runtime/vm/virtual_memory_fuchsia.cc - sdk.git - Git at Google

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 #include "vm/globals.h"
 #if defined(HOST_OS_FUCHSIA)

 #include "vm/virtual_memory.h"

 #include <magenta/process.h>
 #include <magenta/status.h>
 #include <magenta/syscalls.h>
 #include <sys/mman.h>
 #include <unistd.h>

 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
 #include "vm/lockers.h"
 #include "vm/memory_region.h"
 #include "vm/os.h"
 #include "vm/os_thread.h"

 // #define VIRTUAL_MEMORY_LOGGING 1
 #if defined(VIRTUAL_MEMORY_LOGGING)
 #define LOG_ERR(msg, ...)                                                      \
   OS::PrintErr("VMVM: %s:%d: " msg, __FILE__, __LINE__, ##__VA_ARGS__)
 #define LOG_INFO(msg, ...)                                                     \
   OS::Print("VMVM: %s:%d: " msg, __FILE__, __LINE__, ##__VA_ARGS__)
 #else
 #define LOG_ERR(msg, ...)
 #define LOG_INFO(msg, ...)
 #endif  // defined(VIRTUAL_MEMORY_LOGGING)

 namespace dart {

 // The Magenta system call to protect memory regions (mx_vmar_protect) takes a
 // VM area (vmar) handle as first argument. We call VirtualMemory::Protect()
 // from the memory freelist code in vm/freelist.cc where the vmar handle is not
 // available. Additionally, there is no mx_vmar system call to retrieve a handle
 // for the leaf vmar given an address. Thus, when memory protections are
 // enabled, we maintain a sorted list of our leaf vmar handles that we can
 // query by address in calls to VirtualMemory::Protect().
 class VmarList : public AllStatic {
  public:
   static void AddVmar(mx_handle_t vmar, uword addr, intptr_t size);
   static void RemoveVmar(uword addr);
   static mx_handle_t LookupVmar(uword addr);

  private:
   static intptr_t LookupVmarIndexLocked(uword addr);

   struct VmarListElement {
     mx_handle_t vmar;
     uword addr;
     intptr_t size;
   };

   static Mutex* vmar_array_lock_;
   static MallocGrowableArray<VmarListElement> vmar_array_;
 };

 Mutex* VmarList::vmar_array_lock_ = new Mutex();
 MallocGrowableArray<VmarList::VmarListElement> VmarList::vmar_array_;

 void VmarList::AddVmar(mx_handle_t vmar, uword addr, intptr_t size) {
   MutexLocker ml(vmar_array_lock_);
   LOG_INFO("AddVmar(%d, %lx, %ld)\n", vmar, addr, size);
   // Sorted insert in increasing order.
   const intptr_t length = vmar_array_.length();
   intptr_t idx;
   for (idx = 0; idx < length; idx++) {
     const VmarListElement& m = vmar_array_.At(idx);
     if (m.addr >= addr) {
       break;
     }
   }
 #if defined(DEBUG)
   if ((length > 0) && (idx < (length - 1))) {
     const VmarListElement& m = vmar_array_.At(idx);
     ASSERT(m.addr != addr);
   }
 #endif
   LOG_INFO("AddVmar(%d, %lx, %ld) at index = %ld\n", vmar, addr, size, idx);
   VmarListElement new_mapping;
   new_mapping.vmar = vmar;
   new_mapping.addr = addr;
   new_mapping.size = size;
   vmar_array_.InsertAt(idx, new_mapping);
 }


 intptr_t VmarList::LookupVmarIndexLocked(uword addr) {
   // Binary search for the vmar containing addr.
   intptr_t imin = 0;
   intptr_t imax = vmar_array_.length();
   while (imax >= imin) {
     const intptr_t imid = ((imax - imin) / 2) + imin;
     const VmarListElement& mapping = vmar_array_.At(imid);
     if ((mapping.addr + mapping.size) <= addr) {
       imin = imid + 1;
     } else if (mapping.addr > addr) {
       imax = imid - 1;
     } else {
       return imid;
     }
   }
   return -1;
 }


 mx_handle_t VmarList::LookupVmar(uword addr) {
   MutexLocker ml(vmar_array_lock_);
   LOG_INFO("LookupVmar(%lx)\n", addr);
   const intptr_t idx = LookupVmarIndexLocked(addr);
   if (idx == -1) {
     LOG_ERR("LookupVmar(%lx) NOT FOUND\n", addr);
     return MX_HANDLE_INVALID;
   }
   LOG_INFO("LookupVmar(%lx) found at %ld\n", addr, idx);
   return vmar_array_[idx].vmar;
 }


