tools/testing/selftests/exec/load_address.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #ifndef _GNU_SOURCE
   3 #define _GNU_SOURCE
   4 #endif
   5 #include <link.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8
   9 struct Statistics {
  10         unsigned long long load_address;
  11         unsigned long long alignment;
  12 };
  13
  14 int ExtractStatistics(struct dl_phdr_info *info, size_t size, void *data)
  15 {
  16         struct Statistics *stats = (struct Statistics *) data;
  17         int i;
  18
  19         if (info->dlpi_name != NULL && info->dlpi_name[0] != '\0') {
  20                 // Ignore headers from other than the executable.
  21                 return 2;
  22         }
  23
  24         stats->load_address = (unsigned long long) info->dlpi_addr;
  25         stats->alignment = 0;
  26
  27         for (i = 0; i < info->dlpi_phnum; i++) {
  28                 if (info->dlpi_phdr[i].p_type != PT_LOAD)
  29                         continue;
  30
  31                 if (info->dlpi_phdr[i].p_align > stats->alignment)
  32                         stats->alignment = info->dlpi_phdr[i].p_align;
  33         }
  34
  35         return 1;  // Terminate dl_iterate_phdr.
  36 }
  37
  38 int main(int argc, char **argv)
  39 {
  40         struct Statistics extracted;
  41         unsigned long long misalign;
  42         int ret;
  43
  44         ret = dl_iterate_phdr(ExtractStatistics, &extracted);
  45         if (ret != 1) {
  46                 fprintf(stderr, "FAILED\n");
  47                 return 1;
  48         }
  49
  50         if (extracted.alignment == 0) {
  51                 fprintf(stderr, "No alignment found\n");
  52                 return 1;
  53         } else if (extracted.alignment & (extracted.alignment - 1)) {
  54                 fprintf(stderr, "Alignment is not a power of 2\n");
  55                 return 1;
  56         }
  57
  58         misalign = extracted.load_address & (extracted.alignment - 1);
  59         if (misalign) {
  60                 printf("alignment = %llu, load_address = %llu\n",
  61                         extracted.alignment, extracted.load_address);
  62                 fprintf(stderr, "FAILED\n");
  63                 return 1;
  64         }
  65
  66         fprintf(stderr, "PASS\n");
  67         return 0;
  68 }