signal.c 22 KB

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  1. /*
  2. * Copyright (C) 1991, 1992 Linus Torvalds
  3. * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
  4. *
  5. * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
  6. * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
  7. * 2000-2002 x86-64 support by Andi Kleen
  8. */
  9. #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10. #include <linux/sched.h>
  11. #include <linux/mm.h>
  12. #include <linux/smp.h>
  13. #include <linux/kernel.h>
  14. #include <linux/errno.h>
  15. #include <linux/wait.h>
  16. #include <linux/tracehook.h>
  17. #include <linux/unistd.h>
  18. #include <linux/stddef.h>
  19. #include <linux/personality.h>
  20. #include <linux/uaccess.h>
  21. #include <linux/user-return-notifier.h>
  22. #include <linux/uprobes.h>
  23. #include <linux/context_tracking.h>
  24. #include <asm/processor.h>
  25. #include <asm/ucontext.h>
  26. #include <asm/i387.h>
  27. #include <asm/fpu-internal.h>
  28. #include <asm/vdso.h>
  29. #include <asm/mce.h>
  30. #include <asm/sighandling.h>
  31. #ifdef CONFIG_X86_64
  32. #include <asm/proto.h>
  33. #include <asm/ia32_unistd.h>
  34. #include <asm/sys_ia32.h>
  35. #endif /* CONFIG_X86_64 */
  36. #include <asm/syscall.h>
  37. #include <asm/syscalls.h>
  38. #include <asm/sigframe.h>
  39. #ifdef CONFIG_X86_32
  40. # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
  41. #else
  42. # define FIX_EFLAGS __FIX_EFLAGS
  43. #endif
  44. #define COPY(x) do { \
  45. get_user_ex(regs->x, &sc->x); \
  46. } while (0)
  47. #define GET_SEG(seg) ({ \
  48. unsigned short tmp; \
  49. get_user_ex(tmp, &sc->seg); \
  50. tmp; \
  51. })
  52. #define COPY_SEG(seg) do { \
  53. regs->seg = GET_SEG(seg); \
  54. } while (0)
  55. #define COPY_SEG_CPL3(seg) do { \
  56. regs->seg = GET_SEG(seg) | 3; \
  57. } while (0)
  58. int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
  59. unsigned long *pax)
  60. {
  61. void __user *buf;
  62. unsigned int tmpflags;
  63. unsigned int err = 0;
  64. /* Always make any pending restarted system calls return -EINTR */
  65. current_thread_info()->restart_block.fn = do_no_restart_syscall;
  66. get_user_try {
  67. #ifdef CONFIG_X86_32
  68. set_user_gs(regs, GET_SEG(gs));
  69. COPY_SEG(fs);
  70. COPY_SEG(es);
  71. COPY_SEG(ds);
  72. #endif /* CONFIG_X86_32 */
  73. COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
  74. COPY(dx); COPY(cx); COPY(ip);
  75. #ifdef CONFIG_X86_64
  76. COPY(r8);
  77. COPY(r9);
  78. COPY(r10);
  79. COPY(r11);
  80. COPY(r12);
  81. COPY(r13);
  82. COPY(r14);
  83. COPY(r15);
  84. #endif /* CONFIG_X86_64 */
  85. #ifdef CONFIG_X86_32
  86. COPY_SEG_CPL3(cs);
  87. COPY_SEG_CPL3(ss);
  88. #else /* !CONFIG_X86_32 */
  89. /* Kernel saves and restores only the CS segment register on signals,
  90. * which is the bare minimum needed to allow mixed 32/64-bit code.
