152c653b3SJeff Dike /* 252c653b3SJeff Dike * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com) 352c653b3SJeff Dike * Licensed under the GPL 452c653b3SJeff Dike */ 552c653b3SJeff Dike 652c653b3SJeff Dike #include <unistd.h> 752c653b3SJeff Dike #include <stdio.h> 852c653b3SJeff Dike #include <stdlib.h> 952c653b3SJeff Dike #include <string.h> 1052c653b3SJeff Dike #include <signal.h> 1152c653b3SJeff Dike #include <errno.h> 1252c653b3SJeff Dike #include <sys/resource.h> 1352c653b3SJeff Dike #include <sys/mman.h> 1452c653b3SJeff Dike #include <sys/user.h> 1552c653b3SJeff Dike #include "kern_util.h" 164ff83ce1SJeff Dike #include "as-layout.h" 1752c653b3SJeff Dike #include "mem_user.h" 1852c653b3SJeff Dike #include "irq_user.h" 1952c653b3SJeff Dike #include "user.h" 2052c653b3SJeff Dike #include "init.h" 2152c653b3SJeff Dike #include "mode.h" 2252c653b3SJeff Dike #include "uml-config.h" 2352c653b3SJeff Dike #include "os.h" 24c13e5690SPaolo 'Blaisorblade' Giarrusso #include "um_malloc.h" 25c539ab73SJeff Dike #include "kern_constants.h" 2652c653b3SJeff Dike 2752c653b3SJeff Dike #define PGD_BOUND (4 * 1024 * 1024) 2852c653b3SJeff Dike #define STACKSIZE (8 * 1024 * 1024) 2952c653b3SJeff Dike #define THREAD_NAME_LEN (256) 3052c653b3SJeff Dike 3152c653b3SJeff Dike static void set_stklim(void) 3252c653b3SJeff Dike { 3352c653b3SJeff Dike struct rlimit lim; 3452c653b3SJeff Dike 3552c653b3SJeff Dike if(getrlimit(RLIMIT_STACK, &lim) < 0){ 3652c653b3SJeff Dike perror("getrlimit"); 3752c653b3SJeff Dike exit(1); 3852c653b3SJeff Dike } 3952c653b3SJeff Dike if((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)){ 4052c653b3SJeff Dike lim.rlim_cur = STACKSIZE; 4152c653b3SJeff Dike if(setrlimit(RLIMIT_STACK, &lim) < 0){ 4252c653b3SJeff Dike perror("setrlimit"); 4352c653b3SJeff Dike exit(1); 4452c653b3SJeff Dike } 4552c653b3SJeff Dike } 4652c653b3SJeff Dike } 4752c653b3SJeff Dike 4852c653b3SJeff Dike static __init void do_uml_initcalls(void) 4952c653b3SJeff Dike { 5052c653b3SJeff Dike initcall_t *call; 5152c653b3SJeff Dike 5252c653b3SJeff Dike call = &__uml_initcall_start; 53f2183125SJeff Dike while (call < &__uml_initcall_end){ 5452c653b3SJeff Dike (*call)(); 5552c653b3SJeff Dike call++; 5652c653b3SJeff Dike } 5752c653b3SJeff Dike } 5852c653b3SJeff Dike 5952c653b3SJeff Dike static void last_ditch_exit(int sig) 6052c653b3SJeff Dike { 6152c653b3SJeff Dike uml_cleanup(); 6252c653b3SJeff Dike exit(1); 6352c653b3SJeff Dike } 6452c653b3SJeff Dike 654b84c69bSJeff Dike static void install_fatal_handler(int sig) 664b84c69bSJeff Dike { 674b84c69bSJeff Dike struct sigaction action; 684b84c69bSJeff Dike 694b84c69bSJeff Dike /* All signals are enabled in this handler ... */ 704b84c69bSJeff Dike sigemptyset(&action.sa_mask); 714b84c69bSJeff Dike 724b84c69bSJeff Dike /* ... including the signal being handled, plus we want the 734b84c69bSJeff Dike * handler reset to the default behavior, so that if an exit 744b84c69bSJeff Dike * handler is hanging for some reason, the UML will just die 754b84c69bSJeff Dike * after this signal is sent a second time. 764b84c69bSJeff Dike */ 774b84c69bSJeff Dike action.sa_flags = SA_RESETHAND | SA_NODEFER; 784b84c69bSJeff Dike action.sa_restorer = NULL; 794b84c69bSJeff Dike action.sa_handler = last_ditch_exit; 804b84c69bSJeff Dike if(sigaction(sig, &action, NULL) < 0){ 814b84c69bSJeff Dike printf("failed to install handler for signal %d - errno = %d\n", 824b84c69bSJeff Dike errno); 834b84c69bSJeff Dike exit(1); 844b84c69bSJeff Dike } 854b84c69bSJeff Dike } 864b84c69bSJeff Dike 87cb98cdcdSMattia Dongili #define UML_LIB_PATH ":/usr/lib/uml" 88cb98cdcdSMattia Dongili 89cb98cdcdSMattia Dongili static void setup_env_path(void) 90cb98cdcdSMattia Dongili { 91cb98cdcdSMattia Dongili char *new_path = NULL; 92cb98cdcdSMattia Dongili char *old_path = NULL; 93cb98cdcdSMattia Dongili int path_len = 0; 94cb98cdcdSMattia Dongili 95cb98cdcdSMattia Dongili old_path = getenv("PATH"); 96cb98cdcdSMattia Dongili /* if no PATH variable is set or it has an empty value 97cb98cdcdSMattia Dongili * just use the default + /usr/lib/uml 98cb98cdcdSMattia Dongili */ 99cb98cdcdSMattia Dongili if (!old_path || (path_len = strlen(old_path)) == 0) { 100cb98cdcdSMattia Dongili putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH); 101cb98cdcdSMattia Dongili return; 102cb98cdcdSMattia Dongili } 103cb98cdcdSMattia Dongili 104cb98cdcdSMattia Dongili /* append /usr/lib/uml to the existing path */ 105cb98cdcdSMattia Dongili path_len += strlen("PATH=" UML_LIB_PATH) + 1; 106cb98cdcdSMattia Dongili new_path = malloc(path_len); 107cb98cdcdSMattia Dongili if (!new_path) { 108cb98cdcdSMattia Dongili perror("coudn't malloc to set a new PATH"); 109cb98cdcdSMattia Dongili return; 110cb98cdcdSMattia Dongili } 111cb98cdcdSMattia Dongili snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path); 112cb98cdcdSMattia Dongili putenv(new_path); 113cb98cdcdSMattia Dongili } 114cb98cdcdSMattia Dongili 11552c653b3SJeff Dike extern int uml_exitcode; 11652c653b3SJeff Dike 11752c653b3SJeff Dike extern void scan_elf_aux( char **envp); 11852c653b3SJeff Dike 11936e45463SJeff Dike int __init main(int argc, char **argv, char **envp) 12052c653b3SJeff Dike { 12152c653b3SJeff Dike char **new_argv; 12252c653b3SJeff Dike int ret, i, err; 12352c653b3SJeff Dike 12452c653b3SJeff Dike set_stklim(); 12552c653b3SJeff Dike 126cb98cdcdSMattia Dongili setup_env_path(); 127cb98cdcdSMattia Dongili 12852c653b3SJeff Dike new_argv = malloc((argc + 1) * sizeof(char *)); 12952c653b3SJeff Dike if(new_argv == NULL){ 13052c653b3SJeff Dike perror("Mallocing argv"); 13152c653b3SJeff Dike exit(1); 13252c653b3SJeff Dike } 13352c653b3SJeff Dike for(i=0;i<argc;i++){ 13452c653b3SJeff Dike new_argv[i] = strdup(argv[i]); 13552c653b3SJeff Dike if(new_argv[i] == NULL){ 13652c653b3SJeff Dike perror("Mallocing an arg"); 13752c653b3SJeff Dike exit(1); 13852c653b3SJeff Dike } 13952c653b3SJeff Dike } 14052c653b3SJeff Dike new_argv[argc] = NULL; 14152c653b3SJeff Dike 1424b84c69bSJeff Dike /* Allow these signals to bring down a UML if all other 1434b84c69bSJeff Dike * methods of control fail. 1444b84c69bSJeff Dike */ 1454b84c69bSJeff Dike install_fatal_handler(SIGINT); 1464b84c69bSJeff Dike install_fatal_handler(SIGTERM); 1474b84c69bSJeff Dike install_fatal_handler(SIGHUP); 14852c653b3SJeff Dike 14952c653b3SJeff Dike scan_elf_aux( envp); 15052c653b3SJeff Dike 15152c653b3SJeff Dike do_uml_initcalls(); 15252c653b3SJeff Dike ret = linux_main(argc, argv); 15352c653b3SJeff Dike 15452c653b3SJeff Dike /* Disable SIGPROF - I have no idea why libc doesn't do this or turn 15552c653b3SJeff Dike * off the profiling time, but UML dies with a SIGPROF just before 15652c653b3SJeff Dike * exiting when profiling is active. 15752c653b3SJeff Dike */ 15852c653b3SJeff Dike change_sig(SIGPROF, 0); 15952c653b3SJeff Dike 16052c653b3SJeff Dike /* This signal stuff used to be in the reboot case. However, 16152c653b3SJeff Dike * sometimes a SIGVTALRM can come in when we're halting (reproducably 16252c653b3SJeff Dike * when writing out gcov information, presumably because that takes 16352c653b3SJeff Dike * some time) and cause a segfault. 16452c653b3SJeff Dike */ 16552c653b3SJeff Dike 16652c653b3SJeff Dike /* stop timers and set SIG*ALRM to be ignored */ 16752c653b3SJeff Dike disable_timer(); 16852c653b3SJeff Dike 16952c653b3SJeff Dike /* disable SIGIO for the fds and set SIGIO to be ignored */ 17052c653b3SJeff Dike err = deactivate_all_fds(); 17152c653b3SJeff Dike if(err) 17252c653b3SJeff Dike printf("deactivate_all_fds failed, errno = %d\n", -err); 17352c653b3SJeff Dike 17452c653b3SJeff Dike /* Let any pending signals fire now. This ensures 17552c653b3SJeff Dike * that they won't be delivered after the exec, when 17652c653b3SJeff Dike * they are definitely not expected. 