LXR linux/tools/testing/selftests/arm64/mte/check_user

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (C) 2020 ARM Limited
   3
   4#define _GNU_SOURCE
   5
   6#include <errno.h>
   7#include <fcntl.h>
   8#include <signal.h>
   9#include <stdlib.h>
  10#include <stdio.h>
  11#include <string.h>
  12#include <ucontext.h>
  13#include <unistd.h>
  14#include <sys/mman.h>
  15
  16#include "kselftest.h"
  17#include "mte_common_util.h"
  18#include "mte_def.h"
  19
  20static size_t page_sz;
  21
  22static int check_usermem_access_fault(int mem_type, int mode, int mapping)
  23{
  24        int fd, i, err;
  25        char val = 'A';
  26        size_t len, read_len;
  27        void *ptr, *ptr_next;
  28
  29        err = KSFT_FAIL;
  30        len = 2 * page_sz;
  31        mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
  32        fd = create_temp_file();
  33        if (fd == -1)
  34                return KSFT_FAIL;
  35        for (i = 0; i < len; i++)
  36                write(fd, &val, sizeof(val));
  37        lseek(fd, 0, 0);
  38        ptr = mte_allocate_memory(len, mem_type, mapping, true);
  39        if (check_allocated_memory(ptr, len, mem_type, true) != KSFT_PASS) {
  40                close(fd);
  41                return KSFT_FAIL;
  42        }
  43        mte_initialize_current_context(mode, (uintptr_t)ptr, len);
  44        /* Copy from file into buffer with valid tag */
  45        read_len = read(fd, ptr, len);
  46        mte_wait_after_trig();
  47        if (cur_mte_cxt.fault_valid || read_len < len)
  48                goto usermem_acc_err;
  49        /* Verify same pattern is read */
  50        for (i = 0; i < len; i++)
  51                if (*(char *)(ptr + i) != val)
  52                        break;
  53        if (i < len)
  54                goto usermem_acc_err;
  55
  56        /* Tag the next half of memory with different value */
  57        ptr_next = (void *)((unsigned long)ptr + page_sz);
  58        ptr_next = mte_insert_new_tag(ptr_next);
  59        mte_set_tag_address_range(ptr_next, page_sz);
  60
  61        lseek(fd, 0, 0);
  62        /* Copy from file into buffer with invalid tag */
  63        read_len = read(fd, ptr, len);
  64        mte_wait_after_trig();
  65        /*
  66         * Accessing user memory in kernel with invalid tag should fail in sync
  67         * mode without fault but may not fail in async mode as per the
  68         * implemented MTE userspace support in Arm64 kernel.
  69         */
  70        if (mode == MTE_SYNC_ERR &&
  71            !cur_mte_cxt.fault_valid && read_len < len) {
  72                err = KSFT_PASS;
  73        } else if (mode == MTE_ASYNC_ERR &&
  74                   !cur_mte_cxt.fault_valid && read_len == len) {
  75                err = KSFT_PASS;
  76        }
  77usermem_acc_err:
  78        mte_free_memory((void *)ptr, len, mem_type, true);
  79        close(fd);
  80        return err;
  81}
  82
  83int main(int argc, char *argv[])
  84{
  85        int err;
  86
  87        page_sz = getpagesize();
  88        if (!page_sz) {
  89                ksft_print_msg("ERR: Unable to get page size\n");
  90                return KSFT_FAIL;
  91        }
  92        err = mte_default_setup();
  93        if (err)
  94                return err;
  95
  96        /* Register signal handlers */
  97        mte_register_signal(SIGSEGV, mte_default_handler);
  98
  99        /* Set test plan */
 100        ksft_set_plan(4);
 101
 102        evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
 103                "Check memory access from kernel in sync mode, private mapping and mmap memory\n");
 104        evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
 105                "Check memory access from kernel in sync mode, shared mapping and mmap memory\n");
 106
 107        evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE),
 108                "Check memory access from kernel in async mode, private mapping and mmap memory\n");
 109        evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED),
 110                "Check memory access from kernel in async mode, shared mapping and mmap memory\n");
 111
 112        mte_restore_setup();
 113        ksft_print_cnts();
 114        return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
 115}
 116