* libs/libc/misc/lib_fdsan.c
*
* SPDX-License-Identifier: BSD-2-Clause
* SPDX-FileCopyrightText: 2018 The Android Open Source Project
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
****************************************************************************/
* Included Files
****************************************************************************/
#include <android/fdsan.h>
#include <debug.h>
#include <pthread.h>
#include <stdio.h>
#include <setjmp.h>
#include <assert.h>
#include <sys/ioctl.h>
* Private Functions
****************************************************************************/
uint64_t android_fdsan_get_tag_value(uint64_t tag)
{
return (uint64_t)((int64_t)(tag << 8) >> 8);
}
const char *android_fdsan_get_tag_type(uint64_t tag)
{
uint64_t high_bits;
uint64_t type = tag >> 56;
switch (type)
{
case ANDROID_FDSAN_OWNER_TYPE_FILE:
return "FILE*";
case ANDROID_FDSAN_OWNER_TYPE_DIR:
return "DIR*";
case ANDROID_FDSAN_OWNER_TYPE_UNIQUE_FD:
return "unique_fd";
case ANDROID_FDSAN_OWNER_TYPE_FILEINPUTSTREAM:
return "FileInputStream";
case ANDROID_FDSAN_OWNER_TYPE_FILEOUTPUTSTREAM:
return "FileOutputStream";
case ANDROID_FDSAN_OWNER_TYPE_RANDOMACCESSFILE:
return "RandomAccessFile";
case ANDROID_FDSAN_OWNER_TYPE_PARCELFILEDESCRIPTOR:
return "ParcelFileDescriptor";
case ANDROID_FDSAN_OWNER_TYPE_SQLITE:
return "sqlite";
case ANDROID_FDSAN_OWNER_TYPE_ART_FDFILE:
return "ART FdFile";
case ANDROID_FDSAN_OWNER_TYPE_DATAGRAMSOCKETIMPL:
return "DatagramSocketImpl";
case ANDROID_FDSAN_OWNER_TYPE_SOCKETIMPL:
return "SocketImpl";
case ANDROID_FDSAN_OWNER_TYPE_ZIPARCHIVE:
return "ZipArchive";
case ANDROID_FDSAN_OWNER_TYPE_GENERIC_00:
default:
return "native object of unknown type";
case ANDROID_FDSAN_OWNER_TYPE_GENERIC_FF:
* If bits 48 to 56 are set,
* this is a sign-extended generic native pointer
********************************************************************/
high_bits = tag >> 48;
if (high_bits == (1 << 16) - 1)
{
return "native object of unknown type";
}
return "Java object of unknown type";
}
}
* Public Functions
****************************************************************************/
uint64_t android_fdsan_create_owner_tag(android_fdsan_owner_type_t type,
uint64_t tag)
{
uint64_t result;
uint64_t mask;
if (tag == 0)
{
return 0;
}
DEBUGASSERT((type & 0xff) == type);
result = (uint64_t)(type) << 56;
mask = ((uint64_t)1 << 56) - 1;
result |= tag & mask;
return result;
}
int android_fdsan_close_with_tag(int fd, uint64_t expected_tag)
{
int ret;
android_fdsan_exchange_owner_tag(fd, expected_tag, 0);
ret = close(fd);
* If we were expecting to close with a tag, abort on EBADF.
**************************************************************************/
if (expected_tag && ret == -1 && get_errno() == EBADF)
{
ferr("double-close of file descriptor %d detected\n", fd);
PANIC();
}
return ret;
}
void android_fdsan_exchange_owner_tag(int fd, uint64_t expected_tag,
uint64_t new_tag)
{
uint64_t tag;
int ret;
ret = ioctl(fd, FIOC_GETTAG_FDSAN, &tag);
if (ret < 0)
{
return;
}
if (tag == expected_tag)
{
ret = ioctl(fd, FIOC_SETTAG_FDSAN, &new_tag);
DEBUGASSERT(ret == 0);
}
else
{
if (expected_tag && tag)
{
ferr("failed to exchange ownership of file descriptor: fd %d is "
"owned by %s 0x%" PRIx64 ", was expected"
"to be owned by %s 0x%" PRIx64 "\n",
fd, android_fdsan_get_tag_type(tag),
android_fdsan_get_tag_value(tag),
android_fdsan_get_tag_type(expected_tag),
android_fdsan_get_tag_value(expected_tag));
PANIC();
}
else if (expected_tag && !tag)
{
ferr("failed to exchange ownership of file descriptor: fd %d is "
"unowned, was expected to be owned by %s 0x%" PRIx64 "\n",
fd, android_fdsan_get_tag_type(expected_tag),
android_fdsan_get_tag_value(expected_tag));
PANIC();
}
else if (!expected_tag && tag)
{
ferr("failed to exchange ownership of file descriptor: fd %d is "
"owned by %s 0x%" PRIx64 ", was expected to be unowned\n",
fd, android_fdsan_get_tag_type(tag),
android_fdsan_get_tag_value(tag));
PANIC();
}
else if (!expected_tag && !tag)
{
* This should never happen: our CAS failed,
* but expected == actual?
******************************************************************/
ferr("fdsan atomic_cmpxchg failed unexpectedly "
"while exchanging owner tag\n");
PANIC();
}
}
}