1 /* 2 * linux/arch/parisc/kernel/signal.c: Architecture-specific signal 3 * handling support. 4 * 5 * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org> 6 * Copyright (C) 2000 Linuxcare, Inc. 7 * 8 * Based on the ia64, i386, and alpha versions. 9 * 10 * Like the IA-64, we are a recent enough port (we are *starting* 11 * with glibc2.2) that we do not need to support the old non-realtime 12 * Linux signals. Therefore we don't. HP/UX signals will go in 13 * arch/parisc/hpux/signal.c when we figure out how to do them. 14 */ 15 16 #include <linux/sched.h> 17 #include <linux/mm.h> 18 #include <linux/smp.h> 19 #include <linux/kernel.h> 20 #include <linux/signal.h> 21 #include <linux/errno.h> 22 #include <linux/wait.h> 23 #include <linux/ptrace.h> 24 #include <linux/tracehook.h> 25 #include <linux/unistd.h> 26 #include <linux/stddef.h> 27 #include <linux/compat.h> 28 #include <linux/elf.h> 29 #include <asm/ucontext.h> 30 #include <asm/rt_sigframe.h> 31 #include <asm/uaccess.h> 32 #include <asm/pgalloc.h> 33 #include <asm/cacheflush.h> 34 #include <asm/asm-offsets.h> 35 36 #ifdef CONFIG_COMPAT 37 #include "signal32.h" 38 #endif 39 40 #define DEBUG_SIG 0 41 #define DEBUG_SIG_LEVEL 2 42 43 #if DEBUG_SIG 44 #define DBG(LEVEL, ...) \ 45 ((DEBUG_SIG_LEVEL >= LEVEL) \ 46 ? printk(__VA_ARGS__) : (void) 0) 47 #else 48 #define DBG(LEVEL, ...) 49 #endif 50 51 /* gcc will complain if a pointer is cast to an integer of different 52 * size. If you really need to do this (and we do for an ELF32 user 53 * application in an ELF64 kernel) then you have to do a cast to an 54 * integer of the same size first. The A() macro accomplishes 55 * this. */ 56 #define A(__x) ((unsigned long)(__x)) 57 58 /* 59 * Atomically swap in the new signal mask, and wait for a signal. 60 */ 61 #ifdef CONFIG_64BIT 62 #include "sys32.h" 63 #endif 64 65 /* 66 * Do a signal return - restore sigcontext. 67 */ 68 69 /* Trampoline for calling rt_sigreturn() */ 70 #define INSN_LDI_R25_0 0x34190000 /* ldi 0,%r25 (in_syscall=0) */ 71 #define INSN_LDI_R25_1 0x34190002 /* ldi 1,%r25 (in_syscall=1) */ 72 #define INSN_LDI_R20 0x3414015a /* ldi __NR_rt_sigreturn,%r20 */ 73 #define INSN_BLE_SR2_R0 0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */ 74 #define INSN_NOP 0x08000240 /* nop */ 75 /* For debugging */ 76 #define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */ 77 78 static long 79 restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) 80 { 81 long err = 0; 82 83 err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr)); 84 err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr)); 85 err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq)); 86 err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq)); 87 err |= __get_user(regs->sar, &sc->sc_sar); 88 DBG(2,"restore_sigcontext: iaoq is 0x%#lx / 0x%#lx\n", 89 regs->iaoq[0],regs->iaoq[1]); 90 DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]); 91 return err; 92 } 93 94 void 95 sys_rt_sigreturn(struct pt_regs *regs, int in_syscall) 96 { 97 struct rt_sigframe __user *frame; 98 sigset_t set; 99 unsigned long usp = (regs->gr[30] & ~(0x01UL)); 100 unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE; 101 #ifdef CONFIG_64BIT 102 compat_sigset_t compat_set; 103 struct compat_rt_sigframe __user * compat_frame; 104 105 if (is_compat_task()) 106 sigframe_size = PARISC_RT_SIGFRAME_SIZE32; 107 #endif 108 109 current_thread_info()->restart_block.fn = do_no_restart_syscall; 110 111 /* Unwind the user stack to get the rt_sigframe structure. */ 112 frame = (struct rt_sigframe __user *) 113 (usp - sigframe_size); 114 DBG(2,"sys_rt_sigreturn: frame is %p\n", frame); 115 116 regs->orig_r28 = 1; /* no restarts for sigreturn */ 117 118 #ifdef CONFIG_64BIT 119 compat_frame = (struct compat_rt_sigframe __user *)frame; 120 121 if (is_compat_task()) { 122 DBG(2,"sys_rt_sigreturn: ELF32 process.