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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 | /* * linux/arch/x86_64/kernel/signal.c * * Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs * * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes * 2000-2002 x86-64 support by Andi Kleen * * $Id: signal.c,v 1.18 2001/10/17 22:30:37 ak Exp $ */ #include <linux/sched.h> #include <linux/mm.h> #include <linux/smp.h> #include <linux/smp_lock.h> #include <linux/kernel.h> #include <linux/signal.h> #include <linux/errno.h> #include <linux/wait.h> #include <linux/ptrace.h> #include <linux/unistd.h> #include <linux/stddef.h> #include <linux/personality.h> #include <linux/compiler.h> #include <asm/ucontext.h> #include <asm/uaccess.h> #include <asm/i387.h> #include <asm/proto.h> /* #define DEBUG_SIG 1 */ #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) void ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct pt_regs * regs); void ia32_setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, struct pt_regs * regs); asmlinkage long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs) { sigset_t saveset, newset; /* XXX: Don't preclude handling different sized sigset_t's. */ if (sigsetsize != sizeof(sigset_t)) return -EINVAL; if (copy_from_user(&newset, unewset, sizeof(newset))) return -EFAULT; sigdelsetmask(&newset, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); saveset = current->blocked; current->blocked = newset; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); #ifdef DEBUG_SIG printk("rt_sigsuspend savset(%lx) newset(%lx) regs(%p) rip(%lx)\n", saveset, newset, regs, regs->rip); #endif regs->rax = -EINTR; while (1) { current->state = TASK_INTERRUPTIBLE; schedule(); if (do_signal(regs, &saveset)) return -EINTR; } } asmlinkage long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, struct pt_regs *regs) { return do_sigaltstack(uss, uoss, regs->rsp); } /* * Do a signal return; undo the signal stack. */ struct rt_sigframe { char *pretcode; struct ucontext uc; struct siginfo info; }; static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, unsigned long *prax) { unsigned int err = 0; /* Always make any pending restarted system calls return -EINTR */ current_thread_info()->restart_block.fn = do_no_restart_syscall; #define COPY(x) err |= __get_user(regs->x, &sc->x) COPY(rdi); COPY(rsi); COPY(rbp); COPY(rsp); COPY(rbx); COPY(rdx); COPY(rcx); COPY(rip); COPY(r8); COPY(r9); COPY(r10); COPY(r11); COPY(r12); COPY(r13); COPY(r14); COPY(r15); { unsigned int tmpflags; err |= __get_user(tmpflags, &sc->eflags); regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5); regs->orig_rax = -1; /* disable syscall checks */ } { struct _fpstate __user * buf; err |= __get_user(buf, &sc->fpstate); if (buf) { if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) goto badframe; err |= restore_i387(buf); } else { struct task_struct *me = current; if (used_math()) { clear_fpu(me); clear_used_math(); } } } err |= __get_user(*prax, &sc->rax); return err; badframe: return 1; } asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) { struct rt_sigframe __user *frame; sigset_t set; unsigned long eax; frame = (struct rt_sigframe __user *)(regs->rsp - 8); if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) { goto badframe; } if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) { goto badframe; } sigdelsetmask(&set, ~_BLOCKABLE); spin_lock_irq(¤t->sighand->siglock); current->blocked = set; recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax)) { goto badframe; } #ifdef DEBUG_SIG printk("%d sigreturn rip:%lx rsp:%lx frame:%p rax:%lx\n",current->pid,regs.rip,regs.rsp,frame,eax); #endif if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->rsp) == -EFAULT) goto badframe; return eax; badframe: signal_fault(regs,frame,"sigreturn"); return 0; } /* * Set up a signal