| 1 | /* |
| 2 | * PowerPC version |
| 3 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) |
| 4 | * |
| 5 | * Derived from "arch/i386/kernel/signal.c" |
| 6 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 7 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU General Public License |
| 11 | * as published by the Free Software Foundation; either version |
| 12 | * 2 of the License, or (at your option) any later version. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/sched.h> |
| 16 | #include <linux/mm.h> |
| 17 | #include <linux/smp.h> |
| 18 | #include <linux/smp_lock.h> |
| 19 | #include <linux/kernel.h> |
| 20 | #include <linux/signal.h> |
| 21 | #include <linux/errno.h> |
| 22 | #include <linux/wait.h> |
| 23 | #include <linux/unistd.h> |
| 24 | #include <linux/stddef.h> |
| 25 | #include <linux/elf.h> |
| 26 | #include <linux/ptrace.h> |
| 27 | #include <linux/module.h> |
| 28 | |
| 29 | #include <asm/sigcontext.h> |
| 30 | #include <asm/ucontext.h> |
| 31 | #include <asm/uaccess.h> |
| 32 | #include <asm/pgtable.h> |
| 33 | #include <asm/unistd.h> |
| 34 | #include <asm/cacheflush.h> |
| 35 | #include <asm/syscalls.h> |
| 36 | #include <asm/vdso.h> |
| 37 | |
| 38 | #define DEBUG_SIG 0 |
| 39 | |
| 40 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
| 41 | |
| 42 | #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) |
| 43 | #define FP_REGS_SIZE sizeof(elf_fpregset_t) |
| 44 | |
| 45 | #define TRAMP_TRACEBACK 3 |
| 46 | #define TRAMP_SIZE 6 |
| 47 | |
| 48 | /* |
| 49 | * When we have signals to deliver, we set up on the user stack, |
| 50 | * going down from the original stack pointer: |
| 51 | * 1) a rt_sigframe struct which contains the ucontext |
| 52 | * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller |
| 53 | * frame for the signal handler. |
| 54 | */ |
| 55 | |
| 56 | struct rt_sigframe { |
| 57 | /* sys_rt_sigreturn requires the ucontext be the first field */ |
| 58 | struct ucontext uc; |
| 59 | unsigned long _unused[2]; |
| 60 | unsigned int tramp[TRAMP_SIZE]; |
| 61 | struct siginfo __user *pinfo; |
| 62 | void __user *puc; |
| 63 | struct siginfo info; |
| 64 | /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */ |
| 65 | char abigap[288]; |
| 66 | } __attribute__ ((aligned (16))); |
| 67 | |
| 68 | long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, unsigned long r5, |
| 69 | unsigned long r6, unsigned long r7, unsigned long r8, |
| 70 | struct pt_regs *regs) |
| 71 | { |
| 72 | return do_sigaltstack(uss, uoss, regs->gpr[1]); |
| 73 | } |
| 74 | |
| 75 | |
| 76 | /* |
| 77 | * Set up the sigcontext for the signal frame. |
| 78 | */ |
| 79 | |
| 80 | static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, |
| 81 | int signr, sigset_t *set, unsigned long handler) |
| 82 | { |
| 83 | /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the |
| 84 | * process never used altivec yet (MSR_VEC is zero in pt_regs of |
| 85 | * the context). This is very important because we must ensure we |
| 86 | * don't lose the VRSAVE content that may have been set prior to |
| 87 | * the process doing its first vector operation |
| 88 | * Userland shall check AT_HWCAP to know wether it can rely on the |
| 89 | * v_regs pointer or not |
| 90 | */ |
| 91 | #ifdef CONFIG_ALTIVEC |
| 92 | elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful); |
| 93 | #endif |
| 94 | long err = 0; |
| 95 | |
| 96 | flush_fp_to_thread(current); |
| 97 | |
| 98 | #ifdef CONFIG_ALTIVEC |
