runtime/mem_map.cc - platform/art - Gitiles

 /*
  * Copyright (C) 2008 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "mem_map.h"

 #include <corkscrew/map_info.h>

 #include "base/stringprintf.h"
 #include "ScopedFd.h"
 #include "utils.h"

 #define USE_ASHMEM 1

 #ifdef USE_ASHMEM
 #include <cutils/ashmem.h>
 #endif

 namespace art {

 #if !defined(NDEBUG)

 static std::ostream& operator<<(std::ostream& os, map_info_t* rhs) {
   for (map_info_t* m = rhs; m != NULL; m = m->next) {
     os << StringPrintf("0x%08x-0x%08x %c%c %s\n",
                        static_cast<uint32_t>(m->start),
                        static_cast<uint32_t>(m->end),
                        m->is_readable ? 'r' : '-', m->is_executable ? 'x' : '-', m->name);
   }
   return os;
 }

 static void CheckMapRequest(byte* addr, size_t byte_count) {
   if (addr == NULL) {
     return;
   }

   uint32_t base = reinterpret_cast<size_t>(addr);
   uint32_t limit = base + byte_count;

   map_info_t* map_info_list = load_map_info_list(getpid());
   for (map_info_t* m = map_info_list; m != NULL; m = m->next) {
     CHECK(!(base >= m->start && base < m->end)     // start of new within old
         && !(limit > m->start && limit < m->end)   // end of new within old
         && !(base <= m->start && limit > m->end))  // start/end of new includes all of old
         << StringPrintf("Requested region 0x%08x-0x%08x overlaps with existing map 0x%08x-0x%08x (%s)\n",
                         base, limit,
                         static_cast<uint32_t>(m->start), static_cast<uint32_t>(m->end), m->name)
         << map_info_list;
   }
   free_map_info_list(map_info_list);
 }

 #else
 static void CheckMapRequest(byte*, size_t) { }
 #endif

 MemMap* MemMap::MapAnonymous(const char* name, byte* addr, size_t byte_count, int prot) {
   if (byte_count == 0) {
     return new MemMap(name, NULL, 0, NULL, 0, prot);
   }
   size_t page_aligned_byte_count = RoundUp(byte_count, kPageSize);
   CheckMapRequest(addr, page_aligned_byte_count);

 #ifdef USE_ASHMEM
   // android_os_Debug.cpp read_mapinfo assumes all ashmem regions associated with the VM are
   // prefixed "dalvik-".
   std::string debug_friendly_name("dalvik-");
   debug_friendly_name += name;
   ScopedFd fd(ashmem_create_region(debug_friendly_name.c_str(), page_aligned_byte_count));
   int flags = MAP_PRIVATE;
   if (fd.get() == -1) {
     PLOG(ERROR) << "ashmem_create_region failed (" << name << ")";
     return NULL;
   }
 #else
   ScopedFd fd(-1);
   int flags = MAP_PRIVATE | MAP_ANONYMOUS;
 #endif

   byte* actual = reinterpret_cast<byte*>(mmap(addr, page_aligned_byte_count, prot, flags, fd.get(), 0));
   if (actual == MAP_FAILED) {
     std::string maps;
     ReadFileToString("/proc/self/maps", &maps);
     PLOG(ERROR) << "mmap(" << reinterpret_cast<void*>(addr) << ", " << page_aligned_byte_count
                 << ", " << prot << ", " << flags << ", " << fd.get() << ", 0) failed for " << name
                 << "\n" << maps;
     return NULL;
   }
   return new MemMap(name, actual, byte_count, actual, page_aligned_byte_count, prot);
 }

