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 #include <linux/sched.h> 10 #include <linux/mm.h> 11 #include <linux/smp.h> 12 #include <linux/kernel.h> 13 #include <linux/errno.h> 14 #include <linux/wait.h> 15 #include <linux/tracehook.h> 16 #include <linux/unistd.h> 17 #include <linux/stddef.h> 18 #include <linux/personality.h> 19 #include <linux/uaccess.h> 20 #include <linux/user-return-notifier.h> 21 22 #include <asm/processor.h> 23 #include <asm/ucontext.h> 24 #include <asm/i387.h> 25 #include <asm/fpu-internal.h> 26 #include <asm/vdso.h> 27 #include <asm/mce.h> 28 #include <asm/sighandling.h> 29 30 #ifdef CONFIG_X86_64 31 #include <asm/proto.h> 32 #include <asm/ia32_unistd.h> 33 #include <asm/sys_ia32.h> 34 #endif /* CONFIG_X86_64 */ 35 36 #include <asm/syscall.h> 37 #include <asm/syscalls.h> 38 39 #include <asm/sigframe.h> 40 41 #ifdef CONFIG_X86_32 42 # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF) 43 #else 44 # define FIX_EFLAGS __FIX_EFLAGS 45 #endif 46 47 #define COPY(x) do { \ 48 get_user_ex(regs->x, &sc->x); \ 49 } while (0) 50 51 #define GET_SEG(seg) ({ \ 52 unsigned short tmp; \ 53 get_user_ex(tmp, &sc->seg); \ 54 tmp; \ 55 }) 56 57 #define COPY_SEG(seg) do { \ 58 regs->seg = GET_SEG(seg); \ 59 } while (0) 60 61 #define COPY_SEG_CPL3(seg) do { \ 62 regs->seg = GET_SEG(seg) | 3; \ 63 } while (0) 64 65 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, 66 unsigned long *pax) 67 { 68 void __user *buf; 69 unsigned int tmpflags; 70 unsigned int err = 0; 71 72 /* Always make any pending restarted system calls return -EINTR */ 73 current_thread_info()->restart_block.fn = do_no_restart_syscall; 74 75 get_user_try { 76 77 #ifdef CONFIG_X86_32 78 set_user_gs(regs, GET_SEG(gs)); 79 COPY_SEG(fs); 80 COPY_SEG(es); 81 COPY_SEG(ds); 82 #endif /* CONFIG_X86_32 */ 83 84 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); 85 COPY(dx); COPY(cx); COPY(ip); 86 87 #ifdef CONFIG_X86_64 88 COPY(r8); 89 COPY(r9); 90 COPY(r10); 91 COPY(r11); 92 COPY(r12); 93 COPY(r13); 94 COPY(r14); 95 COPY(r15); 96 #endif /* CONFIG_X86_64 */ 97 98 #ifdef CONFIG_X86_32 99 COPY_SEG_CPL3(cs); 100 COPY_SEG_CPL3(ss); 101 #else /* !CONFIG_X86_32 */ 102 /* Kernel saves and restores only the CS segment register on signals, 103 * which is the bare minimum needed to allow mixed 32/64-bit code. 104 * App's signal handler can save/restore other segments if needed. */ 105 COPY_SEG_CPL3(cs); 106 #endif /* CONFIG_X86_32 */ 107 108 get_user_ex(tmpflags, &sc->flags); 109 regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); 110 regs->orig_ax = -1; /* disable syscall checks */ 111 112 get_user_ex(buf, &sc->fpstate); 113 err |= restore_i387_xstate(buf); 114 115 get_user_ex(*pax, &sc->ax); 116 } get_user_catch(err); 117 118 return err; 119 } 120 121 int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, 122 struct pt_regs *regs, unsigned long mask) 123 { 124 int err = 0; 125 126 put_user_try { 127 128 #ifdef CONFIG_X86_32 129 put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs); 130 put_user_ex(regs->fs, (unsigned int __user *)&sc->fs); 131 put_user_ex(regs->es, (unsigned int __user *)&sc->es); 132 put_user_ex(regs->ds, (unsigned int __user *)&sc->ds); 133 #endif /* CONFIG_X86_32 */ 134 135 put_user_ex(regs->di, &sc->di); 136 put_user_ex(regs->si, &sc->si); 137 put_user_ex(regs->bp, &sc->bp); 138 put_user_ex(regs->sp, &sc->sp); 139 put_user_ex(regs->bx, &sc->bx); 140 put_user_ex(regs->dx, &sc->dx); 141 put_user_ex(regs->cx, &sc->cx); 142 put_user_ex(regs->ax, &sc->ax); 143 #ifdef CONFIG_X86_64 144 put_user_ex(regs->r8, &sc->r8); 145 put_user_ex(regs->r9, &sc->r9); 146 put_user_ex(regs->r10, &sc->r10); 147 