107 lines
3.2 KiB
C
107 lines
3.2 KiB
C
/* This test program is part of GDB, the GNU debugger.
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Copyright 2021-2022 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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/* Exercise AArch64's Memory Tagging Extension with tagged pointers. */
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/* This test was based on the documentation for the AArch64 Memory Tagging
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Extension from the Linux Kernel, found in the sources in
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Documentation/arm64/memory-tagging-extension.rst. */
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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/auxv.h>
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#include <sys/mman.h>
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#include <sys/prctl.h>
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/* From arch/arm64/include/uapi/asm/hwcap.h */
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#define HWCAP2_MTE (1 << 18)
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/* From arch/arm64/include/uapi/asm/mman.h */
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#define PROT_MTE 0x20
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/* From include/uapi/linux/prctl.h */
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#define PR_SET_TAGGED_ADDR_CTRL 55
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#define PR_GET_TAGGED_ADDR_CTRL 56
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#define PR_TAGGED_ADDR_ENABLE (1UL << 0)
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#define PR_MTE_TCF_SHIFT 1
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#define PR_MTE_TCF_NONE (0UL << PR_MTE_TCF_SHIFT)
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#define PR_MTE_TCF_SYNC (1UL << PR_MTE_TCF_SHIFT)
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#define PR_MTE_TCF_ASYNC (2UL << PR_MTE_TCF_SHIFT)
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#define PR_MTE_TCF_MASK (3UL << PR_MTE_TCF_SHIFT)
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#define PR_MTE_TAG_SHIFT 3
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#define PR_MTE_TAG_MASK (0xffffUL << PR_MTE_TAG_SHIFT)
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void
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access_memory (unsigned char *tagged_ptr, unsigned char *untagged_ptr)
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{
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tagged_ptr[0] = 'a';
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}
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int
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main (int argc, char **argv)
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{
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unsigned char *tagged_ptr;
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unsigned char *untagged_ptr;
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unsigned long page_sz = sysconf (_SC_PAGESIZE);
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unsigned long hwcap2 = getauxval(AT_HWCAP2);
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/* Bail out if MTE is not supported. */
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if (!(hwcap2 & HWCAP2_MTE))
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return 1;
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/* Enable the tagged address ABI, synchronous MTE tag check faults and
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allow all non-zero tags in the randomly generated set. */
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if (prctl (PR_SET_TAGGED_ADDR_CTRL,
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PR_TAGGED_ADDR_ENABLE | PR_MTE_TCF_SYNC
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| (0xfffe << PR_MTE_TAG_SHIFT),
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0, 0, 0))
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{
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perror ("prctl () failed");
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return 1;
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}
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/* Create a mapping that will have PROT_MTE set. */
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tagged_ptr = mmap (0, page_sz, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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if (tagged_ptr == MAP_FAILED)
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{
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perror ("mmap () failed");
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return 1;
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}
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/* Create another mapping that won't have PROT_MTE set. */
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untagged_ptr = mmap (0, page_sz, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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if (untagged_ptr == MAP_FAILED)
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{
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perror ("mmap () failed");
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return 1;
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}
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/* Enable MTE on the above anonymous mmap. */
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if (mprotect (tagged_ptr, page_sz, PROT_READ | PROT_WRITE | PROT_MTE))
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{
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perror ("mprotect () failed");
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return 1;
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}
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access_memory (tagged_ptr, untagged_ptr);
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return 0;
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}
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