| 99 | err |= __put_user(v_regs, &sc->v_regs); |
| 100 | |
| 101 | /* save altivec registers */ |
| 102 | if (current->thread.used_vr) { |
| 103 | flush_altivec_to_thread(current); |
| 104 | /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ |
| 105 | err |= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128)); |
| 106 | /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) |
| 107 | * contains valid data. |
| 108 | */ |
| 109 | regs->msr |= MSR_VEC; |
| 110 | } |
| 111 | /* We always copy to/from vrsave, it's 0 if we don't have or don't |
| 112 | * use altivec. |
| 113 | */ |
| 114 | err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); |
| 115 | #else /* CONFIG_ALTIVEC */ |
| 116 | err |= __put_user(0, &sc->v_regs); |
| 117 | #endif /* CONFIG_ALTIVEC */ |
| 118 | err |= __put_user(&sc->gp_regs, &sc->regs); |
| 119 | WARN_ON(!FULL_REGS(regs)); |
| 120 | err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); |
| 121 | err |= __copy_to_user(&sc->fp_regs, ¤t->thread.fpr, FP_REGS_SIZE); |
| 122 | err |= __put_user(signr, &sc->signal); |
| 123 | err |= __put_user(handler, &sc->handler); |
| 124 | if (set != NULL) |
| 125 | err |= __put_user(set->sig[0], &sc->oldmask); |
| 126 | |
| 127 | return err; |
| 128 | } |
| 129 | |
| 130 | /* |
| 131 | * Restore the sigcontext from the signal frame. |
| 132 | */ |
| 133 | |
| 134 | static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, |
| 135 | struct sigcontext __user *sc) |
| 136 | { |
| 137 | #ifdef CONFIG_ALTIVEC |
| 138 | elf_vrreg_t __user *v_regs; |
| 139 | #endif |
| 140 | unsigned long err = 0; |
| 141 | unsigned long save_r13 = 0; |
| 142 | elf_greg_t *gregs = (elf_greg_t *)regs; |
| 143 | unsigned long msr; |
| 144 | int i; |
| 145 | |
| 146 | /* If this is not a signal return, we preserve the TLS in r13 */ |
| 147 | if (!sig) |
| 148 | save_r13 = regs->gpr[13]; |
| 149 | |
| 150 | /* copy everything before MSR */ |
| 151 | err |= __copy_from_user(regs, &sc->gp_regs, |
| 152 | PT_MSR*sizeof(unsigned long)); |
| 153 | |
| 154 | /* get MSR separately, transfer the LE bit if doing signal return */ |
| 155 | err |= __get_user(msr, &sc->gp_regs[PT_MSR]); |
| 156 | if (sig) |
| 157 | regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); |
| 158 | |
| 159 | /* skip SOFTE */ |
| 160 | for (i = PT_MSR+1; i <= PT_RESULT; i++) { |
| 161 | if (i == PT_SOFTE) |
| 162 | continue; |
| 163 | err |= __get_user(gregs[i], &sc->gp_regs[i]); |
| 164 | } |
| 165 | |
| 166 | if (!sig) |
| 167 | regs->gpr[13] = save_r13; |
| 168 | if (set != NULL) |
| 169 | err |= __get_user(set->sig[0], &sc->oldmask); |
| 170 | |
| 171 | /* |
| 172 | * Do this before updating the thread state in |
| 173 | * current->thread.fpr/vr. That way, if we get preempted |
| 174 | * and another task grabs the FPU/Altivec, it won't be |
| 175 | * tempted to save the current CPU state into the thread_struct |
| 176 | * and corrupt what we are writing there. |
| 177 | */ |
| 178 | discard_lazy_cpu_state(); |
| 179 | |
| 180 | err |= __copy_from_user(¤t->thread.fpr, &sc->fp_regs, FP_REGS_SIZE); |
| 181 | |
| 182 | #ifdef CONFIG_ALTIVEC |
| 183 | err |= __get_user(v_regs, &sc->v_regs); |
| 184 | if (err) |
| 185 | return err; |
| 186 | if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128))) |
| 187 | return -EFAULT; |
| 188 | /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ |
| 189 | if (v_regs != 0 && (msr & MSR_VEC) != 0) |
| 190 | err |= __copy_from_user(current->thread.vr, v_regs, |
