![Al Viro](/assets/img/avatar_default.png)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
264 lines
5.8 KiB
C
264 lines
5.8 KiB
C
/*
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* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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* Licensed under the GPL
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <errno.h>
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#include <signal.h>
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#include <string.h>
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#include <sys/resource.h>
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#include "as-layout.h"
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#include "init.h"
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#include "kern_util.h"
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#include "os.h"
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#include "um_malloc.h"
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#define PGD_BOUND (4 * 1024 * 1024)
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#define STACKSIZE (8 * 1024 * 1024)
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#define THREAD_NAME_LEN (256)
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long elf_aux_hwcap;
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static void set_stklim(void)
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{
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struct rlimit lim;
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if (getrlimit(RLIMIT_STACK, &lim) < 0) {
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perror("getrlimit");
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exit(1);
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}
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if ((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)) {
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lim.rlim_cur = STACKSIZE;
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if (setrlimit(RLIMIT_STACK, &lim) < 0) {
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perror("setrlimit");
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exit(1);
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}
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}
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}
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static __init void do_uml_initcalls(void)
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{
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initcall_t *call;
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call = &__uml_initcall_start;
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while (call < &__uml_initcall_end) {
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(*call)();
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call++;
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}
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}
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static void last_ditch_exit(int sig)
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{
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uml_cleanup();
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exit(1);
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}
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static void install_fatal_handler(int sig)
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{
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struct sigaction action;
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/* All signals are enabled in this handler ... */
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sigemptyset(&action.sa_mask);
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/*
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* ... including the signal being handled, plus we want the
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* handler reset to the default behavior, so that if an exit
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* handler is hanging for some reason, the UML will just die
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* after this signal is sent a second time.
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*/
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action.sa_flags = SA_RESETHAND | SA_NODEFER;
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action.sa_restorer = NULL;
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action.sa_handler = last_ditch_exit;
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if (sigaction(sig, &action, NULL) < 0) {
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printf("failed to install handler for signal %d - errno = %d\n",
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sig, errno);
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exit(1);
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}
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}
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#define UML_LIB_PATH ":" OS_LIB_PATH "/uml"
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static void setup_env_path(void)
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{
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char *new_path = NULL;
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char *old_path = NULL;
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int path_len = 0;
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old_path = getenv("PATH");
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/*
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* if no PATH variable is set or it has an empty value
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* just use the default + /usr/lib/uml
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*/
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if (!old_path || (path_len = strlen(old_path)) == 0) {
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if (putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH))
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perror("couldn't putenv");
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return;
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}
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/* append /usr/lib/uml to the existing path */
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path_len += strlen("PATH=" UML_LIB_PATH) + 1;
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new_path = malloc(path_len);
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if (!new_path) {
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perror("couldn't malloc to set a new PATH");
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return;
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}
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snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path);
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if (putenv(new_path)) {
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perror("couldn't putenv to set a new PATH");
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free(new_path);
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}
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}
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extern void scan_elf_aux( char **envp);
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int __init main(int argc, char **argv, char **envp)
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{
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char **new_argv;
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int ret, i, err;
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set_stklim();
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setup_env_path();
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new_argv = malloc((argc + 1) * sizeof(char *));
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if (new_argv == NULL) {
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perror("Mallocing argv");
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exit(1);
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}
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for (i = 0; i < argc; i++) {
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new_argv[i] = strdup(argv[i]);
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if (new_argv[i] == NULL) {
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perror("Mallocing an arg");
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exit(1);
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}
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}
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new_argv[argc] = NULL;
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/*
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* Allow these signals to bring down a UML if all other
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* methods of control fail.
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*/
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install_fatal_handler(SIGINT);
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install_fatal_handler(SIGTERM);
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#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
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scan_elf_aux(envp);
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#endif
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do_uml_initcalls();
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ret = linux_main(argc, argv);
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/*
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* Disable SIGPROF - I have no idea why libc doesn't do this or turn
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* off the profiling time, but UML dies with a SIGPROF just before
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* exiting when profiling is active.
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*/
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change_sig(SIGPROF, 0);
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/*
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* This signal stuff used to be in the reboot case. However,
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* sometimes a SIGVTALRM can come in when we're halting (reproducably
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* when writing out gcov information, presumably because that takes
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* some time) and cause a segfault.
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*/
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/* stop timers and set SIGVTALRM to be ignored */
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disable_timer();
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/* disable SIGIO for the fds and set SIGIO to be ignored */
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err = deactivate_all_fds();
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if (err)
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printf("deactivate_all_fds failed, errno = %d\n", -err);
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/*
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* Let any pending signals fire now. This ensures
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* that they won't be delivered after the exec, when
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* they are definitely not expected.
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*/
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unblock_signals();
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/* Reboot */
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if (ret) {
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printf("\n");
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execvp(new_argv[0], new_argv);
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perror("Failed to exec kernel");
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ret = 1;
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}
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printf("\n");
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return uml_exitcode;
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}
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extern void *__real_malloc(int);
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void *__wrap_malloc(int size)
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{
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void *ret;
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if (!kmalloc_ok)
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return __real_malloc(size);
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else if (size <= UM_KERN_PAGE_SIZE)
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/* finding contiguous pages can be hard*/
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ret = uml_kmalloc(size, UM_GFP_KERNEL);
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else ret = vmalloc(size);
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/*
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* glibc people insist that if malloc fails, errno should be
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* set by malloc as well. So we do.
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*/
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if (ret == NULL)
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errno = ENOMEM;
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return ret;
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}
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void *__wrap_calloc(int n, int size)
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{
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void *ptr = __wrap_malloc(n * size);
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if (ptr == NULL)
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return NULL;
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memset(ptr, 0, n * size);
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return ptr;
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}
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extern void __real_free(void *);
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extern unsigned long high_physmem;
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void __wrap_free(void *ptr)
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{
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unsigned long addr = (unsigned long) ptr;
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/*
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* We need to know how the allocation happened, so it can be correctly
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* freed. This is done by seeing what region of memory the pointer is
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* in -
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* physical memory - kmalloc/kfree
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* kernel virtual memory - vmalloc/vfree
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* anywhere else - malloc/free
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* If kmalloc is not yet possible, then either high_physmem and/or
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* end_vm are still 0 (as at startup), in which case we call free, or
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* we have set them, but anyway addr has not been allocated from those
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* areas. So, in both cases __real_free is called.
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*
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* CAN_KMALLOC is checked because it would be bad to free a buffer
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* with kmalloc/vmalloc after they have been turned off during
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* shutdown.
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* XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so
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* there is a possibility for memory leaks.
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*/
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if ((addr >= uml_physmem) && (addr < high_physmem)) {
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if (kmalloc_ok)
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kfree(ptr);
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}
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else if ((addr >= start_vm) && (addr < end_vm)) {
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if (kmalloc_ok)
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vfree(ptr);
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}
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else __real_free(ptr);
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}
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