  91. * App's signal handler can save/restore other segments if needed. */
  92. COPY_SEG_CPL3(cs);
  93. #endif /* CONFIG_X86_32 */
  94. get_user_ex(tmpflags, &sc->flags);
  95. regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
  96. regs->orig_ax = -1; /* disable syscall checks */
  97. get_user_ex(buf, &sc->fpstate);
  98. get_user_ex(*pax, &sc->ax);
  99. } get_user_catch(err);
  100. err |= restore_xstate_sig(buf, config_enabled(CONFIG_X86_32));
  101. return err;
  102. }
  103. int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
  104. struct pt_regs *regs, unsigned long mask)
  105. {
  106. int err = 0;
  107. put_user_try {
  108. #ifdef CONFIG_X86_32
  109. put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs);
  110. put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
  111. put_user_ex(regs->es, (unsigned int __user *)&sc->es);
  112. put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
  113. #endif /* CONFIG_X86_32 */
  114. put_user_ex(regs->di, &sc->di);
  115. put_user_ex(regs->si, &sc->si);
  116. put_user_ex(regs->bp, &sc->bp);
  117. put_user_ex(regs->sp, &sc->sp);
  118. put_user_ex(regs->bx, &sc->bx);
  119. put_user_ex(regs->dx, &sc->dx);
  120. put_user_ex(regs->cx, &sc->cx);
  121. put_user_ex(regs->ax, &sc->ax);
  122. #ifdef CONFIG_X86_64
  123. put_user_ex(regs->r8, &sc->r8);
  124. put_user_ex(regs->r9, &sc->r9);
  125. put_user_ex(regs->r10, &sc->r10);
  126. put_user_ex(regs->r11, &sc->r11);
  127. put_user_ex(regs->r12, &sc->r12);
  128. put_user_ex(regs->r13, &sc->r13);
  129. put_user_ex(regs->r14, &sc->r14);
  130. put_user_ex(regs->r15, &sc->r15);
  131. #endif /* CONFIG_X86_64 */
  132. put_user_ex(current->thread.trap_nr, &sc->trapno);
  133. put_user_ex(current->thread.error_code, &sc->err);
  134. put_user_ex(regs->ip, &sc->ip);
  135. #ifdef CONFIG_X86_32
  136. put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
  137. put_user_ex(regs->flags, &sc->flags);
  138. put_user_ex(regs->sp, &sc->sp_at_signal);
  139. put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
  140. #else /* !CONFIG_X86_32 */
  141. put_user_ex(regs->flags, &sc->flags);
  142. put_user_ex(regs->cs, &sc->cs);
  143. put_user_ex(0, &sc->gs);
  144. put_user_ex(0, &sc->fs);
  145. #endif /* CONFIG_X86_32 */
  146. put_user_ex(fpstate, &sc->fpstate);
  147. /* non-iBCS2 extensions.. */
  148. put_user_ex(mask, &sc->oldmask);
  149. put_user_ex(current->thread.cr2, &sc->cr2);
  150. } put_user_catch(err);
  151. return err;
  152. }
  153. /*
  154. * Set up a signal frame.
  155. */
  156. /*
  157. * Determine which stack to use..
  158. */
  159. static unsigned long align_sigframe(unsigned long sp)
  160. {
  161. #ifdef CONFIG_X86_32
  162. /*
  163. * Align the stack pointer according to the i386 ABI,
  164. * i.e. so that on function entry ((sp + 4) & 15) == 0.
  165. */
  166. sp = ((sp + 4) & -16ul) - 4;
  167. #else /* !CONFIG_X86_32 */
  168. sp = round_down(sp, 16) - 8;
  169. #endif
  170. return sp;
  171. }
  172. static inline void __user *
  173. get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
  174. void __user **fpstate)
  175. {
  176. /* Default to using normal stack */
  177. unsigned long math_size = 0;
  178. unsigned long sp = regs->sp;
  179. unsigned long buf_fx = 0;
  180. int onsigstack = on_sig_stack(sp);
  181. /* redzone */
  182. if (config_enabled(CONFIG_X86_64))
  183. sp -= 128;
  184. if (!onsigstack) {
  185. /* This is the X/Open sanctioned signal stack switching. */
  186. if (ka->sa.sa_flags & SA_ONSTACK) {
  187. if (current->sas_ss_size)
  188. sp = current->sas_ss_sp + current->sas_ss_size;
  189. } else if (config_enabled(CONFIG_X86_32) &&
  190. (regs->ss & 0xffff) != __USER_DS &&
  191. !(ka->sa.sa_flags & SA_RESTORER) &&
  192. ka->sa.sa_restorer) {
  193. /* This is the legacy signal stack switching. */
  194. sp = (unsigned long) ka->sa.sa_restorer;
  195. }
  196. }
  197. if (used_math()) {
  198. sp = alloc_mathframe(sp, config_enabled(CONFIG_X86_32),
  199. &buf_fx, &math_size);
  200. *fpstate = (void __user *)sp;
  201. }
  202. sp = align_sigframe(sp - frame_size);
  203. /*
  204. * If we are on the alternate signal stack and would overflow it, don't.