| 191 | 33 * sizeof(vector128)); |
| 192 | else if (current->thread.used_vr) |
| 193 | memset(current->thread.vr, 0, 33 * sizeof(vector128)); |
| 194 | /* Always get VRSAVE back */ |
| 195 | if (v_regs != 0) |
| 196 | err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); |
| 197 | else |
| 198 | current->thread.vrsave = 0; |
| 199 | #endif /* CONFIG_ALTIVEC */ |
| 200 | |
| 201 | /* Force reload of FP/VEC */ |
| 202 | regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC); |
| 203 | |
| 204 | return err; |
| 205 | } |
| 206 | |
| 207 | /* |
| 208 | * Allocate space for the signal frame |
| 209 | */ |
| 210 | static inline void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, |
| 211 | size_t frame_size) |
| 212 | { |
| 213 | unsigned long newsp; |
| 214 | |
| 215 | /* Default to using normal stack */ |
| 216 | newsp = regs->gpr[1]; |
| 217 | |
| 218 | if ((ka->sa.sa_flags & SA_ONSTACK) && current->sas_ss_size) { |
| 219 | if (! on_sig_stack(regs->gpr[1])) |
| 220 | newsp = (current->sas_ss_sp + current->sas_ss_size); |
| 221 | } |
| 222 | |
| 223 | return (void __user *)((newsp - frame_size) & -16ul); |
| 224 | } |
| 225 | |
| 226 | /* |
| 227 | * Setup the trampoline code on the stack |
| 228 | */ |
| 229 | static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) |
| 230 | { |
| 231 | int i; |
| 232 | long err = 0; |
| 233 | |
| 234 | /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ |
| 235 | err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]); |
| 236 | /* li r0, __NR_[rt_]sigreturn| */ |
| 237 | err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]); |
| 238 | /* sc */ |
| 239 | err |= __put_user(0x44000002UL, &tramp[2]); |
| 240 | |
| 241 | /* Minimal traceback info */ |
| 242 | for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) |
| 243 | err |= __put_user(0, &tramp[i]); |
| 244 | |
| 245 | if (!err) |
| 246 | flush_icache_range((unsigned long) &tramp[0], |
| 247 | (unsigned long) &tramp[TRAMP_SIZE]); |
| 248 | |
| 249 | return err; |
| 250 | } |
| 251 | |
| 252 | /* |
| 253 | * Restore the user process's signal mask (also used by signal32.c) |
| 254 | */ |
| 255 | void restore_sigmask(sigset_t *set) |
| 256 | { |
| 257 | sigdelsetmask(set, ~_BLOCKABLE); |
| 258 | spin_lock_irq(¤t->sighand->siglock); |
| 259 | current->blocked = *set; |
| 260 | recalc_sigpending(); |
| 261 | spin_unlock_irq(¤t->sighand->siglock); |
| 262 | } |
| 263 | |
| 264 | |
| 265 | /* |
| 266 | * Handle {get,set,swap}_context operations |
| 267 | */ |
| 268 | int sys_swapcontext(struct ucontext __user *old_ctx, |
| 269 | struct ucontext __user *new_ctx, |
| 270 | long ctx_size, long r6, long r7, long r8, struct pt_regs *regs) |
| 271 | { |
| 272 | unsigned char tmp; |
| 273 | sigset_t set; |
| 274 | |
| 275 | /* Context size is for future use. Right now, we only make sure |
| 276 | * we are passed something we understand |
| 277 | */ |
| 278 | if (ctx_size < sizeof(struct ucontext)) |
| 279 | return -EINVAL; |
| 280 | |
| 281 | if (old_ctx != NULL) { |
| 282 | if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx)) |
| 283 | || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0) |
| 284 | || __copy_to_user(&old_ctx->uc_sigmask, |
| 285 | ¤t->blocked, sizeof(sigset_t))) |
| 286 | return -EFAULT; |
| 287 | } |
| 288 | if (new_ctx == NULL) |
| 289 | return 0; |
| 290 | if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx)) |
| 291 | || __get_user(tmp, (u8 __user *) new_ctx) |
