1/* 2 * linux/arch/h8300/kernel/signal.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file COPYING in the main directory of this archive 8 * for more details. 9 */ 10 11/* 12 * uClinux H8/300 support by Yoshinori Sato <ysato@users.sourceforge.jp> 13 * and David McCullough <davidm@snapgear.com> 14 * 15 * Based on 16 * Linux/m68k by Hamish Macdonald 17 */ 18 19/* 20 * ++roman (07/09/96): implemented signal stacks (specially for tosemu on 21 * Atari :-) Current limitation: Only one sigstack can be active at one time. 22 * If a second signal with SA_ONSTACK set arrives while working on a sigstack, 23 * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested 24 * signal handlers! 25 */ 26 27#include <linux/sched.h> 28#include <linux/mm.h> 29#include <linux/kernel.h> 30#include <linux/signal.h> 31#include <linux/syscalls.h> 32#include <linux/errno.h> 33#include <linux/wait.h> 34#include <linux/ptrace.h> 35#include <linux/unistd.h> 36#include <linux/stddef.h> 37#include <linux/highuid.h> 38#include <linux/personality.h> 39#include <linux/tty.h> 40#include <linux/binfmts.h> 41#include <linux/freezer.h> 42#include <linux/tracehook.h> 43 44#include <asm/setup.h> 45#include <asm/uaccess.h> 46#include <asm/pgtable.h> 47#include <asm/traps.h> 48#include <asm/ucontext.h> 49 50#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) 51 52asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset); 53 54/* 55 * Atomically swap in the new signal mask, and wait for a signal. 56 */ 57asmlinkage int do_sigsuspend(struct pt_regs *regs) 58{ 59 old_sigset_t mask = regs->er3; 60 sigset_t saveset; 61 62 mask &= _BLOCKABLE; 63 spin_lock_irq(¤t->sighand->siglock); 64 saveset = current->blocked; 65 siginitset(¤t->blocked, mask); 66 recalc_sigpending(); 67 spin_unlock_irq(¤t->sighand->siglock); 68 69 regs->er0 = -EINTR; 70 while (1) { 71 current->state = TASK_INTERRUPTIBLE; 72 schedule(); 73 if (do_signal(regs, &saveset)) 74 return -EINTR; 75 } 76} 77 78asmlinkage int 79do_rt_sigsuspend(struct pt_regs *regs) 80{ 81 sigset_t *unewset = (sigset_t *)regs->er1; 82 size_t sigsetsize = (size_t)regs->er2; 83 sigset_t saveset, newset; 84 85 /* XXX: Don't preclude handling different sized sigset_t's. */ 86 if (sigsetsize != sizeof(sigset_t)) 87 return -EINVAL; 88 89 if (copy_from_user(&newset, unewset, sizeof(newset))) 90 return -EFAULT; 91 sigdelsetmask(&newset, ~_BLOCKABLE); 92 93 spin_lock_irq(¤t->sighand->siglock); 94 saveset = current->blocked; 95 current->blocked = newset; 96 recalc_sigpending(); 97 spin_unlock_irq(¤t->sighand->siglock); 98 99 regs->er0 = -EINTR; 100 while (1) { 101 current->state = TASK_INTERRUPTIBLE; 102 schedule(); 103 if (do_signal(regs, &saveset)) 104 return -EINTR; 105 } 106} 107 108asmlinkage int 109sys_sigaction(int sig, const struct old_sigaction *act, 110 struct old_sigaction *oact) 111{ 112 struct k_sigaction new_ka, old_ka; 113 int ret; 114 115 if (act) { 116 old_sigset_t mask; 117 if (!access_ok(VERIFY_READ, act, sizeof(*act)) || 118 __get_user(new_ka.sa.sa_handler, &act->sa_handler) || 119 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) 120 return -EFAULT; 121 __get_user(new_ka.sa.sa_flags, &act->sa_flags); 122 __get_user(mask, &act->sa_mask); 123 siginitset(&new_ka.sa.sa_mask, mask); 124 } 125 126 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); 127 128 if (!ret && oact) { 129 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || 130 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || 131 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) 132 return -EFAULT; 133 __put_user(old_ka.sa.sa_flags, &oact->sa_flags); 134 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); 135 } 136 137 return ret; 138} 139 140asmlinkage int 141sys_sigaltstack(const stack_t *uss, stack_t *uoss) 142{ 143 return do_sigaltstack(uss, uoss, rdusp()); 144} 145 146 147/* 148 * Do a signal return; undo the signal stack. 