root/tools/testing/selftests/arm64/tags_test.c

DEFINITIONS

1. main

   1 // SPDX-License-Identifier: GPL-2.0
   2 
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6 #include <stdint.h>
   7 #include <sys/prctl.h>
   8 #include <sys/utsname.h>
   9 
  10 #define SHIFT_TAG(tag)          ((uint64_t)(tag) << 56)
  11 #define SET_TAG(ptr, tag)       (((uint64_t)(ptr) & ~SHIFT_TAG(0xff)) | \
  12                                         SHIFT_TAG(tag))
  13 
  14 int main(void)
  15 {
  16         static int tbi_enabled = 0;
  17         unsigned long tag = 0;
  18         struct utsname *ptr;
  19         int err;
  20 
  21         if (prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE, 0, 0, 0) == 0)
  22                 tbi_enabled = 1;
  23         ptr = (struct utsname *)malloc(sizeof(*ptr));
  24         if (tbi_enabled)
  25                 tag = 0x42;
  26         ptr = (struct utsname *)SET_TAG(ptr, tag);
  27         err = uname(ptr);
  28         free(ptr);
  29 
  30         return err;
  31 }