libdex/SysUtil.cpp - platform/dalvik - Git at Google

 /*
  * 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.
  */

 /*
  * System utilities.
  */
 #include "DexFile.h"
 #include "SysUtil.h"

 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>
 #if !defined(__MINGW32__)
 # include <sys/mman.h>
 #endif
 #include <limits.h>
 #include <errno.h>

 #include <JNIHelp.h>        // TEMP_FAILURE_RETRY may or may not be in unistd


 /*
  * Create an anonymous shared memory segment large enough to hold "length"
  * bytes.  The actual segment may be larger because mmap() operates on
  * page boundaries (usually 4K).
  */
 static void* sysCreateAnonShmem(size_t length)
 {
 #if !defined(__MINGW32__)
     void* ptr;

     ptr = mmap(NULL, length, PROT_READ | PROT_WRITE,
             MAP_SHARED | MAP_ANON, -1, 0);
     if (ptr == MAP_FAILED) {
         ALOGW("mmap(%d, RW, SHARED|ANON) failed: %s", (int) length,
             strerror(errno));
         return NULL;
     }

     return ptr;
 #else
     ALOGE("sysCreateAnonShmem not implemented.");
     return NULL;
 #endif
 }

 /*
  * Create a private anonymous storage area.
  */
 int sysCreatePrivateMap(size_t length, MemMapping* pMap)
 {
     void* memPtr;

     memPtr = sysCreateAnonShmem(length);
     if (memPtr == NULL)
         return -1;

     pMap->addr = pMap->baseAddr = memPtr;
     pMap->length = pMap->baseLength = length;
     return 0;
 }

 /*
  * Determine the current offset and remaining length of the open file.
  */
 static int getFileStartAndLength(int fd, off_t *start_, size_t *length_)
 {
     off_t start, end;
     size_t length;

     assert(start_ != NULL);
     assert(length_ != NULL);

     start = lseek(fd, 0L, SEEK_CUR);
     end = lseek(fd, 0L, SEEK_END);
     (void) lseek(fd, start, SEEK_SET);

     if (start == (off_t) -1 || end == (off_t) -1) {
         ALOGE("could not determine length of file");
         return -1;
     }

     length = end - start;
     if (length == 0) {
         ALOGE("file is empty");
         return -1;
     }

     *start_ = start;
     *length_ = length;

     return 0;
 }

 #if defined(__MINGW32__)
 int sysFakeMapFile(int fd, MemMapping* pMap)
 {
     /* No MMAP, just fake it by copying the bits.
        For Win32 we could use MapViewOfFile if really necessary
        (see libs/utils/FileMap.cpp).
     */
     off_t start;
     size_t length;
     void* memPtr;

     assert(pMap != NULL);

     if (getFileStartAndLength(fd, &start, &length) < 0)
         return -1;

     memPtr = malloc(length);
     if (read(fd, memPtr, length) < 0) {
         ALOGW("read(fd=%d, start=%d, length=%d) failed: %s", (int) length,
             fd, (int) start, strerror(errno));
         return -1;
     }

     pMap->baseAddr = pMap->addr = memPtr;
     pMap->baseLength = pMap->length = length;

     return 0;
 }
 #endif

 /*
  * Map a file (from fd's current offset) into a private, read-write memory
  * segment that will be marked read-only (a/k/a "writable read-only").  The
  * file offset must be a multiple of the system page size.
  *
  * In some cases the mapping will be fully writable (e.g. for files on
  * FAT filesystems).
  *
  * On success, returns 0 and fills out "pMap".  On failure, returns a nonzero
  * value and does not disturb "pMap".
  */
 int sysMapFileInShmemWritableReadOnly(int fd, MemMapping* pMap)
 {
 #if !defined(__MINGW32__)
     off_t start;
     size_t length;
     void* memPtr;

     assert(pMap != NULL);

     if (getFileStartAndLength(fd, &start, &length) < 0)
         return -1;