put_user_ex(regs->r11, &sc->r11); 148 put_user_ex(regs->r12, &sc->r12); 149 put_user_ex(regs->r13, &sc->r13); 150 put_user_ex(regs->r14, &sc->r14); 151 put_user_ex(regs->r15, &sc->r15); 152 #endif /* CONFIG_X86_64 */ 153 154 put_user_ex(current->thread.trap_nr, &sc->trapno); 155 put_user_ex(current->thread.error_code, &sc->err); 156 put_user_ex(regs->ip, &sc->ip); 157 #ifdef CONFIG_X86_32 158 put_user_ex(regs->cs, (unsigned int __user *)&sc->cs); 159 put_user_ex(regs->flags, &sc->flags); 160 put_user_ex(regs->sp, &sc->sp_at_signal); 161 put_user_ex(regs->ss, (unsigned int __user *)&sc->ss); 162 #else /* !CONFIG_X86_32 */ 163 put_user_ex(regs->flags, &sc->flags); 164 put_user_ex(regs->cs, &sc->cs); 165 put_user_ex(0, &sc->gs); 166 put_user_ex(0, &sc->fs); 167 #endif /* CONFIG_X86_32 */ 168 169 put_user_ex(fpstate, &sc->fpstate); 170 171 /* non-iBCS2 extensions.. */ 172 put_user_ex(mask, &sc->oldmask); 173 put_user_ex(current->thread.cr2, &sc->cr2); 174 } put_user_catch(err); 175 176 return err; 177 } 178 179 /* 180 * Set up a signal frame. 181 */ 182 183 /* 184 * Determine which stack to use.. 185 */ 186 static unsigned long align_sigframe(unsigned long sp) 187 { 188 #ifdef CONFIG_X86_32 189 /* 190 * Align the stack pointer according to the i386 ABI, 191 * i.e. so that on function entry ((sp + 4) & 15) == 0. 192 */ 193 sp = ((sp + 4) & -16ul) - 4; 194 #else /* !CONFIG_X86_32 */ 195 sp = round_down(sp, 16) - 8; 196 #endif 197 return sp; 198 } 199 200 static inline void __user * 201 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, 202 void __user **fpstate) 203 { 204 /* Default to using normal stack */ 205 unsigned long sp = regs->sp; 206 int onsigstack = on_sig_stack(sp); 207 208 #ifdef CONFIG_X86_64 209 /* redzone */ 210 sp -= 128; 211 #endif /* CONFIG_X86_64 */ 212 213 if (!onsigstack) { 214 /* This is the X/Open sanctioned signal stack switching. */ 215 if (ka->sa.sa_flags & SA_ONSTACK) { 216 if (current->sas_ss_size) 217 sp = current->sas_ss_sp + current->sas_ss_size; 218 } else { 219 #ifdef CONFIG_X86_32 220 /* This is the legacy signal stack switching. */ 221 if ((regs->ss & 0xffff) != __USER_DS && 222 !(ka->sa.sa_flags & SA_RESTORER) && 223 ka->sa.sa_restorer) 224 sp = (unsigned long) ka->sa.sa_restorer; 225 #endif /* CONFIG_X86_32 */ 226 } 227 } 228 229 if (used_math()) { 230 sp -= sig_xstate_size; 231 #ifdef CONFIG_X86_64 232 sp = round_down(sp, 64); 233 #endif /* CONFIG_X86_64 */ 234 *fpstate = (void __user *)sp; 235 } 236 237 sp = align_sigframe(sp - frame_size); 238 239 /* 240 * If we are on the alternate signal stack and would overflow it, don't. 241 * Return an always-bogus address instead so we will die with SIGSEGV. 242 */ 243 if (onsigstack && !likely(on_sig_stack(sp))) 244 return (void __user *)-1L; 245 246 /* save i387 state */ 247 if (used_math() && save_i387_xstate(*fpstate) < 0) 248 return (void __user *)-1L; 249 250 return (void __user *)sp; 251 } 252 253 #ifdef CONFIG_X86_32 254 static const struct { 255 u16 poplmovl; 256 u32 val; 257 u16 int80; 258 } __attribute__((packed)) retcode = { 259 0xb858, /* popl %eax; movl $..., %eax */ 260 __NR_sigreturn, 261 0x80cd, /* int $0x80 */ 262 }; 263 264 static const struct { 265 u8 movl; 266 u32 val; 267 u16 int80; 268 u8 pad; 269 } __attribute__((packed)) rt_retcode = { 270 0xb8, /* movl $..., %eax */ 271 __NR_rt_sigreturn, 272 0x80cd, /* int $0x80 */ 273 0 274 }; 275 276 static int 277 __setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, 278 struct pt_regs *regs) 279 { 280 struct sigframe __user *frame; 281 void __user *restorer; 282 int err = 0; 283 void __user *fpstate = NULL; 284 285 frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); 