zircon/system/ulib/fzl/tests/vmo-probe.cc

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "vmo-probe.h"

#include <lib/zx/vmo.h>
#include <zircon/rights.h>

#include <zxtest/zxtest.h>

namespace vmo_probe {

void probe_access(void* addr, AccessType access_type, bool expect_can_access) {
  printf("probe_access for addr: %lu\n", (size_t)addr);

  switch (access_type) {
    case AccessType::Rd: {
      auto rd_fn = [addr] { g_access_check_var = reinterpret_cast<uint32_t*>(addr)[0]; };
      if (expect_can_access) {
        ASSERT_NO_DEATH(rd_fn, "Read probe failed when it should have succeeded.");
      } else {
        ASSERT_DEATH(rd_fn, "Read probe succeeded when it should have failed.");
      }
    } break;

    case AccessType::Wr: {
      auto wr_fn = [addr] { reinterpret_cast<uint32_t*>(addr)[0] = g_access_check_var; };
      if (expect_can_access) {
        ASSERT_NO_DEATH(wr_fn, "Write probe failed when it should have succeeded.");
      } else {
        ASSERT_DEATH(wr_fn, "Write probe succeeded when it should have failed.");
      }
    } break;
  }
}

void probe_verify_region(void* start, size_t size, uint32_t access) {
  auto uint_base = reinterpret_cast<uintptr_t>(start);
  void* probe_points[] = {
      reinterpret_cast<void*>(uint_base),
      reinterpret_cast<void*>(uint_base + (size / 2)),
      reinterpret_cast<void*>(uint_base + size - sizeof(uint32_t)),
  };

  printf("prove_verify_region for addr: %lu, size: %lu\n", (size_t)start, size);
  for (void* probe_point : probe_points) {
    ASSERT_NO_FATAL_FAILURE(probe_access(probe_point, AccessType::Rd, access & ZX_VM_PERM_READ));
    ASSERT_NO_FATAL_FAILURE(probe_access(probe_point, AccessType::Wr, access & ZX_VM_PERM_WRITE));
  }
}

}  // namespace vmo_probe