Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | * |
| 6 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 7 | * Copyright (C) 1994 - 2000 Ralf Baechle |
| 8 | * Copyright (C) 1999, 2000 Silicon Graphics, Inc. |
| 9 | */ |
| 10 | #include <linux/config.h> |
| 11 | #include <linux/sched.h> |
| 12 | #include <linux/mm.h> |
| 13 | #include <linux/personality.h> |
| 14 | #include <linux/smp.h> |
| 15 | #include <linux/smp_lock.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/signal.h> |
| 18 | #include <linux/errno.h> |
| 19 | #include <linux/wait.h> |
| 20 | #include <linux/ptrace.h> |
| 21 | #include <linux/unistd.h> |
| 22 | #include <linux/compiler.h> |
| 23 | |
| 24 | #include <asm/asm.h> |
| 25 | #include <linux/bitops.h> |
| 26 | #include <asm/cacheflush.h> |
| 27 | #include <asm/fpu.h> |
| 28 | #include <asm/sim.h> |
| 29 | #include <asm/uaccess.h> |
| 30 | #include <asm/ucontext.h> |
| 31 | #include <asm/cpu-features.h> |
| 32 | |
| 33 | #include "signal-common.h" |
| 34 | |
| 35 | #define DEBUG_SIG 0 |
| 36 | |
| 37 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
| 38 | |
| 39 | static int do_signal(sigset_t *oldset, struct pt_regs *regs); |
| 40 | |
| 41 | /* |
| 42 | * Atomically swap in the new signal mask, and wait for a signal. |
| 43 | */ |
| 44 | |
| 45 | #ifdef CONFIG_TRAD_SIGNALS |
| 46 | save_static_function(sys_sigsuspend); |
| 47 | __attribute_used__ noinline static int |
| 48 | _sys_sigsuspend(nabi_no_regargs struct pt_regs regs) |
| 49 | { |
| 50 | sigset_t *uset, saveset, newset; |
| 51 | |
| 52 | uset = (sigset_t *) regs.regs[4]; |
| 53 | if (copy_from_user(&newset, uset, sizeof(sigset_t))) |
| 54 | return -EFAULT; |
| 55 | sigdelsetmask(&newset, ~_BLOCKABLE); |
| 56 | |
| 57 | spin_lock_irq(¤t->sighand->siglock); |
| 58 | saveset = current->blocked; |
| 59 | current->blocked = newset; |
| 60 | recalc_sigpending(); |
| 61 | spin_unlock_irq(¤t->sighand->siglock); |
| 62 | |
| 63 | regs.regs[2] = EINTR; |
| 64 | regs.regs[7] = 1; |
| 65 | while (1) { |
| 66 | current->state = TASK_INTERRUPTIBLE; |
| 67 | schedule(); |
| 68 | if (do_signal(&saveset, ®s)) |
| 69 | return -EINTR; |
| 70 | } |
| 71 | } |
| 72 | #endif |
| 73 | |
| 74 | save_static_function(sys_rt_sigsuspend); |
| 75 | __attribute_used__ noinline static int |
| 76 | _sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs) |
| 77 | { |
| 78 | sigset_t *unewset, saveset, newset; |
| 79 | size_t sigsetsize; |
| 80 | |
| 81 | /* XXX Don't preclude handling different sized sigset_t's. */ |
| 82 | sigsetsize = regs.regs[5]; |
| 83 | if (sigsetsize != sizeof(sigset_t)) |
| 84 | return -EINVAL; |
| 85 | |
| 86 | unewset = (sigset_t *) regs.regs[4]; |
| 87 | if (copy_from_user(&newset, unewset, sizeof(newset))) |
| 88 | return -EFAULT; |
| 89 | sigdelsetmask(&newset, ~_BLOCKABLE); |
| 90 | |
| 91 | spin_lock_irq(¤t->sighand->siglock); |
| 92 | saveset = current->blocked; |
| 93 | current->blocked = newset; |
| 94 | recalc_sigpending(); |
| 95 | spin_unlock_irq(¤t->sighand->siglock); |
| 96 | |
| 97 | regs.regs[2] = EINTR; |
| 98 | regs.regs[7] = 1; |
| 99 | while (1) { |
| 100 | current->state = TASK_INTERRUPTIBLE; |
| 101 | schedule(); |
| 102 | if (do_signal(&saveset, ®s)) |
| 103 | return -EINTR; |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | #ifdef CONFIG_TRAD_SIGNALS |
| 108 | asmlinkage int sys_sigaction(int sig, const struct sigaction *act, |
| 109 | struct sigaction *oact) |