286 287 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 288 return -EFAULT; 289 290 if (__put_user(sig, &frame->sig)) 291 return -EFAULT; 292 293 if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) 294 return -EFAULT; 295 296 if (_NSIG_WORDS > 1) { 297 if (__copy_to_user(&frame->extramask, &set->sig[1], 298 sizeof(frame->extramask))) 299 return -EFAULT; 300 } 301 302 if (current->mm->context.vdso) 303 restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn); 304 else 305 restorer = &frame->retcode; 306 if (ka->sa.sa_flags & SA_RESTORER) 307 restorer = ka->sa.sa_restorer; 308 309 /* Set up to return from userspace. */ 310 err |= __put_user(restorer, &frame->pretcode); 311 312 /* 313 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 314 * 315 * WE DO NOT USE IT ANY MORE! It's only left here for historical 316 * reasons and because gdb uses it as a signature to notice 317 * signal handler stack frames. 318 */ 319 err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode); 320 321 if (err) 322 return -EFAULT; 323 324 /* Set up registers for signal handler */ 325 regs->sp = (unsigned long)frame; 326 regs->ip = (unsigned long)ka->sa.sa_handler; 327 regs->ax = (unsigned long)sig; 328 regs->dx = 0; 329 regs->cx = 0; 330 331 regs->ds = __USER_DS; 332 regs->es = __USER_DS; 333 regs->ss = __USER_DS; 334 regs->cs = __USER_CS; 335 336 return 0; 337 } 338 339 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 340 sigset_t *set, struct pt_regs *regs) 341 { 342 struct rt_sigframe __user *frame; 343 void __user *restorer; 344 int err = 0; 345 void __user *fpstate = NULL; 346 347 frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); 348 349 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 350 return -EFAULT; 351 352 put_user_try { 353 put_user_ex(sig, &frame->sig); 354 put_user_ex(&frame->info, &frame->pinfo); 355 put_user_ex(&frame->uc, &frame->puc); 356 err |= copy_siginfo_to_user(&frame->info, info); 357 358 /* 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(current->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(current->sas_ss_size, &frame->uc.uc_stack.ss_size); 368 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, 369 regs, set->sig[0]); 370 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 371 372 /* Set up to return from userspace. */ 373 restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn); 374 if (ka->sa.sa_flags & SA_RESTORER) 375 restorer = ka->sa.sa_restorer; 376 put_user_ex(restorer, &frame->pretcode); 377 378 /* 379 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 380 * 381 * WE DO NOT USE IT ANY MORE! It's only left here for historical 382 * reasons and because gdb uses it as a signature to notice 383 * signal handler stack frames. 384 */ 385 put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode); 386 } put_user_catch(err); 387 388 if (err) 389 return -EFAULT; 390 391 /* Set up registers for signal handler */ 392 regs->sp = (unsigned long)frame; 393 regs->ip = (unsigned long)ka->sa.sa_handler; 394 regs->ax = (unsigned long)sig; 395 regs->dx = (unsigned long)&frame->info; 396 regs->cx = (unsigned long)&frame->uc; 397 398 regs->ds = __USER_DS; 399 regs->es = __USER_DS; 400 regs->ss = __USER_DS; 401 regs->cs = __USER_CS; 402 403 return 0; 404 } 405 #else /* !CONFIG_X86_32 */ 406 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 407 sigset_t *set, struct pt_regs *regs) 408 { 409 struct rt_sigframe __user *frame; 410 void __user *fp = NULL; 411 int err = 0; 412 struct task_struct *me = current; 413 414 frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp); 415 416 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 417 return -EFAULT; 