1 /* 2 * Architecture-specific signal handling support. 3 * 4 * Copyright (C) 1999-2004 Hewlett-Packard Co 5 * David Mosberger-Tang <davidm@hpl.hp.com> 6 * 7 * Derived from i386 and Alpha versions. 8 */ 9 10 #include <linux/errno.h> 11 #include <linux/kernel.h> 12 #include <linux/mm.h> 13 #include <linux/ptrace.h> 14 #include <linux/tracehook.h> 15 #include <linux/sched.h> 16 #include <linux/signal.h> 17 #include <linux/smp.h> 18 #include <linux/stddef.h> 19 #include <linux/tty.h> 20 #include <linux/binfmts.h> 21 #include <linux/unistd.h> 22 #include <linux/wait.h> 23 24 #include <asm/ia32.h> 25 #include <asm/intrinsics.h> 26 #include <asm/uaccess.h> 27 #include <asm/rse.h> 28 #include <asm/sigcontext.h> 29 30 #include "sigframe.h" 31 32 #define DEBUG_SIG 0 33 #define STACK_ALIGN 16 /* minimal alignment for stack pointer */ 34 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) 35 36 #if _NSIG_WORDS > 1 37 # define PUT_SIGSET(k,u) __copy_to_user((u)->sig, (k)->sig, sizeof(sigset_t)) 38 # define GET_SIGSET(k,u) __copy_from_user((k)->sig, (u)->sig, sizeof(sigset_t)) 39 #else 40 # define PUT_SIGSET(k,u) __put_user((k)->sig[0], &(u)->sig[0]) 41 # define GET_SIGSET(k,u) __get_user((k)->sig[0], &(u)->sig[0]) 42 #endif 43 44 asmlinkage long 45 sys_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, long arg2, 46 long arg3, long arg4, long arg5, long arg6, long arg7, 47 struct pt_regs regs) 48 { 49 return do_sigaltstack(uss, uoss, regs.r12); 50 } 51 52 static long 53 restore_sigcontext (struct sigcontext __user *sc, struct sigscratch *scr) 54 { 55 unsigned long ip, flags, nat, um, cfm, rsc; 56 long err; 57 58 /* Always make any pending restarted system calls return -EINTR */ 59 current_thread_info()->restart_block.fn = do_no_restart_syscall; 60 61 /* restore scratch that always needs gets updated during signal delivery: */ 62 err = __get_user(flags, &sc->sc_flags); 63 err |= __get_user(nat, &sc->sc_nat); 64 err |= __get_user(ip, &sc->sc_ip); /* instruction pointer */ 65 err |= __get_user(cfm, &sc->sc_cfm); 66 err |= __get_user(um, &sc->sc_um); /* user mask */ 67 err |= __get_user(rsc, &sc->sc_ar_rsc); 68 err |= __get_user(scr->pt.ar_unat, &sc->sc_ar_unat); 69 err |= __get_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); 70 err |= __get_user(scr->pt.ar_pfs, &sc->sc_ar_pfs); 71 err |= __get_user(scr->pt.pr, &sc->sc_pr); /* predicates */ 72 err |= __get_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */ 73 err |= __get_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */ 74 err |= __copy_from_user(&scr->pt.r1, &sc->sc_gr[1], 8); /* r1 */ 75 err |= __copy_from_user(&scr->pt.r8, &sc->sc_gr[8], 4*8); /* r8-r11 */ 76 err |= __copy_from_user(&scr->pt.r12, &sc->sc_gr[12], 2*8); /* r12-r13 */ 77 err |= __copy_from_user(&scr->pt.r15, &sc->sc_gr[15], 8); /* r15 */ 78 79 scr->pt.cr_ifs = cfm | (1UL << 63); 80 scr->pt.ar_rsc = rsc | (3 << 2); /* force PL3 */ 81 82 /* establish new instruction pointer: */ 83 scr->pt.cr_iip = ip & ~0x3UL; 84 ia64_psr(&scr->pt)->ri = ip & 0x3; 85 scr->pt.cr_ipsr = (scr->pt.cr_ipsr & ~IA64_PSR_UM) | (um & IA64_PSR_UM); 86 87 scr->scratch_unat = ia64_put_scratch_nat_bits(&scr->pt, nat); 88 89 if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) { 90 /* Restore most scratch-state only when not in syscall. */ 91 err |= __get_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */ 92 err |= __get_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */ 93 err |= __get_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */ 94 err |= __copy_from_user(&scr->pt.ar_csd, &sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */ 95 err |= __copy_from_user(&scr->pt.r2, &sc->sc_gr[2], 2*8); /* r2-r3 */ 96 err |= __copy_from_user(&scr->pt.r16, &sc->sc_gr[16], 16*8); /* r16-r31 */ 97 } 98 99 if ((flags & IA64_SC_FLAG_FPH_VALID) != 0) { 100 struct ia64_psr *psr = ia64_psr(&scr->pt); 101 102 err |= __copy_from_user(current->thread.fph, &sc->sc_fr[32], 96*16); 103 psr->mfh = 0; /* drop signal handler's fph contents... */ 104 preempt_disable(); 105 if (psr->dfh) 106 ia64_drop_fpu(current); 107 else { 108 /* We already own the local fph, otherwise psr->dfh wouldn't be 0. */ 109 __ia64_load_fpu(current->thread.fph); 110 ia64_set_local_fpu_owner(current); 111 } 112 preempt_enable(); 113 } 114 return err; 115 } 116 117 int 118 copy_siginfo_to_user (siginfo_t __user *to, siginfo_t *from) 119 { 120 if (!access_ok(VERIFY_WRITE, to, sizeof(siginfo_t))) 121 return -EFAULT; 122 if (from->si_code < 0) { 123 if (__copy_to_user(to, from, sizeof(siginfo_t))) 124 return -EFAULT; 125 return 0; 126 } else { 127 int err; 128 129 /* 130 * If you change siginfo_t structure, please be sure this code is fixed 131 * accordingly. It should never copy any pad contained in the structure 132 * to avoid security leaks, but must copy the generic 3 ints plus the 133 * relevant union member. 134 */ 135 err = __put_user(from->si_signo, &to->si_signo); 136 err |= __put_user(from->si_errno, &to->si_errno); 137 err |= __put_user((short)from->si_code, &to->si_code); 138 switch (from->si_code >> 16) { 139 case __SI_FAULT >> 16: 140 err |= __put_user(from->si_flags, &to->si_flags); 141 err |= __put_user(from->si_isr, &to->si_isr); 142 case __SI_POLL >> 16: 143 err |= __put_user(from->si_addr, &to->si_addr); 144 err |= __put_user(from->si_imm, &to->si_imm); 145 break; 146 case __SI_TIMER >> 16: 147 err |= __put_user(from->si_tid, &to->si_tid); 148 err |= __put_user(from->si_overrun, &to->si_overrun); 149 err |= __put_user(from->si_ptr, &to->si_ptr); 150 break; 151 case __SI_RT >> 16: /* Not generated by the kernel as of now. */ 152 case __SI_MESGQ >> 16: 153 err |= __put_user(from->si_uid, &to->si_uid); 154 err |= __put_user(from->si_pid, &to->si_pid); 155 err |= __put_user(from->si_ptr, &to->si_ptr); 156 break; 157 case __SI_CHLD >> 16: 158 err |= __put_user(from->si_utime, &to->si_utime); 159 err |= __put_user(from->si_stime, &to->si_stime); 160 err |= __put_user(from->si_status, &to->si_status); 161 default: 162 err |= __put_user(from->si_uid, &to->si_uid); 163 err |= __put_user(from->si_pid, &to->si_pid); 164 break; 165 } 166 return err; 167 } 168 } 169 170 long 171 ia64_rt_sigreturn (struct sigscratch *scr) 172 { 173 extern char ia64_strace_leave_kernel, ia64_leave_kernel; 174 struct sigcontext __user *sc; 175 struct siginfo si; 176 sigset_t set; 177 long retval; 178 179 sc = &((struct sigframe __user *) (scr->pt.r12 + 16))->sc; 180 181 /* 182 * When we return to the previously executing context, r8 and r10 have already 183 * been setup the way we want them. Indeed, if the signal wasn't delivered while 184 * in a system call, we must not touch r8 or r10 as otherwise user-level state 185 * could be corrupted. 