tools/testing/selftests/damon/huge_count_read_write.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Author: SeongJae Park <sj@kernel.org>
   4  */
   5
   6 #include <fcntl.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9 #include <stdio.h>
  10
  11 #pragma GCC diagnostic push
  12 #if __GNUC__ >= 11 && __GNUC_MINOR__ >= 1
  13 /* Ignore read(2) overflow and write(2) overread compile warnings */
  14 #pragma GCC diagnostic ignored "-Wstringop-overread"
  15 #pragma GCC diagnostic ignored "-Wstringop-overflow"
  16 #endif
  17
  18 void write_read_with_huge_count(char *file)
  19 {
  20         int filedesc = open(file, O_RDWR);
  21         char buf[256];
  22         int ret;
  23
  24         printf("%s %s\n", __func__, file);
  25         if (filedesc < 0) {
  26                 fprintf(stderr, "failed opening %s\n", file);
  27                 exit(1);
  28         }
  29
  30         write(filedesc, "", 0xfffffffful);
  31         ret = read(filedesc, buf, 0xfffffffful);
  32         close(filedesc);
  33 }
  34
  35 #pragma GCC diagnostic pop
  36
  37 int main(int argc, char *argv[])
  38 {
  39         if (argc != 2) {
  40                 fprintf(stderr, "Usage: %s <file>\n", argv[0]);
  41                 exit(1);
  42         }
  43         write_read_with_huge_count(argv[1]);
  44
  45         return 0;
  46 }