1 /* 2 * Based on arch/arm/kernel/signal.c 3 * 4 * Copyright (C) 1995-2009 Russell King 5 * Copyright (C) 2012 ARM Ltd. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include <linux/compat.h> 21 #include <linux/errno.h> 22 #include <linux/kernel.h> 23 #include <linux/signal.h> 24 #include <linux/personality.h> 25 #include <linux/freezer.h> 26 #include <linux/stddef.h> 27 #include <linux/uaccess.h> 28 #include <linux/sizes.h> 29 #include <linux/string.h> 30 #include <linux/tracehook.h> 31 #include <linux/ratelimit.h> 32 #include <linux/syscalls.h> 33 34 #include <asm/debug-monitors.h> 35 #include <asm/elf.h> 36 #include <asm/cacheflush.h> 37 #include <asm/ucontext.h> 38 #include <asm/unistd.h> 39 #include <asm/fpsimd.h> 40 #include <asm/ptrace.h> 41 #include <asm/signal32.h> 42 #include <asm/vdso.h> 43 44 /* 45 * Do a signal return; undo the signal stack. These are aligned to 128-bit. 46 */ 47 struct rt_sigframe { 48 struct siginfo info; 49 struct ucontext uc; 50 }; 51 52 struct frame_record { 53 u64 fp; 54 u64 lr; 55 }; 56 57 struct rt_sigframe_user_layout { 58 struct rt_sigframe __user *sigframe; 59 struct frame_record __user *next_frame; 60 61 unsigned long size; /* size of allocated sigframe data */ 62 unsigned long limit; /* largest allowed size */ 63 64 unsigned long fpsimd_offset; 65 unsigned long esr_offset; 66 unsigned long extra_offset; 67 unsigned long end_offset; 68 }; 69 70 #define BASE_SIGFRAME_SIZE round_up(sizeof(struct rt_sigframe), 16) 71 #define TERMINATOR_SIZE round_up(sizeof(struct _aarch64_ctx), 16) 72 #define EXTRA_CONTEXT_SIZE round_up(sizeof(struct extra_context), 16) 73 74 static void init_user_layout(struct rt_sigframe_user_layout *user) 75 { 76 const size_t reserved_size = 77 sizeof(user->sigframe->uc.uc_mcontext.__reserved); 78 79 memset(user, 0, sizeof(*user)); 80 user->size = offsetof(struct rt_sigframe, uc.uc_mcontext.__reserved); 81 82 user->limit = user->size + reserved_size; 83 84 user->limit -= TERMINATOR_SIZE; 85 user->limit -= EXTRA_CONTEXT_SIZE; 86 /* Reserve space for extension and terminator ^ */ 87 } 88 89 static size_t sigframe_size(struct rt_sigframe_user_layout const *user) 90 { 91 return round_up(max(user->size, sizeof(struct rt_sigframe)), 16); 92 } 93 94 /* 95 * Sanity limit on the approximate maximum size of signal frame we'll 96 * try to generate. Stack alignment padding and the frame record are 97 * not taken into account. This limit is not a guarantee and is 98 * NOT ABI. 99 */ 100 #define SIGFRAME_MAXSZ SZ_64K 101 102 static int __sigframe_alloc(struct rt_sigframe_user_layout *user, 103 unsigned long *offset, size_t size, bool extend) 104 { 105 size_t padded_size = round_up(size, 16); 106 107 if (padded_size > user->limit - user->size && 108 !user->extra_offset && 109 extend) { 110 int ret; 111 112 user->limit += EXTRA_CONTEXT_SIZE; 113 ret = __sigframe_alloc(user, &user->extra_offset, 114 sizeof(struct extra_context), false); 115 if (ret) { 116 user->limit -= EXTRA_CONTEXT_SIZE; 117 return ret; 118 } 119 120 /* Reserve space for the __reserved[] terminator */ 121 user->size += TERMINATOR_SIZE; 122 123 /* 124 * Allow expansion up to SIGFRAME_MAXSZ, ensuring space for 125 * the terminator: 126 */ 127 user->limit = SIGFRAME_MAXSZ - TERMINATOR_SIZE; 128 } 129 130 /* Still not enough space? Bad luck! */ 131 if (padded_size > user->limit - user->size) 132 return -ENOMEM; 133 134 *offset = user->size; 135 user->size += padded_size; 136 137 return 0; 138 } 139 140 /* 141 * Allocate space for an optional record of <size> bytes in the user 142 * signal frame. The offset from the signal frame base address to the 143 * allocated block is assigned to *offset. 