 MemMap* MemMap::MapFileAtAddress(byte* addr, size_t byte_count,
                                  int prot, int flags, int fd, off_t start, bool reuse) {
   CHECK_NE(0, prot);
   CHECK_NE(0, flags & (MAP_SHARED | MAP_PRIVATE));
   if (byte_count == 0) {
     return new MemMap("file", NULL, 0, NULL, 0, prot);
   }
   // Adjust 'offset' to be page-aligned as required by mmap.
   int page_offset = start % kPageSize;
   off_t page_aligned_offset = start - page_offset;
   // Adjust 'byte_count' to be page-aligned as we will map this anyway.
   size_t page_aligned_byte_count = RoundUp(byte_count + page_offset, kPageSize);
   // The 'addr' is modified (if specified, ie non-null) to be page aligned to the file but not
   // necessarily to virtual memory. mmap will page align 'addr' for us.
   byte* page_aligned_addr = (addr == NULL) ? NULL : (addr - page_offset);
   if (!reuse) {
     // reuse means it is okay that it overlaps an existing page mapping.
     // Only use this if you actually made the page reservation yourself.
     CheckMapRequest(page_aligned_addr, page_aligned_byte_count);
   } else {
     CHECK(addr != NULL);
   }
   byte* actual = reinterpret_cast<byte*>(mmap(page_aligned_addr,
                                               page_aligned_byte_count,
                                               prot,
                                               flags,
                                               fd,
                                               page_aligned_offset));
   if (actual == MAP_FAILED) {
     std::string maps;
     ReadFileToString("/proc/self/maps", &maps);
     PLOG(ERROR) << "mmap(" << reinterpret_cast<void*>(page_aligned_addr)
                 << ", " << page_aligned_byte_count
                 << ", " << prot << ", " << flags << ", " << fd << ", " << page_aligned_offset
                 << ") failed\n" << maps;
     return NULL;
   }
   return new MemMap("file", actual + page_offset, byte_count, actual, page_aligned_byte_count,
                     prot);
 }

 MemMap::~MemMap() {
   if (base_begin_ == NULL && base_size_ == 0) {
     return;
   }
   int result = munmap(base_begin_, base_size_);
   if (result == -1) {
     PLOG(FATAL) << "munmap failed";
   }
 }

 MemMap::MemMap(const std::string& name, byte* begin, size_t size, void* base_begin,
                size_t base_size, int prot)
     : name_(name), begin_(begin), size_(size), base_begin_(base_begin), base_size_(base_size),
       prot_(prot) {
   if (size_ == 0) {
     CHECK(begin_ == NULL);
     CHECK(base_begin_ == NULL);
     CHECK_EQ(base_size_, 0U);
   } else {
     CHECK(begin_ != NULL);
     CHECK(base_begin_ != NULL);
     CHECK_NE(base_size_, 0U);
   }
 };

 void MemMap::UnMapAtEnd(byte* new_end) {
   DCHECK_GE(new_end, Begin());
   DCHECK_LE(new_end, End());
   size_t unmap_size = End() - new_end;
   munmap(new_end, unmap_size);
   size_ -= unmap_size;
 }

 bool MemMap::Protect(int prot) {
   if (base_begin_ == NULL && base_size_ == 0) {
     prot_ = prot;
     return true;
   }

   if (mprotect(base_begin_, base_size_, prot) == 0) {
     prot_ = prot;
     return true;
   }

   PLOG(ERROR) << "mprotect(" << reinterpret_cast<void*>(base_begin_) << ", " << base_size_ << ", "
               << prot << ") failed";
   return false;
 }

 bool MemMap::ProtectRegion(uint8_t* addr, size_t length, int prot) {
   CHECK_GE(addr, base_begin_);
   CHECK_LT(addr + length, reinterpret_cast<const uint8_t*>(base_begin_) + base_size_);

   /*
    * Align "addr" to a page boundary and adjust "length" appropriately.
    * (The address must be page-aligned, the length doesn't need to be,
    * but we do need to ensure we cover the same range.)
    */
   uint8_t* alignAddr = reinterpret_cast<uint8_t*>(RoundDown(reinterpret_cast<uintptr_t>(addr),
                                                             kPageSize));
   size_t alignLength = length + (addr - alignAddr);

   if (mprotect(alignAddr, alignLength, prot) == 0) {
     prot_ = prot;
     return true;
   }

   PLOG(ERROR) << "mprotect(" << reinterpret_cast<void*>(alignAddr) << ", " << alignLength << ", "
               << prot << ") failed";
   return false;
 }

