1 /* 2 * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com) 3 * Licensed under the GPL 4 */ 5 6 #include <unistd.h> 7 #include <stdio.h> 8 #include <stdlib.h> 9 #include <string.h> 10 #include <signal.h> 11 #include <errno.h> 12 #include <sys/resource.h> 13 #include <sys/mman.h> 14 #include <sys/user.h> 15 #include <asm/page.h> 16 #include "user_util.h" 17 #include "kern_util.h" 18 #include "mem_user.h" 19 #include "irq_user.h" 20 #include "user.h" 21 #include "init.h" 22 #include "mode.h" 23 #include "choose-mode.h" 24 #include "uml-config.h" 25 #include "os.h" 26 27 /* Set in set_stklim, which is called from main and __wrap_malloc. 28 * __wrap_malloc only calls it if main hasn't started. 29 */ 30 unsigned long stacksizelim; 31 32 /* Set in main */ 33 char *linux_prog; 34 35 #define PGD_BOUND (4 * 1024 * 1024) 36 #define STACKSIZE (8 * 1024 * 1024) 37 #define THREAD_NAME_LEN (256) 38 39 static void set_stklim(void) 40 { 41 struct rlimit lim; 42 43 if(getrlimit(RLIMIT_STACK, &lim) < 0){ 44 perror("getrlimit"); 45 exit(1); 46 } 47 if((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)){ 48 lim.rlim_cur = STACKSIZE; 49 if(setrlimit(RLIMIT_STACK, &lim) < 0){ 50 perror("setrlimit"); 51 exit(1); 52 } 53 } 54 stacksizelim = (lim.rlim_cur + PGD_BOUND - 1) & ~(PGD_BOUND - 1); 55 } 56 57 static __init void do_uml_initcalls(void) 58 { 59 initcall_t *call; 60 61 call = &__uml_initcall_start; 62 while (call < &__uml_initcall_end){ 63 (*call)(); 64 call++; 65 } 66 } 67 68 static void last_ditch_exit(int sig) 69 { 70 signal(SIGINT, SIG_DFL); 71 signal(SIGTERM, SIG_DFL); 72 signal(SIGHUP, SIG_DFL); 73 uml_cleanup(); 74 exit(1); 75 } 76 77 #define UML_LIB_PATH ":/usr/lib/uml" 78 79 static void setup_env_path(void) 80 { 81 char *new_path = NULL; 82 char *old_path = NULL; 83 int path_len = 0; 84 85 old_path = getenv("PATH"); 86 /* if no PATH variable is set or it has an empty value 87 * just use the default + /usr/lib/uml 88 */ 89 if (!old_path || (path_len = strlen(old_path)) == 0) { 90 putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH); 91 return; 92 } 93 94 /* append /usr/lib/uml to the existing path */ 95 path_len += strlen("PATH=" UML_LIB_PATH) + 1; 96 new_path = malloc(path_len); 97 if (!new_path) { 98 perror("coudn't malloc to set a new PATH"); 99 return; 100 } 101 snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path); 102 putenv(new_path); 103 } 104 105 extern int uml_exitcode; 106 107 extern void scan_elf_aux( char **envp); 108 109 int main(int argc, char **argv, char **envp) 110 { 111 char **new_argv; 112 int ret, i, err; 113 114 #ifdef UML_CONFIG_CMDLINE_ON_HOST 115 /* Allocate memory for thread command lines */ 116 if(argc < 2 || strlen(argv[1]) < THREAD_NAME_LEN - 1){ 117 118 char padding[THREAD_NAME_LEN] = { 119 [ 0 ... THREAD_NAME_LEN - 2] = ' ', '\0' 120 }; 121 122 new_argv = malloc((argc + 2) * sizeof(char*)); 123 if(!new_argv) { 124 perror("Allocating extended argv"); 125 exit(1); 126 } 127 128 new_argv[0] = argv[0]; 129 new_argv[1] = padding; 130 131 for(i = 2; i <= argc; i++) 132 new_argv[i] = argv[i - 1]; 133 new_argv[argc + 1] = NULL; 134 135 execvp(new_argv[0], new_argv); 136 perror("execing with extended args"); 137 exit(1); 138 } 139 #endif 140 141 linux_prog = argv[0]; 142 143 set_stklim(); 144 145 setup_env_path(); 146 147 new_argv = malloc((argc + 1) * sizeof(char *)); 148 if(new_argv == NULL){ 149 perror("Mallocing argv"); 150 exit(1); 151 } 152 for(i=0;i<argc;i++){ 153 new_argv[i] = strdup(argv[i]); 154 if(new_argv[i] == NULL){ 