arch/um/kernel/main.c

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