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/*
* Memory tagging, basic fail cases, asynchronous signals.
*
* Copyright (c) 2021 Linaro Ltd
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "mte.h"
void pass(int sig, siginfo_t *info, void *uc)
{
assert(info->si_code == SEGV_MTEAERR);
exit(0);
}
int main(int ac, char **av)
{
struct sigaction sa;
long *p0, *p1, *p2;
long excl = 1;
enable_mte(PR_MTE_TCF_ASYNC);
p0 = alloc_mte_mem(sizeof(*p0));
/* Create two differently tagged pointers. */
asm("irg %0,%1,%2" : "=r"(p1) : "r"(p0), "r"(excl));
asm("gmi %0,%1,%0" : "+r"(excl) : "r" (p1));
assert(excl != 1);
asm("irg %0,%1,%2" : "=r"(p2) : "r"(p0), "r"(excl));
assert(p1 != p2);
/* Store the tag from the first pointer. */
asm("stg %0, [%0]" : : "r"(p1));
*p1 = 0;
memset(&sa, 0, sizeof(sa));
sa.sa_sigaction = pass;
sa.sa_flags = SA_SIGINFO;
sigaction(SIGSEGV, &sa, NULL);
/*
* Signal for async error will happen eventually.
* For a real kernel this should be after the next IRQ (e.g. timer).
* For qemu linux-user, we kick the cpu and exit at the next TB.
* In either case, loop until this happens (or killed by timeout).
* For extra sauce, yield, producing EXCP_YIELD to cpu_loop().
*/
asm("str %0, [%0]; yield" : : "r"(p2));
while (1);
}
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