1 // Copyright 2022 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/memory/platform_shared_memory_mapper.h"
6
7 #include "base/logging.h"
8
9 #include <lib/zx/vmar.h>
10 #include "base/fuchsia/fuchsia_logging.h"
11
12 namespace base {
13
Map(subtle::PlatformSharedMemoryHandle handle,bool write_allowed,uint64_t offset,size_t size)14 absl::optional<span<uint8_t>> PlatformSharedMemoryMapper::Map(
15 subtle::PlatformSharedMemoryHandle handle,
16 bool write_allowed,
17 uint64_t offset,
18 size_t size) {
19 uintptr_t addr;
20 zx_vm_option_t options = ZX_VM_REQUIRE_NON_RESIZABLE | ZX_VM_PERM_READ;
21 if (write_allowed)
22 options |= ZX_VM_PERM_WRITE;
23 zx_status_t status = zx::vmar::root_self()->map(options, /*vmar_offset=*/0,
24 *handle, offset, size, &addr);
25 if (status != ZX_OK) {
26 ZX_DLOG(ERROR, status) << "zx_vmar_map";
27 return absl::nullopt;
28 }
29
30 return make_span(reinterpret_cast<uint8_t*>(addr), size);
31 }
32
Unmap(span<uint8_t> mapping)33 void PlatformSharedMemoryMapper::Unmap(span<uint8_t> mapping) {
34 uintptr_t addr = reinterpret_cast<uintptr_t>(mapping.data());
35 zx_status_t status = zx::vmar::root_self()->unmap(addr, mapping.size());
36 if (status != ZX_OK)
37 ZX_DLOG(ERROR, status) << "zx_vmar_unmap";
38 }
39
40 } // namespace base
41