17752c653b3SJeff Dike */ 17852c653b3SJeff Dike unblock_signals(); 17952c653b3SJeff Dike 18052c653b3SJeff Dike /* Reboot */ 18152c653b3SJeff Dike if(ret){ 18252c653b3SJeff Dike printf("\n"); 18352c653b3SJeff Dike execvp(new_argv[0], new_argv); 18452c653b3SJeff Dike perror("Failed to exec kernel"); 18552c653b3SJeff Dike ret = 1; 18652c653b3SJeff Dike } 18752c653b3SJeff Dike printf("\n"); 188a5ed1ffaSJeff Dike return uml_exitcode; 18952c653b3SJeff Dike } 19052c653b3SJeff Dike 19152c653b3SJeff Dike extern void *__real_malloc(int); 19252c653b3SJeff Dike 19352c653b3SJeff Dike void *__wrap_malloc(int size) 19452c653b3SJeff Dike { 19552c653b3SJeff Dike void *ret; 19652c653b3SJeff Dike 197*6aa802ceSJeff Dike if(!kmalloc_ok) 198a5ed1ffaSJeff Dike return __real_malloc(size); 199c539ab73SJeff Dike else if(size <= UM_KERN_PAGE_SIZE) 200c539ab73SJeff Dike /* finding contiguous pages can be hard*/ 201e4c4bf99SJeff Dike ret = kmalloc(size, UM_GFP_KERNEL); 202e4c4bf99SJeff Dike else ret = vmalloc(size); 20352c653b3SJeff Dike 20452c653b3SJeff Dike /* glibc people insist that if malloc fails, errno should be 20552c653b3SJeff Dike * set by malloc as well. So we do. 20652c653b3SJeff Dike */ 20752c653b3SJeff Dike if(ret == NULL) 20852c653b3SJeff Dike errno = ENOMEM; 20952c653b3SJeff Dike 210a5ed1ffaSJeff Dike return ret; 21152c653b3SJeff Dike } 21252c653b3SJeff Dike 21352c653b3SJeff Dike void *__wrap_calloc(int n, int size) 21452c653b3SJeff Dike { 21552c653b3SJeff Dike void *ptr = __wrap_malloc(n * size); 21652c653b3SJeff Dike 217a5ed1ffaSJeff Dike if(ptr == NULL) 218a5ed1ffaSJeff Dike return NULL; 21952c653b3SJeff Dike memset(ptr, 0, n * size); 220a5ed1ffaSJeff Dike return ptr; 22152c653b3SJeff Dike } 22252c653b3SJeff Dike 22352c653b3SJeff Dike extern void __real_free(void *); 22452c653b3SJeff Dike 22552c653b3SJeff Dike extern unsigned long high_physmem; 22652c653b3SJeff Dike 22752c653b3SJeff Dike void __wrap_free(void *ptr) 22852c653b3SJeff Dike { 22952c653b3SJeff Dike unsigned long addr = (unsigned long) ptr; 23052c653b3SJeff Dike 23152c653b3SJeff Dike /* We need to know how the allocation happened, so it can be correctly 23252c653b3SJeff Dike * freed. This is done by seeing what region of memory the pointer is 23352c653b3SJeff Dike * in - 23452c653b3SJeff Dike * physical memory - kmalloc/kfree 23552c653b3SJeff Dike * kernel virtual memory - vmalloc/vfree 23652c653b3SJeff Dike * anywhere else - malloc/free 23752c653b3SJeff Dike * If kmalloc is not yet possible, then either high_physmem and/or 23852c653b3SJeff Dike * end_vm are still 0 (as at startup), in which case we call free, or 23952c653b3SJeff Dike * we have set them, but anyway addr has not been allocated from those 24052c653b3SJeff Dike * areas. So, in both cases __real_free is called. 24152c653b3SJeff Dike * 24252c653b3SJeff Dike * CAN_KMALLOC is checked because it would be bad to free a buffer 24352c653b3SJeff Dike * with kmalloc/vmalloc after they have been turned off during 24452c653b3SJeff Dike * shutdown. 24552c653b3SJeff Dike * XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so 24652c653b3SJeff Dike * there is a possibility for memory leaks. 24752c653b3SJeff Dike */ 24852c653b3SJeff Dike 24952c653b3SJeff Dike if((addr >= uml_physmem) && (addr < high_physmem)){ 250*6aa802ceSJeff Dike if(kmalloc_ok) 25152c653b3SJeff Dike kfree(ptr); 25252c653b3SJeff Dike } 25352c653b3SJeff Dike else if((addr >= start_vm) && (addr < end_vm)){ 254*6aa802ceSJeff Dike if(kmalloc_ok) 25552c653b3SJeff Dike vfree(ptr); 25652c653b3SJeff Dike } 25752c653b3SJeff Dike else __real_free(ptr); 25852c653b3SJeff Dike } 259