| 292 | || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1)) |
| 293 | return -EFAULT; |
| 294 | |
| 295 | /* |
| 296 | * If we get a fault copying the context into the kernel's |
| 297 | * image of the user's registers, we can't just return -EFAULT |
| 298 | * because the user's registers will be corrupted. For instance |
| 299 | * the NIP value may have been updated but not some of the |
| 300 | * other registers. Given that we have done the access_ok |
| 301 | * and successfully read the first and last bytes of the region |
| 302 | * above, this should only happen in an out-of-memory situation |
| 303 | * or if another thread unmaps the region containing the context. |
| 304 | * We kill the task with a SIGSEGV in this situation. |
| 305 | */ |
| 306 | |
| 307 | if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) |
| 308 | do_exit(SIGSEGV); |
| 309 | restore_sigmask(&set); |
| 310 | if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext)) |
| 311 | do_exit(SIGSEGV); |
| 312 | |
| 313 | /* This returns like rt_sigreturn */ |
| 314 | set_thread_flag(TIF_RESTOREALL); |
| 315 | return 0; |
| 316 | } |
| 317 | |
| 318 | |
| 319 | /* |
| 320 | * Do a signal return; undo the signal stack. |
| 321 | */ |
| 322 | |
| 323 | int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, |
| 324 | unsigned long r6, unsigned long r7, unsigned long r8, |
| 325 | struct pt_regs *regs) |
| 326 | { |
| 327 | struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; |
| 328 | sigset_t set; |
| 329 | |
| 330 | /* Always make any pending restarted system calls return -EINTR */ |
| 331 | current_thread_info()->restart_block.fn = do_no_restart_syscall; |
| 332 | |
| 333 | if (!access_ok(VERIFY_READ, uc, sizeof(*uc))) |
| 334 | goto badframe; |
| 335 | |
| 336 | if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) |
| 337 | goto badframe; |
| 338 | restore_sigmask(&set); |
| 339 | if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext)) |
| 340 | goto badframe; |
| 341 | |
| 342 | /* do_sigaltstack expects a __user pointer and won't modify |
| 343 | * what's in there anyway |
| 344 | */ |
| 345 | do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]); |
| 346 | |
| 347 | set_thread_flag(TIF_RESTOREALL); |
| 348 | return 0; |
| 349 | |
| 350 | badframe: |
| 351 | #if DEBUG_SIG |
| 352 | printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n", |
| 353 | regs, uc, &uc->uc_mcontext); |
| 354 | #endif |
| 355 | force_sig(SIGSEGV, current); |
| 356 | return 0; |
| 357 | } |
| 358 | |
| 359 | static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info, |
| 360 | sigset_t *set, struct pt_regs *regs) |
| 361 | { |
| 362 | /* Handler is *really* a pointer to the function descriptor for |
| 363 | * the signal routine. The first entry in the function |
| 364 | * descriptor is the entry address of signal and the second |
| 365 | * entry is the TOC value we need to use. |
| 366 | */ |
| 367 | func_descr_t __user *funct_desc_ptr; |
| 368 | struct rt_sigframe __user *frame; |
| 369 | unsigned long newsp = 0; |
| 370 | long err = 0; |
| 371 | |
| 372 | frame = get_sigframe(ka, regs, sizeof(*frame)); |
| 373 | |
| 374 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| 375 | goto badframe; |
| 376 | |
| 377 | err |= __put_user(&frame->info, &frame->pinfo); |
| 378 | err |= __put_user(&frame->uc, &frame->puc); |
| 379 | err |= copy_siginfo_to_user(&frame->info, info); |
| 380 | if (err) |
| 381 | goto badframe; |
| 382 | |