| 110 | { |
| 111 | struct k_sigaction new_ka, old_ka; |
| 112 | int ret; |
| 113 | int err = 0; |
| 114 | |
| 115 | if (act) { |
| 116 | old_sigset_t mask; |
| 117 | |
| 118 | if (!access_ok(VERIFY_READ, act, sizeof(*act))) |
| 119 | return -EFAULT; |
| 120 | err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler); |
| 121 | err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags); |
| 122 | err |= __get_user(mask, &act->sa_mask.sig[0]); |
| 123 | if (err) |
| 124 | return -EFAULT; |
| 125 | |
| 126 | siginitset(&new_ka.sa.sa_mask, mask); |
| 127 | } |
| 128 | |
| 129 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); |
| 130 | |
| 131 | if (!ret && oact) { |
| 132 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact))) |
| 133 | return -EFAULT; |
| 134 | err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
| 135 | err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler); |
| 136 | err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig); |
| 137 | err |= __put_user(0, &oact->sa_mask.sig[1]); |
| 138 | err |= __put_user(0, &oact->sa_mask.sig[2]); |
| 139 | err |= __put_user(0, &oact->sa_mask.sig[3]); |
| 140 | if (err) |
| 141 | return -EFAULT; |
| 142 | } |
| 143 | |
| 144 | return ret; |
| 145 | } |
| 146 | #endif |
| 147 | |
| 148 | asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs) |
| 149 | { |
| 150 | const stack_t *uss = (const stack_t *) regs.regs[4]; |
| 151 | stack_t *uoss = (stack_t *) regs.regs[5]; |
| 152 | unsigned long usp = regs.regs[29]; |
| 153 | |
| 154 | return do_sigaltstack(uss, uoss, usp); |
| 155 | } |
| 156 | |
| 157 | #if PLAT_TRAMPOLINE_STUFF_LINE |
| 158 | #define __tramp __attribute__((aligned(PLAT_TRAMPOLINE_STUFF_LINE))) |
| 159 | #else |
| 160 | #define __tramp |
| 161 | #endif |
| 162 | |
| 163 | #ifdef CONFIG_TRAD_SIGNALS |
| 164 | struct sigframe { |
| 165 | u32 sf_ass[4]; /* argument save space for o32 */ |
| 166 | u32 sf_code[2] __tramp; /* signal trampoline */ |
| 167 | struct sigcontext sf_sc __tramp; |
| 168 | sigset_t sf_mask; |
| 169 | }; |
| 170 | #endif |
| 171 | |
| 172 | struct rt_sigframe { |
| 173 | u32 rs_ass[4]; /* argument save space for o32 */ |
| 174 | u32 rs_code[2] __tramp; /* signal trampoline */ |
| 175 | struct siginfo rs_info __tramp; |
| 176 | struct ucontext rs_uc; |
| 177 | }; |
| 178 | |
| 179 | #ifdef CONFIG_TRAD_SIGNALS |
| 180 | save_static_function(sys_sigreturn); |
| 181 | __attribute_used__ noinline static void |
| 182 | _sys_sigreturn(nabi_no_regargs struct pt_regs regs) |
| 183 | { |
| 184 | struct sigframe *frame; |
| 185 | sigset_t blocked; |
| 186 | |
| 187 | frame = (struct sigframe *) regs.regs[29]; |
| 188 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| 189 | goto badframe; |
| 190 | if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked))) |
| 191 | goto badframe; |
| 192 | |
| 193 | sigdelsetmask(&blocked, ~_BLOCKABLE); |
| 194 | spin_lock_irq(¤t->sighand->siglock); |
| 195 | current->blocked = blocked; |
| 196 | recalc_sigpending(); |
| 197 | spin_unlock_irq(¤t->sighand->siglock); |
| 198 | |
| 199 | if (restore_sigcontext(®s, &frame->sf_sc)) |
| 200 | goto badframe; |
| 201 | |
| 202 | /* |
| 203 | * Don't let your children do this ... |
| 204 | */ |
| 205 | if (current_thread_info()->flags & TIF_SYSCALL_TRACE) |
| 206 | do_syscall_trace(®s, 1); |
| 207 | __asm__ __volatile__( |
| 208 | "move\t$29, %0\n\t" |
| 209 | "j\tsyscall_exit" |