  205. * Return an always-bogus address instead so we will die with SIGSEGV.
  206. */
  207. if (onsigstack && !likely(on_sig_stack(sp)))
  208. return (void __user *)-1L;
  209. /* save i387 and extended state */
  210. if (used_math() &&
  211. save_xstate_sig(*fpstate, (void __user *)buf_fx, math_size) < 0)
  212. return (void __user *)-1L;
  213. return (void __user *)sp;
  214. }
  215. #ifdef CONFIG_X86_32
  216. static const struct {
  217. u16 poplmovl;
  218. u32 val;
  219. u16 int80;
  220. } __attribute__((packed)) retcode = {
  221. 0xb858, /* popl %eax; movl $..., %eax */
  222. __NR_sigreturn,
  223. 0x80cd, /* int $0x80 */
  224. };
  225. static const struct {
  226. u8 movl;
  227. u32 val;
  228. u16 int80;
  229. u8 pad;
  230. } __attribute__((packed)) rt_retcode = {
  231. 0xb8, /* movl $..., %eax */
  232. __NR_rt_sigreturn,
  233. 0x80cd, /* int $0x80 */
  234. 0
  235. };
  236. static int
  237. __setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
  238. struct pt_regs *regs)
  239. {
  240. struct sigframe __user *frame;
  241. void __user *restorer;
  242. int err = 0;
  243. void __user *fpstate = NULL;
  244. frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
  245. if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
  246. return -EFAULT;
  247. if (__put_user(sig, &frame->sig))
  248. return -EFAULT;
  249. if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
  250. return -EFAULT;
  251. if (_NSIG_WORDS > 1) {
  252. if (__copy_to_user(&frame->extramask, &set->sig[1],
  253. sizeof(frame->extramask)))
  254. return -EFAULT;
  255. }
  256. if (current->mm->context.vdso)
  257. restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
  258. else
  259. restorer = &frame->retcode;
  260. if (ka->sa.sa_flags & SA_RESTORER)
  261. restorer = ka->sa.sa_restorer;
  262. /* Set up to return from userspace. */
  263. err |= __put_user(restorer, &frame->pretcode);
  264. /*
  265. * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
  266. *
  267. * WE DO NOT USE IT ANY MORE! It's only left here for historical
  268. * reasons and because gdb uses it as a signature to notice
  269. * signal handler stack frames.
  270. */
  271. err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
  272. if (err)
  273. return -EFAULT;
  274. /* Set up registers for signal handler */
  275. regs->sp = (unsigned long)frame;
  276. regs->ip = (unsigned long)ka->sa.sa_handler;
  277. regs->ax = (unsigned long)sig;
  278. regs->dx = 0;
  279. regs->cx = 0;
  280. regs->ds = __USER_DS;
  281. regs->es = __USER_DS;
  282. regs->ss = __USER_DS;
  283. regs->cs = __USER_CS;
  284. return 0;
  285. }
  286. static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
  287. sigset_t *set, struct pt_regs *regs)
  288. {
  289. struct rt_sigframe __user *frame;
  290. void __user *restorer;
  291. int err = 0;
  292. void __user *fpstate = NULL;
  293. frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
  294. if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
  295. return -EFAULT;
  296. put_user_try {
  297. put_user_ex(sig, &frame->sig);
  298. put_user_ex(&frame->info, &frame->pinfo);
  299. put_user_ex(&frame->uc, &frame->puc);
  300. /* Create the ucontext. */
  301. if (cpu_has_xsave)
  302. put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
  303. else
  304. put_user_ex(0, &frame->uc.uc_flags);
  305. put_user_ex(0, &frame->uc.uc_link);
  306. put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
  307. put_user_ex(sas_ss_flags(regs->sp),
  308. &frame->uc.uc_stack.ss_flags);
  309. put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
  310. /* Set up to return from userspace. */
  311. restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
  312. if (ka->sa.sa_flags & SA_RESTORER)
  313. restorer = ka->sa.sa_restorer;
  314. put_user_ex(restorer, &frame->pretcode);
  315. /*
  316. * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
  317. *
  318. * WE DO NOT USE IT ANY MORE! It's only left here for historical
  319. * reasons and because gdb uses it as a signature to notice
  320. * signal handler stack frames.
