tests/tcg/aarch64/mte-3.c

   1 /*
   2  * Memory tagging, basic fail cases, asynchronous signals.
   3  *
   4  * Copyright (c) 2021 Linaro Ltd
   5  * SPDX-License-Identifier: GPL-2.0-or-later
   6  */
   7
   8 #include "mte.h"
   9
  10 void pass(int sig, siginfo_t *info, void *uc)
  11 {
  12     assert(info->si_code == SEGV_MTEAERR);
  13     exit(0);
  14 }
  15
  16 int main(int ac, char **av)
  17 {
  18     struct sigaction sa;
  19     long *p0, *p1, *p2;
  20     long excl = 1;
  21
  22     enable_mte(PR_MTE_TCF_ASYNC);
  23     p0 = alloc_mte_mem(sizeof(*p0));
  24
  25     /* Create two differently tagged pointers.  */
  26     asm("irg %0,%1,%2" : "=r"(p1) : "r"(p0), "r"(excl));
  27     asm("gmi %0,%1,%0" : "+r"(excl) : "r" (p1));
  28     assert(excl != 1);
  29     asm("irg %0,%1,%2" : "=r"(p2) : "r"(p0), "r"(excl));
  30     assert(p1 != p2);
  31
  32     /* Store the tag from the first pointer.  */
  33     asm("stg %0, [%0]" : : "r"(p1));
  34
  35     *p1 = 0;
  36
  37     memset(&sa, 0, sizeof(sa));
  38     sa.sa_sigaction = pass;
  39     sa.sa_flags = SA_SIGINFO;
  40     sigaction(SIGSEGV, &sa, NULL);
  41
  42     /*
  43      * Signal for async error will happen eventually.
  44      * For a real kernel this should be after the next IRQ (e.g. timer).
  45      * For qemu linux-user, we kick the cpu and exit at the next TB.
  46      * In either case, loop until this happens (or killed by timeout).
  47      * For extra sauce, yield, producing EXCP_YIELD to cpu_loop().
  48      */
  49     asm("str %0, [%0]; yield" : : "r"(p2));
  50     while (1);
  51 }