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