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         printf("\n");
  35   }
  36
  37   printf("kernel on CPU %d: ", cpuid);
  38   util_stacktrace();
  39
  40 #if 0
  41   if(get_cpulocal_var(proc_ptr)) {
  42           printf("current process : ");
  43           proc_stacktrace(get_cpulocal_var(proc_ptr));
  44   }
  45 #endif
  46
  47   /* Abort MINIX. */
  48   minix_shutdown(NULL);
  49 }
  50
  51 /*===========================================================================*
  52  *                              kputc                                        *
  53  *===========================================================================*/
  54 void kputc(c)
  55 int c;                                  /* character to append */
  56 {
  57 /* Accumulate a single character for a kernel message. Send a notification
  58  * to the output drivers if an END_OF_KMESS is encountered.
  59  */
  60   if (c != END_OF_KMESS) {
  61       int maxblpos = sizeof(kmess.kmess_buf) - 2;
  62 #ifdef DEBUG_SERIAL
  63       if (kinfo.do_serial_debug) {
  64         if(c == '\n')
  65                 ser_putc('\r');
  66         ser_putc(c);
  67       }
  68 #endif
  69       kmess.km_buf[kmess.km_next] = c;  /* put normal char in buffer */
  70       kmess.kmess_buf[kmess.blpos] = c;
  71       if (kmess.km_size < sizeof(kmess.km_buf))
  72           kmess.km_size += 1;
  73       kmess.km_next = (kmess.km_next + 1) % _KMESS_BUF_SIZE;
  74       if(kmess.blpos == maxblpos) {
  75         memmove(kmess.kmess_buf,
  76                 kmess.kmess_buf+1, sizeof(kmess.kmess_buf)-1);
  77       } else kmess.blpos++;
  78   } else if (!(kinfo.minix_panicing || kinfo.do_serial_debug)) {
  79         send_diag_sig();
  80   }
  81 }
  82
  83 /*===========================================================================*
  84  *                              _exit                                        *
  85  *===========================================================================*/
  86 void _exit(e)
  87 int e;                                  /* error code */
  88 {
  89   panic("_exit called from within the kernel, should not happen. (err %i)", e);
  90 }