zircon/kernel/lib/unittest/user_memory.cc

// Copyright 2018 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#include <lib/unittest/unittest.h>
#include <lib/unittest/user_memory.h>

#include <fbl/auto_call.h>

namespace testing {

UserMemory::~UserMemory() {
  zx_status_t status = mapping_->Unmap(mapping_->base(), mapping_->size());
  DEBUG_ASSERT(status == ZX_OK);
}

// static
ktl::unique_ptr<UserMemory> UserMemory::Create(size_t size) {
  size = ROUNDUP_PAGE_SIZE(size);

  fbl::RefPtr<VmObject> vmo;
  zx_status_t status = VmObjectPaged::Create(PMM_ALLOC_FLAG_ANY, 0u, size, &vmo);
  if (status != ZX_OK) {
    unittest_printf("VmObjectPaged::Create failed: %d\n", status);
    return nullptr;
  }

  fbl::RefPtr<VmAspace> aspace(vmm_aspace_to_obj(Thread::Current::Get()->aspace_));

  DEBUG_ASSERT(aspace);
  DEBUG_ASSERT(aspace->is_user());
  fbl::RefPtr<VmAddressRegion> root_vmar = aspace->RootVmar();
  constexpr uint32_t vmar_flags =
      VMAR_FLAG_CAN_MAP_READ | VMAR_FLAG_CAN_MAP_WRITE | VMAR_FLAG_CAN_MAP_EXECUTE;
  fbl::RefPtr<VmMapping> mapping;
  constexpr uint arch_mmu_flags = ARCH_MMU_FLAG_PERM_READ | ARCH_MMU_FLAG_PERM_WRITE;
  status = root_vmar->CreateVmMapping(/* offset= */ 0, size, /* align_pow2= */ 0, vmar_flags, vmo,
                                      0, arch_mmu_flags, "unittest", &mapping);
  if (status != ZX_OK) {
    unittest_printf("CreateVmMapping failed: %d\n", status);
    return nullptr;
  }
  auto unmap = fbl::MakeAutoCall([&]() {
    if (mapping) {
      zx_status_t status = mapping->Unmap(mapping->base(), mapping->size());
      DEBUG_ASSERT(status == ZX_OK);
    }
  });

  fbl::AllocChecker ac;
  ktl::unique_ptr<UserMemory> mem(new (&ac) UserMemory(mapping, vmo));
  if (!ac.check()) {
    unittest_printf("failed to allocate from heap\n");
    return nullptr;
  }
  // Unmapping is now UserMemory's responsibility.
  unmap.cancel();

  return mem;
}

}  // namespace testing