\n"); 123 if (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set))) 124 goto give_sigsegv; 125 sigset_32to64(&set,&compat_set); 126 } else 127 #endif 128 { 129 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) 130 goto give_sigsegv; 131 } 132 133 set_current_blocked(&set); 134 135 /* Good thing we saved the old gr[30], eh? */ 136 #ifdef CONFIG_64BIT 137 if (is_compat_task()) { 138 DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n", 139 &compat_frame->uc.uc_mcontext); 140 // FIXME: Load upper half from register file 141 if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, 142 &compat_frame->regs, regs)) 143 goto give_sigsegv; 144 DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", 145 usp, &compat_frame->uc.uc_stack); 146 if (compat_restore_altstack(&compat_frame->uc.uc_stack)) 147 goto give_sigsegv; 148 } else 149 #endif 150 { 151 DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n", 152 &frame->uc.uc_mcontext); 153 if (restore_sigcontext(&frame->uc.uc_mcontext, regs)) 154 goto give_sigsegv; 155 DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", 156 usp, &frame->uc.uc_stack); 157 if (restore_altstack(&frame->uc.uc_stack)) 158 goto give_sigsegv; 159 } 160 161 162 163 /* If we are on the syscall path IAOQ will not be restored, and 164 * if we are on the interrupt path we must not corrupt gr31. 165 */ 166 if (in_syscall) 167 regs->gr[31] = regs->iaoq[0]; 168 #if DEBUG_SIG 169 DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]); 170 show_regs(regs); 171 #endif 172 return; 173 174 give_sigsegv: 175 DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n"); 176 force_sig(SIGSEGV, current); 177 return; 178 } 179 180 /* 181 * Set up a signal frame. 182 */ 183 184 static inline void __user * 185 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) 186 { 187 /*FIXME: ELF32 vs. ELF64 has different frame_size, but since we 188 don't use the parameter it doesn't matter */ 189 190 DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n", 191 (unsigned long)ka, sp, frame_size); 192 193 /* Align alternate stack and reserve 64 bytes for the signal 194 handler's frame marker. */ 195 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp)) 196 sp = (current->sas_ss_sp + 0x7f) & ~0x3f; /* Stacks grow up! */ 197 198 DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp); 199 return (void __user *) sp; /* Stacks grow up. Fun. */ 200 } 201 202 static long 203 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall) 204 205 { 206 unsigned long flags = 0; 207 long err = 0; 208 209 if (on_sig_stack((unsigned long) sc)) 210 flags |= PARISC_SC_FLAG_ONSTACK; 211 if (in_syscall) { 212 flags |= PARISC_SC_FLAG_IN_SYSCALL; 213 /* regs->iaoq is undefined in the syscall return path */ 214 err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]); 215 err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]); 216 err |= __put_user(regs->sr[3], &sc->sc_iasq[0]); 217 err |= __put_user(regs->sr[3], &sc->sc_iasq[1]); 218 DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n", 219 regs->gr[31], regs->gr[31]+4); 220 } else { 221 err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq)); 222 err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq)); 223 DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n", 224 regs->iaoq[0], regs->iaoq[1]); 225 } 226 227 err |= __put_user(flags, &sc->sc_flags); 228 err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr)); 229 