418 419 if (ka->sa.sa_flags & SA_SIGINFO) { 420 if (copy_siginfo_to_user(&frame->info, info)) 421 return -EFAULT; 422 } 423 424 put_user_try { 425 /* Create the ucontext. */ 426 if (cpu_has_xsave) 427 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); 428 else 429 put_user_ex(0, &frame->uc.uc_flags); 430 put_user_ex(0, &frame->uc.uc_link); 431 put_user_ex(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp); 432 put_user_ex(sas_ss_flags(regs->sp), 433 &frame->uc.uc_stack.ss_flags); 434 put_user_ex(me->sas_ss_size, &frame->uc.uc_stack.ss_size); 435 err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]); 436 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 437 438 /* Set up to return from userspace. If provided, use a stub 439 already in userspace. */ 440 /* x86-64 should always use SA_RESTORER. */ 441 if (ka->sa.sa_flags & SA_RESTORER) { 442 put_user_ex(ka->sa.sa_restorer, &frame->pretcode); 443 } else { 444 /* could use a vstub here */ 445 err |= -EFAULT; 446 } 447 } put_user_catch(err); 448 449 if (err) 450 return -EFAULT; 451 452 /* Set up registers for signal handler */ 453 regs->di = sig; 454 /* In case the signal handler was declared without prototypes */ 455 regs->ax = 0; 456 457 /* This also works for non SA_SIGINFO handlers because they expect the 458 next argument after the signal number on the stack. */ 459 regs->si = (unsigned long)&frame->info; 460 regs->dx = (unsigned long)&frame->uc; 461 regs->ip = (unsigned long) ka->sa.sa_handler; 462 463 regs->sp = (unsigned long)frame; 464 465 /* Set up the CS register to run signal handlers in 64-bit mode, 466 even if the handler happens to be interrupting 32-bit code. */ 467 regs->cs = __USER_CS; 468 469 return 0; 470 } 471 #endif /* CONFIG_X86_32 */ 472 473 #ifdef CONFIG_X86_32 474 /* 475 * Atomically swap in the new signal mask, and wait for a signal. 476 */ 477 asmlinkage int 478 sys_sigsuspend(int history0, int history1, old_sigset_t mask) 479 { 480 sigset_t blocked; 481 482 current->saved_sigmask = current->blocked; 483 484 mask &= _BLOCKABLE; 485 siginitset(&blocked, mask); 486 set_current_blocked(&blocked); 487 488 current->state = TASK_INTERRUPTIBLE; 489 schedule(); 490 491 set_restore_sigmask(); 492 return -ERESTARTNOHAND; 493 } 494 495 asmlinkage int 496 sys_sigaction(int sig, const struct old_sigaction __user *act, 497 struct old_sigaction __user *oact) 498 { 499 struct k_sigaction new_ka, old_ka; 500 int ret = 0; 501 502 if (act) { 503 old_sigset_t mask; 504 505 if (!access_ok(VERIFY_READ, act, sizeof(*act))) 506 return -EFAULT; 507 508 get_user_try { 509 get_user_ex(new_ka.sa.sa_handler, &act->sa_handler); 510 get_user_ex(new_ka.sa.sa_flags, &act->sa_flags); 511 get_user_ex(mask, &act->sa_mask); 512 get_user_ex(new_ka.sa.sa_restorer, &act->sa_restorer); 513 } get_user_catch(ret); 514 515 if (ret) 516 return -EFAULT; 517 siginitset(&new_ka.sa.sa_mask, mask); 518 } 519 520 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); 521 522 if (!ret && oact) { 523 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact))) 524 return -EFAULT; 525 526 put_user_try { 527 put_user_ex(old_ka.sa.sa_handler, &oact->sa_handler); 528 put_user_ex(old_ka.sa.sa_flags, &oact->sa_flags); 529 put_user_ex(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); 530 put_user_ex(old_ka.sa.sa_restorer, &oact->sa_restorer); 531 } put_user_catch(ret); 532 533 if (ret) 534 return -EFAULT; 535 } 536 537 return ret; 538 } 539 #endif /* CONFIG_X86_32 */ 540 541 long 542 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, 543 struct pt_regs *regs) 544 { 545 return do_sigaltstack(uss, uoss, regs->sp); 546 } 547 548 /* 549 * Do a signal return; undo the signal stack. 