186 */ 187 retval = (long) &ia64_leave_kernel; 188 if (test_thread_flag(TIF_SYSCALL_TRACE) 189 || test_thread_flag(TIF_SYSCALL_AUDIT)) 190 /* 191 * strace expects to be notified after sigreturn returns even though the 192 * context to which we return may not be in the middle of a syscall. 193 * Thus, the return-value that strace displays for sigreturn is 194 * meaningless. 195 */ 196 retval = (long) &ia64_strace_leave_kernel; 197 198 if (!access_ok(VERIFY_READ, sc, sizeof(*sc))) 199 goto give_sigsegv; 200 201 if (GET_SIGSET(&set, &sc->sc_mask)) 202 goto give_sigsegv; 203 204 sigdelsetmask(&set, ~_BLOCKABLE); 205 206 spin_lock_irq(¤t->sighand->siglock); 207 { 208 current->blocked = set; 209 recalc_sigpending(); 210 } 211 spin_unlock_irq(¤t->sighand->siglock); 212 213 if (restore_sigcontext(sc, scr)) 214 goto give_sigsegv; 215 216 #if DEBUG_SIG 217 printk("SIG return (%s:%d): sp=%lx ip=%lx\n", 218 current->comm, current->pid, scr->pt.r12, scr->pt.cr_iip); 219 #endif 220 /* 221 * It is more difficult to avoid calling this function than to 222 * call it and ignore errors. 223 */ 224 do_sigaltstack(&sc->sc_stack, NULL, scr->pt.r12); 225 return retval; 226 227 give_sigsegv: 228 si.si_signo = SIGSEGV; 229 si.si_errno = 0; 230 si.si_code = SI_KERNEL; 231 si.si_pid = task_pid_vnr(current); 232 si.si_uid = current_uid(); 233 si.si_addr = sc; 234 force_sig_info(SIGSEGV, &si, current); 235 return retval; 236 } 237 238 /* 239 * This does just the minimum required setup of sigcontext. 240 * Specifically, it only installs data that is either not knowable at 241 * the user-level or that gets modified before execution in the 242 * trampoline starts. Everything else is done at the user-level. 243 */ 244 static long 245 setup_sigcontext (struct sigcontext __user *sc, sigset_t *mask, struct sigscratch *scr) 246 { 247 unsigned long flags = 0, ifs, cfm, nat; 248 long err = 0; 249 250 ifs = scr->pt.cr_ifs; 251 252 if (on_sig_stack((unsigned long) sc)) 253 flags |= IA64_SC_FLAG_ONSTACK; 254 if ((ifs & (1UL << 63)) == 0) 255 /* if cr_ifs doesn't have the valid bit set, we got here through a syscall */ 256 flags |= IA64_SC_FLAG_IN_SYSCALL; 257 cfm = ifs & ((1UL << 38) - 1); 258 ia64_flush_fph(current); 259 if ((current->thread.flags & IA64_THREAD_FPH_VALID)) { 260 flags |= IA64_SC_FLAG_FPH_VALID; 261 err = __copy_to_user(&sc->sc_fr[32], current->thread.fph, 96*16); 262 } 263 264 nat = ia64_get_scratch_nat_bits(&scr->pt, scr->scratch_unat); 265 266 err |= __put_user(flags, &sc->sc_flags); 267 err |= __put_user(nat, &sc->sc_nat); 268 err |= PUT_SIGSET(mask, &sc->sc_mask); 269 err |= __put_user(cfm, &sc->sc_cfm); 270 err |= __put_user(scr->pt.cr_ipsr & IA64_PSR_UM, &sc->sc_um); 271 err |= __put_user(scr->pt.ar_rsc, &sc->sc_ar_rsc); 272 err |= __put_user(scr->pt.ar_unat, &sc->sc_ar_unat); /* ar.unat */ 273 err |= __put_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); /* ar.fpsr */ 274 err |= __put_user(scr->pt.ar_pfs, &sc->sc_ar_pfs); 275 err |= __put_user(scr->pt.pr, &sc->sc_pr); /* predicates */ 276 err |= __put_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */ 277 err |= __put_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */ 278 err |= __copy_to_user(&sc->sc_gr[1], &scr->pt.r1, 8); /* r1 */ 279 err |= __copy_to_user(&sc->sc_gr[8], &scr->pt.r8, 4*8); /* r8-r11 */ 280 err |= __copy_to_user(&sc->sc_gr[12], &scr->pt.r12, 2*8); /* r12-r13 */ 281 err |= __copy_to_user(&sc->sc_gr[15], &scr->pt.r15, 8); /* r15 */ 282 