     memPtr = mmap(NULL, length, PROT_READ | PROT_WRITE, MAP_FILE | MAP_PRIVATE,
             fd, start);
     if (memPtr == MAP_FAILED) {
         ALOGW("mmap(%d, R/W, FILE|PRIVATE, %d, %d) failed: %s", (int) length,
             fd, (int) start, strerror(errno));
         return -1;
     }
     if (mprotect(memPtr, length, PROT_READ) < 0) {
         /* this fails with EACCESS on FAT filesystems, e.g. /sdcard */
         int err = errno;
         ALOGV("mprotect(%p, %zd, PROT_READ) failed: %s",
             memPtr, length, strerror(err));
         ALOGD("mprotect(RO) failed (%d), file will remain read-write", err);
     }

     pMap->baseAddr = pMap->addr = memPtr;
     pMap->baseLength = pMap->length = length;

     return 0;
 #else
     return sysFakeMapFile(fd, pMap);
 #endif
 }

 /*
  * Map part of a file into a shared, read-only memory segment.  The "start"
  * offset is absolute, not relative.
  *
  * On success, returns 0 and fills out "pMap".  On failure, returns a nonzero
  * value and does not disturb "pMap".
  */
 int sysMapFileSegmentInShmem(int fd, off_t start, size_t length,
     MemMapping* pMap)
 {
 #if !defined(__MINGW32__)
     size_t actualLength;
     off_t actualStart;
     int adjust;
     void* memPtr;

     assert(pMap != NULL);

     /* adjust to be page-aligned */
     adjust = start % SYSTEM_PAGE_SIZE;
     actualStart = start - adjust;
     actualLength = length + adjust;

     memPtr = mmap(NULL, actualLength, PROT_READ, MAP_FILE | MAP_SHARED,
                 fd, actualStart);
     if (memPtr == MAP_FAILED) {
         ALOGW("mmap(%d, R, FILE|SHARED, %d, %d) failed: %s",
             (int) actualLength, fd, (int) actualStart, strerror(errno));
         return -1;
     }

     pMap->baseAddr = memPtr;
     pMap->baseLength = actualLength;
     pMap->addr = (char*)memPtr + adjust;
     pMap->length = length;

     LOGVV("mmap seg (st=%d ln=%d): bp=%p bl=%d ad=%p ln=%d",
         (int) start, (int) length,
         pMap->baseAddr, (int) pMap->baseLength,
         pMap->addr, (int) pMap->length);

     return 0;
 #else
     ALOGE("sysMapFileSegmentInShmem not implemented.");
     return -1;
 #endif
 }

 /*
  * Change the access rights on one or more pages to read-only or read-write.
  *
  * Returns 0 on success.
  */
 int sysChangeMapAccess(void* addr, size_t length, int wantReadWrite,
     MemMapping* pMap)
 {
 #if !defined(__MINGW32__)
     /*
      * Verify that "addr" is part of this mapping file.
      */
     if (addr < pMap->baseAddr ||
         (u1*)addr >= (u1*)pMap->baseAddr + pMap->baseLength)
     {
         ALOGE("Attempted to change %p; map is %p - %p",
             addr, pMap->baseAddr, (u1*)pMap->baseAddr + pMap->baseLength);
         return -1;
     }

     /*
      * 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.)
      */
     u1* alignAddr = (u1*) ((uintptr_t) addr & ~(SYSTEM_PAGE_SIZE-1));
     size_t alignLength = length + ((u1*) addr - alignAddr);

     //ALOGI("%p/%zd --> %p/%zd", addr, length, alignAddr, alignLength);
     int prot = wantReadWrite ? (PROT_READ|PROT_WRITE) : (PROT_READ);
     if (mprotect(alignAddr, alignLength, prot) != 0) {
         int err = errno;
         ALOGV("mprotect (%p,%zd,%d) failed: %s",
             alignAddr, alignLength, prot, strerror(errno));
         return (errno != 0) ? errno : -1;
     }
 #endif

     /* for "fake" mapping, no need to do anything */
     return 0;
 }

 /*
  * Release a memory mapping.
  */
 void sysReleaseShmem(MemMapping* pMap)
 {
 #if !defined(__MINGW32__)
     if (pMap->baseAddr == NULL && pMap->baseLength == 0)
         return;

     if (munmap(pMap->baseAddr, pMap->baseLength) < 0) {
         ALOGW("munmap(%p, %zd) failed: %s",
             pMap->baseAddr, pMap->baseLength, strerror(errno));
     } else {
         ALOGV("munmap(%p, %zd) succeeded", pMap->baseAddr, pMap->baseLength);
         pMap->baseAddr = NULL;
         pMap->baseLength = 0;
     }
 #else
     /* Free the bits allocated by sysMapFileInShmem. */
     if (pMap->baseAddr != NULL) {
       free(pMap->baseAddr);
       pMap->baseAddr = NULL;
     }
     pMap->baseLength = 0;
 #endif
 }

