bionic/libc/stdio/stdio_ext.cpp
Yabin Cui 76144aaa63 Change _stdio_handles_locking into _caller_handles_locking.
It is reported by tsan that funlockfile() can unlock an unlocked mutex.
It happens when printf() is called before fopen() or other stdio stuff.
As FLOCKFILE(fp) is called before __sinit(), _stdio_handles_locking is false,
and _FLOCK(fp) will not be locked. But then cantwrite(fp) in __vfprintf()
calls__sinit(), which makes _stdio_handles_locking become true, and
FUNLOCKFILE(fp) unlocks _FLOCK(fp).

Change _stdio_handles_locking into _caller_handles_locking,
so __sinit() won't change its value. Add test due to my previous fault.

Bug: 25392375
Change-Id: I483e3c3cdb28da65e62f1fd9615bf58c5403b4dd
2015-11-20 17:44:26 -08:00

106 lines
2.9 KiB
C++

/*
* Copyright (C) 2014 The Android Open Source Project
* All rights reserved.
*
* 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.
*/
#include <stdio_ext.h>
#include <stdlib.h>
#include "local.h"
#include "private/libc_logging.h"
size_t __fbufsize(FILE* fp) {
return fp->_bf._size;
}
/* For a _SRW stream, we don't know whether we last read or wrote.
int __freading(FILE* fp) {
return (fp->_flags & _SRD) != 0 || ...;
}
*/
/* For a _SRW stream, we don't know whether we last read or wrote.
int __fwriting(FILE*) {
return (fp->_flags & _SWR) != 0 || ...;
}
*/
int __freadable(FILE* fp) {
return (fp->_flags & (__SRD|__SRW)) != 0;
}
int __fwritable(FILE* fp) {
return (fp->_flags & (__SWR|__SRW)) != 0;
}
int __flbf(FILE* fp) {
return (fp->_flags & __SLBF) != 0;
}
void __fpurge(FILE* fp) {
fpurge(fp);
}
size_t __fpending(FILE* fp) {
return fp->_p - fp->_bf._base;
}
void _flushlbf() {
// If we flush all streams, we know we've flushed all the line-buffered streams.
fflush(NULL);
}
int __fsetlocking(FILE* fp, int type) {
int old_state = _EXT(fp)->_caller_handles_locking ? FSETLOCKING_BYCALLER : FSETLOCKING_INTERNAL;
if (type == FSETLOCKING_QUERY) {
return old_state;
}
if (type != FSETLOCKING_INTERNAL && type != FSETLOCKING_BYCALLER) {
// The API doesn't let us report an error, so blow up.
__libc_fatal("Bad type (%d) passed to __fsetlocking", type);
}
_EXT(fp)->_caller_handles_locking = (type == FSETLOCKING_BYCALLER);
return old_state;
}
void clearerr_unlocked(FILE* fp) {
return __sclearerr(fp);
}
int feof_unlocked(FILE* fp) {
return __sfeof(fp);
}
int ferror_unlocked(FILE* fp) {
return __sferror(fp);
}
int fileno_unlocked(FILE* fp) {
return __sfileno(fp);
}