test/debug/kwrite.c

   1 /*
   2  * Tool to read/write kernel memory.
   3  *
   4  * Compile with
   5         cc -o kwrite kwrite.c -lkvm
   6  *
   7  * $DragonFly: src/test/debug/kwrite.c,v 1.1 2006/01/09 15:05:45 corecode Exp $
   8  */
   9
  10 #include <fcntl.h>
  11 #include <kvm.h>
  12 #include <limits.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <errno.h>
  16 #include <err.h>
  17
  18 static void
  19 usage(void)
  20 {
  21         fprintf(stderr, "usage: kwrite addr[/width] [bval] [bval]\n");
  22         exit(1);
  23 }
  24
  25 int
  26 main(int argc, char **argv)
  27 {
  28         char errbuf[_POSIX2_LINE_MAX];
  29         kvm_t *kvm;
  30         unsigned long addr, width = 1, i;
  31         char *endptr, *endptr2;
  32
  33         if (argc < 2)
  34                 usage();
  35
  36         errno = 0;
  37         addr = strtoul(argv[1], &endptr, 0);
  38         if (endptr == argv[1])
  39                 errx(1, "no addr");
  40         if (errno != 0)
  41                 err(1, "addr '%s'", argv[1]);
  42         switch (*endptr) {
  43         case 0:
  44                 break;
  45         case '/':
  46                 endptr++;
  47                 width = strtoul(endptr, &endptr2, 0);
  48                 if (endptr2 == endptr)
  49                         errx(1, "no width");
  50                 if (errno != 0)
  51                         err(1, "width '%s'", endptr);
  52                 break;
  53         default:
  54                 errx(1, "invalid addr '%s'", argv[1]);
  55         }
  56
  57         kvm = kvm_openfiles(NULL, NULL, NULL, O_RDWR, errbuf);
  58         if (kvm == NULL)
  59                 errx(1, "%s", errbuf);
  60
  61         if (argc < 3) {
  62                 for (i = 0; i < width; i++) {
  63                         char b;
  64
  65                         if (kvm_read(kvm, addr + i, &b, 1) != 1)
  66                                 errx(1, "%s", kvm_geterr(kvm));
  67                         printf("%#0*lx %02x\n",
  68                                 (int)sizeof(addr) * 2, addr + i, b);
  69                 }
  70         } else {
  71                 if (argc < width + 2)
  72                         errx(1, "too few values for width %ld", width);
  73                 width = argc - 2;
  74                 for (i = 0; i < width; i++) {
  75                         long v;
  76                         char b, bo;
  77
  78                         errno = 0;
  79                         v = strtol(argv[2 + i], &endptr, 0);
  80                         if (endptr == argv[2 + i] || *endptr != 0)
  81                                 errx(1, "invalid value '%s'", argv[2 + i]);
  82                         if (errno != 0 || v < 0 || v > 256) {
  83                                 if (errno == 0) errno = ERANGE;
  84                                 errx(1, "value '%s'", argv[2 + i]);
  85                         }
  86                         b = v;
  87
  88                         if (kvm_read(kvm, addr + i, &bo, 1) != 1)
  89                                 errx(1, "%s", kvm_geterr(kvm));
  90                         printf("%#0*lx %02x -> %02x\n",
  91                                (int)sizeof(addr) * 2, addr + i, bo, b);
  92                         if (kvm_write(kvm, addr + i, &b, 1) != 1)
  93                                 errx(1, "%s", kvm_geterr(kvm));
  94                 }
  95         }
  96
  97         return 0;
  98 }