err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip); 283 284 if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) { 285 /* Copy scratch regs to sigcontext if the signal didn't interrupt a syscall. */ 286 err |= __put_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */ 287 err |= __put_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */ 288 err |= __put_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */ 289 err |= __copy_to_user(&sc->sc_ar25, &scr->pt.ar_csd, 2*8); /* ar.csd & ar.ssd */ 290 err |= __copy_to_user(&sc->sc_gr[2], &scr->pt.r2, 2*8); /* r2-r3 */ 291 err |= __copy_to_user(&sc->sc_gr[16], &scr->pt.r16, 16*8); /* r16-r31 */ 292 } 293 return err; 294 } 295 296 /* 297 * Check whether the register-backing store is already on the signal stack. 298 */ 299 static inline int 300 rbs_on_sig_stack (unsigned long bsp) 301 { 302 return (bsp - current->sas_ss_sp < current->sas_ss_size); 303 } 304 305 static long 306 force_sigsegv_info (int sig, void __user *addr) 307 { 308 unsigned long flags; 309 struct siginfo si; 310 311 if (sig == SIGSEGV) { 312 /* 313 * Acquiring siglock around the sa_handler-update is almost 314 * certainly overkill, but this isn't a 315 * performance-critical path and I'd rather play it safe 316 * here than having to debug a nasty race if and when 317 * something changes in kernel/signal.c that would make it 318 * no longer safe to modify sa_handler without holding the 319 * lock. 320 */ 321 spin_lock_irqsave(¤t->sighand->siglock, flags); 322 current->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; 323 spin_unlock_irqrestore(¤t->sighand->siglock, flags); 324 } 325 si.si_signo = SIGSEGV; 326 si.si_errno = 0; 327 si.si_code = SI_KERNEL; 328 si.si_pid = task_pid_vnr(current); 329 si.si_uid = current_uid(); 330 si.si_addr = addr; 331 force_sig_info(SIGSEGV, &si, current); 332 return 0; 333 } 334 335 static long 336 setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, 337 struct sigscratch *scr) 338 { 339 extern char __kernel_sigtramp[]; 340 unsigned long tramp_addr, new_rbs = 0, new_sp; 341 struct sigframe __user *frame; 342 long err; 343 344 new_sp = scr->pt.r12; 345 tramp_addr = (unsigned long) __kernel_sigtramp; 346 if (ka->sa.sa_flags & SA_ONSTACK) { 347 int onstack = sas_ss_flags(new_sp); 348 349 if (onstack == 0) { 350 new_sp = current->sas_ss_sp + current->sas_ss_size; 351 /* 352 * We need to check for the register stack being on the 353 * signal stack separately, because it's switched 354 * separately (memory stack is switched in the kernel, 355 * register stack is switched in the signal trampoline). 356 */ 357 if (!rbs_on_sig_stack(scr->pt.ar_bspstore)) 358 new_rbs = ALIGN(current->sas_ss_sp, 359 sizeof(long)); 360 } else if (onstack == SS_ONSTACK) { 361 unsigned long check_sp; 362 363 /* 364 * If we are on the alternate signal stack and would 365 * overflow it, don't. Return an always-bogus address 366 * instead so we will die with SIGSEGV. 