frame. */ static inline int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned long mask, struct task_struct *me) { int err = 0; unsigned long eflags; err |= __put_user(0, &sc->gs); err |= __put_user(0, &sc->fs); err |= __put_user(regs->rdi, &sc->rdi); err |= __put_user(regs->rsi, &sc->rsi); err |= __put_user(regs->rbp, &sc->rbp); err |= __put_user(regs->rsp, &sc->rsp); err |= __put_user(regs->rbx, &sc->rbx); err |= __put_user(regs->rdx, &sc->rdx); err |= __put_user(regs->rcx, &sc->rcx); err |= __put_user(regs->rax, &sc->rax); err |= __put_user(regs->r8, &sc->r8); err |= __put_user(regs->r9, &sc->r9); err |= __put_user(regs->r10, &sc->r10); err |= __put_user(regs->r11, &sc->r11); err |= __put_user(regs->r12, &sc->r12); err |= __put_user(regs->r13, &sc->r13); err |= __put_user(regs->r14, &sc->r14); err |= __put_user(regs->r15, &sc->r15); err |= __put_user(me->thread.trap_no, &sc->trapno); err |= __put_user(me->thread.error_code, &sc->err); err |= __put_user(regs->rip, &sc->rip); eflags = regs->eflags; if (current->ptrace & PT_PTRACED) { eflags &= ~TF_MASK; } err |= __put_user(eflags, &sc->eflags); err |= __put_user(mask, &sc->oldmask); err |= __put_user(me->thread.cr2, &sc->cr2); return err; } /* * Determine which stack to use.. */ static void __user * get_stack(struct k_sigaction *ka, struct pt_regs *regs, unsigned long size) { unsigned long rsp; /* Default to using normal stack - redzone*/ rsp = regs->rsp - 128; /* This is the X/Open sanctioned signal stack switching. */ /* RED-PEN: redzone on that stack? */ if (ka->sa.sa_flags & SA_ONSTACK) { if (sas_ss_flags(rsp) == 0) rsp = current->sas_ss_sp + current->sas_ss_size; } return (void __user *)round_down(rsp - size, 16); } static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct pt_regs * regs) { struct rt_sigframe __user *frame; struct _fpstate __user *fp = NULL; int err = 0; struct task_struct *me = current; if (used_math()) { fp = get_stack(ka, regs, sizeof(struct _fpstate)); frame = (void __user *)round_down((unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8; if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate))) { goto give_sigsegv; } if (save_i387(fp) < 0) err |= -1; } else { frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8; } if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) { goto give_sigsegv; } if (ka->sa.sa_flags & SA_SIGINFO) { err |= copy_siginfo_to_user(&frame->info, info); if (err) { goto give_sigsegv; } } /* Create the ucontext. */ err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp); err |= __put_user(sas_ss_flags(regs->rsp), &frame->uc.uc_stack.ss_flags); err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size); err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me); err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate); if (sizeof(*set) == 16) { __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]); __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]); } else { err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); } /* Set up to return from userspace. If provided, use a stub already in userspace. */ /* x86-64 should always use SA_RESTORER. */ if (ka->sa.sa_flags & SA_RESTORER) { err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); } else { /* could use a vstub here */ goto give_sigsegv; } if (err) { goto give_sigsegv; } #ifdef DEBUG_SIG printk("%d old rip %lx old rsp %lx old rax %lx\n", current->pid,regs->rip,regs->rsp,regs->rax); #endif /* Set up registers for signal handler */ { struct exec_domain *ed = current_thread_info()->exec_domain; if (unlikely(ed && ed->signal_invmap && sig < 32)) sig = ed->signal_invmap[sig]; } regs->rdi = sig; /* In case the signal handler was declared without prototypes */ regs->rax = 0; /* This also works for non SA_SIGINFO handlers because they expect the next argument after the signal number on the