1/* 2 * Copyright (C) 2002- 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3 * Licensed under the GPL 4 */ 5 6#include <stdlib.h> 7#include <unistd.h> 8#include <sched.h> 9#include <errno.h> 10#include <string.h> 11#include <sys/mman.h> 12#include <sys/ptrace.h> 13#include <sys/wait.h> 14#include <asm/unistd.h> 15#include "as-layout.h" 16#include "chan_user.h" 17#include "kern_constants.h" 18#include "kern_util.h" 19#include "mem.h" 20#include "os.h" 21#include "process.h" 22#include "proc_mm.h" 23#include "ptrace_user.h" 24#include "registers.h" 25#include "skas.h" 26#include "skas_ptrace.h" 27#include "user.h" 28#include "sysdep/stub.h" 29 30int is_skas_winch(int pid, int fd, void *data) 31{ 32 if (pid != getpgrp()) 33 return 0; 34 35 register_winch_irq(-1, fd, -1, data, 0); 36 return 1; 37} 38 39static int ptrace_dump_regs(int pid) 40{ 41 unsigned long regs[MAX_REG_NR]; 42 int i; 43 44 if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0) 45 return -errno; 46 47 printk(UM_KERN_ERR "Stub registers -\n"); 48 for (i = 0; i < ARRAY_SIZE(regs); i++) 49 printk(UM_KERN_ERR "\t%d - %lx\n", i, regs[i]); 50 51 return 0; 52} 53 54/* 55 * Signals that are OK to receive in the stub - we'll just continue it. 56 * SIGWINCH will happen when UML is inside a detached screen. 57 */ 58#define STUB_SIG_MASK ((1 << SIGVTALRM) | (1 << SIGWINCH)) 59 60/* Signals that the stub will finish with - anything else is an error */ 61#define STUB_DONE_MASK (1 << SIGTRAP) 62 63void wait_stub_done(int pid) 64{ 65 int n, status, err; 66 67 while (1) { 68 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL)); 69 if ((n < 0) || !WIFSTOPPED(status)) 70 goto bad_wait; 71 72 if (((1 << WSTOPSIG(status)) & STUB_SIG_MASK) == 0) 73 break; 74 75 err = ptrace(PTRACE_CONT, pid, 0, 0); 76 if (err) { 77 printk(UM_KERN_ERR "wait_stub_done : continue failed, " 78 "errno = %d\n", errno); 79 fatal_sigsegv(); 80 } 81 } 82 83 if (((1 << WSTOPSIG(status)) & STUB_DONE_MASK) != 0) 84 return; 85 86bad_wait: 87 err = ptrace_dump_regs(pid); 88 if (err) 89 printk(UM_KERN_ERR "Failed to get registers from stub, " 90 "errno = %d\n", -err); 91 printk(UM_KERN_ERR "wait_stub_done : failed to wait for SIGTRAP, " 92 "pid = %d, n = %d, errno = %d, status = 0x%x\n", pid, n, errno, 93 status); 94 fatal_sigsegv(); 95} 96 97extern unsigned long current_stub_stack(void); 98 99static void get_skas_faultinfo(int pid, struct faultinfo *fi) 100{ 101 int err; 102 103 if (ptrace_faultinfo) { 104 err = ptrace(PTRACE_FAULTINFO, pid, 0, fi); 105 if (err) { 106 printk(UM_KERN_ERR "get_skas_faultinfo - " 107 "PTRACE_FAULTINFO failed, errno = %d\n", errno); 108 fatal_sigsegv(); 109 } 110 111 /* Special handling for i386, which has different structs */ 112 if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo)) 113 memset((char *)fi + sizeof(struct ptrace_faultinfo), 0, 114 sizeof(struct faultinfo) - 115 sizeof(struct ptrace_faultinfo)); 116 } 117 else { 118 unsigned long fpregs[FP_SIZE]; 119 120 err = get_fp_registers(pid, fpregs); 121 if (err < 0) { 122 printk(UM_KERN_ERR "save_fp_registers returned %d\n", 123 err); 124 fatal_sigsegv(); 125 } 126 err = ptrace(PTRACE_CONT, pid, 0, SIGSEGV); 127 if (err) { 128 printk(UM_KERN_ERR "Failed to continue stub, pid = %d, " 129 "errno = %d\n", pid, errno); 130 fatal_sigsegv(); 131 } 132 wait_stub_done(pid); 133 134 /* 135 * faultinfo is prepared by the stub-segv-handler at start of 136 * the stub stack page. We just have to copy it. 137 */ 138 memcpy(fi, (void *)current_stub_stack(), sizeof(*fi)); 139 140 err = put_fp_registers(pid, fpregs); 141 if (err < 0) { 142 printk(UM_KERN_ERR "put_fp_registers returned %d\n", 143 err); 144 fatal_sigsegv(); 145 } 146 } 147} 148 149static void handle_segv(int pid, struct uml_pt_regs * regs) 150{ 151 get_skas_faultinfo(pid, ®s->faultinfo); 152 segv(regs->faultinfo, 0, 1, NULL); 153} 154 155/* 156 * To use the same value of using_sysemu as the caller, ask it that value 157 * (in local_using_sysemu 158 */ 159static void handle_trap(int pid, struct uml_pt_regs *regs, 160 int local_using_sysemu) 161{ 162 int err, status; 163 164 if ((UPT_IP(regs) >= STUB_START) && (UPT_IP(regs) < STUB_END)) 165 fatal_sigsegv(); 166 167 /* Mark this as a syscall */ 168 UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->gp); 169 170 if (!local_using_sysemu) 171 { 172 err = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET, 173 __NR_getpid); 174 if (err < 0) { 175 printk(UM_KERN_ERR "handle_trap - nullifying syscall " 176 "failed, errno = %d\n", errno); 177 fatal_sigsegv(); 178 } 179 180 err = ptrace(PTRACE_SYSCALL, pid, 0, 0); 181 if (err < 0) { 182 printk(UM_KERN_ERR "handle_trap - continuing to end of " 183 "syscall failed, errno = %d\n", errno); 184 fatal_sigsegv(); 185 } 186 187 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL)); 188 if ((err < 0) || !WIFSTOPPED(status) || 189 (WSTOPSIG(status) != SIGTRAP + 0x80)) { 190 err = ptrace_dump_regs(pid); 191 if (err) 192 printk(UM_KERN_ERR "Failed to get registers " 193 "from process, errno = %d\n", -err); 194 printk(UM_KERN_ERR "handle_trap - failed to wait at " 195 "end of syscall, errno = %d, status = %d\n", 196 errno, status); 197 fatal_sigsegv(); 198 } 199 } 200 201 handle_syscall(regs); 202} 203 204extern int __syscall_stub_start; 205 206static int userspace_tramp(void *stack) 207{ 208 void *addr; 209 int err; 210 211 ptrace(PTRACE_TRACEME, 0, 0, 0); 212 213 signal(SIGTERM, SIG_DFL); 214 signal(SIGWINCH, SIG_IGN); 215 err = set_interval(); 216 if (err) { 217 printk(UM_KERN_ERR "userspace_tramp - setting timer failed, " 218 "errno = %d\n", err); 219 exit(1); 220 } 221 222 if (!proc_mm) { 223 /* 224 * This has a pte, but it can't be mapped in with the usual 225 * tlb_flush mechanism because this is part of that mechanism 226 */ 227 int fd; 228 unsigned long long offset; 229 fd = phys_mapping(to_phys(&__syscall_stub_start), &offset); 230 addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE, 231 PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset); 232 if (addr == MAP_FAILED) { 233 printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, " 234 "errno = %d\n", STUB_CODE, errno); 235 exit(1); 236 } 237 238 if (stack != NULL) { 239 fd = phys_mapping(to_phys(stack), &offset); 240 addr = mmap((void *) STUB_DATA, 241 UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE, 242 MAP_FIXED | MAP_SHARED, fd, offset); 243 if (addr == MAP_FAILED) { 244 printk(UM_KERN_ERR "mapping segfault stack " 245 "at 0x%lx