cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
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mte-4.c (855B)

      1/*
      2 * Memory tagging, re-reading tag checks.
      3 *
      4 * Copyright (c) 2021 Linaro Ltd
      5 * SPDX-License-Identifier: GPL-2.0-or-later
      6 */
      7
      8#include "mte.h"
      9
     10void __attribute__((noinline)) tagset(void *p, size_t size)
     11{
     12    size_t i;
     13    for (i = 0; i < size; i += 16) {
     14        asm("stg %0, [%0]" : : "r"(p + i));
     15    }
     16}
     17
     18void __attribute__((noinline)) tagcheck(void *p, size_t size)
     19{
     20    size_t i;
     21    void *c;
     22
     23    for (i = 0; i < size; i += 16) {
     24        asm("ldg %0, [%1]" : "=r"(c) : "r"(p + i), "0"(p));
     25        assert(c == p);
     26    }
     27}
     28
     29int main(int ac, char **av)
     30{
     31    size_t size = getpagesize() * 4;
     32    long excl = 1;
     33    int *p0, *p1;
     34
     35    enable_mte(PR_MTE_TCF_ASYNC);
     36    p0 = alloc_mte_mem(size);
     37
     38    /* Tag the pointer. */
     39    asm("irg %0,%1,%2" : "=r"(p1) : "r"(p0), "r"(excl));
     40
     41    tagset(p1, size);
     42    tagcheck(p1, size);
     43
     44    return 0;
     45}