 }  // namespace art
	/*
	* Copyright (C) 2008 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "mem_map.h"

	#include <corkscrew/map_info.h>

	#include "base/stringprintf.h"
	#include "ScopedFd.h"
	#include "utils.h"

	#define USE_ASHMEM 1

	#ifdef USE_ASHMEM
	#include <cutils/ashmem.h>
	#endif

	namespace art {

	#if !defined(NDEBUG)

	static std::ostream& operator<<(std::ostream& os, map_info_t* rhs) {
	for (map_info_t* m = rhs; m != NULL; m = m->next) {
	os << StringPrintf("0x%08x-0x%08x %c%c %s\n",
	static_cast<uint32_t>(m->start),
	static_cast<uint32_t>(m->end),
	m->is_readable ? 'r' : '-', m->is_executable ? 'x' : '-', m->name);
	}
	return os;
	}

	static void CheckMapRequest(byte* addr, size_t byte_count) {
	if (addr == NULL) {
	return;
	}

	uint32_t base = reinterpret_cast<size_t>(addr);
	uint32_t limit = base + byte_count;

	map_info_t* map_info_list = load_map_info_list(getpid());
	for (map_info_t* m = map_info_list; m != NULL; m = m->next) {
	CHECK(!(base >= m->start && base < m->end) // start of new within old
	&& !(limit > m->start && limit < m->end) // end of new within old
	&& !(base <= m->start && limit > m->end)) // start/end of new includes all of old
	<< StringPrintf("Requested region 0x%08x-0x%08x overlaps with existing map 0x%08x-0x%08x (%s)\n",
	base, limit,
	static_cast<uint32_t>(m->start), static_cast<uint32_t>(m->end), m->name)
	<< map_info_list;
	}
	free_map_info_list(map_info_list);
	}

	#else
	static void CheckMapRequest(byte*, size_t) { }
	#endif

	MemMap* MemMap::MapAnonymous(const char* name, byte* addr, size_t byte_count, int prot) {
	if (byte_count == 0) {
	return new MemMap(name, NULL, 0, NULL, 0, prot);
	}
	size_t page_aligned_byte_count = RoundUp(byte_count, kPageSize);
	CheckMapRequest(addr, page_aligned_byte_count);

	#ifdef USE_ASHMEM
	// android_os_Debug.cpp read_mapinfo assumes all ashmem regions associated with the VM are
	// prefixed "dalvik-".
	std::string debug_friendly_name("dalvik-");
	debug_friendly_name += name;
	ScopedFd fd(ashmem_create_region(debug_friendly_name.c_str(), page_aligned_byte_count));
	int flags = MAP_PRIVATE;
	if (fd.get() == -1) {
	PLOG(ERROR) << "ashmem_create_region failed (" << name << ")";
	return NULL;
	}
	#else
	ScopedFd fd(-1);
	int flags = MAP_PRIVATE \| MAP_ANONYMOUS;
	#endif

	byte* actual = reinterpret_cast<byte*>(mmap(addr, page_aligned_byte_count, prot, flags, fd.get(), 0));
	if (actual == MAP_FAILED) {
	std::string maps;
	ReadFileToString("/proc/self/maps", &maps);
	PLOG(ERROR) << "mmap(" << reinterpret_cast<void*>(addr) << ", " << page_aligned_byte_count
	<< ", " << prot << ", " << flags << ", " << fd.get() << ", 0) failed for " << name
	<< "\n" << maps;
	return NULL;
	}
	return new MemMap(name, actual, byte_count, actual, page_aligned_byte_count, prot);
	}