err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr)); 230 err |= __put_user(regs->sar, &sc->sc_sar); 231 DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]); 232 233 return err; 234 } 235 236 static long 237 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 238 sigset_t *set, struct pt_regs *regs, int in_syscall) 239 { 240 struct rt_sigframe __user *frame; 241 unsigned long rp, usp; 242 unsigned long haddr, sigframe_size; 243 int err = 0; 244 #ifdef CONFIG_64BIT 245 compat_int_t compat_val; 246 struct compat_rt_sigframe __user * compat_frame; 247 compat_sigset_t compat_set; 248 #endif 249 250 usp = (regs->gr[30] & ~(0x01UL)); 251 /*FIXME: frame_size parameter is unused, remove it. */ 252 frame = get_sigframe(ka, usp, sizeof(*frame)); 253 254 DBG(1,"SETUP_RT_FRAME: START\n"); 255 DBG(1,"setup_rt_frame: frame %p info %p\n", frame, info); 256 257 258 #ifdef CONFIG_64BIT 259 260 compat_frame = (struct compat_rt_sigframe __user *)frame; 261 262 if (is_compat_task()) { 263 DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info); 264 err |= copy_siginfo_to_user32(&compat_frame->info, info); 265 err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]); 266 DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc); 267 DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext); 268 err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, 269 &compat_frame->regs, regs, in_syscall); 270 sigset_64to32(&compat_set,set); 271 err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set)); 272 } else 273 #endif 274 { 275 DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info); 276 err |= copy_siginfo_to_user(&frame->info, info); 277 err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]); 278 DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc); 279 DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext); 280 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall); 281 /* FIXME: Should probably be converted as well for the compat case */ 282 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 283 } 284 285 if (err) 286 goto give_sigsegv; 287 288 /* Set up to return from userspace. If provided, use a stub 289 already in userspace. The first words of tramp are used to 290 save the previous sigrestartblock trampoline that might be 291 on the stack. We start the sigreturn trampoline at 292 SIGRESTARTBLOCK_TRAMP+X. */ 293 err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0, 294 &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]); 295 err |= __put_user(INSN_LDI_R20, 296 &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]); 297 err |= __put_user(INSN_BLE_SR2_R0, 298 &frame->tramp[SIGRESTARTBLOCK_TRAMP+2]); 299 err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]); 300 301 #if DEBUG_SIG 302 /* Assert that we're flushing in the correct space... */ 303 { 304 unsigned long sid; 305 asm ("mfsp %%sr3,%0" : "=r" (sid)); 306 DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n", 307 sid, frame->tramp); 308 } 309 #endif 310 311 flush_user_dcache_range((unsigned long) &frame->tramp[0], 312 (unsigned long) &frame->tramp[TRAMP_SIZE]); 313 flush_user_icache_range((unsigned long) &frame->tramp[0], 314 (unsigned long) &frame->tramp[TRAMP_SIZE]); 315 316 /* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP 317 * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP 318 * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP 319 */ 320 rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP]; 321 322 if (err) 323 goto give_sigsegv; 324 325 haddr = A(ka->sa.sa_handler); 326 /* The sa_handler may be a pointer to a function descriptor */ 327 #ifdef CONFIG_64BIT 328 if (is_compat_task()) { 