pebble/tests/fw/test_memory_layout.c

/*
 * Copyright 2024 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "clar.h"

#include "kernel/memory_layout.h"

#include "stubs_logging.h"
#include "stubs_mpu.h"
#include "stubs_passert.h"
#include "stubs_serial.h"

// Tests
///////////////////////////////////////////////////////////
void test_memory_layout__pointer_in_region(void) {
  MpuRegion region = {
    .base_address = 1000,
    .size = 1000
  };

  cl_assert(!memory_layout_is_pointer_in_region(&region, (void*) 0));
  cl_assert(!memory_layout_is_pointer_in_region(&region, (void*) 999));
  cl_assert(memory_layout_is_pointer_in_region(&region, (void*) 1000));
  cl_assert(memory_layout_is_pointer_in_region(&region, (void*) 1500));
  cl_assert(memory_layout_is_pointer_in_region(&region, (void*) 1999));
  cl_assert(!memory_layout_is_pointer_in_region(&region, (void*) 2000));
  cl_assert(!memory_layout_is_pointer_in_region(&region, (void*) 9999));
}

void test_memory_layout__cstring_in_region(void) {
  const char buffer[] = "yyyxxxstrstr\0badstrxxxyyy";
  const char *valid_str = buffer + 6; // skip yyyxxx, equal to "strstr"
  const char *invalid_str = buffer + 6 + 7; // skip yyyxxx + strstr\0, equal to "badstr" but no trailing null

  MpuRegion region = {
    .base_address = (uintptr_t) buffer + 3, // Skip leading yyy
    .size = sizeof(buffer) - 1 - 3 - 3 // Skip trailing null, leading yyy, trailing yyy
  };

  // In the leading y's region
  cl_assert(!memory_layout_is_cstring_in_region(&region, buffer, 10));

  // Valid string
  cl_assert(memory_layout_is_cstring_in_region(&region, valid_str, 10));
  // Max length is not long enough to find the null
  cl_assert(!memory_layout_is_cstring_in_region(&region, valid_str, 3));

  // Invalid string, there is a null after the y's but the y's should be after the end of the region
  cl_assert(!memory_layout_is_cstring_in_region(&region, invalid_str, 100));
  // Invalid string, no null.
  cl_assert(!memory_layout_is_cstring_in_region(&region, invalid_str, 3));
}