minix/kernel/utility.c

   1 /* This file contains a collection of miscellaneous procedures:
   2  *   panic:    abort MINIX due to a fatal error
   3  *   kputc:          buffered putc used by kernel printf
   4  */
   5
   6 #include "kernel/kernel.h"
   7 #include "arch_proto.h"
   8
   9 #include <minix/syslib.h>
  10 #include <unistd.h>
  11 #include <stdarg.h>
  12 #include <signal.h>
  13 #include <string.h>
  14
  15 #include <minix/sys_config.h>
  16
  17 #define ARE_PANICING 0xDEADC0FF
  18
  19 /*===========================================================================*
  20  *                      panic                                          *
  21  *===========================================================================*/
  22 void panic(const char *fmt, ...)
  23 {
  24   va_list arg;
  25   /* The system has run aground of a fatal kernel error. Terminate execution. */
  26   if (kinfo.minix_panicing == ARE_PANICING) {
  27         reset();
  28   }
  29   kinfo.minix_panicing = ARE_PANICING;
  30   if (fmt != NULL) {
  31         printf("kernel panic: ");
  32         va_start(arg, fmt);
  33         vprintf(fmt, arg);
  34         va_end(arg);
  35         printf("\n");
  36   }
  37
  38   printf("kernel on CPU %d: ", cpuid);
  39   util_stacktrace();
  40
  41 #if 0
  42   if(get_cpulocal_var(proc_ptr)) {
  43           printf("current process : ");
  44           proc_stacktrace(get_cpulocal_var(proc_ptr));
  45   }
  46 #endif
  47
  48   /* Abort MINIX. */
  49   minix_shutdown(0);
  50 }
  51
  52 /*===========================================================================*
  53  *                              kputc                                        *
  54  *===========================================================================*/
  55 void kputc(
  56   int c                                 /* character to append */
  57 )
  58 {
  59 /* Accumulate a single character for a kernel message. Send a notification
  60  * to the output drivers if an END_OF_KMESS is encountered.
  61  */
  62   if (c != END_OF_KMESS) {
  63       int maxblpos = sizeof(kmess.kmess_buf) - 2;
  64 #ifdef DEBUG_SERIAL
  65       if (kinfo.do_serial_debug) {
  66         if(c == '\n')
  67                 ser_putc('\r');
  68         ser_putc(c);
  69       }
  70 #endif
  71       kmess.km_buf[kmess.km_next] = c;  /* put normal char in buffer */
  72       kmess.kmess_buf[kmess.blpos] = c;
  73       if (kmess.km_size < sizeof(kmess.km_buf))
  74           kmess.km_size += 1;
  75       kmess.km_next = (kmess.km_next + 1) % _KMESS_BUF_SIZE;
  76       if(kmess.blpos == maxblpos) {
  77         memmove(kmess.kmess_buf,
  78                 kmess.kmess_buf+1, sizeof(kmess.kmess_buf)-1);
  79       } else kmess.blpos++;
  80   } else if (!(kinfo.minix_panicing || kinfo.do_serial_debug)) {
  81         send_diag_sig();
  82   }
  83 }
  84
  85 /*===========================================================================*
  86  *                              _exit                                        *
  87  *===========================================================================*/
  88 void _exit(
  89   int e                                 /* error code */
  90 )
  91 {
  92   panic("_exit called from within the kernel, should not happen. (err %i)", e);
  93 }