550 */ 551 #ifdef CONFIG_X86_32 552 unsigned long sys_sigreturn(struct pt_regs *regs) 553 { 554 struct sigframe __user *frame; 555 unsigned long ax; 556 sigset_t set; 557 558 frame = (struct sigframe __user *)(regs->sp - 8); 559 560 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 561 goto badframe; 562 if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 563 && __copy_from_user(&set.sig[1], &frame->extramask, 564 sizeof(frame->extramask)))) 565 goto badframe; 566 567 sigdelsetmask(&set, ~_BLOCKABLE); 568 set_current_blocked(&set); 569 570 if (restore_sigcontext(regs, &frame->sc, &ax)) 571 goto badframe; 572 return ax; 573 574 badframe: 575 signal_fault(regs, frame, "sigreturn"); 576 577 return 0; 578 } 579 #endif /* CONFIG_X86_32 */ 580 581 long sys_rt_sigreturn(struct pt_regs *regs) 582 { 583 struct rt_sigframe __user *frame; 584 unsigned long ax; 585 sigset_t set; 586 587 frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); 588 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 589 goto badframe; 590 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) 591 goto badframe; 592 593 sigdelsetmask(&set, ~_BLOCKABLE); 594 set_current_blocked(&set); 595 596 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) 597 goto badframe; 598 599 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) 600 goto badframe; 601 602 return ax; 603 604 badframe: 605 signal_fault(regs, frame, "rt_sigreturn"); 606 return 0; 607 } 608 609 /* 610 * OK, we're invoking a handler: 611 */ 612 static int signr_convert(int sig) 613 { 614 #ifdef CONFIG_X86_32 615 struct thread_info *info = current_thread_info(); 616 617 if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32) 618 return info->exec_domain->signal_invmap[sig]; 619 #endif /* CONFIG_X86_32 */ 620 return sig; 621 } 622 623 #ifdef CONFIG_X86_32 624 625 #define is_ia32 1 626 #define ia32_setup_frame __setup_frame 627 #define ia32_setup_rt_frame __setup_rt_frame 628 629 #else /* !CONFIG_X86_32 */ 630 631 #ifdef CONFIG_IA32_EMULATION 632 #define is_ia32 test_thread_flag(TIF_IA32) 633 #else /* !CONFIG_IA32_EMULATION */ 634 #define is_ia32 0 635 #endif /* CONFIG_IA32_EMULATION */ 636 637 #ifdef CONFIG_X86_X32_ABI 638 #define is_x32 test_thread_flag(TIF_X32) 639 640 static int x32_setup_rt_frame(int sig, struct k_sigaction *ka, 641 siginfo_t *info, compat_sigset_t *set, 642 struct pt_regs *regs); 643 #else /* !CONFIG_X86_X32_ABI */ 644 #define is_x32 0 645 #endif /* CONFIG_X86_X32_ABI */ 646 647 int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 648 sigset_t *set, struct pt_regs *regs); 649 int ia32_setup_frame(int sig, struct k_sigaction *ka, 650 sigset_t *set, struct pt_regs *regs); 651 652 #endif /* CONFIG_X86_32 */ 653 654 static int 655 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 656 struct pt_regs *regs) 657 { 658 int usig = signr_convert(sig); 659 sigset_t *set = ¤t->blocked; 660 int ret; 661 662 if (current_thread_info()->status & TS_RESTORE_SIGMASK) 663 set = ¤t->saved_sigmask; 664 665 /* Set up the stack frame */ 666 if (is_ia32) { 667 if (ka->sa.sa_flags & SA_SIGINFO) 668 ret = ia32_setup_rt_frame(usig, ka, info, set, regs); 669 else 670 ret = ia32_setup_frame(usig, ka, set, regs); 671 #ifdef CONFIG_X86_X32_ABI 672 } else if (is_x32) { 673 ret = x32_setup_rt_frame(usig, ka, info, 674 (compat_sigset_t *)set, regs); 675 #endif 676 } else { 677 ret = __setup_rt_frame(sig, ka, info, set, regs); 678 } 679 680 if (ret) { 681 force_sigsegv(sig, current); 682 return -EFAULT; 683 } 684 685 current_thread_info()->status &= ~TS_RESTORE_SIGMASK; 686 return ret; 687 } 688 689 static int 690 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, 691 struct pt_regs *regs) 692 { 693 int ret; 694 695 /* Are we from a system call? */ 696 if (syscall_get_nr(current, regs) >= 0) { 697 /* If so, check system call restarting.. */ 698 switch (syscall_get_error(current, regs)) { 699 case -ERESTART_RESTARTBLOCK: 700 case -ERESTARTNOHAND: 701 regs->ax = -EINTR; 702 break; 703 704 case -ERESTARTSYS: 705 if (!