367 */ 368 check_sp = (new_sp - sizeof(*frame)) & -STACK_ALIGN; 369 if (!likely(on_sig_stack(check_sp))) 370 return force_sigsegv_info(sig, (void __user *) 371 check_sp); 372 } 373 } 374 frame = (void __user *) ((new_sp - sizeof(*frame)) & -STACK_ALIGN); 375 376 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 377 return force_sigsegv_info(sig, frame); 378 379 err = __put_user(sig, &frame->arg0); 380 err |= __put_user(&frame->info, &frame->arg1); 381 err |= __put_user(&frame->sc, &frame->arg2); 382 err |= __put_user(new_rbs, &frame->sc.sc_rbs_base); 383 err |= __put_user(0, &frame->sc.sc_loadrs); /* initialize to zero */ 384 err |= __put_user(ka->sa.sa_handler, &frame->handler); 385 386 err |= copy_siginfo_to_user(&frame->info, info); 387 388 err |= __put_user(current->sas_ss_sp, &frame->sc.sc_stack.ss_sp); 389 err |= __put_user(current->sas_ss_size, &frame->sc.sc_stack.ss_size); 390 err |= __put_user(sas_ss_flags(scr->pt.r12), &frame->sc.sc_stack.ss_flags); 391 err |= setup_sigcontext(&frame->sc, set, scr); 392 393 if (unlikely(err)) 394 return force_sigsegv_info(sig, frame); 395 396 scr->pt.r12 = (unsigned long) frame - 16; /* new stack pointer */ 397 scr->pt.ar_fpsr = FPSR_DEFAULT; /* reset fpsr for signal handler */ 398 scr->pt.cr_iip = tramp_addr; 399 ia64_psr(&scr->pt)->ri = 0; /* start executing in first slot */ 400 ia64_psr(&scr->pt)->be = 0; /* force little-endian byte-order */ 401 /* 402 * Force the interruption function mask to zero. This has no effect when a 403 * system-call got interrupted by a signal (since, in that case, scr->pt_cr_ifs is 404 * ignored), but it has the desirable effect of making it possible to deliver a 405 * signal with an incomplete register frame (which happens when a mandatory RSE 406 * load faults). Furthermore, it has no negative effect on the getting the user's 407 * dirty partition preserved, because that's governed by scr->pt.loadrs. 408 */ 409 scr->pt.cr_ifs = (1UL << 63); 410 411 /* 412 * Note: this affects only the NaT bits of the scratch regs (the ones saved in 413 * pt_regs), which is exactly what we want. 414 */ 415 scr->scratch_unat = 0; /* ensure NaT bits of r12 is clear */ 416 417 #if DEBUG_SIG 418 printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%p\n", 419 current->comm, current->pid, sig, scr->pt.r12, frame->sc.sc_ip, frame->handler); 420 #endif 421 return 1; 422 } 423 424 static long 425 handle_signal (unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset, 426 struct sigscratch *scr) 427 { 428 if (IS_IA32_PROCESS(&scr->pt)) { 429 /* send signal to IA-32 process */ 430 if (!ia32_setup_frame1(sig, ka, info, oldset, &scr->pt)) 431 return 0; 432 } else 433 /* send signal to IA-64 process */ 434 if (!setup_frame(sig, ka, info, oldset, scr)) 435 return 0; 436 437 spin_lock_irq(¤t->sighand->siglock); 438 sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); 439 if (!(ka->sa.sa_flags & SA_NODEFER)) 440 sigaddset(¤t->blocked, sig); 441 recalc_sigpending(); 442 spin_unlock_irq(¤t->sighand->siglock); 443 444 /* 445 * Let tracing know that we've done the handler setup. 446 */ 447 tracehook_signal_handler(sig, info, ka, &scr->pt, 448 test_thread_flag(TIF_SINGLESTEP)); 449 450 return 1; 451 } 452 453 /* 454 * Note that `init' is a special process: it doesn't get signals it doesn't want to 455 * handle. Thus you cannot kill init even with a SIGKILL even by mistake. 456 */ 457 void 458 ia64_do_signal (struct sigscratch *scr, long in_syscall) 459 { 460 struct k_sigaction ka; 461 sigset_t *oldset; 462 siginfo_t info; 463 long restart = in_syscall; 464 long errno = scr->pt.r8; 465 # define ERR_CODE(c) (IS_IA32_PROCESS(&scr->pt) ? -(c) : (c)) 466 467 /* 468 * In the ia64_leave_kernel code path, we want the common case to go fast, which 469 * is why we may in certain cases get here from kernel mode. Just return without 470 * doing anything if so. 471 */ 472 if (!user_mode(&scr->pt)) 473 return; 474 475 if (current_thread_info()->status & TS_RESTORE_SIGMASK) 476 oldset = ¤t->saved_sigmask; 477 else 478 oldset = ¤t->blocked; 479 480 /* 481 * This only loops in the rare cases of handle_signal() failing, in which case we 482 * need to push through a forced SIGSEGV. 