[RFA]: race safe fwalk
Tue Mar 9 21:30:00 GMT 2004
This time with attachment.
There is a possible race between fwalk and fopen:
When a thread make a call to fopen the FILE * _flags will be set to 1 in
findfp to mark it used and later it will be changed to the real FILE flag.
When another thread calls fwalk during that time fwalk will treat the
FILE as already opened and calls the callback functions with the yet
unopened and only partially initialized FILE *.
This can be avoided by checking for fp->_flags != 0 && fp->_flags != 1.
Since _flags is signed short i did not check for _flags > 1. The flag
should be set as the last step in an open call.
I do not think that 1 is a valid _flag for an open file. Correct me if
2004-03-08 Thomas Pfaff <firstname.lastname@example.org>
* libc/stdio/fdopen.c (_fdopen_r): Add missing
Set FILE flags as the last step.
* libc/stdio/fopen.c (_fopen_r): Set FILE flags as the last
* libc/stdio/fwalk.c: Check for _flags != 1 to make sure that
file is really open.
* libc/stdio64/fdopen64.c (_fdopen64_r): Set FILE flags as the
* libc/stdio64/fopen64.c (_fopen64_r): Ditto.
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