| 210 | :/* no outputs */ |
| 211 | :"r" (®s)); |
| 212 | /* Unreached */ |
| 213 | |
| 214 | badframe: |
| 215 | force_sig(SIGSEGV, current); |
| 216 | } |
| 217 | #endif |
| 218 | |
| 219 | save_static_function(sys_rt_sigreturn); |
| 220 | __attribute_used__ noinline static void |
| 221 | _sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs) |
| 222 | { |
| 223 | struct rt_sigframe *frame; |
| 224 | sigset_t set; |
| 225 | stack_t st; |
| 226 | |
| 227 | frame = (struct rt_sigframe *) regs.regs[29]; |
| 228 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| 229 | goto badframe; |
| 230 | if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set))) |
| 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(®s, &frame->rs_uc.uc_mcontext)) |
| 240 | goto badframe; |
| 241 | |
| 242 | if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st))) |
| 243 | goto badframe; |
| 244 | /* It is more difficult to avoid calling this function than to |
| 245 | call it and ignore errors. */ |
| 246 | do_sigaltstack(&st, NULL, regs.regs[29]); |
| 247 | |
| 248 | /* |
| 249 | * Don't let your children do this ... |
| 250 | */ |
| 251 | __asm__ __volatile__( |
| 252 | "move\t$29, %0\n\t" |
| 253 | "j\tsyscall_exit" |
| 254 | :/* no outputs */ |
| 255 | :"r" (®s)); |
| 256 | /* Unreached */ |
| 257 | |
| 258 | badframe: |
| 259 | force_sig(SIGSEGV, current); |
| 260 | } |
| 261 | |
| 262 | #ifdef CONFIG_TRAD_SIGNALS |
| 263 | static void inline setup_frame(struct k_sigaction * ka, struct pt_regs *regs, |
| 264 | int signr, sigset_t *set) |
| 265 | { |
| 266 | struct sigframe *frame; |
| 267 | int err = 0; |
| 268 | |
| 269 | frame = get_sigframe(ka, regs, sizeof(*frame)); |
| 270 | if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) |
| 271 | goto give_sigsegv; |
| 272 | |
| 273 | /* |
| 274 | * Set up the return code ... |
| 275 | * |
| 276 | * li v0, __NR_sigreturn |
| 277 | * syscall |
| 278 | */ |
| 279 | if (PLAT_TRAMPOLINE_STUFF_LINE) |
| 280 | __clear_user(frame->sf_code, PLAT_TRAMPOLINE_STUFF_LINE); |
| 281 | err |= __put_user(0x24020000 + __NR_sigreturn, frame->sf_code + 0); |
| 282 | err |= __put_user(0x0000000c , frame->sf_code + 1); |
| 283 | flush_cache_sigtramp((unsigned long) frame->sf_code); |
| 284 | |
| 285 | err |= setup_sigcontext(regs, &frame->sf_sc); |
| 286 | err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set)); |
| 287 | if (err) |
| 288 | goto give_sigsegv; |
| 289 | |
| 290 | /* |
| 291 | * Arguments to signal handler: |
| 292 | * |
| 293 | * a0 = signal number |
| 294 | * a1 = 0 (should be cause) |
| 295 | * a2 = pointer to struct sigcontext |
| 296 | * |
| 297 | * $25 and c0_epc point to the signal handler, $29 points to the |
| 298 | * struct sigframe. |
| 299 | */ |
| 300 | regs->regs[ 4] = signr; |
| 301 | regs->regs[ 5] = 0; |
| 302 | regs->regs[ 6] = (unsigned long) &frame->sf_sc; |
| 303 | regs->regs[29] = (unsigned long) frame; |
| 304 | regs->regs[31] = (unsigned long) frame->sf_code; |
| 305 | regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler; |
| 306 | |
| 307 | #if DEBUG_SIG |
| 308 | printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n", |
| 309 | current->comm, current->pid, |
| 310 | frame, regs->cp0_epc, frame->regs[31]); |
| 311 | #endif |
| 312 | return; |
| 313 | |
| 314 | give_sigsegv: |
| 315 | force_sigsegv(signr, current); |
| 316 | } |
| 317 | #endif |
| 318 | |
| 319 | static void inline setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs, |