 /*
  * Make a copy of a MemMapping.
  */
 void sysCopyMap(MemMapping* dst, const MemMapping* src)
 {
     memcpy(dst, src, sizeof(MemMapping));
 }

 /*
  * Write until all bytes have been written.
  *
  * Returns 0 on success, or an errno value on failure.
  */
 int sysWriteFully(int fd, const void* buf, size_t count, const char* logMsg)
 {
     while (count != 0) {
         ssize_t actual = TEMP_FAILURE_RETRY(write(fd, buf, count));
         if (actual < 0) {
             int err = errno;
             ALOGE("%s: write failed: %s", logMsg, strerror(err));
             return err;
         } else if (actual != (ssize_t) count) {
             ALOGD("%s: partial write (will retry): (%d of %zd)",
                 logMsg, (int) actual, count);
             buf = (const void*) (((const u1*) buf) + actual);
         }
         count -= actual;
     }

     return 0;
 }

 /* See documentation comment in header file. */
 int sysCopyFileToFile(int outFd, int inFd, size_t count)
 {
     const size_t kBufSize = 32768;
     unsigned char buf[kBufSize];

     while (count != 0) {
         size_t getSize = (count > kBufSize) ? kBufSize : count;

         ssize_t actual = TEMP_FAILURE_RETRY(read(inFd, buf, getSize));
         if (actual != (ssize_t) getSize) {
             ALOGW("sysCopyFileToFile: copy read failed (%d vs %zd)",
                 (int) actual, getSize);
             return -1;
         }

         if (sysWriteFully(outFd, buf, getSize, "sysCopyFileToFile") != 0)
             return -1;

         count -= getSize;
     }

     return 0;
 }
	/*
	* 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.
	*/

	/*
	* System utilities.
	*/
	#include "DexFile.h"
	#include "SysUtil.h"

	#include <stdlib.h>
	#include <stdio.h>
	#include <unistd.h>
	#include <string.h>
	#if !defined(__MINGW32__)
	# include <sys/mman.h>
	#endif
	#include <limits.h>
	#include <errno.h>

	#include <JNIHelp.h> // TEMP_FAILURE_RETRY may or may not be in unistd


	/*
	* Create an anonymous shared memory segment large enough to hold "length"
	* bytes. The actual segment may be larger because mmap() operates on
	* page boundaries (usually 4K).
	*/
	static void* sysCreateAnonShmem(size_t length)
	{
	#if !defined(__MINGW32__)
	void* ptr;

	ptr = mmap(NULL, length, PROT_READ \| PROT_WRITE,
	MAP_SHARED \| MAP_ANON, -1, 0);
	if (ptr == MAP_FAILED) {
	ALOGW("mmap(%d, RW, SHARED\|ANON) failed: %s", (int) length,
	strerror(errno));
	return NULL;
	}

	return ptr;
	#else
	ALOGE("sysCreateAnonShmem not implemented.");
	return NULL;
	#endif
	}

	/*
	* Create a private anonymous storage area.
	*/
	int sysCreatePrivateMap(size_t length, MemMapping* pMap)
	{
	void* memPtr;

	memPtr = sysCreateAnonShmem(length);
	if (memPtr == NULL)
	return -1;

	pMap->addr = pMap->baseAddr = memPtr;
	pMap->length = pMap->baseLength = length;
	return 0;
	}

	/*
	* Determine the current offset and remaining length of the open file.
	*/
	static int getFileStartAndLength(int fd, off_t start_, size_t length_)
	{
	off_t start, end;
	size_t length;

	assert(start_ != NULL);
	assert(length_ != NULL);

	start = lseek(fd, 0L, SEEK_CUR);
	end = lseek(fd, 0L, SEEK_END);
	(void) lseek(fd, start, SEEK_SET);

	if (start == (off_t) -1 \|\| end == (off_t) -1) {
	ALOGE("could not determine length of file");
	return -1;
	}

	length = end - start;
	if (length == 0) {
	ALOGE("file is empty");
	return -1;
	}

