1/* 2 * arch/v850/kernel/signal.c -- Signal handling 3 * 4 * Copyright (C) 2001,02,03 NEC Electronics Corporation 5 * Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org> 6 * Copyright (C) 1999,2000,2002 Niibe Yutaka & Kaz Kojima 7 * Copyright (C) 1991,1992 Linus Torvalds 8 * 9 * This file is subject to the terms and conditions of the GNU General 10 * Public License. See the file COPYING in the main directory of this 11 * archive for more details. 12 * 13 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson 14 * 15 * This file was derived from the sh version, arch/sh/kernel/signal.c 16 */ 17 18#include <linux/mm.h> 19#include <linux/smp.h> 20#include <linux/kernel.h> 21#include <linux/signal.h> 22#include <linux/errno.h> 23#include <linux/wait.h> 24#include <linux/ptrace.h> 25#include <linux/unistd.h> 26#include <linux/stddef.h> 27#include <linux/personality.h> 28#include <linux/tty.h> 29 30#include <asm/ucontext.h> 31#include <asm/uaccess.h> 32#include <asm/pgtable.h> 33#include <asm/pgalloc.h> 34#include <asm/thread_info.h> 35#include <asm/cacheflush.h> 36 37#define DEBUG_SIG 0 38 39#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) 40 41asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset); 42 43/* 44 * Atomically swap in the new signal mask, and wait for a signal. 45 */ 46asmlinkage int 47sys_sigsuspend(old_sigset_t mask, struct pt_regs *regs) 48{ 49 sigset_t saveset; 50 51 mask &= _BLOCKABLE; 52 spin_lock_irq(¤t->sighand->siglock); 53 saveset = current->blocked; 54 siginitset(¤t->blocked, mask); 55 recalc_sigpending(); 56 spin_unlock_irq(¤t->sighand->siglock); 57 58 regs->gpr[GPR_RVAL] = -EINTR; 59 while (1) { 60 current->state = TASK_INTERRUPTIBLE; 61 schedule(); 62 if (do_signal(regs, &saveset)) 63 return -EINTR; 64 } 65} 66 67asmlinkage int 68sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, 69 struct pt_regs *regs) 70{ 71 sigset_t saveset, newset; 72 73 if (sigsetsize != sizeof(sigset_t)) 74 return -EINVAL; 75 76 if (copy_from_user(&newset, unewset, sizeof(newset))) 77 return -EFAULT; 78 sigdelsetmask(&newset, ~_BLOCKABLE); 79 spin_lock_irq(¤t->sighand->siglock); 80 saveset = current->blocked; 81 current->blocked = newset; 82 recalc_sigpending(); 83 spin_unlock_irq(¤t->sighand->siglock); 84 85 regs->gpr[GPR_RVAL] = -EINTR; 86 while (1) { 87 current->state = TASK_INTERRUPTIBLE; 88 schedule(); 89 if (do_signal(regs, &saveset)) 90 return -EINTR; 91 } 92} 93 94asmlinkage int 95sys_sigaction(int sig, const struct old_sigaction *act, 96 struct old_sigaction *oact) 97{ 98 struct k_sigaction new_ka, old_ka; 99 int ret; 100 101 if (act) { 102 old_sigset_t mask; 103 if (!access_ok(VERIFY_READ, act, sizeof(*act)) || 104 __get_user(new_ka.sa.sa_handler, &act->sa_handler) || 105 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) 106 return -EFAULT; 107 __get_user(new_ka.sa.sa_flags, &act->sa_flags); 108 __get_user(mask, &act->sa_mask); 109 siginitset(&new_ka.sa.sa_mask, mask); 110 } 111 112 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); 113 114 if (!ret && oact) { 115 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || 116 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || 117 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) 118 return -EFAULT; 119 __put_user(old_ka.sa.sa_flags, &oact->sa_flags); 120 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); 121 } 122 123 return ret; 124} 125 126asmlinkage int 127sys_sigaltstack(const stack_t *uss, stack_t *uoss, 128 struct pt_regs *regs) 129{ 130 return do_sigaltstack(uss, uoss, regs->gpr[GPR_SP]); 131} 132 133 134/* 135 * Do a signal return; undo the signal stack. 