (!user_mode(regs))
  541. return;
  542. if (current_thread_info()->status & TS_RESTORE_SIGMASK)
  543. oldset = &current->saved_sigmask;
  544. else
  545. oldset = &current->blocked;
  546. signr = get_signal_to_deliver(&info, &ka, regs, NULL);
  547. if (signr > 0) {
  548. /*
  549. * Re-enable any watchpoints before delivering the
  550. * signal to user space. The processor register will
  551. * have been cleared if the watchpoint triggered
  552. * inside the kernel.
  553. */
  554. if (current->thread.debugreg7)
  555. set_debugreg(current->thread.debugreg7, 7);
  556. /* Whee! Actually deliver the signal. */
  557. if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
  558. /*
  559. * A signal was successfully delivered; the saved
  560. * sigmask will have been stored in the signal frame,
  561. * and will be restored by sigreturn, so we can simply
  562. * clear the TS_RESTORE_SIGMASK flag.
  563. */
  564. current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
  565. }
  566. return;
  567. }
  568. /* Did we come from a system call? */
  569. if (syscall_get_nr(current, regs) >= 0) {
  570. /* Restart the system call - no handlers present */
  571. switch (syscall_get_error(current, regs)) {
  572. case -ERESTARTNOHAND:
  573. case -ERESTARTSYS:
  574. case -ERESTARTNOINTR:
  575. regs->ax = regs->orig_ax;
  576. regs->ip -= 2;
  577. break;
  578. case -ERESTART_RESTARTBLOCK:
  579. regs->ax = NR_restart_syscall;
  580. regs->ip -= 2;
  581. break;
  582. }
  583. }
  584. /*
  585. * If there's no signal to deliver, we just put the saved sigmask
  586. * back.
  587. */
  588. if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
  589. current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
  590. sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
  591. }
  592. }
  593. /*
  594. * notification of userspace execution resumption
  595. * - triggered by the TIF_WORK_MASK flags
  596. */
  597. void
  598. do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
  599. {
  600. #if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
  601. /* notify userspace of pending MCEs */
  602. if (thread_info_flags & _TIF_MCE_NOTIFY)
  603. mce_notify_user();
  604. #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
  605. /* deal with pending signal delivery */
  606. if (thread_info_flags & _TIF_SIGPENDING)
  607. do_signal(regs);
  608. if (thread_info_flags & _TIF_NOTIFY_RESUME) {
  609. clear_thread_flag(TIF_NOTIFY_RESUME);
  610. tracehook_notify_resume(regs);
  611. }
  612. #ifdef CONFIG_X86_32
  613. clear_thread_flag(TIF_IRET);
  614. #endif /* CONFIG_X86_32 */
  615. }
  616. void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
  617. {
  618. struct task_struct *me = current;
  619. if (show_unhandled_signals && printk_ratelimit()) {
  620. printk(KERN_INFO
  621. "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
  622. me->comm, me->pid, where, frame,
  623. regs->ip, regs->sp, regs->orig_ax);
  624. print_vma_addr(" in ", regs->ip);
  625. printk(KERN_CONT "\n");
  626. }
  627. force_sig(SIGSEGV, me);
  628. }