 void VmarList::RemoveVmar(uword addr) {
   MutexLocker ml(vmar_array_lock_);
   LOG_INFO("RemoveVmar(%lx)\n", addr);
   const intptr_t idx = LookupVmarIndexLocked(addr);
   ASSERT(idx != -1);
 #if defined(DEBUG)
   mx_handle_t vmar = vmar_array_[idx].vmar;
 #endif
   // Swap idx to the end, and then RemoveLast()
   const intptr_t length = vmar_array_.length();
   for (intptr_t i = idx; i < length - 1; i++) {
     vmar_array_.Swap(i, i + 1);
   }
 #if defined(DEBUG)
   const VmarListElement& mapping = vmar_array_.Last();
   ASSERT(mapping.vmar == vmar);
 #endif
   vmar_array_.RemoveLast();
 }


 uword VirtualMemory::page_size_ = 0;


 void VirtualMemory::InitOnce() {
   page_size_ = getpagesize();
 }


 VirtualMemory* VirtualMemory::ReserveInternal(intptr_t size) {
   mx_handle_t vmar = MX_HANDLE_INVALID;
   uword addr = 0;
   const uint32_t flags = MX_VM_FLAG_COMPACT | MX_VM_FLAG_CAN_MAP_SPECIFIC |
                          MX_VM_FLAG_CAN_MAP_READ | MX_VM_FLAG_CAN_MAP_WRITE |
                          MX_VM_FLAG_CAN_MAP_EXECUTE;
   mx_status_t status =
       mx_vmar_allocate(mx_vmar_root_self(), 0, size, flags, &vmar, &addr);
   if (status != NO_ERROR) {
     LOG_ERR("mx_vmar_allocate(size = %ld) failed: %s\n", size,
             mx_status_get_string(status));
     return NULL;
   }
   VmarList::AddVmar(vmar, addr, size);
   MemoryRegion region(reinterpret_cast<void*>(addr), size);
   return new VirtualMemory(region, vmar);
 }


 VirtualMemory::~VirtualMemory() {
   if (vm_owns_region()) {
     mx_handle_t vmar = static_cast<mx_handle_t>(handle());
     mx_status_t status = mx_vmar_destroy(vmar);
     if (status != NO_ERROR) {
       LOG_ERR("mx_vmar_destroy failed: %s\n", mx_status_get_string(status));
     }
     status = mx_handle_close(vmar);
     if (status != NO_ERROR) {
       LOG_ERR("mx_handle_close failed: %s\n", mx_status_get_string(status));
     }
     VmarList::RemoveVmar(start());
   }
 }


 bool VirtualMemory::FreeSubSegment(int32_t handle,
                                    void* address,
                                    intptr_t size) {
   mx_handle_t vmar = static_cast<mx_handle_t>(handle);
   mx_status_t status =
       mx_vmar_unmap(vmar, reinterpret_cast<uintptr_t>(address), size);
   if (status != NO_ERROR) {
     LOG_ERR("mx_vmar_unmap failed: %s\n", mx_status_get_string(status));
     return false;
   }
   return true;
 }


 bool VirtualMemory::Commit(uword addr, intptr_t size, bool executable) {
   ASSERT(Contains(addr));
   ASSERT(Contains(addr + size) || (addr + size == end()));
   mx_handle_t vmo = MX_HANDLE_INVALID;
   mx_status_t status = mx_vmo_create(size, 0u, &vmo);
   if (status != NO_ERROR) {
     LOG_ERR("mx_vmo_create(%ld) failed: %s\n", size,
             mx_status_get_string(status));
     return false;
   }

   mx_handle_t vmar = static_cast<mx_handle_t>(handle());
   const size_t offset = addr - start();
   const uint32_t flags = MX_VM_FLAG_SPECIFIC | MX_VM_FLAG_PERM_READ |
                          MX_VM_FLAG_PERM_WRITE |
                          (executable ? MX_VM_FLAG_PERM_EXECUTE : 0);
   uintptr_t mapped_addr;
   status = mx_vmar_map(vmar, offset, vmo, 0, size, flags, &mapped_addr);
   if (status != NO_ERROR) {
     mx_handle_close(vmo);
     LOG_ERR("mx_vmar_map(%ld, %ld, %u) failed: %s\n", offset, size, flags,
             mx_status_get_string(status));
     return false;
   }
   if (addr != mapped_addr) {
     mx_handle_close(vmo);
     LOG_ERR("mx_vmar_map: addr != mapped_addr: %lx != %lx\n", addr,
             mapped_addr);
     return false;
   }
   mx_handle_close(vmo);
   LOG_INFO("Commit(%lx, %ld, %s): success\n", addr, size,
            executable ? "executable" : "");
   return true;
 }