	*start_ = start;
	*length_ = length;

	return 0;
	}

	#if defined(__MINGW32__)
	int sysFakeMapFile(int fd, MemMapping* pMap)
	{
	/* No MMAP, just fake it by copying the bits.
	For Win32 we could use MapViewOfFile if really necessary
	(see libs/utils/FileMap.cpp).
	*/
	off_t start;
	size_t length;
	void* memPtr;

	assert(pMap != NULL);

	if (getFileStartAndLength(fd, &start, &length) < 0)
	return -1;

	memPtr = malloc(length);
	if (read(fd, memPtr, length) < 0) {
	ALOGW("read(fd=%d, start=%d, length=%d) failed: %s", (int) length,
	fd, (int) start, strerror(errno));
	return -1;
	}

	pMap->baseAddr = pMap->addr = memPtr;
	pMap->baseLength = pMap->length = length;

	return 0;
	}
	#endif

	/*
	* Map a file (from fd's current offset) into a private, read-write memory
	* segment that will be marked read-only (a/k/a "writable read-only"). The
	* file offset must be a multiple of the system page size.
	*
	* In some cases the mapping will be fully writable (e.g. for files on
	* FAT filesystems).
	*
	* On success, returns 0 and fills out "pMap". On failure, returns a nonzero
	* value and does not disturb "pMap".
	*/
	int sysMapFileInShmemWritableReadOnly(int fd, MemMapping* pMap)
	{
	#if !defined(__MINGW32__)
	off_t start;
	size_t length;
	void* memPtr;

	assert(pMap != NULL);

	if (getFileStartAndLength(fd, &start, &length) < 0)
	return -1;

	memPtr = mmap(NULL, length, PROT_READ \| PROT_WRITE, MAP_FILE \| MAP_PRIVATE,
	fd, start);
	if (memPtr == MAP_FAILED) {
	ALOGW("mmap(%d, R/W, FILE\|PRIVATE, %d, %d) failed: %s", (int) length,
	fd, (int) start, strerror(errno));
	return -1;
	}
	if (mprotect(memPtr, length, PROT_READ) < 0) {
	/* this fails with EACCESS on FAT filesystems, e.g. /sdcard */
	int err = errno;
	ALOGV("mprotect(%p, %zd, PROT_READ) failed: %s",
	memPtr, length, strerror(err));
	ALOGD("mprotect(RO) failed (%d), file will remain read-write", err);
	}

	pMap->baseAddr = pMap->addr = memPtr;
	pMap->baseLength = pMap->length = length;

	return 0;
	#else
	return sysFakeMapFile(fd, pMap);
	#endif
	}

	/*
	* Map part of a file into a shared, read-only memory segment. The "start"
	* offset is absolute, not relative.
	*
	* On success, returns 0 and fills out "pMap". On failure, returns a nonzero
	* value and does not disturb "pMap".
	*/
	int sysMapFileSegmentInShmem(int fd, off_t start, size_t length,
	MemMapping* pMap)
	{
	#if !defined(__MINGW32__)
	size_t actualLength;
	off_t actualStart;
	int adjust;
	void* memPtr;

	assert(pMap != NULL);

	/* adjust to be page-aligned */
	adjust = start % SYSTEM_PAGE_SIZE;
	actualStart = start - adjust;
	actualLength = length + adjust;

	memPtr = mmap(NULL, actualLength, PROT_READ, MAP_FILE \| MAP_SHARED,
	fd, actualStart);
	if (memPtr == MAP_FAILED) {
	ALOGW("mmap(%d, R, FILE\|SHARED, %d, %d) failed: %s",
	(int) actualLength, fd, (int) actualStart, strerror(errno));
	return -1;
	}

	pMap->baseAddr = memPtr;
	pMap->baseLength = actualLength;
	pMap->addr = (char*)memPtr + adjust;
	pMap->length = length;

	LOGVV("mmap seg (st=%d ln=%d): bp=%p bl=%d ad=%p ln=%d",
	(int) start, (int) length,
	pMap->baseAddr, (int) pMap->baseLength,
	pMap->addr, (int) pMap->length);

	return 0;
	#else
	ALOGE("sysMapFileSegmentInShmem not implemented.");
	return -1;
	#endif
	}

