[Python-checkins] r61652 - in python/trunk: Doc/library/fcntl.rst Lib/test/test_fcntl.py Modules/fcntlmodule.c
gregory.p.smith
python-checkins at python.org
Thu Mar 20 00:03:26 CET 2008
Author: gregory.p.smith
Date: Thu Mar 20 00:03:25 2008
New Revision: 61652
Modified:
python/trunk/Doc/library/fcntl.rst
python/trunk/Lib/test/test_fcntl.py
python/trunk/Modules/fcntlmodule.c
Log:
Prevent ioctl op codes from being sign extended from int to unsigned long
when used on platforms that actually define ioctl as taking an unsigned long.
(the BSDs and OS X / Darwin)
Adds a unittest for fcntl.ioctl that tests what happens with both positive and
negative numbers.
This was done because of issue1471 but I'm not able to reproduce -that- problem
in the first place on Linux 32bit or 64bit or OS X 10.4 & 10.5 32bit or 64 bit.
Modified: python/trunk/Doc/library/fcntl.rst
==============================================================================
--- python/trunk/Doc/library/fcntl.rst (original)
+++ python/trunk/Doc/library/fcntl.rst Thu Mar 20 00:03:25 2008
@@ -50,6 +50,8 @@
operations are typically defined in the library module :mod:`termios` and the
argument handling is even more complicated.
+ The op parameter is limited to values that can fit in 32-bits.
+
The parameter *arg* can be one of an integer, absent (treated identically to the
integer ``0``), an object supporting the read-only buffer interface (most likely
a plain Python string) or an object supporting the read-write buffer interface.
Modified: python/trunk/Lib/test/test_fcntl.py
==============================================================================
--- python/trunk/Lib/test/test_fcntl.py (original)
+++ python/trunk/Lib/test/test_fcntl.py Thu Mar 20 00:03:25 2008
@@ -5,12 +5,18 @@
"""
import struct
import fcntl
-import os, sys
+import os
+import struct
+import sys
import unittest
from test.test_support import verbose, TESTFN, unlink, run_unittest
# TODO - Write tests for ioctl(), flock() and lockf().
+try:
+ import termios
+except ImportError:
+ termios = None
def get_lockdata():
if sys.platform.startswith('atheos'):
@@ -82,8 +88,29 @@
self.f.close()
+class TestIoctl(unittest.TestCase):
+ if termios:
+ def test_ioctl_signed_unsigned_code_param(self):
+ if termios.TIOCSWINSZ < 0:
+ set_winsz_opcode_maybe_neg = termios.TIOCSWINSZ
+ set_winsz_opcode_pos = termios.TIOCSWINSZ & 0xffffffffL
+ else:
+ set_winsz_opcode_pos = termios.TIOCSWINSZ
+ set_winsz_opcode_maybe_neg, = struct.unpack("i",
+ struct.pack("I", termios.TIOCSWINSZ))
+
+ # We're just testing that these calls do not raise exceptions.
+ saved_winsz = fcntl.ioctl(0, termios.TIOCGWINSZ, "\0"*8)
+ our_winsz = struct.pack("HHHH",80,25,0,0)
+ # test both with a positive and potentially negative ioctl code
+ new_winsz = fcntl.ioctl(0, set_winsz_opcode_pos, our_winsz)
+ new_winsz = fcntl.ioctl(0, set_winsz_opcode_maybe_neg, our_winsz)
+ fcntl.ioctl(0, set_winsz_opcode_maybe_neg, saved_winsz)
+
+
def test_main():
run_unittest(TestFcntl)
+ run_unittest(TestIoctl)
if __name__ == '__main__':
test_main()
Modified: python/trunk/Modules/fcntlmodule.c
==============================================================================
--- python/trunk/Modules/fcntlmodule.c (original)
+++ python/trunk/Modules/fcntlmodule.c Thu Mar 20 00:03:25 2008
@@ -97,11 +97,20 @@
{
#define IOCTL_BUFSZ 1024
int fd;
- /* In PyArg_ParseTuple below, use the unsigned int 'I' format for
- the signed int 'code' variable, because Python turns 0x8000000
- into a large positive number (PyLong, or PyInt on 64-bit
- platforms,) whereas C expects it to be a negative int */
- int code;
+ /* In PyArg_ParseTuple below, we use the unsigned non-checked 'I'
+ format for the 'code' parameter because Python turns 0x8000000
+ into either a large positive number (PyLong or PyInt on 64-bit
+ platforms) or a negative number on others (32-bit PyInt)
+ whereas the system expects it to be a 32bit bit field value
+ regardless of it being passed as an int or unsigned long on
+ various platforms. See the termios.TIOCSWINSZ constant across
+ platforms for an example of thise.
+
+ If any of the 64bit platforms ever decide to use more than 32bits
+ in their unsigned long ioctl codes this will break and need
+ special casing based on the platform being built on.
+ */
+ unsigned int code;
int arg;
int ret;
char *str;
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