  321. */
  322. put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
  323. } put_user_catch(err);
  324. err |= copy_siginfo_to_user(&frame->info, info);
  325. err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
  326. regs, set->sig[0]);
  327. err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
  328. if (err)
  329. return -EFAULT;
  330. /* Set up registers for signal handler */
  331. regs->sp = (unsigned long)frame;
  332. regs->ip = (unsigned long)ka->sa.sa_handler;
  333. regs->ax = (unsigned long)sig;
  334. regs->dx = (unsigned long)&frame->info;
  335. regs->cx = (unsigned long)&frame->uc;
  336. regs->ds = __USER_DS;
  337. regs->es = __USER_DS;
  338. regs->ss = __USER_DS;
  339. regs->cs = __USER_CS;
  340. return 0;
  341. }
  342. #else /* !CONFIG_X86_32 */
  343. static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
  344. sigset_t *set, struct pt_regs *regs)
  345. {
  346. struct rt_sigframe __user *frame;
  347. void __user *fp = NULL;
  348. int err = 0;
  349. struct task_struct *me = current;
  350. frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp);
  351. if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
  352. return -EFAULT;
  353. if (ka->sa.sa_flags & SA_SIGINFO) {
  354. if (copy_siginfo_to_user(&frame->info, info))
  355. return -EFAULT;
  356. }
  357. put_user_try {
  358. /* Create the ucontext. */
  359. if (cpu_has_xsave)
  360. put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
  361. else
  362. put_user_ex(0, &frame->uc.uc_flags);
  363. put_user_ex(0, &frame->uc.uc_link);
  364. put_user_ex(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
  365. put_user_ex(sas_ss_flags(regs->sp),
  366. &frame->uc.uc_stack.ss_flags);
  367. put_user_ex(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
  368. /* Set up to return from userspace. If provided, use a stub
  369. already in userspace. */
  370. /* x86-64 should always use SA_RESTORER. */
  371. if (ka->sa.sa_flags & SA_RESTORER) {
  372. put_user_ex(ka->sa.sa_restorer, &frame->pretcode);
  373. } else {
  374. /* could use a vstub here */
  375. err |= -EFAULT;
  376. }
  377. } put_user_catch(err);
  378. err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
  379. err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
  380. if (err)
  381. return -EFAULT;
  382. /* Set up registers for signal handler */
  383. regs->di = sig;
  384. /* In case the signal handler was declared without prototypes */
  385. regs->ax = 0;
  386. /* This also works for non SA_SIGINFO handlers because they expect the
  387. next argument after the signal number on the stack. */
  388. regs->si = (unsigned long)&frame->info;
  389. regs->dx = (unsigned long)&frame->uc;
  390. regs->ip = (unsigned long) ka->sa.sa_handler;
  391. regs->sp = (unsigned long)frame;
  392. /* Set up the CS register to run signal handlers in 64-bit mode,
  393. even if the handler happens to be interrupting 32-bit code. */
  394. regs->cs = __USER_CS;
  395. return 0;
  396. }
  397. #endif /* CONFIG_X86_32 */
  398. static int x32_setup_rt_frame(int sig, struct k_sigaction *ka,
  399. siginfo_t *info, compat_sigset_t *set,
  400. struct pt_regs *regs)
  401. {
  402. #ifdef CONFIG_X86_X32_ABI
  403. struct rt_sigframe_x32 __user *frame;
  404. void __user *restorer;
  405. int err = 0;
  406. void __user *fpstate = NULL;
  407. frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
  408. if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