| 383 | /* Create the ucontext. */ |
| 384 | err |= __put_user(0, &frame->uc.uc_flags); |
| 385 | err |= __put_user(0, &frame->uc.uc_link); |
| 386 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); |
| 387 | err |= __put_user(sas_ss_flags(regs->gpr[1]), |
| 388 | &frame->uc.uc_stack.ss_flags); |
| 389 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); |
| 390 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL, |
| 391 | (unsigned long)ka->sa.sa_handler); |
| 392 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
| 393 | if (err) |
| 394 | goto badframe; |
| 395 | |
| 396 | /* Make sure signal handler doesn't get spurious FP exceptions */ |
| 397 | current->thread.fpscr.val = 0; |
| 398 | |
| 399 | /* Set up to return from userspace. */ |
| 400 | if (vdso64_rt_sigtramp && current->mm->context.vdso_base) { |
| 401 | regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp; |
| 402 | } else { |
| 403 | err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); |
| 404 | if (err) |
| 405 | goto badframe; |
| 406 | regs->link = (unsigned long) &frame->tramp[0]; |
| 407 | } |
| 408 | funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler; |
| 409 | |
| 410 | /* Allocate a dummy caller frame for the signal handler. */ |
| 411 | newsp = (unsigned long)frame - __SIGNAL_FRAMESIZE; |
| 412 | err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); |
| 413 | |
| 414 | /* Set up "regs" so we "return" to the signal handler. */ |
| 415 | err |= get_user(regs->nip, &funct_desc_ptr->entry); |
| 416 | /* enter the signal handler in big-endian mode */ |
| 417 | regs->msr &= ~MSR_LE; |
| 418 | regs->gpr[1] = newsp; |
| 419 | err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); |
| 420 | regs->gpr[3] = signr; |
| 421 | regs->result = 0; |
| 422 | if (ka->sa.sa_flags & SA_SIGINFO) { |
| 423 | err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); |
| 424 | err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); |
| 425 | regs->gpr[6] = (unsigned long) frame; |
| 426 | } else { |
| 427 | regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; |
| 428 | } |
| 429 | if (err) |
| 430 | goto badframe; |
| 431 | |
| 432 | return 1; |
| 433 | |
| 434 | badframe: |
| 435 | #if DEBUG_SIG |
| 436 | printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n", |
| 437 | regs, frame, newsp); |
| 438 | #endif |
| 439 | force_sigsegv(signr, current); |
| 440 | return 0; |
| 441 | } |
| 442 | |
| 443 | |
| 444 | /* |
| 445 | * OK, we're invoking a handler |
| 446 | */ |
| 447 | static int handle_signal(unsigned long sig, struct k_sigaction *ka, |
| 448 | siginfo_t *info, sigset_t *oldset, struct pt_regs *regs) |
| 449 | { |
| 450 | int ret; |
| 451 | |
| 452 | /* Set up Signal Frame */ |
| 453 | ret = setup_rt_frame(sig, ka, info, oldset, regs); |
| 454 | |
| 455 | if (ret) { |
| 456 | spin_lock_irq(¤t->sighand->siglock); |
| 457 | sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); |
| 458 | if (!(ka->sa.sa_flags & SA_NODEFER)) |
| 459 | sigaddset(¤t->blocked,sig); |
| 460 | recalc_sigpending(); |
| 461 | spin_unlock_irq(¤t->sighand->siglock); |
| 462 | } |
| 463 | |
| 464 | return ret; |
| 465 | } |
| 466 | |
| 467 | static inline void syscall_restart(struct pt_regs *regs, struct k_sigaction *ka) |
| 468 | { |
| 469 | switch ((int)regs->result) { |
| 470 | case -ERESTART_RESTARTBLOCK: |
| 471 | case -ERESTARTNOHAND: |
| 472 | /* ERESTARTNOHAND means that the syscall should only be |