 bool VirtualMemory::Protect(void* address, intptr_t size, Protection mode) {
   ASSERT(Thread::Current()->IsMutatorThread() ||
          Isolate::Current()->mutator_thread()->IsAtSafepoint());
   const uword start_address = reinterpret_cast<uword>(address);
   const uword end_address = start_address + size;
   const uword page_address = Utils::RoundDown(start_address, PageSize());
   mx_handle_t vmar = VmarList::LookupVmar(page_address);
   ASSERT(vmar != MX_HANDLE_INVALID);
   uint32_t prot = 0;
   switch (mode) {
     case kNoAccess:
       // MG-426: mx_vmar_protect() requires at least on permission.
       prot = MX_VM_FLAG_PERM_READ;
       break;
     case kReadOnly:
       prot = MX_VM_FLAG_PERM_READ;
       break;
     case kReadWrite:
       prot = MX_VM_FLAG_PERM_READ | MX_VM_FLAG_PERM_WRITE;
       break;
     case kReadExecute:
       prot = MX_VM_FLAG_PERM_READ | MX_VM_FLAG_PERM_EXECUTE;
       break;
     case kReadWriteExecute:
       prot = MX_VM_FLAG_PERM_READ | MX_VM_FLAG_PERM_WRITE |
              MX_VM_FLAG_PERM_EXECUTE;
       break;
   }
   mx_status_t status =
       mx_vmar_protect(vmar, page_address, end_address - page_address, prot);
   if (status != NO_ERROR) {
     LOG_ERR("mx_vmar_protect(%lx, %lx, %x) success: %s\n", page_address,
             end_address - page_address, prot, mx_status_get_string(status));
     return false;
   }
   LOG_INFO("mx_vmar_protect(%lx, %lx, %x) success\n", page_address,
            end_address - page_address, prot);
   return true;
 }

 }  // namespace dart

 #endif  // defined(HOST_OS_FUCHSIA)
	// Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	#include "vm/globals.h"
	#if defined(HOST_OS_FUCHSIA)

	#include "vm/virtual_memory.h"

	#include <magenta/process.h>
	#include <magenta/status.h>
	#include <magenta/syscalls.h>
	#include <sys/mman.h>
	#include <unistd.h>

	#include "platform/assert.h"
	#include "vm/allocation.h"
	#include "vm/growable_array.h"
	#include "vm/isolate.h"
	#include "vm/lockers.h"
	#include "vm/memory_region.h"
	#include "vm/os.h"
	#include "vm/os_thread.h"

	// #define VIRTUAL_MEMORY_LOGGING 1
	#if defined(VIRTUAL_MEMORY_LOGGING)
	#define LOG_ERR(msg, ...) \
	OS::PrintErr("VMVM: %s:%d: " msg, __FILE__, __LINE__, ##__VA_ARGS__)
	#define LOG_INFO(msg, ...) \
	OS::Print("VMVM: %s:%d: " msg, __FILE__, __LINE__, ##__VA_ARGS__)
	#else
	#define LOG_ERR(msg, ...)
	#define LOG_INFO(msg, ...)
	#endif // defined(VIRTUAL_MEMORY_LOGGING)

	namespace dart {

	// The Magenta system call to protect memory regions (mx_vmar_protect) takes a
	// VM area (vmar) handle as first argument. We call VirtualMemory::Protect()
	// from the memory freelist code in vm/freelist.cc where the vmar handle is not
	// available. Additionally, there is no mx_vmar system call to retrieve a handle
	// for the leaf vmar given an address. Thus, when memory protections are
	// enabled, we maintain a sorted list of our leaf vmar handles that we can
	// query by address in calls to VirtualMemory::Protect().
	class VmarList : public AllStatic {
	public:
	static void AddVmar(mx_handle_t vmar, uword addr, intptr_t size);
	static void RemoveVmar(uword addr);
	static mx_handle_t LookupVmar(uword addr);

	private:
	static intptr_t LookupVmarIndexLocked(uword addr);

	struct VmarListElement {
	mx_handle_t vmar;
	uword addr;
	intptr_t size;
	};

	static Mutex* vmar_array_lock_;
	static MallocGrowableArray<VmarListElement> vmar_array_;
	};