144 */ 145 static int sigframe_alloc(struct rt_sigframe_user_layout *user, 146 unsigned long *offset, size_t size) 147 { 148 return __sigframe_alloc(user, offset, size, true); 149 } 150 151 /* Allocate the null terminator record and prevent further allocations */ 152 static int sigframe_alloc_end(struct rt_sigframe_user_layout *user) 153 { 154 int ret; 155 156 /* Un-reserve the space reserved for the terminator: */ 157 user->limit += TERMINATOR_SIZE; 158 159 ret = sigframe_alloc(user, &user->end_offset, 160 sizeof(struct _aarch64_ctx)); 161 if (ret) 162 return ret; 163 164 /* Prevent further allocation: */ 165 user->limit = user->size; 166 return 0; 167 } 168 169 static void __user *apply_user_offset( 170 struct rt_sigframe_user_layout const *user, unsigned long offset) 171 { 172 char __user *base = (char __user *)user->sigframe; 173 174 return base + offset; 175 } 176 177 static int preserve_fpsimd_context(struct fpsimd_context __user *ctx) 178 { 179 struct fpsimd_state *fpsimd = ¤t->thread.fpsimd_state; 180 int err; 181 182 /* dump the hardware registers to the fpsimd_state structure */ 183 fpsimd_preserve_current_state(); 184 185 /* copy the FP and status/control registers */ 186 err = __copy_to_user(ctx->vregs, fpsimd->vregs, sizeof(fpsimd->vregs)); 187 __put_user_error(fpsimd->fpsr, &ctx->fpsr, err); 188 __put_user_error(fpsimd->fpcr, &ctx->fpcr, err); 189 190 /* copy the magic/size information */ 191 __put_user_error(FPSIMD_MAGIC, &ctx->head.magic, err); 192 __put_user_error(sizeof(struct fpsimd_context), &ctx->head.size, err); 193 194 return err ? -EFAULT : 0; 195 } 196 197 static int restore_fpsimd_context(struct fpsimd_context __user *ctx) 198 { 199 struct fpsimd_state fpsimd; 200 __u32 magic, size; 201 int err = 0; 202 203 /* check the magic/size information */ 204 __get_user_error(magic, &ctx->head.magic, err); 205 __get_user_error(size, &ctx->head.size, err); 206 if (err) 207 return -EFAULT; 208 if (magic != FPSIMD_MAGIC || size != sizeof(struct fpsimd_context)) 209 return -EINVAL; 210 211 /* copy the FP and status/control registers */ 212 err = __copy_from_user(fpsimd.vregs, ctx->vregs, 213 sizeof(fpsimd.vregs)); 214 __get_user_error(fpsimd.fpsr, &ctx->fpsr, err); 215 __get_user_error(fpsimd.fpcr, &ctx->fpcr, err); 216 217 /* load the hardware registers from the fpsimd_state structure */ 218 if (!err) 219 fpsimd_update_current_state(&fpsimd); 220 221 return err ? -EFAULT : 0; 222 } 223 224 struct user_ctxs { 225 struct fpsimd_context __user *fpsimd; 226 }; 227 228 static int parse_user_sigframe(struct user_ctxs *user, 229 struct rt_sigframe __user *sf) 230 { 231 struct sigcontext __user *const sc = &sf->uc.uc_mcontext; 232 struct _aarch64_ctx __user *head; 233 char __user *base = (char __user *)&sc->__reserved; 234 size_t offset = 0; 235 size_t limit = sizeof(sc->__reserved); 236 bool have_extra_context = false; 237 char const __user *const sfp = (char const __user *)sf; 238 239 user->fpsimd = NULL; 240 241 if (!IS_ALIGNED((unsigned long)base, 16)) 242 goto invalid; 243 244 while (1) { 245 int err = 0; 246 u32 magic, size; 247 char const __user *userp; 248 struct extra_context const __user *extra; 249 u64 extra_datap; 250 u32 extra_size; 251 struct _aarch64_ctx const __user *end; 252 u32 end_magic, end_size; 253 254 if (limit - offset < sizeof(*head)) 255 goto invalid; 256 257 if (!IS_ALIGNED(offset, 16)) 258 goto invalid; 259 260 head = (struct _aarch64_ctx __user *)(base + offset); 261 __get_user_error(magic, &head->magic, err); 262 __get_user_error(size, &head->size, err); 263 if (err) 264 return err; 265 266 if (limit - offset < size) 267 goto invalid; 268 269 switch (magic) { 270 case 0: 271 if (size) 272 goto invalid; 273 274 goto done; 275 276 case FPSIMD_MAGIC: 277 if (user->fpsimd) 278 goto invalid; 279 280 if (size < sizeof(*user->fpsimd)) 281 goto invalid; 282 283 user->fpsimd = (struct fpsimd_context __user *)head; 284 break; 285 286 case ESR_MAGIC: 287 /* ignore */ 288 break; 289 290 case EXTRA_MAGIC: 291 if (have_extra_context) 292 goto invalid; 293 294 if (size < sizeof(*extra)) 295 goto invalid; 296 297 userp = (char const __user *)head; 298 299 extra = (struct extra_context const __user *)userp; 300 userp += size; 301 302 __get_user_error(extra_datap, &extra->datap, err); 303 __get_user_error(extra_size, &extra->size, err); 304 if (err) 305 return err; 306 307 /* Check for the dummy terminator in __reserved[]: */ 308 309 if (limit - offset - size < TERMINATOR_SIZE) 310 goto invalid; 311 312 end = (struct _aarch64_ctx const __user *)userp; 313 userp += TERMINATOR_SIZE; 314 315 __get_user_error(end_magic, &end->magic, err); 316 __get_user_error(end_size, &end->size, err); 317 if (err) 318 return err; 319 320 if (end_magic || end_size) 321 goto invalid; 322 323 /* Prevent looping/repeated parsing of extra_context */ 324 have_extra_context = true; 325 326 base = (__force void __user *)extra_datap; 327 if (!IS_ALIGNED((unsigned long)base, 16)) 328 goto invalid; 329 330 if (!IS_ALIGNED(extra_size, 16)) 331 goto invalid; 332 333 if (base != userp) 334 goto invalid; 335 336 /* Reject "unreasonably large" frames: */ 337 if (extra_size > sfp + SIGFRAME_MAXSZ - userp) 338 goto invalid; 339 340 /* 341 * Ignore trailing terminator in __reserved[] 342 * and start parsing extra data: 343 */ 344 offset = 0; 345 limit = extra_size; 346 continue; 347 348 default: 349 goto invalid; 350 } 351 352 if (size < sizeof(*head)) 353 goto invalid; 354 355 if (limit - offset < size) 356 goto invalid; 357 358 offset += size; 359 } 360 361 done: 362 if (!user->fpsimd) 363 goto invalid; 364 365 return 0; 366 367 invalid: 368 return -EINVAL; 369 } 370 371 static int restore_sigframe(struct pt_regs *regs, 372 struct rt_sigframe __user *sf) 373 { 374 sigset_t set; 375 int i, err; 376 struct user_ctxs user; 377 378 err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); 379 if (err == 0) 380 set_current_blocked(&set); 381 382 for (i = 0; i < 31; i++) 383 __get_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i], 384 err); 385 __get_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err); 386 __get_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err); 387 __get_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err); 388 389 /* 390 * Avoid sys_rt_sigreturn() restarting. 