failed, errno = %d\n", 246 STUB_DATA, errno); 247 exit(1); 248 } 249 } 250 } 251 if (!ptrace_faultinfo && (stack != NULL)) { 252 struct sigaction sa; 253 254 unsigned long v = STUB_CODE + 255 (unsigned long) stub_segv_handler - 256 (unsigned long) &__syscall_stub_start; 257 258 set_sigstack((void *) STUB_DATA, UM_KERN_PAGE_SIZE); 259 sigemptyset(&sa.sa_mask); 260 sa.sa_flags = SA_ONSTACK | SA_NODEFER; 261 sa.sa_handler = (void *) v; 262 sa.sa_restorer = NULL; 263 if (sigaction(SIGSEGV, &sa, NULL) < 0) { 264 printk(UM_KERN_ERR "userspace_tramp - setting SIGSEGV " 265 "handler failed - errno = %d\n", errno); 266 exit(1); 267 } 268 } 269 270 kill(os_getpid(), SIGSTOP); 271 return 0; 272} 273 274/* Each element set once, and only accessed by a single processor anyway */ 275#undef NR_CPUS 276#define NR_CPUS 1 277int userspace_pid[NR_CPUS]; 278 279int start_userspace(unsigned long stub_stack) 280{ 281 void *stack; 282 unsigned long sp; 283 int pid, status, n, flags, err; 284 285 stack = mmap(NULL, UM_KERN_PAGE_SIZE, 286 PROT_READ | PROT_WRITE | PROT_EXEC, 287 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 288 if (stack == MAP_FAILED) { 289 err = -errno; 290 printk(UM_KERN_ERR "start_userspace : mmap failed, " 291 "errno = %d\n", errno); 292 return err; 293 } 294 295 sp = (unsigned long) stack + UM_KERN_PAGE_SIZE - sizeof(void *); 296 297 flags = CLONE_FILES; 298 if (proc_mm) 299 flags |= CLONE_VM; 300 else 301 flags |= SIGCHLD; 302 303 pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack); 304 if (pid < 0) { 305 err = -errno; 306 printk(UM_KERN_ERR "start_userspace : clone failed, " 307 "errno = %d\n", errno); 308 return err; 309 } 310 311 do { 312 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED | __WALL)); 313 if (n < 0) { 314 err = -errno; 315 printk(UM_KERN_ERR "start_userspace : wait failed, " 316 "errno = %d\n", errno); 317 goto out_kill; 318 } 319 } while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM)); 320 321 if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) { 322 err = -EINVAL; 323 printk(UM_KERN_ERR "start_userspace : expected SIGSTOP, got " 324 "status = %d\n", status); 325 goto out_kill; 326 } 327 328 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, 329 (void *) PTRACE_O_TRACESYSGOOD) < 0) { 330 err = -errno; 331 printk(UM_KERN_ERR "start_userspace : PTRACE_OLDSETOPTIONS " 332 "failed, errno = %d\n", errno); 333 goto out_kill; 334 } 335 336 if (munmap(stack, UM_KERN_PAGE_SIZE) < 0) { 337 err = -errno; 338 printk(UM_KERN_ERR "start_userspace : munmap failed, " 339 "errno = %d\n", errno); 340 goto out_kill; 341 } 342 343 return pid; 344 345 out_kill: 346 os_kill_ptraced_process(pid, 1); 347 return err; 348} 349 350void userspace(struct uml_pt_regs *regs) 351{ 352 struct itimerval timer; 353 unsigned long long nsecs, now; 354 int err, status, op, pid = userspace_pid[0]; 355 /* To prevent races if using_sysemu changes under us.*/ 356 int local_using_sysemu; 357 358 if (getitimer(ITIMER_VIRTUAL, &timer)) 359 printk(UM_KERN_ERR "Failed to get itimer, errno = %d\n", errno); 360 nsecs = timer.it_value.tv_sec * UM_NSEC_PER_SEC + 361 timer.it_value.tv_usec * UM_NSEC_PER_USEC; 362 nsecs += os_nsecs(); 363 364 while (1) { 365 /* 366 * This can legitimately fail if the process loads a 367 * bogus value into a segment register. It will 368 * segfault and PTRACE_GETREGS will read that value 369 * out of the process. However, PTRACE_SETREGS will 370 * fail. In this case, there is nothing to do but 371 * just kill the process. 