	Mutex* VmarList::vmar_array_lock_ = new Mutex();
	MallocGrowableArray<VmarList::VmarListElement> VmarList::vmar_array_;

	void VmarList::AddVmar(mx_handle_t vmar, uword addr, intptr_t size) {
	MutexLocker ml(vmar_array_lock_);
	LOG_INFO("AddVmar(%d, %lx, %ld)\n", vmar, addr, size);
	// Sorted insert in increasing order.
	const intptr_t length = vmar_array_.length();
	intptr_t idx;
	for (idx = 0; idx < length; idx++) {
	const VmarListElement& m = vmar_array_.At(idx);
	if (m.addr >= addr) {
	break;
	}
	}
	#if defined(DEBUG)
	if ((length > 0) && (idx < (length - 1))) {
	const VmarListElement& m = vmar_array_.At(idx);
	ASSERT(m.addr != addr);
	}
	#endif
	LOG_INFO("AddVmar(%d, %lx, %ld) at index = %ld\n", vmar, addr, size, idx);
	VmarListElement new_mapping;
	new_mapping.vmar = vmar;
	new_mapping.addr = addr;
	new_mapping.size = size;
	vmar_array_.InsertAt(idx, new_mapping);
	}


	intptr_t VmarList::LookupVmarIndexLocked(uword addr) {
	// Binary search for the vmar containing addr.
	intptr_t imin = 0;
	intptr_t imax = vmar_array_.length();
	while (imax >= imin) {
	const intptr_t imid = ((imax - imin) / 2) + imin;
	const VmarListElement& mapping = vmar_array_.At(imid);
	if ((mapping.addr + mapping.size) <= addr) {
	imin = imid + 1;
	} else if (mapping.addr > addr) {
	imax = imid - 1;
	} else {
	return imid;
	}
	}
	return -1;
	}


	mx_handle_t VmarList::LookupVmar(uword addr) {
	MutexLocker ml(vmar_array_lock_);
	LOG_INFO("LookupVmar(%lx)\n", addr);
	const intptr_t idx = LookupVmarIndexLocked(addr);
	if (idx == -1) {
	LOG_ERR("LookupVmar(%lx) NOT FOUND\n", addr);
	return MX_HANDLE_INVALID;
	}
	LOG_INFO("LookupVmar(%lx) found at %ld\n", addr, idx);
	return vmar_array_[idx].vmar;
	}


	void VmarList::RemoveVmar(uword addr) {
	MutexLocker ml(vmar_array_lock_);
	LOG_INFO("RemoveVmar(%lx)\n", addr);
	const intptr_t idx = LookupVmarIndexLocked(addr);
	ASSERT(idx != -1);
	#if defined(DEBUG)
	mx_handle_t vmar = vmar_array_[idx].vmar;
	#endif
	// Swap idx to the end, and then RemoveLast()
	const intptr_t length = vmar_array_.length();
	for (intptr_t i = idx; i < length - 1; i++) {
	vmar_array_.Swap(i, i + 1);
	}
	#if defined(DEBUG)
	const VmarListElement& mapping = vmar_array_.Last();
	ASSERT(mapping.vmar == vmar);
	#endif
	vmar_array_.RemoveLast();
	}


	uword VirtualMemory::page_size_ = 0;


	void VirtualMemory::InitOnce() {
	page_size_ = getpagesize();
	}


	VirtualMemory* VirtualMemory::ReserveInternal(intptr_t size) {
	mx_handle_t vmar = MX_HANDLE_INVALID;
	uword addr = 0;
	const uint32_t flags = MX_VM_FLAG_COMPACT \| MX_VM_FLAG_CAN_MAP_SPECIFIC \|
	MX_VM_FLAG_CAN_MAP_READ \| MX_VM_FLAG_CAN_MAP_WRITE \|
	MX_VM_FLAG_CAN_MAP_EXECUTE;
	mx_status_t status =
	mx_vmar_allocate(mx_vmar_root_self(), 0, size, flags, &vmar, &addr);
	if (status != NO_ERROR) {
	LOG_ERR("mx_vmar_allocate(size = %ld) failed: %s\n", size,
	mx_status_get_string(status));
	return NULL;
	}
	VmarList::AddVmar(vmar, addr, size);
	MemoryRegion region(reinterpret_cast<void*>(addr), size);
	return new VirtualMemory(region, vmar);
	}