(ka->sa.sa_flags & SA_RESTART)) { 706 regs->ax = -EINTR; 707 break; 708 } 709 /* fallthrough */ 710 case -ERESTARTNOINTR: 711 regs->ax = regs->orig_ax; 712 regs->ip -= 2; 713 break; 714 } 715 } 716 717 /* 718 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF 719 * flag so that register information in the sigcontext is correct. 720 */ 721 if (unlikely(regs->flags & X86_EFLAGS_TF) && 722 likely(test_and_clear_thread_flag(TIF_FORCED_TF))) 723 regs->flags &= ~X86_EFLAGS_TF; 724 725 ret = setup_rt_frame(sig, ka, info, regs); 726 727 if (ret) 728 return ret; 729 730 /* 731 * Clear the direction flag as per the ABI for function entry. 732 */ 733 regs->flags &= ~X86_EFLAGS_DF; 734 735 /* 736 * Clear TF when entering the signal handler, but 737 * notify any tracer that was single-stepping it. 738 * The tracer may want to single-step inside the 739 * handler too. 740 */ 741 regs->flags &= ~X86_EFLAGS_TF; 742 743 block_sigmask(ka, sig); 744 745 tracehook_signal_handler(sig, info, ka, regs, 746 test_thread_flag(TIF_SINGLESTEP)); 747 748 return 0; 749 } 750 751 #ifdef CONFIG_X86_32 752 #define NR_restart_syscall __NR_restart_syscall 753 #else /* !CONFIG_X86_32 */ 754 #define NR_restart_syscall \ 755 test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall 756 #endif /* CONFIG_X86_32 */ 757 758 /* 759 * Note that 'init' is a special process: it doesn't get signals it doesn't 760 * want to handle. Thus you cannot kill init even with a SIGKILL even by 761 * mistake. 762 */ 763 static void do_signal(struct pt_regs *regs) 764 { 765 struct k_sigaction ka; 766 siginfo_t info; 767 int signr; 768 769 /* 770 * We want the common case to go fast, which is why we may in certain 771 * cases get here from kernel mode. Just return without doing anything 772 * if so. 773 * X86_32: vm86 regs switched out by assembly code before reaching 774 * here, so testing against kernel CS suffices. 775 */ 776 if (!user_mode(regs)) 777 return; 778 779 signr = get_signal_to_deliver(&info, &ka, regs, NULL); 780 if (signr > 0) { 781 /* Whee! Actually deliver the signal. */ 782 handle_signal(signr, &info, &ka, regs); 783 return; 784 } 785 786 /* Did we come from a system call? */ 787 if (syscall_get_nr(current, regs) >= 0) { 788 /* Restart the system call - no handlers present */ 789 switch (syscall_get_error(current, regs)) { 790 case -ERESTARTNOHAND: 791 case -ERESTARTSYS: 792 case -ERESTARTNOINTR: 793 regs->ax = regs->orig_ax; 794 regs->ip -= 2; 795 break; 796 797 case -ERESTART_RESTARTBLOCK: 798 regs->ax = NR_restart_syscall; 799 regs->ip -= 2; 800 break; 801 } 802 } 803 804 /* 805 * If there's no signal to deliver, we just put the saved sigmask 806 * back. 807 */ 808 if (current_thread_info()->status & TS_RESTORE_SIGMASK) { 809 current_thread_info()->status &= ~TS_RESTORE_SIGMASK; 810 set_current_blocked(¤t->saved_sigmask); 811 } 812 } 813 814 /* 815 * notification of userspace execution resumption 816 * - triggered by the TIF_WORK_MASK flags 817 */ 818 void 819 do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) 820 { 821 #ifdef CONFIG_X86_MCE 822 /* notify userspace of pending MCEs */ 823 if (thread_info_flags & _TIF_MCE_NOTIFY) 824 mce_notify_process(); 825 #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */ 826 827 /* deal with pending signal delivery */ 828 if (thread_info_flags & _TIF_SIGPENDING) 829 do_signal(regs); 830 831 if (thread_info_flags & _TIF_NOTIFY_RESUME) { 832 clear_thread_flag(TIF_NOTIFY_RESUME); 833 tracehook_notify_resume(regs); 834 if (current->replacement_session_keyring) 835 key_replace_session_keyring(); 836 } 837 if (thread_info_flags & _TIF_USER_RETURN_NOTIFY) 838 fire_user_return_notifiers(); 839 840 #ifdef CONFIG_X86_32 841 clear_thread_flag(TIF_IRET); 842 #endif /* CONFIG_X86_32 */ 843 } 844 845 void signal_fault(struct pt_regs *regs, void __user *frame, char *where) 846 { 847 struct task_struct *me = current; 848 849 if (show_unhandled_signals && printk_ratelimit()) { 850 printk("%s" 851 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx", 852 task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, 853 me->comm, me->pid, where, frame, 854 regs->ip, regs->sp, regs->orig_ax); 855 print_vma_addr(" in ", regs->ip); 856 printk(KERN_CONT "\n"); 857 } 858 859 force_sig(SIGSEGV, me); 860 } 861 862 #ifdef CONFIG_X86_X32_ABI 863 static int x32_setup_rt_frame(int sig, struct k_sigaction *ka, 864 siginfo_t *info, compat_sigset_t *set, 865 struct pt_regs *regs) 866 { 867 struct rt_sigframe_x32 __user *frame; 868 void __user *restorer; 869 int err = 0; 870 void __user *fpstate = NULL; 871 872 frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); 873 874 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 875 return -EFAULT; 876 877 if (ka->sa.sa_flags & SA_SIGINFO) { 878 if (copy_siginfo_to_user32(&frame->info, info)) 879 return -EFAULT; 880 } 881 882 put_user_try { 883 /* Create the ucontext. */ 884 if (cpu_has_xsave) 885 put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); 886 else 887 put_user_ex(0, &frame->uc.uc_flags); 888 put_user_ex(0, &frame->uc.uc_link); 889 put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); 890 put_user_ex(sas_ss_flags(regs->sp), 891 &frame->uc.uc_stack.ss_flags); 892 put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size); 893 put_user_ex(0, &frame->uc.uc__pad0); 894 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, 895 regs, set->sig[0]); 896 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 897 898 if (ka->sa.sa_flags & SA_RESTORER) { 899 restorer = ka->sa.sa_restorer; 900 } else { 901 /* could use a vstub here */ 902 restorer = NULL; 903 err |= -EFAULT; 904 } 905 put_user_ex(restorer, &frame->pretcode); 906 } put_user_catch(err); 907 908 if (err) 909 return -EFAULT; 910 911 /* Set up registers for signal handler */ 912 regs->sp = (unsigned long) frame; 913 regs->ip = (unsigned long) ka->sa.sa_handler; 914 915 /* We use the x32 calling convention here... */ 916 regs->di = sig; 917 regs->si = (unsigned long) &frame->info; 918 regs->dx = (unsigned long) &frame->uc; 919 920 loadsegment(ds, __USER_DS); 921 loadsegment(es, __USER_DS); 922 923 regs->cs = __USER_CS; 924 regs->ss = __USER_DS; 925 926 return 0; 927 } 928 929 asmlinkage long sys32_x32_rt_sigreturn(struct pt_regs *regs) 930 { 931 struct rt_sigframe_x32 __user *frame; 932 sigset_t set; 933 unsigned long ax; 934 struct pt_regs tregs; 935 936 frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8); 937 938 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 939 goto badframe; 940 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) 941 goto badframe; 942 943 sigdelsetmask(&set, ~_BLOCKABLE); 944 set_current_blocked(&set); 945 946 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) 947 goto badframe; 948 949 tregs = *regs; 950 if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT) 951 goto badframe; 952 953 return ax; 954 955 badframe: 956 signal_fault(regs, frame, "x32 rt_sigreturn"); 957 return 0; 958 } 959 #endif 960