372 */ 373 if (ptrace(PTRACE_SETREGS, pid, 0, regs->gp)) 374 fatal_sigsegv(); 375 376 /* Now we set local_using_sysemu to be used for one loop */ 377 local_using_sysemu = get_using_sysemu(); 378 379 op = SELECT_PTRACE_OPERATION(local_using_sysemu, 380 singlestepping(NULL)); 381 382 if (ptrace(op, pid, 0, 0)) { 383 printk(UM_KERN_ERR "userspace - ptrace continue " 384 "failed, op = %d, errno = %d\n", op, errno); 385 fatal_sigsegv(); 386 } 387 388 CATCH_EINTR(err = waitpid(pid, &status, WUNTRACED | __WALL)); 389 if (err < 0) { 390 printk(UM_KERN_ERR "userspace - wait failed, " 391 "errno = %d\n", errno); 392 fatal_sigsegv(); 393 } 394 395 regs->is_user = 1; 396 if (ptrace(PTRACE_GETREGS, pid, 0, regs->gp)) { 397 printk(UM_KERN_ERR "userspace - PTRACE_GETREGS failed, " 398 "errno = %d\n", errno); 399 fatal_sigsegv(); 400 } 401 402 UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */ 403 404 if (WIFSTOPPED(status)) { 405 int sig = WSTOPSIG(status); 406 switch (sig) { 407 case SIGSEGV: 408 if (PTRACE_FULL_FAULTINFO || 409 !ptrace_faultinfo) { 410 get_skas_faultinfo(pid, 411 ®s->faultinfo); 412 (*sig_info[SIGSEGV])(SIGSEGV, regs); 413 } 414 else handle_segv(pid, regs); 415 break; 416 case SIGTRAP + 0x80: 417 handle_trap(pid, regs, local_using_sysemu); 418 break; 419 case SIGTRAP: 420 relay_signal(SIGTRAP, regs); 421 break; 422 case SIGVTALRM: 423 now = os_nsecs(); 424 if (now < nsecs) 425 break; 426 block_signals(); 427 (*sig_info[sig])(sig, regs); 428 unblock_signals(); 429 nsecs = timer.it_value.tv_sec * 430 UM_NSEC_PER_SEC + 431 timer.it_value.tv_usec * 432 UM_NSEC_PER_USEC; 433 nsecs += os_nsecs(); 434 break; 435 case SIGIO: 436 case SIGILL: 437 case SIGBUS: 438 case SIGFPE: 439 case SIGWINCH: 440 block_signals(); 441 (*sig_info[sig])(sig, regs); 442 unblock_signals(); 443 break; 444 default: 445 printk(UM_KERN_ERR "userspace - child stopped " 446 "with signal %d\n", sig); 447 fatal_sigsegv(); 448 } 449 pid = userspace_pid[0]; 450 interrupt_end(); 451 452 /* Avoid -ERESTARTSYS handling in host */ 453 if (PT_SYSCALL_NR_OFFSET != PT_SYSCALL_RET_OFFSET) 454 PT_SYSCALL_NR(regs->gp) = -1; 455 } 456 } 457} 458 459static unsigned long thread_regs[MAX_REG_NR]; 460 461static int __init init_thread_regs(void) 462{ 463 get_safe_registers(thread_regs); 464 /* Set parent's instruction pointer to start of clone-stub */ 465 thread_regs[REGS_IP_INDEX] = STUB_CODE + 466 (unsigned long) stub_clone_handler - 467 (unsigned long) &__syscall_stub_start; 468 thread_regs[REGS_SP_INDEX] = STUB_DATA + UM_KERN_PAGE_SIZE - 469 sizeof(void *); 470#ifdef __SIGNAL_FRAMESIZE 471 thread_regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE; 472#endif 473 return 0; 474} 475 476__initcall(init_thread_regs); 477 478int copy_context_skas0(unsigned long new_stack, int pid) 479{ 480 struct timeval tv = { .tv_sec = 0, .tv_usec = UM_USEC_PER_SEC / UM_HZ }; 481 int err; 482 unsigned long current_stack = current_stub_stack(); 483 struct stub_data *data = (struct stub_data *) current_stack; 484 struct stub_data *child_data = (struct stub_data *) new_stack; 485 unsigned long long new_offset; 486 int new_fd = phys_mapping(to_phys((void *)new_stack), &new_offset); 487 488 /* 489 * prepare offset and fd of child's stack as argument for parent's 490 * and child's mmap2 calls 491 */ 492 *data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset), 493 .fd = new_fd, 494 .timer = ((struct itimerval) 495 { .it_value = tv, 496 .it_interval = tv }) }); 497 498 err = ptrace_setregs(pid, thread_regs); 499 if (err < 0) { 500 err = -errno; 501 printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_SETREGS " 502 "failed, pid = %d, errno = %d\n", pid, -err); 503 return err; 504 } 505 506 /* set a well known return code for detection of child write failure */ 507 child_data->err = 12345678; 508 509 /* 510 * Wait, until parent has finished its work: read child's pid from 511 * parent's stack, and check, if bad result. 512 */ 513 err = ptrace(PTRACE_CONT, pid, 0, 0); 514 if (err) { 515 err = -errno; 516 printk(UM_KERN_ERR "Failed to continue new process, pid = %d, " 517 "errno = %d\n", pid, errno); 518 return err; 519 } 520 521 wait_stub_done(pid); 522 523 pid = data->err; 524 if (pid < 0) { 525 printk(UM_KERN_ERR "copy_context_skas0 - stub-parent reports " 526 "error %d\n", -pid); 527 return pid; 528 } 529 530 /* 531 * Wait, until child has finished too: read child's result from 532 * child's stack and check it. 533 */ 534 wait_stub_done(pid); 535 if (child_data->err != STUB_DATA) { 536 printk(UM_KERN_ERR "copy_context_skas0 - stub-child reports " 537 "error %ld\n", child_data->err); 538 err = child_data->err; 539 goto out_kill; 540 } 541 542 if (ptrace(PTRACE_OLDSETOPTIONS, pid, NULL, 543 (void *)PTRACE_O_TRACESYSGOOD) < 0) { 544 err = -errno; 545 printk(UM_KERN_ERR "copy_context_skas0 : PTRACE_OLDSETOPTIONS " 546 "failed, errno = %d\n", errno); 547 goto out_kill; 548 } 549 550 return pid; 551 552 out_kill: 553 os_kill_ptraced_process(pid, 1); 554 return err; 555} 556 557/* 558 * This is used only, if stub pages are needed, while proc_mm is 559 * available. Opening /proc/mm creates a new mm_context, which lacks 560 * the stub-pages. Thus, we map them using /proc/mm-fd 561 */ 562int map_stub_pages(int fd, unsigned long code, unsigned long data, 563 unsigned long stack) 564{ 565 struct proc_mm_op mmop; 566 int n; 567 unsigned long long code_offset; 568 int code_fd = phys_mapping(to_phys((void *) &__syscall_stub_start), 569 &code_offset); 570 571 mmop = ((struct proc_mm_op) { .op = MM_MMAP, 572 .u = 573 { .mmap = 574 { .addr = code, 575 .len = UM_KERN_PAGE_SIZE, 576 .prot = PROT_EXEC, 577 .flags = MAP_FIXED | MAP_PRIVATE, 578 .fd = code_fd, 579 .offset = code_offset 580 } } }); 581 CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop))); 582 if (n != sizeof(mmop)) { 583 n = errno; 584 printk(UM_KERN_ERR "mmap args - addr = 0x%lx, fd = %d, " 585 "offset = %llx\n", code, code_fd, 586 (unsigned long long) code_offset); 587 printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for code " 588 "failed, err = %d\n", n); 589 return -n; 590 } 591 592 if (stack) { 593 unsigned long long map_offset; 594 int map_fd = phys_mapping(to_phys((void *)stack), &map_offset); 