stack. */ regs->rsi = (unsigned long)&frame->info; regs->rdx = (unsigned long)&frame->uc; regs->rip = (unsigned long) ka->sa.sa_handler; regs->rsp = (unsigned long)frame; set_fs(USER_DS); if (regs->eflags & TF_MASK) { if ((current->ptrace & (PT_PTRACED | PT_DTRACE)) == (PT_PTRACED | PT_DTRACE)) { ptrace_notify(SIGTRAP); } else { regs->eflags &= ~TF_MASK; } } #ifdef DEBUG_SIG printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", current->comm, current->pid, frame, regs->rip, frame->pretcode); #endif return; give_sigsegv: force_sigsegv(sig, current); } /* * OK, we're invoking a handler */ static void handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs) { #ifdef DEBUG_SIG printk("handle_signal pid:%d sig:%lu rip:%lx rsp:%lx regs=%p\n", current->pid, sig, regs->rip, regs->rsp, regs); #endif /* Are we from a system call? */ if ((long)regs->orig_rax >= 0) { /* If so, check system call restarting.. */ switch (regs->rax) { case -ERESTART_RESTARTBLOCK: case -ERESTARTNOHAND: regs->rax = -EINTR; break; case -ERESTARTSYS: if (!(ka->sa.sa_flags & SA_RESTART)) { regs->rax = -EINTR; break; } /* fallthrough */ case -ERESTARTNOINTR: regs->rax = regs->orig_rax; regs->rip -= 2; } } #ifdef CONFIG_IA32_EMULATION if (test_thread_flag(TIF_IA32)) { if (ka->sa.sa_flags & SA_SIGINFO) ia32_setup_rt_frame(sig, ka, info, oldset, regs); else ia32_setup_frame(sig, ka, oldset, regs); } else #endif setup_rt_frame(sig, ka, info, oldset, regs); if (!(ka->sa.sa_flags & SA_NODEFER)) { spin_lock_irq(¤t->sighand->siglock); sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); sigaddset(¤t->blocked,sig); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); } } /* * Note that 'init' is a special process: it doesn't get signals it doesn't * want to handle. Thus you cannot kill init even with a SIGKILL even by * mistake. */ int do_signal(struct pt_regs *regs, sigset_t *oldset) { struct k_sigaction ka; siginfo_t info; int signr; /* * We want the common case to go fast, which * is why we may in certain cases get here from * kernel mode. Just return without doing anything * if so. */ if ((regs->cs & 3) != 3) { return 1; } if (try_to_freeze(0)) goto no_signal; if (!oldset) oldset = ¤t->blocked; signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { /* Reenable any watchpoints before delivering the * signal to user space. The processor register will * have been cleared if the watchpoint triggered * inside the kernel. */ if (current->thread.debugreg7) asm volatile("movq %0,%%db7" : : "r" (current->thread.debugreg7)); /* Whee! Actually deliver the signal. */ handle_signal(signr, &info, &ka, oldset, regs); return 1; } no_signal: /* Did we come from a system call? */ if ((long)regs->orig_rax >= 0) { /* Restart the system call - no handlers present */ long res = regs->rax; if (res == -ERESTARTNOHAND || res == -ERESTARTSYS || res == -ERESTARTNOINTR) { regs->rax = regs->orig_rax; regs->rip -= 2; } if (regs->rax == (unsigned long)-ERESTART_RESTARTBLOCK) { regs->rax = __NR_restart_syscall; regs->rip -= 2; } } return 0; } void do_notify_resume(struct pt_regs *regs, sigset_t *oldset, __u32 thread_info_flags) { #ifdef DEBUG_SIG printk("do_notify_resume flags:%x rip:%lx rsp:%lx caller:%lx pending:%lx\n", thread_info_flags, regs->rip, regs->rsp, __builtin_return_address(0),signal_pending(current)); #endif /* Pending single-step? */ if (thread_info_flags & _TIF_SINGLESTEP) { regs->eflags |= TF_MASK; clear_thread_flag(TIF_SINGLESTEP); } /* deal with pending signal delivery */ if (thread_info_flags & _TIF_SIGPENDING) do_signal(regs,oldset); } void signal_fault(struct pt_regs *regs, void __user *frame, char *where) { struct task_struct *me = current; if (exception_trace) printk("%s[%d] bad frame in %s frame:%p rip:%lx rsp:%lx orax:%lx\n", me->comm,me->pid,where,frame,regs->rip,regs->rsp,regs->orig_rax); force_sig(SIGSEGV, me); } |