| 320 | int signr, sigset_t *set, siginfo_t *info) |
| 321 | { |
| 322 | struct rt_sigframe *frame; |
| 323 | int err = 0; |
| 324 | |
| 325 | frame = get_sigframe(ka, regs, sizeof(*frame)); |
| 326 | if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) |
| 327 | goto give_sigsegv; |
| 328 | |
| 329 | /* |
| 330 | * Set up the return code ... |
| 331 | * |
| 332 | * li v0, __NR_rt_sigreturn |
| 333 | * syscall |
| 334 | */ |
| 335 | if (PLAT_TRAMPOLINE_STUFF_LINE) |
| 336 | __clear_user(frame->rs_code, PLAT_TRAMPOLINE_STUFF_LINE); |
| 337 | err |= __put_user(0x24020000 + __NR_rt_sigreturn, frame->rs_code + 0); |
| 338 | err |= __put_user(0x0000000c , frame->rs_code + 1); |
| 339 | flush_cache_sigtramp((unsigned long) frame->rs_code); |
| 340 | |
| 341 | /* Create siginfo. */ |
| 342 | err |= copy_siginfo_to_user(&frame->rs_info, info); |
| 343 | |
| 344 | /* Create the ucontext. */ |
| 345 | err |= __put_user(0, &frame->rs_uc.uc_flags); |
| 346 | err |= __put_user(0, &frame->rs_uc.uc_link); |
| 347 | err |= __put_user((void *)current->sas_ss_sp, |
| 348 | &frame->rs_uc.uc_stack.ss_sp); |
| 349 | err |= __put_user(sas_ss_flags(regs->regs[29]), |
| 350 | &frame->rs_uc.uc_stack.ss_flags); |
| 351 | err |= __put_user(current->sas_ss_size, |
| 352 | &frame->rs_uc.uc_stack.ss_size); |
| 353 | err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext); |
| 354 | err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set)); |
| 355 | |
| 356 | if (err) |
| 357 | goto give_sigsegv; |
| 358 | |
| 359 | /* |
| 360 | * Arguments to signal handler: |
| 361 | * |
| 362 | * a0 = signal number |
| 363 | * a1 = 0 (should be cause) |
| 364 | * a2 = pointer to ucontext |
| 365 | * |
| 366 | * $25 and c0_epc point to the signal handler, $29 points to |
| 367 | * the struct rt_sigframe. |
| 368 | */ |
| 369 | regs->regs[ 4] = signr; |
| 370 | regs->regs[ 5] = (unsigned long) &frame->rs_info; |
| 371 | regs->regs[ 6] = (unsigned long) &frame->rs_uc; |
| 372 | regs->regs[29] = (unsigned long) frame; |
| 373 | regs->regs[31] = (unsigned long) frame->rs_code; |
| 374 | regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler; |
| 375 | |
| 376 | #if DEBUG_SIG |
| 377 | printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n", |
| 378 | current->comm, current->pid, |
| 379 | frame, regs->cp0_epc, regs->regs[31]); |
| 380 | #endif |
| 381 | return; |
| 382 | |
| 383 | give_sigsegv: |
| 384 | force_sigsegv(signr, current); |
| 385 | } |
| 386 | |
| 387 | extern void setup_rt_frame_n32(struct k_sigaction * ka, |
| 388 | struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info); |
| 389 | |
| 390 | static inline void handle_signal(unsigned long sig, siginfo_t *info, |
| 391 | struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs) |
| 392 | { |
| 393 | switch(regs->regs[0]) { |
| 394 | case ERESTART_RESTARTBLOCK: |
| 395 | case ERESTARTNOHAND: |
| 396 | regs->regs[2] = EINTR; |
| 397 | break; |
| 398 | case ERESTARTSYS: |
| 399 | if(!(ka->sa.sa_flags & SA_RESTART)) { |
| 400 | regs->regs[2] = EINTR; |
| 401 | break; |
| 402 | } |
| 403 | /* fallthrough */ |
| 404 | case ERESTARTNOINTR: /* Userland will reload $v0. */ |
| 405 | regs->regs[7] = regs->regs[26]; |
| 406 | regs->cp0_epc -= 8; |
| 407 | } |
| 408 | |
| 409 | regs->regs[0] = 0; /* Don't deal with this again. */ |
| 410 | |
| 411 | #ifdef CONFIG_TRAD_SIGNALS |
| 412 | if (ka->sa.sa_flags & SA_SIGINFO) { |