595 mmop = ((struct proc_mm_op) 596 { .op = MM_MMAP, 597 .u = 598 { .mmap = 599 { .addr = data, 600 .len = UM_KERN_PAGE_SIZE, 601 .prot = PROT_READ | PROT_WRITE, 602 .flags = MAP_FIXED | MAP_SHARED, 603 .fd = map_fd, 604 .offset = map_offset 605 } } }); 606 CATCH_EINTR(n = write(fd, &mmop, sizeof(mmop))); 607 if (n != sizeof(mmop)) { 608 n = errno; 609 printk(UM_KERN_ERR "map_stub_pages : /proc/mm map for " 610 "data failed, err = %d\n", n); 611 return -n; 612 } 613 } 614 615 return 0; 616} 617 618void new_thread(void *stack, jmp_buf *buf, void (*handler)(void)) 619{ 620 (*buf)[0].JB_IP = (unsigned long) handler; 621 (*buf)[0].JB_SP = (unsigned long) stack + UM_THREAD_SIZE - 622 sizeof(void *); 623} 624 625#define INIT_JMP_NEW_THREAD 0 626#define INIT_JMP_CALLBACK 1 627#define INIT_JMP_HALT 2 628#define INIT_JMP_REBOOT 3 629 630void switch_threads(jmp_buf *me, jmp_buf *you) 631{ 632 if (UML_SETJMP(me) == 0) 633 UML_LONGJMP(you, 1); 634} 635 636static jmp_buf initial_jmpbuf; 637 638static void (*cb_proc)(void *arg); 639static void *cb_arg; 640static jmp_buf *cb_back; 641 642int start_idle_thread(void *stack, jmp_buf *switch_buf) 643{ 644 int n; 645 646 set_handler(SIGWINCH, (__sighandler_t) sig_handler, 647 SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGVTALRM, -1); 648 649 /* 650 * Can't use UML_SETJMP or UML_LONGJMP here because they save 651 * and restore signals, with the possible side-effect of 652 * trying to handle any signals which came when they were 653 * blocked, which can't be done on this stack. 654 * Signals must be blocked when jumping back here and restored 655 * after returning to the jumper. 656 */ 657 n = setjmp(initial_jmpbuf); 658 switch (n) { 659 case INIT_JMP_NEW_THREAD: 660 (*switch_buf)[0].JB_IP = (unsigned long) new_thread_handler; 661 (*switch_buf)[0].JB_SP = (unsigned long) stack + 662 UM_THREAD_SIZE - sizeof(void *); 663 break; 664 case INIT_JMP_CALLBACK: 665 (*cb_proc)(cb_arg); 666 longjmp(*cb_back, 1); 667 break; 668 case INIT_JMP_HALT: 669 kmalloc_ok = 0; 670 return 0; 671 case INIT_JMP_REBOOT: 672 kmalloc_ok = 0; 673 return 1; 674 default: 675 printk(UM_KERN_ERR "Bad sigsetjmp return in " 676 "start_idle_thread - %d\n", n); 677 fatal_sigsegv(); 678 } 679 longjmp(*switch_buf, 1); 680} 681 682void initial_thread_cb_skas(void (*proc)(void *), void *arg) 683{ 684 jmp_buf here; 685 686 cb_proc = proc; 687 cb_arg = arg; 688 cb_back = &here; 689 690 block_signals(); 691 if (UML_SETJMP(&here) == 0) 692 UML_LONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK); 693 unblock_signals(); 694 695 cb_proc = NULL; 696 cb_arg = NULL; 697 cb_back = NULL; 698} 699 700void halt_skas(void) 701{ 702 block_signals(); 703 UML_LONGJMP(&initial_jmpbuf, INIT_JMP_HALT); 704} 705 706void reboot_skas(void) 707{ 708 block_signals(); 709 UML_LONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT); 710} 711 712void __switch_mm(struct mm_id *mm_idp) 713{ 714 int err; 715 716 if (proc_mm) { 717 err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0, 718 mm_idp->u.mm_fd); 719 if (err) { 720 printk(UM_KERN_ERR "__switch_mm - PTRACE_SWITCH_MM " 721 "failed, errno = %d\n", errno); 722 fatal_sigsegv(); 723 } 724 } 725 else userspace_pid[0] = mm_idp->u.pid; 726} 727