136 */ 137 138struct sigframe 139{ 140 struct sigcontext sc; 141 unsigned long extramask[_NSIG_WORDS-1]; 142 unsigned long tramp[2]; /* signal trampoline */ 143}; 144 145struct rt_sigframe 146{ 147 struct siginfo info; 148 struct ucontext uc; 149 unsigned long tramp[2]; /* signal trampoline */ 150}; 151 152static int 153restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *rval_p) 154{ 155 unsigned int err = 0; 156 157#define COPY(x) err |= __get_user(regs->x, &sc->regs.x) 158 COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]); 159 COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]); 160 COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]); 161 COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]); 162 COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]); 163 COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]); 164 COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]); 165 COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]); 166 COPY(pc); COPY(psw); 167 COPY(ctpc); COPY(ctpsw); COPY(ctbp); 168#undef COPY 169 170 return err; 171} 172 173asmlinkage int sys_sigreturn(struct pt_regs *regs) 174{ 175 struct sigframe *frame = (struct sigframe *)regs->gpr[GPR_SP]; 176 sigset_t set; 177 int rval; 178 179 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 180 goto badframe; 181 182 if (__get_user(set.sig[0], &frame->sc.oldmask) 183 || (_NSIG_WORDS > 1 184 && __copy_from_user(&set.sig[1], &frame->extramask, 185 sizeof(frame->extramask)))) 186 goto badframe; 187 188 sigdelsetmask(&set, ~_BLOCKABLE); 189 spin_lock_irq(¤t->sighand->siglock); 190 current->blocked = set; 191 recalc_sigpending(); 192 spin_unlock_irq(¤t->sighand->siglock); 193 194 if (restore_sigcontext(regs, &frame->sc, &rval)) 195 goto badframe; 196 return rval; 197 198badframe: 199 force_sig(SIGSEGV, current); 200 return 0; 201} 202 203asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) 204{ 205 struct rt_sigframe *frame = (struct rt_sigframe *)regs->gpr[GPR_SP]; 206 sigset_t set; 207 stack_t st; 208 int rval; 209 210 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 211 goto badframe; 212 213 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) 214 goto badframe; 215 216 sigdelsetmask(&set, ~_BLOCKABLE); 217 spin_lock_irq(¤t->sighand->siglock); 218 current->blocked = set; 219 recalc_sigpending(); 220 spin_unlock_irq(¤t->sighand->siglock); 221 222 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval)) 223 goto badframe; 224 225 if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st))) 226 goto badframe; 227 /* It is more difficult to avoid calling this function than to 228 call it and ignore errors. */ 229 do_sigaltstack(&st, NULL, regs->gpr[GPR_SP]); 230 231 return rval; 232 233badframe: 234 force_sig(SIGSEGV, current); 235 return 0; 236} 237 238/* 239 * Set up a signal frame. 240 */ 241 242static int 243setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs, 244 unsigned long mask) 245{ 246 int err = 0; 247 248#define COPY(x) err |= __put_user(regs->x, &sc->regs.x) 249 COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]); 250 COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]); 251 COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]); 252 COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]); 253 COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]); 254 COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]); 255 COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]); 256 COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]); 257 COPY(pc); COPY(psw); 258 COPY(ctpc); COPY(ctpsw); COPY(ctbp); 259#undef COPY 260 261 err |= __put_user(mask, &sc->oldmask); 262 263 return err; 264} 265 266/* 267 * Determine which stack to use.. 268 */ 269static inline void * 270get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) 271{ 272 /* Default to using normal stack */ 273 unsigned long sp = regs->gpr[GPR_SP]; 274 275 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp)) 276 sp = current->sas_ss_sp + current->sas_ss_size; 277 278 return (void *)((sp - frame_size) & -8UL); 279} 280 281static void setup_frame(int sig, struct k_sigaction *ka, 282 sigset_t *set, struct pt_regs *regs) 283{ 284 struct sigframe *frame; 285 int err = 0; 286 int signal; 287 288 frame = get_sigframe(ka, regs, sizeof(*frame)); 289 290 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 291 goto give_sigsegv; 292 293 signal = current_thread_info()->exec_domain 294 && current_thread_info()->exec_domain->signal_invmap 295 && sig < 32 296 ? current_thread_info()->exec_domain->signal_invmap[sig] 297 : sig; 298 299 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); 300 301 if (_NSIG_WORDS > 1) { 302 err |= __copy_to_user(frame->extramask, &set->sig[1], 303 sizeof(frame->extramask)); 304 } 305 306 /* Set up to return from userspace. If provided, use a stub 307 already in userspace. */ 308 if (ka->sa.sa_flags & SA_RESTORER) { 309 regs->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer; 310 } else { 311 /* Note, these encodings are _little endian_! */ 312 313 /* addi __NR_sigreturn, r0, r12 */ 314 err |= __put_user(0x6600 | (__NR_sigreturn << 16), 315 frame->tramp + 0); 316 /* trap 0 */ 317 err |= __put_user(0x010007e0, 318 frame->tramp + 1); 319 320 regs->gpr[GPR_LP] = (unsigned long)frame->tramp; 321 322 flush_cache_sigtramp (regs->gpr[GPR_LP]); 323 } 324 325 if (err) 326 goto give_sigsegv; 327 328 /* Set up registers for signal handler. */ 329 regs->pc = (v850_reg_t) ka->sa.sa_handler; 330 regs->gpr[GPR_SP] = (v850_reg_t)frame; 331 /* Signal handler args: */ 332 regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */ 333 regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->sc;/* arg 1: sigcontext */ 334 335 set_fs(USER_DS); 336 337#if DEBUG_SIG 338 printk("SIG deliver (%s:%d): sp=%p pc=%08lx ra=%08lx\n", 339 current->comm, current->pid, frame, regs->pc, ); 340#endif 341 342 return; 343 344give_sigsegv: 345 force_sigsegv(sig, current); 346} 347 348static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 349 sigset_t *set, struct pt_regs *regs) 350{ 351 struct rt_sigframe *frame; 352 int err = 0; 353 int signal; 354 355 frame = get_sigframe(ka, regs, sizeof(*frame)); 356 357 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 358 goto give_sigsegv; 359 360 signal = current_thread_info()->exec_domain 361 && current_thread_info()->exec_domain->signal_invmap 362 && sig < 32 363 ? current_thread_info()->exec_domain->signal_invmap[sig] 364 : sig; 365 366 err |= copy_siginfo_to_user(&frame->info, info); 367 368 /* Create the ucontext. */ 369 err |= __put_user(0, &frame->uc.uc_flags); 370 err |= __put_user(0, &frame->uc.uc_link); 371 err |= __put_user((void *)current->sas_ss_sp, 372 &frame->uc.uc_stack.ss_sp); 373 err |= __put_user(sas_ss_flags(regs->gpr[GPR_SP]), 374 &frame->uc.uc_stack.ss_flags); 375 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); 376 err |= setup_sigcontext(&frame->uc.uc_mcontext, 377 regs, set->sig[0]); 378 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 379 380 /* Set up to return from userspace. If provided, use a stub 381 already in userspace. */ 382 if (ka->sa.sa_flags & SA_RESTORER) { 383 regs->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer; 384 } else { 385 /* Note, these encodings are _little endian_! */ 386 387 /* addi __NR_sigreturn, r0, r12 */ 388 err |= __put_user(0x6600 | (__NR_sigreturn << 16), 389 frame->tramp + 0); 