	VirtualMemory::~VirtualMemory() {
	if (vm_owns_region()) {
	mx_handle_t vmar = static_cast<mx_handle_t>(handle());
	mx_status_t status = mx_vmar_destroy(vmar);
	if (status != NO_ERROR) {
	LOG_ERR("mx_vmar_destroy failed: %s\n", mx_status_get_string(status));
	}
	status = mx_handle_close(vmar);
	if (status != NO_ERROR) {
	LOG_ERR("mx_handle_close failed: %s\n", mx_status_get_string(status));
	}
	VmarList::RemoveVmar(start());
	}
	}


	bool VirtualMemory::FreeSubSegment(int32_t handle,
	void* address,
	intptr_t size) {
	mx_handle_t vmar = static_cast<mx_handle_t>(handle);
	mx_status_t status =
	mx_vmar_unmap(vmar, reinterpret_cast<uintptr_t>(address), size);
	if (status != NO_ERROR) {
	LOG_ERR("mx_vmar_unmap failed: %s\n", mx_status_get_string(status));
	return false;
	}
	return true;
	}


	bool VirtualMemory::Commit(uword addr, intptr_t size, bool executable) {
	ASSERT(Contains(addr));
	ASSERT(Contains(addr + size) \|\| (addr + size == end()));
	mx_handle_t vmo = MX_HANDLE_INVALID;
	mx_status_t status = mx_vmo_create(size, 0u, &vmo);
	if (status != NO_ERROR) {
	LOG_ERR("mx_vmo_create(%ld) failed: %s\n", size,
	mx_status_get_string(status));
	return false;
	}

	mx_handle_t vmar = static_cast<mx_handle_t>(handle());
	const size_t offset = addr - start();
	const uint32_t flags = MX_VM_FLAG_SPECIFIC \| MX_VM_FLAG_PERM_READ \|
	MX_VM_FLAG_PERM_WRITE \|
	(executable ? MX_VM_FLAG_PERM_EXECUTE : 0);
	uintptr_t mapped_addr;
	status = mx_vmar_map(vmar, offset, vmo, 0, size, flags, &mapped_addr);
	if (status != NO_ERROR) {
	mx_handle_close(vmo);
	LOG_ERR("mx_vmar_map(%ld, %ld, %u) failed: %s\n", offset, size, flags,
	mx_status_get_string(status));
	return false;
	}
	if (addr != mapped_addr) {
	mx_handle_close(vmo);
	LOG_ERR("mx_vmar_map: addr != mapped_addr: %lx != %lx\n", addr,
	mapped_addr);
	return false;
	}
	mx_handle_close(vmo);
	LOG_INFO("Commit(%lx, %ld, %s): success\n", addr, size,
	executable ? "executable" : "");
	return true;
	}


	bool VirtualMemory::Protect(void* address, intptr_t size, Protection mode) {
	ASSERT(Thread::Current()->IsMutatorThread() \|\|
	Isolate::Current()->mutator_thread()->IsAtSafepoint());
	const uword start_address = reinterpret_cast<uword>(address);
	const uword end_address = start_address + size;
	const uword page_address = Utils::RoundDown(start_address, PageSize());
	mx_handle_t vmar = VmarList::LookupVmar(page_address);
	ASSERT(vmar != MX_HANDLE_INVALID);
	uint32_t prot = 0;
	switch (mode) {
	case kNoAccess:
	// MG-426: mx_vmar_protect() requires at least on permission.
	prot = MX_VM_FLAG_PERM_READ;
	break;
	case kReadOnly:
	prot = MX_VM_FLAG_PERM_READ;
	break;
	case kReadWrite:
	prot = MX_VM_FLAG_PERM_READ \| MX_VM_FLAG_PERM_WRITE;
	break;
	case kReadExecute:
	prot = MX_VM_FLAG_PERM_READ \| MX_VM_FLAG_PERM_EXECUTE;
	break;
	case kReadWriteExecute:
	prot = MX_VM_FLAG_PERM_READ \| MX_VM_FLAG_PERM_WRITE \|
	MX_VM_FLAG_PERM_EXECUTE;
	break;
	}
	mx_status_t status =
	mx_vmar_protect(vmar, page_address, end_address - page_address, prot);
	if (status != NO_ERROR) {
	LOG_ERR("mx_vmar_protect(%lx, %lx, %x) success: %s\n", page_address,
	end_address - page_address, prot, mx_status_get_string(status));
	return false;
	}
	LOG_INFO("mx_vmar_protect(%lx, %lx, %x) success\n", page_address,
	end_address - page_address, prot);
	return true;
	}

	} // namespace dart

	#endif // defined(HOST_OS_FUCHSIA)