	/*
	* Change the access rights on one or more pages to read-only or read-write.
	*
	* Returns 0 on success.
	*/
	int sysChangeMapAccess(void* addr, size_t length, int wantReadWrite,
	MemMapping* pMap)
	{
	#if !defined(__MINGW32__)
	/*
	* Verify that "addr" is part of this mapping file.
	*/
	if (addr < pMap->baseAddr \|\|
	(u1)addr >= (u1)pMap->baseAddr + pMap->baseLength)
	{
	ALOGE("Attempted to change %p; map is %p - %p",
	addr, pMap->baseAddr, (u1*)pMap->baseAddr + pMap->baseLength);
	return -1;
	}

	/*
	* 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.)
	*/
	u1* alignAddr = (u1*) ((uintptr_t) addr & ~(SYSTEM_PAGE_SIZE-1));
	size_t alignLength = length + ((u1*) addr - alignAddr);

	//ALOGI("%p/%zd --> %p/%zd", addr, length, alignAddr, alignLength);
	int prot = wantReadWrite ? (PROT_READ\|PROT_WRITE) : (PROT_READ);
	if (mprotect(alignAddr, alignLength, prot) != 0) {
	int err = errno;
	ALOGV("mprotect (%p,%zd,%d) failed: %s",
	alignAddr, alignLength, prot, strerror(errno));
	return (errno != 0) ? errno : -1;
	}
	#endif

	/* for "fake" mapping, no need to do anything */
	return 0;
	}

	/*
	* Release a memory mapping.
	*/
	void sysReleaseShmem(MemMapping* pMap)
	{
	#if !defined(__MINGW32__)
	if (pMap->baseAddr == NULL && pMap->baseLength == 0)
	return;

	if (munmap(pMap->baseAddr, pMap->baseLength) < 0) {
	ALOGW("munmap(%p, %zd) failed: %s",
	pMap->baseAddr, pMap->baseLength, strerror(errno));
	} else {
	ALOGV("munmap(%p, %zd) succeeded", pMap->baseAddr, pMap->baseLength);
	pMap->baseAddr = NULL;
	pMap->baseLength = 0;
	}
	#else
	/* Free the bits allocated by sysMapFileInShmem. */
	if (pMap->baseAddr != NULL) {
	free(pMap->baseAddr);
	pMap->baseAddr = NULL;
	}
	pMap->baseLength = 0;
	#endif
	}

	/*
	* Make a copy of a MemMapping.
	*/
	void sysCopyMap(MemMapping* dst, const MemMapping* src)
	{
	memcpy(dst, src, sizeof(MemMapping));
	}

	/*
	* Write until all bytes have been written.
	*
	* Returns 0 on success, or an errno value on failure.
	*/
	int sysWriteFully(int fd, const void* buf, size_t count, const char* logMsg)
	{
	while (count != 0) {
	ssize_t actual = TEMP_FAILURE_RETRY(write(fd, buf, count));
	if (actual < 0) {
	int err = errno;
	ALOGE("%s: write failed: %s", logMsg, strerror(err));
	return err;
	} else if (actual != (ssize_t) count) {
	ALOGD("%s: partial write (will retry): (%d of %zd)",
	logMsg, (int) actual, count);
	buf = (const void) (((const u1) buf) + actual);
	}
	count -= actual;
	}

	return 0;
	}

	/* See documentation comment in header file. */
	int sysCopyFileToFile(int outFd, int inFd, size_t count)
	{
	const size_t kBufSize = 32768;
	unsigned char buf[kBufSize];

	while (count != 0) {
	size_t getSize = (count > kBufSize) ? kBufSize : count;

	ssize_t actual = TEMP_FAILURE_RETRY(read(inFd, buf, getSize));
	if (actual != (ssize_t) getSize) {
	ALOGW("sysCopyFileToFile: copy read failed (%d vs %zd)",
	(int) actual, getSize);
	return -1;
	}

	if (sysWriteFully(outFd, buf, getSize, "sysCopyFileToFile") != 0)
	return -1;

	count -= getSize;
	}

	return 0;
	}