| 413 | #else |
| 414 | if (1) { |
| 415 | #endif |
| 416 | #ifdef CONFIG_MIPS32_N32 |
| 417 | if ((current->thread.mflags & MF_ABI_MASK) == MF_N32) |
| 418 | setup_rt_frame_n32 (ka, regs, sig, oldset, info); |
| 419 | else |
| 420 | #endif |
| 421 | setup_rt_frame(ka, regs, sig, oldset, info); |
| 422 | } |
| 423 | #ifdef CONFIG_TRAD_SIGNALS |
| 424 | else |
| 425 | setup_frame(ka, regs, sig, oldset); |
| 426 | #endif |
| 427 | |
| 428 | if (!(ka->sa.sa_flags & SA_NODEFER)) { |
| 429 | spin_lock_irq(¤t->sighand->siglock); |
| 430 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); |
| 431 | sigaddset(¤t->blocked,sig); |
| 432 | recalc_sigpending(); |
| 433 | spin_unlock_irq(¤t->sighand->siglock); |
| 434 | } |
| 435 | } |
| 436 | |
| 437 | extern int do_signal32(sigset_t *oldset, struct pt_regs *regs); |
| 438 | extern int do_irix_signal(sigset_t *oldset, struct pt_regs *regs); |
| 439 | |
| 440 | static int do_signal(sigset_t *oldset, struct pt_regs *regs) |
| 441 | { |
| 442 | struct k_sigaction ka; |
| 443 | siginfo_t info; |
| 444 | int signr; |
| 445 | |
| 446 | #ifdef CONFIG_BINFMT_ELF32 |
| 447 | if ((current->thread.mflags & MF_ABI_MASK) == MF_O32) { |
| 448 | return do_signal32(oldset, regs); |
| 449 | } |
| 450 | #endif |
| 451 | |
| 452 | /* |
| 453 | * We want the common case to go fast, which is why we may in certain |
| 454 | * cases get here from kernel mode. Just return without doing anything |
| 455 | * if so. |
| 456 | */ |
| 457 | if (!user_mode(regs)) |
| 458 | return 1; |
| 459 | |
| 460 | if (try_to_freeze(0)) |
| 461 | goto no_signal; |
| 462 | |
| 463 | if (!oldset) |
| 464 | oldset = ¤t->blocked; |
| 465 | |
| 466 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
| 467 | if (signr > 0) { |
| 468 | handle_signal(signr, &info, &ka, oldset, regs); |
| 469 | return 1; |
| 470 | } |
| 471 | |
| 472 | no_signal: |
| 473 | /* |
| 474 | * Who's code doesn't conform to the restartable syscall convention |
| 475 | * dies here!!! The li instruction, a single machine instruction, |
| 476 | * must directly be followed by the syscall instruction. |
| 477 | */ |
| 478 | if (regs->regs[0]) { |
| 479 | if (regs->regs[2] == ERESTARTNOHAND || |
| 480 | regs->regs[2] == ERESTARTSYS || |
| 481 | regs->regs[2] == ERESTARTNOINTR) { |
| 482 | regs->regs[7] = regs->regs[26]; |
| 483 | regs->cp0_epc -= 8; |
| 484 | } |
| 485 | if (regs->regs[2] == ERESTART_RESTARTBLOCK) { |
| 486 | regs->regs[2] = __NR_restart_syscall; |
| 487 | regs->regs[7] = regs->regs[26]; |
| 488 | regs->cp0_epc -= 4; |
| 489 | } |
| 490 | } |
| 491 | return 0; |
| 492 | } |
| 493 | |
| 494 | /* |
| 495 | * notification of userspace execution resumption |
| 496 | * - triggered by current->work.notify_resume |
| 497 | */ |
| 498 | asmlinkage void do_notify_resume(struct pt_regs *regs, sigset_t *oldset, |
| 499 | __u32 thread_info_flags) |
| 500 | { |
| 501 | /* deal with pending signal delivery */ |
| 502 | if (thread_info_flags & _TIF_SIGPENDING) { |
| 503 | #ifdef CONFIG_BINFMT_ELF32 |
| 504 | if (likely((current->thread.mflags & MF_ABI_MASK) == MF_O32)) { |
| 505 | do_signal32(oldset, regs); |
| 506 | return; |
| 507 | } |
| 508 | #endif |
| 509 | #ifdef CONFIG_BINFMT_IRIX |
| 510 | if (unlikely(current->personality != PER_LINUX)) { |
| 511 | do_irix_signal(oldset, regs); |
| 512 | return; |
| 513 | } |
| 514 | #endif |
| 515 | do_signal(oldset, regs); |
| 516 | } |
| 517 | } |