ID: 39648
Updated by: [EMAIL PROTECTED]
Reported By: wharmby at uk dot ibm dot com
-Status: Open
+Status: Assigned
Bug Type: Unknown/Other Function
Operating System: Linux RHEL4
PHP Version: 5CVS-2006-11-27 (snap)
-Assigned To:
+Assigned To: iliaa
Previous Comments:
------------------------------------------------------------------------
[2006-11-27 17:05:42] wharmby at uk dot ibm dot com
Description:
------------
The current implementation of the chown() and chgrp()
functions on Linux use the non-reentrant getpwnam() and
getgrnam() C library calls respectively rather than the
reentrant getpwnam_r() and getgrnam_r(). Therefore using
either chown() or chgrp() on Linux in a ZTS enabled build
could lead to unpredictable/undesirable results.
The following patch, which was built against the latest snapshot (Nov
27th, 2006, 0730 GMT) modifies the code in
ext/standard/filestat.c to use the reentrant versions of
these functions and so make these 2 functions thread safe:
http://pastebin.ca/259657
However, I am concerned that this patch relies on the C
library supporting the POSIX.1 functions getpwnam_r(),
getgrnam_r() and sysconf(). These are all implemented by
GNU libc but are there other C libraries used to build PHP
which may not have the necessary support ? Or is it
reasonable to assume that all C libraries used when buiding
PHP will be POSIX.1 compliant ?
N.B There are other uses of these non-reentrant functions in
the PHP code base (e.g posix.c and fopen_wrappers.c) and I
m happy to produce the necessary patches to fix these uses
if this fix proves satisfactory.
Andy Wharmby
IBM United Kingdom Limited
Reproduce code:
---------------
---------------
Problem found by code inspection. As with most thread safety issues
difficult to produce a simple testcase which will show a reproducible
crash but current Linux executable is clearly
not reentrant.
Expected result:
----------------
N/A
Actual result:
--------------
N/A
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Edit this bug report at http://bugs.php.net/?id=39648&edit=1
