fcntl_ioctl still not 100% sane with unsigned longs

[ngie-eign]

BPO	16124
Nosy	@loewis, @gpshead, @tpn, @ngie-eign, @asvetlov, @serhiy-storchaka
Files	python-issue16124.patch python-issue16124.patch python-issue16124.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2012-10-04.03:46:54.896>
labels = ['extension-modules', 'type-bug']
title = 'fcntl_ioctl still not 100% sane with unsigned longs'
updated_at = <Date 2015-02-15.10:00:39.805>
user = 'https://github.com/ngie-eign'

bugs.python.org fields:

activity = <Date 2015-02-15.10:00:39.805>
actor = 'ngie'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Extension Modules']
creation = <Date 2012-10-04.03:46:54.896>
creator = 'ngie'
dependencies = []
files = ['27952', '27954', '27955']
hgrepos = []
issue_num = 16124
keywords = ['patch']
message_count = 11.0
messages = ['171918', '172112', '175348', '175354', '175355', '175356', '175357', '175358', '236030', '236031', '236032']
nosy_count = 6.0
nosy_names = ['loewis', 'gregory.p.smith', 'trent', 'ngie', 'asvetlov', 'serhiy.storchaka']
pr_nums = []
priority = 'normal'
resolution = None
stage = 'test needed'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue16124'
versions = ['Python 2.7', 'Python 3.4', 'Python 3.5']

[ngie-eign]

As discussed in ID bpo-1471, the type for request is not 100% correct on some platforms (FreeBSD, NetBSD, and OpenBSD, for instance) and the custom platform that I'm using unfortunately uses non-32-bit int ioctls. An autoconf test needs to be added for these platforms and the request parameter needs to be handled properly (I'll take charge of doing that).

[asvetlov]

Is it affected for 3.3 and 3.4 also?

[ngie-eign]

Yes. Submitting a patch to fix this based on hg master shortly..

[ngie-eign]

$ uname -a
FreeBSD bayonetta.local 9.1-PRERELEASE FreeBSD 9.1-PRERELEASE #0 r240836M: Sat Sep 22 12:30:11 PDT 2012     gcooper@bayonetta.local:/usr/obj/store/freebsd/stable/9/sys/BAYONETTA  amd64
$ ./configure --prefix=/scratch/python-bin/3k/
...
$ make all; make install
...
$ /scratch/python-bin/3k/bin/python3 Lib/test/test_ioctl.py
test_ioctl (__main__.IoctlTests) ... ok
test_ioctl_mutate (__main__.IoctlTests) ... ok
test_ioctl_mutate_1024 (__main__.IoctlTests) ... ok
test_ioctl_mutate_2048 (__main__.IoctlTests) ... ok
test_ioctl_signed_unsigned_code_param (__main__.IoctlTests) ... ok

---

Ran 5 tests in 0.003s

OK

[ngie-eign]

Sorry; previous patch is not applicable to this issue. This one is.

[ngie-eign]

And I missed the int -> unsigned int part. Resubmitting one last time for tonight..

[ngie-eign]

Grr... Let's try again.

[ngie-eign]

... g'night.

[serhiy-storchaka]

This looks as a duplicate of bpo-521723 and bpo-1471. Do you have tests that demonstrate a failure with using ioctl on OpenBSD? May be there are problems on 64-bit big-endian platforms (or even on 64-bit little-endian if additional parameters are passed to ioctl).

[ngie-eign]

Yes, it's a duplicate. That being said, documentation alone it should be unsigned long for Darwin (OS/X), FreeBSD, OpenBSD. Looking at the definition for ioctl(2), the below example would cause a failure.

I need to hunt around for a practical example as I don't have one offhand (it's something that was found a long time ago in a couple of python 2.6 at my current employer because they have ioctl's that go beyond the 32-bit boundary IIRC...)

fuji:~ ngie$ clang -Wall -c test_ioctl.c
fuji:~ ngie$ clang -DBROKEN -Wall -c test_ioctl.c
test_ioctl.c:9:9: warning: incompatible pointer types initializing 'ioctl_t'
      (aka 'int (*)(int, int, ...)') with an expression of type 'int (int,
      unsigned long, ...)' [-Wincompatible-pointer-types]
ioctl_t _ioctl = ioctl;
        ^        ~~~~~
1 warning generated.
fuji:~ ngie$ cat test_ioctl.c 
#include <sys/ioctl.h>

#ifdef BROKEN
typedef int (*ioctl_t)(int, int, ...);
#else
typedef int (*ioctl_t)(int, unsigned long, ...);
#endif

ioctl_t _ioctl = ioctl;
fuji:~ ngie$ uname -a
Darwin fuji.local 13.4.0 Darwin Kernel Version 13.4.0: Wed Dec 17 19:05:52 PST 2014; root:xnu-2422.115.10~1/RELEASE_X86_64 x86_64

[ngie-eign]

Another note: mixed endianness might have been a factor as previous versions of the product that were shipped used bi-arch x86 (32-bit userland on 64-bit kernel.

[serhiy-storchaka]

This was fixed in #69214. The documentation will be updated in #132742.