391 */ 392 forget_syscall(regs); 393 394 err |= !valid_user_regs(®s->user_regs, current); 395 if (err == 0) 396 err = parse_user_sigframe(&user, sf); 397 398 if (err == 0) 399 err = restore_fpsimd_context(user.fpsimd); 400 401 return err; 402 } 403 404 asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) 405 { 406 struct rt_sigframe __user *frame; 407 408 /* Always make any pending restarted system calls return -EINTR */ 409 current->restart_block.fn = do_no_restart_syscall; 410 411 /* 412 * Since we stacked the signal on a 128-bit boundary, then 'sp' should 413 * be word aligned here. 414 */ 415 if (regs->sp & 15) 416 goto badframe; 417 418 frame = (struct rt_sigframe __user *)regs->sp; 419 420 if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) 421 goto badframe; 422 423 if (restore_sigframe(regs, frame)) 424 goto badframe; 425 426 if (restore_altstack(&frame->uc.uc_stack)) 427 goto badframe; 428 429 return regs->regs[0]; 430 431 badframe: 432 if (show_unhandled_signals) 433 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n", 434 current->comm, task_pid_nr(current), __func__, 435 regs->pc, regs->sp); 436 force_sig(SIGSEGV, current); 437 return 0; 438 } 439 440 /* Determine the layout of optional records in the signal frame */ 441 static int setup_sigframe_layout(struct rt_sigframe_user_layout *user) 442 { 443 int err; 444 445 err = sigframe_alloc(user, &user->fpsimd_offset, 446 sizeof(struct fpsimd_context)); 447 if (err) 448 return err; 449 450 /* fault information, if valid */ 451 if (current->thread.fault_code) { 452 err = sigframe_alloc(user, &user->esr_offset, 453 sizeof(struct esr_context)); 454 if (err) 455 return err; 456 } 457 458 return sigframe_alloc_end(user); 459 } 460 461 462 static int setup_sigframe(struct rt_sigframe_user_layout *user, 463 struct pt_regs *regs, sigset_t *set) 464 { 465 int i, err = 0; 466 struct rt_sigframe __user *sf = user->sigframe; 467 468 /* set up the stack frame for unwinding */ 469 __put_user_error(regs->regs[29], &user->next_frame->fp, err); 470 __put_user_error(regs->regs[30], &user->next_frame->lr, err); 471 472 for (i = 0; i < 31; i++) 473 __put_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i], 474 err); 475 __put_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err); 476 __put_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err); 477 __put_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err); 478 479 __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err); 480 481 err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set)); 482 483 if (err == 0) { 484 struct fpsimd_context __user *fpsimd_ctx = 485 apply_user_offset(user, user->fpsimd_offset); 486 err |= preserve_fpsimd_context(fpsimd_ctx); 487 } 488 489 /* fault information, if valid */ 490 if (err == 0 && user->esr_offset) { 491 struct esr_context __user *esr_ctx = 492 apply_user_offset(user, user->esr_offset); 493 494 __put_user_error(ESR_MAGIC, &esr_ctx->head.magic, err); 495 __put_user_error(sizeof(*esr_ctx), &esr_ctx->head.size, err); 496 __put_user_error(current->thread.fault_code, &esr_ctx->esr, err); 497 } 498 499 if (err == 0 && user->extra_offset) { 500 char __user *sfp = (char __user *)user->sigframe; 501 char __user *userp = 502 apply_user_offset(user, user->extra_offset); 503 504 struct extra_context __user *extra; 505 struct _aarch64_ctx __user *end; 506 u64 extra_datap; 507 u32 extra_size; 508 509 extra = (struct extra_context __user *)userp; 510 userp += EXTRA_CONTEXT_SIZE; 511 512 end = (struct _aarch64_ctx __user *)userp; 513 userp += TERMINATOR_SIZE; 514 515 /* 516 * extra_datap is just written to the signal frame. 517 * The value gets cast back to a void __user * 518 * during sigreturn. 