483 */ 484 while (1) { 485 int signr = get_signal_to_deliver(&info, &ka, &scr->pt, NULL); 486 487 /* 488 * get_signal_to_deliver() may have run a debugger (via notify_parent()) 489 * and the debugger may have modified the state (e.g., to arrange for an 490 * inferior call), thus it's important to check for restarting _after_ 491 * get_signal_to_deliver(). 492 */ 493 if (IS_IA32_PROCESS(&scr->pt)) { 494 if (in_syscall) { 495 if (errno >= 0) 496 restart = 0; 497 else 498 errno = -errno; 499 } 500 } else if ((long) scr->pt.r10 != -1) 501 /* 502 * A system calls has to be restarted only if one of the error codes 503 * ERESTARTNOHAND, ERESTARTSYS, or ERESTARTNOINTR is returned. If r10 504 * isn't -1 then r8 doesn't hold an error code and we don't need to 505 * restart the syscall, so we can clear the "restart" flag here. 506 */ 507 restart = 0; 508 509 if (signr <= 0) 510 break; 511 512 if (unlikely(restart)) { 513 switch (errno) { 514 case ERESTART_RESTARTBLOCK: 515 case ERESTARTNOHAND: 516 scr->pt.r8 = ERR_CODE(EINTR); 517 /* note: scr->pt.r10 is already -1 */ 518 break; 519 520 case ERESTARTSYS: 521 if ((ka.sa.sa_flags & SA_RESTART) == 0) { 522 scr->pt.r8 = ERR_CODE(EINTR); 523 /* note: scr->pt.r10 is already -1 */ 524 break; 525 } 526 case ERESTARTNOINTR: 527 if (IS_IA32_PROCESS(&scr->pt)) { 528 scr->pt.r8 = scr->pt.r1; 529 scr->pt.cr_iip -= 2; 530 } else 531 ia64_decrement_ip(&scr->pt); 532 restart = 0; /* don't restart twice if handle_signal() fails... */ 533 } 534 } 535 536 /* 537 * Whee! Actually deliver the signal. If the delivery failed, we need to 538 * continue to iterate in this loop so we can deliver the SIGSEGV... 539 */ 540 if (handle_signal(signr, &ka, &info, oldset, scr)) { 541 /* 542 * A signal was successfully delivered; the saved 543 * sigmask will have been stored in the signal frame, 544 * and will be restored by sigreturn, so we can simply 545 * clear the TS_RESTORE_SIGMASK flag. 546 */ 547 current_thread_info()->status &= ~TS_RESTORE_SIGMASK; 548 return; 549 } 550 } 551 552 /* Did we come from a system call? */ 553 if (restart) { 554 /* Restart the system call - no handlers present */ 555 if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR 556 || errno == ERESTART_RESTARTBLOCK) 557 { 558 if (IS_IA32_PROCESS(&scr->pt)) { 559 scr->pt.r8 = scr->pt.r1; 560 scr->pt.cr_iip -= 2; 561 if (errno == ERESTART_RESTARTBLOCK) 562 scr->pt.r8 = 0; /* x86 version of __NR_restart_syscall */ 563 } else { 564 /* 565 * Note: the syscall number is in r15 which is saved in 566 * pt_regs so all we need to do here is adjust ip so that 567 * the "break" instruction gets re-executed. 568 */ 569 ia64_decrement_ip(&scr->pt); 570 if (errno == ERESTART_RESTARTBLOCK) 571 scr->pt.r15 = __NR_restart_syscall; 572 } 573 } 574 } 575 576 /* if there's no signal to deliver, we just put the saved sigmask 577 * back */ 578 if (current_thread_info()->status & TS_RESTORE_SIGMASK) { 579 current_thread_info()->status &= ~TS_RESTORE_SIGMASK; 580 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); 581 } 582 } 583