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// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Platform-specific code for MacOS goes here. Code shared between iOS and
// macOS is in platform-darwin.cc, while the POSIX-compatible are in in
// platform-posix.cc.
#include <mach/mach.h>
#include <mach/mach_vm.h>
#include <mach/vm_map.h>
#include "src/base/platform/platform.h"
namespace v8 {
namespace base {
namespace {
vm_prot_t GetVMProtFromMemoryPermission(OS::MemoryPermission access) {
switch (access) {
case OS::MemoryPermission::kNoAccess:
case OS::MemoryPermission::kNoAccessWillJitLater:
return VM_PROT_NONE;
case OS::MemoryPermission::kRead:
return VM_PROT_READ;
case OS::MemoryPermission::kReadWrite:
return VM_PROT_READ | VM_PROT_WRITE;
case OS::MemoryPermission::kReadWriteExecute:
return VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
case OS::MemoryPermission::kReadExecute:
return VM_PROT_READ | VM_PROT_EXECUTE;
}
UNREACHABLE();
}
kern_return_t mach_vm_map_wrapper(mach_vm_address_t* address,
mach_vm_size_t size, int flags,
mach_port_t port,
memory_object_offset_t offset,
vm_prot_t prot) {
vm_prot_t current_prot = prot;
vm_prot_t maximum_prot = current_prot;
return mach_vm_map(mach_task_self(), address, size, 0, flags, port, offset,
FALSE, current_prot, maximum_prot, VM_INHERIT_NONE);
}
} // namespace
// static
PlatformSharedMemoryHandle OS::CreateSharedMemoryHandleForTesting(size_t size) {
mach_vm_size_t vm_size = size;
mach_port_t port;
kern_return_t kr = mach_make_memory_entry_64(
mach_task_self(), &vm_size, 0,
MAP_MEM_NAMED_CREATE | VM_PROT_READ | VM_PROT_WRITE, &port,
MACH_PORT_NULL);
if (kr != KERN_SUCCESS) return kInvalidSharedMemoryHandle;
return SharedMemoryHandleFromMachMemoryEntry(port);
}
// static
void OS::DestroySharedMemoryHandle(PlatformSharedMemoryHandle handle) {
DCHECK_NE(kInvalidSharedMemoryHandle, handle);
mach_port_t port = MachMemoryEntryFromSharedMemoryHandle(handle);
CHECK_EQ(KERN_SUCCESS, mach_port_deallocate(mach_task_self(), port));
}
// static
void* OS::AllocateShared(void* hint, size_t size, MemoryPermission access,
PlatformSharedMemoryHandle handle, uint64_t offset) {
DCHECK_EQ(0, size % AllocatePageSize());
mach_vm_address_t addr = reinterpret_cast<mach_vm_address_t>(hint);
vm_prot_t prot = GetVMProtFromMemoryPermission(access);
mach_port_t shared_mem_port = MachMemoryEntryFromSharedMemoryHandle(handle);
kern_return_t kr = mach_vm_map_wrapper(&addr, size, VM_FLAGS_FIXED,
shared_mem_port, offset, prot);
if (kr != KERN_SUCCESS) {
// Retry without hint.
kr = mach_vm_map_wrapper(&addr, size, VM_FLAGS_ANYWHERE, shared_mem_port,
offset, prot);
}
if (kr != KERN_SUCCESS) return nullptr;
return reinterpret_cast<void*>(addr);
}
bool AddressSpaceReservation::AllocateShared(void* address, size_t size,
OS::MemoryPermission access,
PlatformSharedMemoryHandle handle,
uint64_t offset) {
DCHECK(Contains(address, size));
vm_prot_t prot = GetVMProtFromMemoryPermission(access);
mach_vm_address_t addr = reinterpret_cast<mach_vm_address_t>(address);
mach_port_t shared_mem_port = MachMemoryEntryFromSharedMemoryHandle(handle);
kern_return_t kr =
mach_vm_map_wrapper(&addr, size, VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE,
shared_mem_port, offset, prot);
return kr == KERN_SUCCESS;
}
} // namespace base
} // namespace v8
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