149 * 150 * Keep the return code on the stack quadword aligned! 151 * That makes the cache flush below easier. 152 */ 153 154struct sigframe 155{ 156 long dummy_er0; 157 long dummy_vector; 158#if defined(CONFIG_CPU_H8S) 159 short dummy_exr; 160#endif 161 long dummy_pc; 162 char *pretcode; 163 unsigned char retcode[8]; 164 unsigned long extramask[_NSIG_WORDS-1]; 165 struct sigcontext sc; 166 int sig; 167} __attribute__((aligned(2),packed)); 168 169struct rt_sigframe 170{ 171 long dummy_er0; 172 long dummy_vector; 173#if defined(CONFIG_CPU_H8S) 174 short dummy_exr; 175#endif 176 long dummy_pc; 177 char *pretcode; 178 struct siginfo *pinfo; 179 void *puc; 180 unsigned char retcode[8]; 181 struct siginfo info; 182 struct ucontext uc; 183 int sig; 184} __attribute__((aligned(2),packed)); 185 186static inline int 187restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc, 188 int *pd0) 189{ 190 int err = 0; 191 unsigned int ccr; 192 unsigned int usp; 193 unsigned int er0; 194 195 /* Always make any pending restarted system calls return -EINTR */ 196 current_thread_info()->restart_block.fn = do_no_restart_syscall; 197 198#define COPY(r) err |= __get_user(regs->r, &usc->sc_##r) /* restore passed registers */ 199 COPY(er1); 200 COPY(er2); 201 COPY(er3); 202 COPY(er5); 203 COPY(pc); 204 ccr = regs->ccr & 0x10; 205 COPY(ccr); 206#undef COPY 207 regs->ccr &= 0xef; 208 regs->ccr |= ccr; 209 regs->orig_er0 = -1; /* disable syscall checks */ 210 err |= __get_user(usp, &usc->sc_usp); 211 wrusp(usp); 212 213 err |= __get_user(er0, &usc->sc_er0); 214 *pd0 = er0; 215 return err; 216} 217 218asmlinkage int do_sigreturn(unsigned long __unused,...) 219{ 220 struct pt_regs *regs = (struct pt_regs *) (&__unused - 1); 221 unsigned long usp = rdusp(); 222 struct sigframe *frame = (struct sigframe *)(usp - 4); 223 sigset_t set; 224 int er0; 225 226 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 227 goto badframe; 228 if (__get_user(set.sig[0], &frame->sc.sc_mask) || 229 (_NSIG_WORDS > 1 && 230 __copy_from_user(&set.sig[1], &frame->extramask, 231 sizeof(frame->extramask)))) 232 goto badframe; 233 234 sigdelsetmask(&set, ~_BLOCKABLE); 235 spin_lock_irq(¤t->sighand->siglock); 236 current->blocked = set; 237 recalc_sigpending(); 238 spin_unlock_irq(¤t->sighand->siglock); 239 240 if (restore_sigcontext(regs, &frame->sc, &er0)) 241 goto badframe; 242 return er0; 243 244badframe: 245 force_sig(SIGSEGV, current); 246 return 0; 247} 248 249asmlinkage int do_rt_sigreturn(unsigned long __unused,...) 250{ 251 struct pt_regs *regs = (struct pt_regs *) &__unused; 252 unsigned long usp = rdusp(); 253 struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4); 254 sigset_t set; 255 int er0; 256 257 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 258 goto badframe; 259 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) 260 goto badframe; 261 262 sigdelsetmask(&set, ~_BLOCKABLE); 263 spin_unlock_irq(¤t->sighand->siglock); 264 current->blocked = set; 265 recalc_sigpending(); 266 spin_lock_irq(¤t->sighand->siglock); 267 268 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &er0)) 269 goto badframe; 270 271 if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT) 272 goto badframe; 273 274 return er0; 275 276badframe: 277 force_sig(SIGSEGV, current); 278 return 0; 279} 280 281static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, 282 unsigned long mask) 283{ 284 int err = 0; 285 286 err |= __put_user(regs->er0, &sc->sc_er0); 287 err |= __put_user(regs->er1, &sc->sc_er1); 288 err |= __put_user(regs->er2, &sc->sc_er2); 289 err |= __put_user(regs->er3, &sc->sc_er3); 290 err |= __put_user(regs->er4, &sc->sc_er4); 291 err |= __put_user(regs->er5, &sc->sc_er5); 292 err |= __put_user(regs->er6, &sc->sc_er6); 