  409. return -EFAULT;
  410. if (ka->sa.sa_flags & SA_SIGINFO) {
  411. if (copy_siginfo_to_user32(&frame->info, info))
  412. return -EFAULT;
  413. }
  414. put_user_try {
  415. /* Create the ucontext. */
  416. if (cpu_has_xsave)
  417. put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
  418. else
  419. put_user_ex(0, &frame->uc.uc_flags);
  420. put_user_ex(0, &frame->uc.uc_link);
  421. put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
  422. put_user_ex(sas_ss_flags(regs->sp),
  423. &frame->uc.uc_stack.ss_flags);
  424. put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
  425. put_user_ex(0, &frame->uc.uc__pad0);
  426. if (ka->sa.sa_flags & SA_RESTORER) {
  427. restorer = ka->sa.sa_restorer;
  428. } else {
  429. /* could use a vstub here */
  430. restorer = NULL;
  431. err |= -EFAULT;
  432. }
  433. put_user_ex(restorer, &frame->pretcode);
  434. } put_user_catch(err);
  435. err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
  436. regs, set->sig[0]);
  437. err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
  438. if (err)
  439. return -EFAULT;
  440. /* Set up registers for signal handler */
  441. regs->sp = (unsigned long) frame;
  442. regs->ip = (unsigned long) ka->sa.sa_handler;
  443. /* We use the x32 calling convention here... */
  444. regs->di = sig;
  445. regs->si = (unsigned long) &frame->info;
  446. regs->dx = (unsigned long) &frame->uc;
  447. loadsegment(ds, __USER_DS);
  448. loadsegment(es, __USER_DS);
  449. regs->cs = __USER_CS;
  450. regs->ss = __USER_DS;
  451. #endif /* CONFIG_X86_X32_ABI */
  452. return 0;
  453. }
  454. #ifdef CONFIG_X86_32
  455. /*
  456. * Atomically swap in the new signal mask, and wait for a signal.
  457. */
  458. asmlinkage int
  459. sys_sigsuspend(int history0, int history1, old_sigset_t mask)
  460. {
  461. sigset_t blocked;
  462. siginitset(&blocked, mask);
  463. return sigsuspend(&blocked);
  464. }
  465. asmlinkage int
  466. sys_sigaction(int sig, const struct old_sigaction __user *act,
  467. struct old_sigaction __user *oact)
  468. {
  469. struct k_sigaction new_ka, old_ka;
  470. int ret = 0;
  471. if (act) {
  472. old_sigset_t mask;
  473. if (!access_ok(VERIFY_READ, act, sizeof(*act)))
  474. return -EFAULT;
  475. get_user_try {
  476. get_user_ex(new_ka.sa.sa_handler, &act->sa_handler);
  477. get_user_ex(new_ka.sa.sa_flags, &act->sa_flags);
  478. get_user_ex(mask, &act->sa_mask);
  479. get_user_ex(new_ka.sa.sa_restorer, &act->sa_restorer);
  480. } get_user_catch(ret);
  481. if (ret)
  482. return -EFAULT;
  483. siginitset(&new_ka.sa.sa_mask, mask);
  484. }
  485. ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
  486. if (!ret && oact) {
  487. if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
  488. return -EFAULT;
  489. put_user_try {
  490. put_user_ex(old_ka.sa.sa_handler, &oact->sa_handler);
  491. put_user_ex(old_ka.sa.sa_flags, &oact->sa_flags);
  492. put_user_ex(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
  493. put_user_ex(old_ka.sa.sa_restorer, &oact->sa_restorer);
  494. } put_user_catch(ret);
  495. if (ret)
  496. return -EFAULT;
  497. }
  498. return ret;
  499. }
  500. #endif /* CONFIG_X86_32 */
  501. long
  502. sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
  503. struct pt_regs *regs)
  504. {
  505. return do_sigaltstack(uss, uoss, regs->sp);
  506. }
  507. /*
  508. * Do a signal return; undo the signal stack.