155 perror("Mallocing an arg"); 156 exit(1); 157 } 158 } 159 new_argv[argc] = NULL; 160 161 set_handler(SIGINT, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1); 162 set_handler(SIGTERM, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1); 163 set_handler(SIGHUP, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1); 164 165 scan_elf_aux( envp); 166 167 do_uml_initcalls(); 168 ret = linux_main(argc, argv); 169 170 /* Disable SIGPROF - I have no idea why libc doesn't do this or turn 171 * off the profiling time, but UML dies with a SIGPROF just before 172 * exiting when profiling is active. 173 */ 174 change_sig(SIGPROF, 0); 175 176 /* This signal stuff used to be in the reboot case. However, 177 * sometimes a SIGVTALRM can come in when we're halting (reproducably 178 * when writing out gcov information, presumably because that takes 179 * some time) and cause a segfault. 180 */ 181 182 /* stop timers and set SIG*ALRM to be ignored */ 183 disable_timer(); 184 185 /* disable SIGIO for the fds and set SIGIO to be ignored */ 186 err = deactivate_all_fds(); 187 if(err) 188 printf("deactivate_all_fds failed, errno = %d\n", -err); 189 190 /* Let any pending signals fire now. This ensures 191 * that they won't be delivered after the exec, when 192 * they are definitely not expected. 193 */ 194 unblock_signals(); 195 196 /* Reboot */ 197 if(ret){ 198 printf("\n"); 199 execvp(new_argv[0], new_argv); 200 perror("Failed to exec kernel"); 201 ret = 1; 202 } 203 printf("\n"); 204 return(uml_exitcode); 205 } 206 207 #define CAN_KMALLOC() \ 208 (kmalloc_ok && CHOOSE_MODE((os_getpid() != tracing_pid), 1)) 209 210 extern void *__real_malloc(int); 211 212 void *__wrap_malloc(int size) 213 { 214 void *ret; 215 216 if(!CAN_KMALLOC()) 217 return(__real_malloc(size)); 218 else if(size <= PAGE_SIZE) /* finding contiguos pages can be hard*/ 219 ret = um_kmalloc(size); 220 else ret = um_vmalloc(size); 221 222 /* glibc people insist that if malloc fails, errno should be 223 * set by malloc as well. So we do. 224 */ 225 if(ret == NULL) 226 errno = ENOMEM; 227 228 return(ret); 229 } 230 231 void *__wrap_calloc(int n, int size) 232 { 233 void *ptr = __wrap_malloc(n * size); 234 235 if(ptr == NULL) return(NULL); 236 memset(ptr, 0, n * size); 237 return(ptr); 238 } 239 240 extern void __real_free(void *); 241 242 extern unsigned long high_physmem; 243 244 void __wrap_free(void *ptr) 245 { 246 unsigned long addr = (unsigned long) ptr; 247 248 /* We need to know how the allocation happened, so it can be correctly 249 * freed. This is done by seeing what region of memory the pointer is 250 * in - 251 * physical memory - kmalloc/kfree 252 * kernel virtual memory - vmalloc/vfree 253 * anywhere else - malloc/free 254 * If kmalloc is not yet possible, then either high_physmem and/or 255 * end_vm are still 0 (as at startup), in which case we call free, or 256 * we have set them, but anyway addr has not been allocated from those 257 * areas. So, in both cases __real_free is called. 258 * 259 * CAN_KMALLOC is checked because it would be bad to free a buffer 260 * with kmalloc/vmalloc after they have been turned off during 261 * shutdown. 262 * XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so 263 * there is a possibility for memory leaks. 264 */ 265 266 if((addr >= uml_physmem) && (addr < high_physmem)){ 267 if(CAN_KMALLOC()) 268 kfree(ptr); 269 } 270 else if((addr >= start_vm) && (addr < end_vm)){ 271 if(CAN_KMALLOC()) 272 vfree(ptr); 273 } 274 else __real_free(ptr); 275 } 276