| 473 | * restarted if there was no handler for the signal, and since |
| 474 | * we only get here if there is a handler, we dont restart. |
| 475 | */ |
| 476 | regs->result = -EINTR; |
| 477 | regs->gpr[3] = EINTR; |
| 478 | regs->ccr |= 0x10000000; |
| 479 | break; |
| 480 | case -ERESTARTSYS: |
| 481 | /* ERESTARTSYS means to restart the syscall if there is no |
| 482 | * handler or the handler was registered with SA_RESTART |
| 483 | */ |
| 484 | if (!(ka->sa.sa_flags & SA_RESTART)) { |
| 485 | regs->result = -EINTR; |
| 486 | regs->gpr[3] = EINTR; |
| 487 | regs->ccr |= 0x10000000; |
| 488 | break; |
| 489 | } |
| 490 | /* fallthrough */ |
| 491 | case -ERESTARTNOINTR: |
| 492 | /* ERESTARTNOINTR means that the syscall should be |
| 493 | * called again after the signal handler returns. |
| 494 | */ |
| 495 | regs->gpr[3] = regs->orig_gpr3; |
| 496 | regs->nip -= 4; |
| 497 | regs->result = 0; |
| 498 | break; |
| 499 | } |
| 500 | } |
| 501 | |
| 502 | /* |
| 503 | * Note that 'init' is a special process: it doesn't get signals it doesn't |
| 504 | * want to handle. Thus you cannot kill init even with a SIGKILL even by |
| 505 | * mistake. |
| 506 | */ |
| 507 | int do_signal(sigset_t *oldset, struct pt_regs *regs) |
| 508 | { |
| 509 | siginfo_t info; |
| 510 | int signr; |
| 511 | struct k_sigaction ka; |
| 512 | |
| 513 | /* |
| 514 | * If the current thread is 32 bit - invoke the |
| 515 | * 32 bit signal handling code |
| 516 | */ |
| 517 | if (test_thread_flag(TIF_32BIT)) |
| 518 | return do_signal32(oldset, regs); |
| 519 | |
| 520 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
| 521 | oldset = ¤t->saved_sigmask; |
| 522 | else if (!oldset) |
| 523 | oldset = ¤t->blocked; |
| 524 | |
| 525 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
| 526 | if (signr > 0) { |
| 527 | int ret; |
| 528 | |
| 529 | /* Whee! Actually deliver the signal. */ |
| 530 | if (TRAP(regs) == 0x0C00) |
| 531 | syscall_restart(regs, &ka); |
| 532 | |
| 533 | /* |
| 534 | * Reenable the DABR before delivering the signal to |
| 535 | * user space. The DABR will have been cleared if it |
| 536 | * triggered inside the kernel. |
| 537 | */ |
| 538 | if (current->thread.dabr) |
| 539 | set_dabr(current->thread.dabr); |
| 540 | |
| 541 | ret = handle_signal(signr, &ka, &info, oldset, regs); |
| 542 | |
| 543 | /* If a signal was successfully delivered, the saved sigmask is in |
| 544 | its frame, and we can clear the TIF_RESTORE_SIGMASK flag */ |
| 545 | if (ret && test_thread_flag(TIF_RESTORE_SIGMASK)) |
| 546 | clear_thread_flag(TIF_RESTORE_SIGMASK); |
| 547 | |
| 548 | return ret; |
| 549 | } |
| 550 | |
| 551 | if (TRAP(regs) == 0x0C00) { /* System Call! */ |
| 552 | if ((int)regs->result == -ERESTARTNOHAND || |
| 553 | (int)regs->result == -ERESTARTSYS || |
| 554 | (int)regs->result == -ERESTARTNOINTR) { |
| 555 | regs->gpr[3] = regs->orig_gpr3; |
| 556 | regs->nip -= 4; /* Back up & retry system call */ |
| 557 | regs->result = 0; |
| 558 | } else if ((int)regs->result == -ERESTART_RESTARTBLOCK) { |
| 559 | regs->gpr[0] = __NR_restart_syscall; |
| 560 | regs->nip -= 4; |
| 561 | regs->result = 0; |
| 562 | } |
| 563 | } |
| 564 | /* No signal to deliver -- put the saved sigmask back */ |
| 565 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) { |
| 566 | clear_thread_flag(TIF_RESTORE_SIGMASK); |
| 567 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
| 568 | } |
| 569 | |
| 570 | return 0; |
| 571 | } |
| 572 | EXPORT_SYMBOL(do_signal); |