  509. */
  510. #ifdef CONFIG_X86_32
  511. unsigned long sys_sigreturn(struct pt_regs *regs)
  512. {
  513. struct sigframe __user *frame;
  514. unsigned long ax;
  515. sigset_t set;
  516. frame = (struct sigframe __user *)(regs->sp - 8);
  517. if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
  518. goto badframe;
  519. if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
  520. && __copy_from_user(&set.sig[1], &frame->extramask,
  521. sizeof(frame->extramask))))
  522. goto badframe;
  523. set_current_blocked(&set);
  524. if (restore_sigcontext(regs, &frame->sc, &ax))
  525. goto badframe;
  526. return ax;
  527. badframe:
  528. signal_fault(regs, frame, "sigreturn");
  529. return 0;
  530. }
  531. #endif /* CONFIG_X86_32 */
  532. long sys_rt_sigreturn(struct pt_regs *regs)
  533. {
  534. struct rt_sigframe __user *frame;
  535. unsigned long ax;
  536. sigset_t set;
  537. frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
  538. if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
  539. goto badframe;
  540. if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
  541. goto badframe;
  542. set_current_blocked(&set);
  543. if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
  544. goto badframe;
  545. if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
  546. goto badframe;
  547. return ax;
  548. badframe:
  549. signal_fault(regs, frame, "rt_sigreturn");
  550. return 0;
  551. }
  552. /*
  553. * OK, we're invoking a handler:
  554. */
  555. static int signr_convert(int sig)
  556. {
  557. #ifdef CONFIG_X86_32
  558. struct thread_info *info = current_thread_info();
  559. if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32)
  560. return info->exec_domain->signal_invmap[sig];
  561. #endif /* CONFIG_X86_32 */
  562. return sig;
  563. }
  564. static int
  565. setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
  566. struct pt_regs *regs)
  567. {
  568. int usig = signr_convert(sig);
  569. sigset_t *set = sigmask_to_save();
  570. compat_sigset_t *cset = (compat_sigset_t *) set;
  571. /* Set up the stack frame */
  572. if (is_ia32_frame()) {
  573. if (ka->sa.sa_flags & SA_SIGINFO)
  574. return ia32_setup_rt_frame(usig, ka, info, cset, regs);
  575. else
  576. return ia32_setup_frame(usig, ka, cset, regs);
  577. } else if (is_x32_frame()) {
  578. return x32_setup_rt_frame(usig, ka, info, cset, regs);
  579. } else {
  580. return __setup_rt_frame(sig, ka, info, set, regs);
  581. }
  582. }
  583. static void
  584. handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
  585. struct pt_regs *regs)
  586. {
  587. /* Are we from a system call? */
  588. if (syscall_get_nr(current, regs) >= 0) {
  589. /* If so, check system call restarting.. */
  590. switch (syscall_get_error(current, regs)) {
  591. case -ERESTART_RESTARTBLOCK:
  592. case -ERESTARTNOHAND:
  593. regs->ax = -EINTR;
  594. break;
  595. case -ERESTARTSYS:
  596. if (!(ka->sa.sa_flags & SA_RESTART)) {
  597. regs->ax = -EINTR;
  598. break;
  599. }
  600. /* fallthrough */
  601. case -ERESTARTNOINTR:
  602. regs->ax = regs->orig_ax;
  603. regs->ip -= 2;
  604. break;
  605. }
  606. }
  607. /*
  608. * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
  609. * flag so that register information in the sigcontext is correct.
  610. */
  611. if (unlikely(regs->flags & X86_EFLAGS_TF) &&
  612. likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
  613. regs->flags &= ~X86_EFLAGS_TF;
  614. if (setup_rt_frame(sig, ka, info, regs) < 0) {
  615. force_sigsegv(sig, current);
  616. return;
  617. }
  618. /*
  619. * Clear the direction flag as per the ABI for function entry.
  620. */
  621. regs->flags &= ~X86_EFLAGS_DF;
  622. /*
  623. * Clear TF when entering the signal handler, but
  624. * notify any tracer that was single-stepping it.
  625. * The tracer may want to single-step inside the
  626. * handler too.