	MemMap* MemMap::MapFileAtAddress(byte* addr, size_t byte_count,
	int prot, int flags, int fd, off_t start, bool reuse) {
	CHECK_NE(0, prot);
	CHECK_NE(0, flags & (MAP_SHARED \| MAP_PRIVATE));
	if (byte_count == 0) {
	return new MemMap("file", NULL, 0, NULL, 0, prot);
	}
	// Adjust 'offset' to be page-aligned as required by mmap.
	int page_offset = start % kPageSize;
	off_t page_aligned_offset = start - page_offset;
	// Adjust 'byte_count' to be page-aligned as we will map this anyway.
	size_t page_aligned_byte_count = RoundUp(byte_count + page_offset, kPageSize);
	// The 'addr' is modified (if specified, ie non-null) to be page aligned to the file but not
	// necessarily to virtual memory. mmap will page align 'addr' for us.
	byte* page_aligned_addr = (addr == NULL) ? NULL : (addr - page_offset);
	if (!reuse) {
	// reuse means it is okay that it overlaps an existing page mapping.
	// Only use this if you actually made the page reservation yourself.
	CheckMapRequest(page_aligned_addr, page_aligned_byte_count);
	} else {
	CHECK(addr != NULL);
	}
	byte* actual = reinterpret_cast<byte*>(mmap(page_aligned_addr,
	page_aligned_byte_count,
	prot,
	flags,
	fd,
	page_aligned_offset));
	if (actual == MAP_FAILED) {
	std::string maps;
	ReadFileToString("/proc/self/maps", &maps);
	PLOG(ERROR) << "mmap(" << reinterpret_cast<void*>(page_aligned_addr)
	<< ", " << page_aligned_byte_count
	<< ", " << prot << ", " << flags << ", " << fd << ", " << page_aligned_offset
	<< ") failed\n" << maps;
	return NULL;
	}
	return new MemMap("file", actual + page_offset, byte_count, actual, page_aligned_byte_count,
	prot);
	}

	MemMap::~MemMap() {
	if (base_begin_ == NULL && base_size_ == 0) {
	return;
	}
	int result = munmap(base_begin_, base_size_);
	if (result == -1) {
	PLOG(FATAL) << "munmap failed";
	}
	}

	MemMap::MemMap(const std::string& name, byte* begin, size_t size, void* base_begin,
	size_t base_size, int prot)
	: name_(name), begin_(begin), size_(size), base_begin_(base_begin), base_size_(base_size),
	prot_(prot) {
	if (size_ == 0) {
	CHECK(begin_ == NULL);
	CHECK(base_begin_ == NULL);
	CHECK_EQ(base_size_, 0U);
	} else {
	CHECK(begin_ != NULL);
	CHECK(base_begin_ != NULL);
	CHECK_NE(base_size_, 0U);
	}
	};

	void MemMap::UnMapAtEnd(byte* new_end) {
	DCHECK_GE(new_end, Begin());
	DCHECK_LE(new_end, End());
	size_t unmap_size = End() - new_end;
	munmap(new_end, unmap_size);
	size_ -= unmap_size;
	}

	bool MemMap::Protect(int prot) {
	if (base_begin_ == NULL && base_size_ == 0) {
	prot_ = prot;
	return true;
	}

	if (mprotect(base_begin_, base_size_, prot) == 0) {
	prot_ = prot;
	return true;
	}

	PLOG(ERROR) << "mprotect(" << reinterpret_cast<void*>(base_begin_) << ", " << base_size_ << ", "
	<< prot << ") failed";
	return false;
	}

	bool MemMap::ProtectRegion(uint8_t* addr, size_t length, int prot) {
	CHECK_GE(addr, base_begin_);
	CHECK_LT(addr + length, reinterpret_cast<const uint8_t*>(base_begin_) + base_size_);

	/*
	* Align "addr" to a page boundary and adjust "length" appropriately.
	* (The address must be page-aligned, the length doesn't need to be,
	* but we do need to ensure we cover the same range.)
	*/
	uint8_t* alignAddr = reinterpret_cast<uint8_t*>(RoundDown(reinterpret_cast<uintptr_t>(addr),
	kPageSize));
	size_t alignLength = length + (addr - alignAddr);

	if (mprotect(alignAddr, alignLength, prot) == 0) {
	prot_ = prot;
	return true;
	}

	PLOG(ERROR) << "mprotect(" << reinterpret_cast<void*>(alignAddr) << ", " << alignLength << ", "
	<< prot << ") failed";
	return false;
	}

	} // namespace art