329 #endif 330 if (haddr & PA_PLABEL_FDESC) { 331 Elf32_Fdesc fdesc; 332 Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3); 333 334 err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); 335 336 if (err) 337 goto give_sigsegv; 338 339 haddr = fdesc.addr; 340 regs->gr[19] = fdesc.gp; 341 } 342 #ifdef CONFIG_64BIT 343 } else { 344 Elf64_Fdesc fdesc; 345 Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3); 346 347 err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc)); 348 349 if (err) 350 goto give_sigsegv; 351 352 haddr = fdesc.addr; 353 regs->gr[19] = fdesc.gp; 354 DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n", 355 haddr, regs->gr[19], in_syscall); 356 } 357 #endif 358 359 /* The syscall return path will create IAOQ values from r31. 360 */ 361 sigframe_size = PARISC_RT_SIGFRAME_SIZE; 362 #ifdef CONFIG_64BIT 363 if (is_compat_task()) 364 sigframe_size = PARISC_RT_SIGFRAME_SIZE32; 365 #endif 366 if (in_syscall) { 367 regs->gr[31] = haddr; 368 #ifdef CONFIG_64BIT 369 if (!test_thread_flag(TIF_32BIT)) 370 sigframe_size |= 1; 371 #endif 372 } else { 373 unsigned long psw = USER_PSW; 374 #ifdef CONFIG_64BIT 375 if (!test_thread_flag(TIF_32BIT)) 376 psw |= PSW_W; 377 #endif 378 379 /* If we are singlestepping, arrange a trap to be delivered 380 when we return to userspace. Note the semantics -- we 381 should trap before the first insn in the handler is 382 executed. Ref: 383 http://sources.redhat.com/ml/gdb/2004-11/msg00245.html 384 */ 385 if (pa_psw(current)->r) { 386 pa_psw(current)->r = 0; 387 psw |= PSW_R; 388 mtctl(-1, 0); 389 } 390 391 regs->gr[0] = psw; 392 regs->iaoq[0] = haddr | 3; 393 regs->iaoq[1] = regs->iaoq[0] + 4; 394 } 395 396 regs->gr[2] = rp; /* userland return pointer */ 397 regs->gr[26] = sig; /* signal number */ 398 399 #ifdef CONFIG_64BIT 400 if (is_compat_task()) { 401 regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */ 402 regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */ 403 } else 404 #endif 405 { 406 regs->gr[25] = A(&frame->info); /* siginfo pointer */ 407 regs->gr[24] = A(&frame->uc); /* ucontext pointer */ 408 } 409 410 DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n", 411 regs->gr[30], sigframe_size, 412 regs->gr[30] + sigframe_size); 413 /* Raise the user stack pointer to make a proper call frame. */ 414 regs->gr[30] = (A(frame) + sigframe_size); 415 416 417 DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n", 418 current->comm, current->pid, frame, regs->gr[30], 419 regs->iaoq[0], regs->iaoq[1], rp); 420 421 return 1; 422 423 give_sigsegv: 424 DBG(1,"setup_rt_frame: sending SIGSEGV\n"); 425 force_sigsegv(sig, current); 426 return 0; 427 } 428 429 /* 430 * OK, we're invoking a handler. 431 */ 432 433 static void 434 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, 435 struct pt_regs *regs, int in_syscall) 436 { 437 sigset_t *oldset = sigmask_to_save(); 438 DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n", 439 sig, ka, info, oldset, regs); 440 441 /* Set up the stack frame */ 442 if (!setup_rt_frame(sig, ka, info, oldset, regs, in_syscall)) 443 return; 444 445 signal_delivered(sig, info, ka, regs, 446 test_thread_flag(TIF_SINGLESTEP) || 447 test_thread_flag(TIF_BLOCKSTEP)); 448 449 DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n", 450 regs->gr[28]); 451 } 452 453 static inline void 454 syscall_restart(struct pt_regs *regs, struct k_sigaction *ka) 455 { 456 if (regs->orig_r28) 457 return; 458 regs->orig_r28 = 1; /* no more restarts */ 459 /* Check the return code */ 460 switch (regs->gr[28]) { 461 case -ERESTART_RESTARTBLOCK: 462 case -ERESTARTNOHAND: 463 DBG(1,"ERESTARTNOHAND: returning -EINTR\n"); 464 regs->gr[28] = -EINTR; 465 break; 466 467 case -ERESTARTSYS: 468 if (!