293 err |= __put_user(rdusp(), &sc->sc_usp); 294 err |= __put_user(regs->pc, &sc->sc_pc); 295 err |= __put_user(regs->ccr, &sc->sc_ccr); 296 err |= __put_user(mask, &sc->sc_mask); 297 298 return err; 299} 300 301static inline void * 302get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) 303{ 304 unsigned long usp; 305 306 /* Default to using normal stack. */ 307 usp = rdusp(); 308 309 /* This is the X/Open sanctioned signal stack switching. */ 310 if (ka->sa.sa_flags & SA_ONSTACK) { 311 if (!sas_ss_flags(usp)) 312 usp = current->sas_ss_sp + current->sas_ss_size; 313 } 314 return (void *)((usp - frame_size) & -8UL); 315} 316 317static void setup_frame (int sig, struct k_sigaction *ka, 318 sigset_t *set, struct pt_regs *regs) 319{ 320 struct sigframe *frame; 321 int err = 0; 322 int usig; 323 unsigned char *ret; 324 325 frame = get_sigframe(ka, regs, sizeof(*frame)); 326 327 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 328 goto give_sigsegv; 329 330 usig = current_thread_info()->exec_domain 331 && current_thread_info()->exec_domain->signal_invmap 332 && sig < 32 333 ? current_thread_info()->exec_domain->signal_invmap[sig] 334 : sig; 335 336 err |= __put_user(usig, &frame->sig); 337 if (err) 338 goto give_sigsegv; 339 340 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); 341 if (err) 342 goto give_sigsegv; 343 344 if (_NSIG_WORDS > 1) { 345 err |= copy_to_user(frame->extramask, &set->sig[1], 346 sizeof(frame->extramask)); 347 if (err) 348 goto give_sigsegv; 349 } 350 351 ret = frame->retcode; 352 if (ka->sa.sa_flags & SA_RESTORER) 353 ret = (unsigned char *)(ka->sa.sa_restorer); 354 else { 355 /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */ 356 err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff), 357 (unsigned long *)(frame->retcode + 0)); 358 err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4)); 359 } 360 361 /* Set up to return from userspace. */ 362 err |= __put_user(ret, &frame->pretcode); 363 364 if (err) 365 goto give_sigsegv; 366 367 /* Set up registers for signal handler */ 368 wrusp ((unsigned long) frame); 369 regs->pc = (unsigned long) ka->sa.sa_handler; 370 regs->er0 = (current_thread_info()->exec_domain 371 && current_thread_info()->exec_domain->signal_invmap 372 && sig < 32 373 ? current_thread_info()->exec_domain->signal_invmap[sig] 374 : sig); 375 regs->er1 = (unsigned long)&(frame->sc); 376 regs->er5 = current->mm->start_data; /* GOT base */ 377 378 return; 379 380give_sigsegv: 381 force_sigsegv(sig, current); 382} 383 384static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info, 385 sigset_t *set, struct pt_regs *regs) 386{ 387 struct rt_sigframe *frame; 388 int err = 0; 389 int usig; 390 unsigned char *ret; 391 392 frame = get_sigframe(ka, regs, sizeof(*frame)); 393 394 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 395 goto give_sigsegv; 396 397 usig = current_thread_info()->exec_domain 398 && current_thread_info()->exec_domain->signal_invmap 399 && sig < 32 400 ? current_thread_info()->exec_domain->signal_invmap[sig] 401 : sig; 402 403 err |= __put_user(usig, &frame->sig); 404 if (err) 405 goto give_sigsegv; 406 407 err |= __put_user(&frame->info, &frame->pinfo); 408 err |= __put_user(&frame->uc, &frame->puc); 409 err |= copy_siginfo_to_user(&frame->info, info); 410 if (err) 411 goto give_sigsegv; 412 413 /* Create the ucontext. */ 414 err |= __put_user(0, &frame->uc.uc_flags); 415 err |= __put_user(0, &frame->uc.uc_link); 416 err |= __put_user((void *)current->sas_ss_sp, 417 &frame->uc.uc_stack.ss_sp); 418 err |= __put_user(sas_ss_flags(rdusp()), 419 &frame->uc.uc_stack.ss_flags); 420 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); 421 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]); 422 err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set)); 423 