519 */ 520 extra_datap = (__force u64)userp; 521 extra_size = sfp + round_up(user->size, 16) - userp; 522 523 __put_user_error(EXTRA_MAGIC, &extra->head.magic, err); 524 __put_user_error(EXTRA_CONTEXT_SIZE, &extra->head.size, err); 525 __put_user_error(extra_datap, &extra->datap, err); 526 __put_user_error(extra_size, &extra->size, err); 527 528 /* Add the terminator */ 529 __put_user_error(0, &end->magic, err); 530 __put_user_error(0, &end->size, err); 531 } 532 533 /* set the "end" magic */ 534 if (err == 0) { 535 struct _aarch64_ctx __user *end = 536 apply_user_offset(user, user->end_offset); 537 538 __put_user_error(0, &end->magic, err); 539 __put_user_error(0, &end->size, err); 540 } 541 542 return err; 543 } 544 545 static int get_sigframe(struct rt_sigframe_user_layout *user, 546 struct ksignal *ksig, struct pt_regs *regs) 547 { 548 unsigned long sp, sp_top; 549 int err; 550 551 init_user_layout(user); 552 err = setup_sigframe_layout(user); 553 if (err) 554 return err; 555 556 sp = sp_top = sigsp(regs->sp, ksig); 557 558 sp = round_down(sp - sizeof(struct frame_record), 16); 559 user->next_frame = (struct frame_record __user *)sp; 560 561 sp = round_down(sp, 16) - sigframe_size(user); 562 user->sigframe = (struct rt_sigframe __user *)sp; 563 564 /* 565 * Check that we can actually write to the signal frame. 566 */ 567 if (!access_ok(VERIFY_WRITE, user->sigframe, sp_top - sp)) 568 return -EFAULT; 569 570 return 0; 571 } 572 573 static void setup_return(struct pt_regs *regs, struct k_sigaction *ka, 574 struct rt_sigframe_user_layout *user, int usig) 575 { 576 __sigrestore_t sigtramp; 577 578 regs->regs[0] = usig; 579 regs->sp = (unsigned long)user->sigframe; 580 regs->regs[29] = (unsigned long)&user->next_frame->fp; 581 regs->pc = (unsigned long)ka->sa.sa_handler; 582 583 if (ka->sa.sa_flags & SA_RESTORER) 584 sigtramp = ka->sa.sa_restorer; 585 else 586 sigtramp = VDSO_SYMBOL(current->mm->context.vdso, sigtramp); 587 588 regs->regs[30] = (unsigned long)sigtramp; 589 } 590 591 static int setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set, 592 struct pt_regs *regs) 593 { 594 struct rt_sigframe_user_layout user; 595 struct rt_sigframe __user *frame; 596 int err = 0; 597 598 if (get_sigframe(&user, ksig, regs)) 599 return 1; 600 601 frame = user.sigframe; 602 603 __put_user_error(0, &frame->uc.uc_flags, err); 604 __put_user_error(NULL, &frame->uc.uc_link, err); 605 606 err |= __save_altstack(&frame->uc.uc_stack, regs->sp); 607 err |= setup_sigframe(&user, regs, set); 608 if (err == 0) { 609 setup_return(regs, &ksig->ka, &user, usig); 610 if (ksig->ka.sa.sa_flags & SA_SIGINFO) { 611 err |= copy_siginfo_to_user(&frame->info, &ksig->info); 612 regs->regs[1] = (unsigned long)&frame->info; 613 regs->regs[2] = (unsigned long)&frame->uc; 614 } 615 } 616 617 return err; 618 } 619 620 static void setup_restart_syscall(struct pt_regs *regs) 621 { 622 if (is_compat_task()) 623 compat_setup_restart_syscall(regs); 624 else 625 regs->regs[8] = __NR_restart_syscall; 626 } 627 628 /* 629 * OK, we're invoking a handler 630 */ 631 static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) 632 { 633 struct task_struct *tsk = current; 634 sigset_t *oldset = sigmask_to_save(); 635 int usig = ksig->sig; 636 int ret; 637 638 /* 639 * Set up the stack frame 640 */ 641 if (is_compat_task()) { 642 if (ksig->ka.sa.sa_flags & SA_SIGINFO) 643 ret = compat_setup_rt_frame(usig, ksig, oldset, regs); 644 else 645 ret = compat_setup_frame(usig, ksig, oldset, regs); 646 } else { 647 ret = setup_rt_frame(usig, ksig, oldset, regs); 648 } 649 650 /* 651 * Check that the resulting registers are actually sane. 652 */ 653 ret |= !valid_user_regs(®s->user_regs, current); 654 655 /* 656 * Fast forward the stepping logic so we step into the signal 657 * handler. 