| 1 | /* |
| 2 | * Linux kernel fallback API definitions for MTE and test helpers. |
| 3 | * |
| 4 | * Copyright (c) 2021 Linaro Ltd |
| 5 | * SPDX-License-Identifier: GPL-2.0-or-later |
| 6 | */ |
| 7 | |
| 8 | #include <assert.h> |
| 9 | #include <string.h> |
| 10 | #include <stdlib.h> |
| 11 | #include <stdio.h> |
| 12 | #include <unistd.h> |
| 13 | #include <signal.h> |
| 14 | #include <sys/mman.h> |
| 15 | #include <sys/prctl.h> |
| 16 | |
| 17 | #ifndef PR_SET_TAGGED_ADDR_CTRL |
| 18 | # define PR_SET_TAGGED_ADDR_CTRL 55 |
| 19 | #endif |
| 20 | #ifndef PR_TAGGED_ADDR_ENABLE |
| 21 | # define PR_TAGGED_ADDR_ENABLE (1UL << 0) |
| 22 | #endif |
| 23 | #ifndef PR_MTE_STORE_ONLY |
| 24 | # define PR_MTE_STORE_ONLY (1UL << 19) |
| 25 | #endif |
| 26 | #ifndef PR_MTE_TCF_SHIFT |
| 27 | # define PR_MTE_TCF_SHIFT 1 |
| 28 | # define PR_MTE_TCF_NONE (0UL << PR_MTE_TCF_SHIFT) |
| 29 | # define PR_MTE_TCF_SYNC (1UL << PR_MTE_TCF_SHIFT) |
| 30 | # define PR_MTE_TCF_ASYNC (2UL << PR_MTE_TCF_SHIFT) |
| 31 | # define PR_MTE_TAG_SHIFT 3 |
| 32 | #endif |
| 33 | |
| 34 | #ifndef PROT_MTE |
| 35 | # define PROT_MTE 0x20 |
| 36 | #endif |
| 37 | |
| 38 | #ifndef SEGV_MTEAERR |
| 39 | # define SEGV_MTEAERR 8 |
| 40 | # define SEGV_MTESERR 9 |
| 41 | #endif |
| 42 | |
| 43 | static void enable_mte(int flags) |
| 44 | { |
| 45 | int r = prctl(PR_SET_TAGGED_ADDR_CTRL, |
| 46 | PR_TAGGED_ADDR_ENABLE | flags | (0xfffe << PR_MTE_TAG_SHIFT), |
| 47 | 0, 0, 0); |
| 48 | if (r < 0) { |
| 49 | perror("PR_SET_TAGGED_ADDR_CTRL"); |
| 50 | exit(2); |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | static void * alloc_mte_mem(size_t size) __attribute__((unused)); |
| 55 | static void * alloc_mte_mem(size_t size) |
| 56 | { |
| 57 | void *p = mmap(NULL, size, PROT_READ | PROT_WRITE | PROT_MTE, |
| 58 | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| 59 | if (p == MAP_FAILED) { |
| 60 | perror("mmap PROT_MTE"); |
| 61 | exit(2); |
| 62 | } |
| 63 | return p; |
| 64 | } |