if (err) 424 goto give_sigsegv; 425 426 /* Set up to return from userspace. */ 427 ret = frame->retcode; 428 if (ka->sa.sa_flags & SA_RESTORER) 429 ret = (unsigned char *)(ka->sa.sa_restorer); 430 else { 431 /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */ 432 err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff), 433 (unsigned long *)(frame->retcode + 0)); 434 err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4)); 435 } 436 err |= __put_user(ret, &frame->pretcode); 437 438 if (err) 439 goto give_sigsegv; 440 441 /* Set up registers for signal handler */ 442 wrusp ((unsigned long) frame); 443 regs->pc = (unsigned long) ka->sa.sa_handler; 444 regs->er0 = (current_thread_info()->exec_domain 445 && current_thread_info()->exec_domain->signal_invmap 446 && sig < 32 447 ? current_thread_info()->exec_domain->signal_invmap[sig] 448 : sig); 449 regs->er1 = (unsigned long)&(frame->info); 450 regs->er2 = (unsigned long)&frame->uc; 451 regs->er5 = current->mm->start_data; /* GOT base */ 452 453 return; 454 455give_sigsegv: 456 force_sigsegv(sig, current); 457} 458 459/* 460 * OK, we're invoking a handler 461 */ 462static void 463handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, 464 sigset_t *oldset, struct pt_regs * regs) 465{ 466 /* are we from a system call? */ 467 if (regs->orig_er0 >= 0) { 468 switch (regs->er0) { 469 case -ERESTART_RESTARTBLOCK: 470 case -ERESTARTNOHAND: 471 regs->er0 = -EINTR; 472 break; 473 474 case -ERESTARTSYS: 475 if (!(ka->sa.sa_flags & SA_RESTART)) { 476 regs->er0 = -EINTR; 477 break; 478 } 479 /* fallthrough */ 480 case -ERESTARTNOINTR: 481 regs->er0 = regs->orig_er0; 482 regs->pc -= 2; 483 } 484 } 485 486 /* set up the stack frame */ 487 if (ka->sa.sa_flags & SA_SIGINFO) 488 setup_rt_frame(sig, ka, info, oldset, regs); 489 else 490 setup_frame(sig, ka, oldset, regs); 491 492 spin_lock_irq(¤t->sighand->siglock); 493 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); 494 if (!(ka->sa.sa_flags & SA_NODEFER)) 495 sigaddset(¤t->blocked,sig); 496 recalc_sigpending(); 497 spin_unlock_irq(¤t->sighand->siglock); 498} 499 500/* 501 * Note that 'init' is a special process: it doesn't get signals it doesn't 502 * want to handle. Thus you cannot kill init even with a SIGKILL even by 503 * mistake. 504 */ 505asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset) 506{ 507 siginfo_t info; 508 int signr; 509 struct k_sigaction ka; 510 511 /* 512 * We want the common case to go fast, which 513 * is why we may in certain cases get here from 514 * kernel mode. Just return without doing anything 515 * if so. 516 */ 517 if ((regs->ccr & 0x10)) 518 return 1; 519 520 if (try_to_freeze()) 521 goto no_signal; 522 523 current->thread.esp0 = (unsigned long) regs; 524 525 if (!oldset) 526 oldset = ¤t->blocked; 527 528 signr = get_signal_to_deliver(&info, &ka, regs, NULL); 529 if (signr > 0) { 530 /* Whee! Actually deliver the signal. */ 531 handle_signal(signr, &info, &ka, oldset, regs); 532 return 1; 533 } 534 no_signal: 535 /* Did we come from a system call? */ 536 if (regs->orig_er0 >= 0) { 537 /* Restart the system call - no handlers present */ 538 if (regs->er0 == -ERESTARTNOHAND || 539 regs->er0 == -ERESTARTSYS || 540 regs->er0 == -ERESTARTNOINTR) { 541 regs->er0 = regs->orig_er0; 542 regs->pc -= 2; 543 } 544 if (regs->er0 == -ERESTART_RESTARTBLOCK){ 545 regs->er0 = __NR_restart_syscall; 546 regs->pc -= 2; 547 } 548 } 549 return 0; 550} 551 552asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags) 553{ 554 if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) 555 do_signal(regs, NULL); 556 557 if (thread_info_flags & _TIF_NOTIFY_RESUME) { 558 clear_thread_flag(TIF_NOTIFY_RESUME); 559 tracehook_notify_resume(regs); 560 if (current->replacement_session_keyring) 561 key_replace_session_keyring(); 562 } 563} 564