658 */ 659 if (!ret) 660 user_fastforward_single_step(tsk); 661 662 signal_setup_done(ret, ksig, 0); 663 } 664 665 /* 666 * Note that 'init' is a special process: it doesn't get signals it doesn't 667 * want to handle. Thus you cannot kill init even with a SIGKILL even by 668 * mistake. 669 * 670 * Note that we go through the signals twice: once to check the signals that 671 * the kernel can handle, and then we build all the user-level signal handling 672 * stack-frames in one go after that. 673 */ 674 static void do_signal(struct pt_regs *regs) 675 { 676 unsigned long continue_addr = 0, restart_addr = 0; 677 int retval = 0; 678 struct ksignal ksig; 679 680 /* 681 * If we were from a system call, check for system call restarting... 682 */ 683 if (in_syscall(regs)) { 684 continue_addr = regs->pc; 685 restart_addr = continue_addr - (compat_thumb_mode(regs) ? 2 : 4); 686 retval = regs->regs[0]; 687 688 /* 689 * Avoid additional syscall restarting via ret_to_user. 690 */ 691 forget_syscall(regs); 692 693 /* 694 * Prepare for system call restart. We do this here so that a 695 * debugger will see the already changed PC. 696 */ 697 switch (retval) { 698 case -ERESTARTNOHAND: 699 case -ERESTARTSYS: 700 case -ERESTARTNOINTR: 701 case -ERESTART_RESTARTBLOCK: 702 regs->regs[0] = regs->orig_x0; 703 regs->pc = restart_addr; 704 break; 705 } 706 } 707 708 /* 709 * Get the signal to deliver. When running under ptrace, at this point 710 * the debugger may change all of our registers. 711 */ 712 if (get_signal(&ksig)) { 713 /* 714 * Depending on the signal settings, we may need to revert the 715 * decision to restart the system call, but skip this if a 716 * debugger has chosen to restart at a different PC. 717 */ 718 if (regs->pc == restart_addr && 719 (retval == -ERESTARTNOHAND || 720 retval == -ERESTART_RESTARTBLOCK || 721 (retval == -ERESTARTSYS && 722 !(ksig.ka.sa.sa_flags & SA_RESTART)))) { 723 regs->regs[0] = -EINTR; 724 regs->pc = continue_addr; 725 } 726 727 handle_signal(&ksig, regs); 728 return; 729 } 730 731 /* 732 * Handle restarting a different system call. As above, if a debugger 733 * has chosen to restart at a different PC, ignore the restart. 734 */ 735 if (in_syscall(regs) && regs->pc == restart_addr) { 736 if (retval == -ERESTART_RESTARTBLOCK) 737 setup_restart_syscall(regs); 738 user_rewind_single_step(current); 739 } 740 741 restore_saved_sigmask(); 742 } 743 744 asmlinkage void do_notify_resume(struct pt_regs *regs, 745 unsigned int thread_flags) 746 { 747 /* 748 * The assembly code enters us with IRQs off, but it hasn't 749 * informed the tracing code of that for efficiency reasons. 750 * Update the trace code with the current status. 751 */ 752 trace_hardirqs_off(); 753 754 do { 755 /* Check valid user FS if needed */ 756 addr_limit_user_check(); 757 758 if (thread_flags & _TIF_NEED_RESCHED) { 759 schedule(); 760 } else { 761 local_irq_enable(); 762 763 if (thread_flags & _TIF_UPROBE) 764 uprobe_notify_resume(regs); 765 766 if (thread_flags & _TIF_SIGPENDING) 767 do_signal(regs); 768 769 if (thread_flags & _TIF_NOTIFY_RESUME) { 770 clear_thread_flag(TIF_NOTIFY_RESUME); 771 tracehook_notify_resume(regs); 772 } 773 774 if (thread_flags & _TIF_FOREIGN_FPSTATE) 775 fpsimd_restore_current_state(); 776 } 777 778 local_irq_disable(); 779 thread_flags = READ_ONCE(current_thread_info()->flags); 780 } while (thread_flags & _TIF_WORK_MASK); 781 } 782