390 /* trap 0 */ 391 err |= __put_user(0x010007e0, 392 frame->tramp + 1); 393 394 regs->gpr[GPR_LP] = (unsigned long)frame->tramp; 395 396 flush_cache_sigtramp (regs->gpr[GPR_LP]); 397 } 398 399 if (err) 400 goto give_sigsegv; 401 402 /* Set up registers for signal handler. */ 403 regs->pc = (v850_reg_t) ka->sa.sa_handler; 404 regs->gpr[GPR_SP] = (v850_reg_t)frame; 405 /* Signal handler args: */ 406 regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */ 407 regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->info; /* arg 1: siginfo */ 408 regs->gpr[GPR_ARG2] = (v850_reg_t)&frame->uc; /* arg 2: ucontext */ 409 410 set_fs(USER_DS); 411 412#if DEBUG_SIG 413 printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", 414 current->comm, current->pid, frame, regs->pc, regs->pr); 415#endif 416 417 return; 418 419give_sigsegv: 420 force_sigsegv(sig, current); 421} 422 423/* 424 * OK, we're invoking a handler 425 */ 426 427static void 428handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, 429 sigset_t *oldset, struct pt_regs * regs) 430{ 431 /* Are we from a system call? */ 432 if (PT_REGS_SYSCALL (regs)) { 433 /* If so, check system call restarting.. */ 434 switch (regs->gpr[GPR_RVAL]) { 435 case -ERESTART_RESTARTBLOCK: 436 current_thread_info()->restart_block.fn = 437 do_no_restart_syscall; 438 /* fall through */ 439 case -ERESTARTNOHAND: 440 regs->gpr[GPR_RVAL] = -EINTR; 441 break; 442 443 case -ERESTARTSYS: 444 if (!(ka->sa.sa_flags & SA_RESTART)) { 445 regs->gpr[GPR_RVAL] = -EINTR; 446 break; 447 } 448 /* fallthrough */ 449 case -ERESTARTNOINTR: 450 regs->gpr[12] = PT_REGS_SYSCALL (regs); 451 regs->pc -= 4; /* Size of `trap 0' insn. */ 452 } 453 454 PT_REGS_SET_SYSCALL (regs, 0); 455 } 456 457 /* Set up the stack frame */ 458 if (ka->sa.sa_flags & SA_SIGINFO) 459 setup_rt_frame(sig, ka, info, oldset, regs); 460 else 461 setup_frame(sig, ka, oldset, regs); 462 463 spin_lock_irq(¤t->sighand->siglock); 464 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); 465 if (!(ka->sa.sa_flags & SA_NODEFER)) 466 sigaddset(¤t->blocked,sig); 467 recalc_sigpending(); 468 spin_unlock_irq(¤t->sighand->siglock); 469} 470 471/* 472 * Note that 'init' is a special process: it doesn't get signals it doesn't 473 * want to handle. Thus you cannot kill init even with a SIGKILL even by 474 * mistake. 475 * 476 * Note that we go through the signals twice: once to check the signals that 477 * the kernel can handle, and then we build all the user-level signal handling 478 * stack-frames in one go after that. 479 */ 480int do_signal(struct pt_regs *regs, sigset_t *oldset) 481{ 482 siginfo_t info; 483 int signr; 484 struct k_sigaction ka; 485 486 /* 487 * We want the common case to go fast, which 488 * is why we may in certain cases get here from 489 * kernel mode. Just return without doing anything 490 * if so. 491 */ 492 if (!user_mode(regs)) 493 return 1; 494 495 if (!oldset) 496 oldset = ¤t->blocked; 497 498 signr = get_signal_to_deliver(&info, &ka, regs, NULL); 499 if (signr > 0) { 500 /* Whee! Actually deliver the signal. */ 501 handle_signal(signr, &info, &ka, oldset, regs); 502 return 1; 503 } 504 505 /* Did we come from a system call? */ 506 if (PT_REGS_SYSCALL (regs)) { 507 int rval = (int)regs->gpr[GPR_RVAL]; 508 /* Restart the system call - no handlers present */ 509 if (rval == -ERESTARTNOHAND 510 || rval == -ERESTARTSYS 511 || rval == -ERESTARTNOINTR) 512 { 513 regs->gpr[12] = PT_REGS_SYSCALL (regs); 514 regs->pc -= 4; /* Size of `trap 0' insn. */ 515 } 516 else if (rval == -ERESTART_RESTARTBLOCK) { 517 regs->gpr[12] = __NR_restart_syscall; 518 regs->pc -= 4; /* Size of `trap 0' insn. */ 519 } 520 } 521 return 0; 522} 523