  627. */
  628. regs->flags &= ~X86_EFLAGS_TF;
  629. signal_delivered(sig, info, ka, regs,
  630. test_thread_flag(TIF_SINGLESTEP));
  631. }
  632. #ifdef CONFIG_X86_32
  633. #define NR_restart_syscall __NR_restart_syscall
  634. #else /* !CONFIG_X86_32 */
  635. #define NR_restart_syscall \
  636. test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
  637. #endif /* CONFIG_X86_32 */
  638. /*
  639. * Note that 'init' is a special process: it doesn't get signals it doesn't
  640. * want to handle. Thus you cannot kill init even with a SIGKILL even by
  641. * mistake.
  642. */
  643. static void do_signal(struct pt_regs *regs)
  644. {
  645. struct k_sigaction ka;
  646. siginfo_t info;
  647. int signr;
  648. signr = get_signal_to_deliver(&info, &ka, regs, NULL);
  649. if (signr > 0) {
  650. /* Whee! Actually deliver the signal. */
  651. handle_signal(signr, &info, &ka, regs);
  652. return;
  653. }
  654. /* Did we come from a system call? */
  655. if (syscall_get_nr(current, regs) >= 0) {
  656. /* Restart the system call - no handlers present */
  657. switch (syscall_get_error(current, regs)) {
  658. case -ERESTARTNOHAND:
  659. case -ERESTARTSYS:
  660. case -ERESTARTNOINTR:
  661. regs->ax = regs->orig_ax;
  662. regs->ip -= 2;
  663. break;
  664. case -ERESTART_RESTARTBLOCK:
  665. regs->ax = NR_restart_syscall;
  666. regs->ip -= 2;
  667. break;
  668. }
  669. }
  670. /*
  671. * If there's no signal to deliver, we just put the saved sigmask
  672. * back.
  673. */
  674. restore_saved_sigmask();
  675. }
  676. /*
  677. * notification of userspace execution resumption
  678. * - triggered by the TIF_WORK_MASK flags
  679. */
  680. void
  681. do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
  682. {
  683. user_exit();
  684. #ifdef CONFIG_X86_MCE
  685. /* notify userspace of pending MCEs */
  686. if (thread_info_flags & _TIF_MCE_NOTIFY)
  687. mce_notify_process();
  688. #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
  689. if (thread_info_flags & _TIF_UPROBE) {
  690. clear_thread_flag(TIF_UPROBE);
  691. uprobe_notify_resume(regs);
  692. }
  693. /* deal with pending signal delivery */
  694. if (thread_info_flags & _TIF_SIGPENDING)
  695. do_signal(regs);
  696. if (thread_info_flags & _TIF_NOTIFY_RESUME) {
  697. clear_thread_flag(TIF_NOTIFY_RESUME);
  698. tracehook_notify_resume(regs);
  699. }
  700. if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)
  701. fire_user_return_notifiers();
  702. user_enter();
  703. }
  704. void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
  705. {
  706. struct task_struct *me = current;
  707. if (show_unhandled_signals && printk_ratelimit()) {
  708. printk("%s"
  709. "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
  710. task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
  711. me->comm, me->pid, where, frame,
  712. regs->ip, regs->sp, regs->orig_ax);
  713. print_vma_addr(" in ", regs->ip);
  714. pr_cont("\n");
  715. }
  716. force_sig(SIGSEGV, me);
  717. }
  718. #ifdef CONFIG_X86_X32_ABI
  719. asmlinkage long sys32_x32_rt_sigreturn(struct pt_regs *regs)
  720. {
  721. struct rt_sigframe_x32 __user *frame;
  722. sigset_t set;
  723. unsigned long ax;
  724. struct pt_regs tregs;
  725. frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
  726. if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
  727. goto badframe;
  728. if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
  729. goto badframe;
  730. set_current_blocked(&set);
  731. if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
  732. goto badframe;
  733. tregs = *regs;
  734. if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
  735. goto badframe;
  736. return ax;
  737. badframe:
  738. signal_fault(regs, frame, "x32 rt_sigreturn");
  739. return 0;
  740. }
  741. #endif