(ka->sa.sa_flags & SA_RESTART)) { 469 DBG(1,"ERESTARTSYS: putting -EINTR\n"); 470 regs->gr[28] = -EINTR; 471 break; 472 } 473 /* fallthrough */ 474 case -ERESTARTNOINTR: 475 /* A syscall is just a branch, so all 476 * we have to do is fiddle the return pointer. 477 */ 478 regs->gr[31] -= 8; /* delayed branching */ 479 break; 480 } 481 } 482 483 static inline void 484 insert_restart_trampoline(struct pt_regs *regs) 485 { 486 if (regs->orig_r28) 487 return; 488 regs->orig_r28 = 1; /* no more restarts */ 489 switch(regs->gr[28]) { 490 case -ERESTART_RESTARTBLOCK: { 491 /* Restart the system call - no handlers present */ 492 unsigned int *usp = (unsigned int *)regs->gr[30]; 493 494 /* Setup a trampoline to restart the syscall 495 * with __NR_restart_syscall 496 * 497 * 0: <return address (orig r31)> 498 * 4: <2nd half for 64-bit> 499 * 8: ldw 0(%sp), %r31 500 * 12: be 0x100(%sr2, %r0) 501 * 16: ldi __NR_restart_syscall, %r20 502 */ 503 #ifdef CONFIG_64BIT 504 put_user(regs->gr[31] >> 32, &usp[0]); 505 put_user(regs->gr[31] & 0xffffffff, &usp[1]); 506 put_user(0x0fc010df, &usp[2]); 507 #else 508 put_user(regs->gr[31], &usp[0]); 509 put_user(0x0fc0109f, &usp[2]); 510 #endif 511 put_user(0xe0008200, &usp[3]); 512 put_user(0x34140000, &usp[4]); 513 514 /* Stack is 64-byte aligned, and we only need 515 * to flush 1 cache line. 516 * Flushing one cacheline is cheap. 517 * "sync" on bigger (> 4 way) boxes is not. 518 */ 519 flush_user_dcache_range(regs->gr[30], regs->gr[30] + 4); 520 flush_user_icache_range(regs->gr[30], regs->gr[30] + 4); 521 522 regs->gr[31] = regs->gr[30] + 8; 523 return; 524 } 525 case -ERESTARTNOHAND: 526 case -ERESTARTSYS: 527 case -ERESTARTNOINTR: { 528 /* Hooray for delayed branching. We don't 529 * have to restore %r20 (the system call 530 * number) because it gets loaded in the delay 531 * slot of the branch external instruction. 532 */ 533 regs->gr[31] -= 8; 534 return; 535 } 536 default: 537 break; 538 } 539 } 540 541 /* 542 * Note that 'init' is a special process: it doesn't get signals it doesn't 543 * want to handle. Thus you cannot kill init even with a SIGKILL even by 544 * mistake. 545 * 546 * We need to be able to restore the syscall arguments (r21-r26) to 547 * restart syscalls. Thus, the syscall path should save them in the 548 * pt_regs structure (it's okay to do so since they are caller-save 549 * registers). As noted below, the syscall number gets restored for 550 * us due to the magic of delayed branching. 551 */ 552 asmlinkage void 553 do_signal(struct pt_regs *regs, long in_syscall) 554 { 555 siginfo_t info; 556 struct k_sigaction ka; 557 int signr; 558 559 DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n", 560 regs, regs->sr[7], in_syscall); 561 562 signr = get_signal_to_deliver(&info, &ka, regs, NULL); 563 DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); 564 565 if (signr > 0) { 566 /* Restart a system call if necessary. */ 567 if (in_syscall) 568 syscall_restart(regs, &ka); 569 570 handle_signal(signr, &info, &ka, regs, in_syscall); 571 return; 572 } 573 574 /* Did we come from a system call? */ 575 if (in_syscall) 576 insert_restart_trampoline(regs); 577 578 DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", 579 regs->gr[28]); 580 581 restore_saved_sigmask(); 582 } 583 584 void do_notify_resume(struct pt_regs *regs, long in_syscall) 585 { 586 if (test_thread_flag(TIF_SIGPENDING)) 587 do_signal(regs, in_syscall); 588 589 if (test_thread_flag(TIF_NOTIFY_RESUME)) { 590 clear_thread_flag(TIF_NOTIFY_RESUME); 591 tracehook_notify_resume(regs); 592 } 593 } 594