Re: [Python-Dev] Include ctypes into core Python?
James Y Knight [EMAIL PROTECTED] writes: On Jan 19, 2006, at 4:24 PM, Thomas Heller wrote: Several of these files are licensed under GPL: aclocal.m4 config-ml.in config.guess config.sub depcomp ltcf-c.sh ltconfig missing Are you sure? The copies of aclocal.m4 and config-ml.in both disagree with you. aclocal seems to have a completely liberal license, and config-ml has a whatever the license of the program it's building license. It seems you are right: config-ml.in: GPL with special exception. config.guess: GPL with special exception. config.sub: GPL with special exception. configure: no limitation depcomp: GPL with special exception. install-sh: X-11 license ltcf-c.sh:GPL with special exception. ltconfig: GPL with special exception. ltmain.sh:GPL with special exception. aclocal.m4: see below Is aclocal.m4 an exception? It has several copyright notices. The first one gives unlimited permissions to copy and/or distribute, but sections after that have no exception clause. I'm unsure what this means. The files that ctypes uses are in CVS here: http://cvs.sourceforge.net/viewcvs.py/ctypes/ctypes/source/gcc/libffi/?only_with_tag=branch_1_0 Thomas ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Thomas Heller wrote: Is it a problem to have these files in the Python source code? I would think so, yes. Including them in the Python distribution, without licensing the entire Python distribution under GPL, would be a GPL violation. The actual libffi appears to have a fairly liberal license (also it still requires to include the LICENSE file, atleast in the source distribution). Importing the original source in /external would be no problem (AFAICT), as long as you then delete them during/after the svn cp. Maybe it would be possible to reimplement the functionality in the setup.py script, but this is way beyond my expertise. Right. Given the large number of people that want to see this happen (not necessarily on python-dev, but on comp.lang.python), I'm sure there is somebody who can come up with a build process. If nobody volunteers to do the actual work, I have no problems with dropping the idea for now. I wouldn't have any problems with just including a Windows port, either. Regards, Martin ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On Jan 19, 2006, at 4:24 PM, Thomas Heller wrote: Several of these files are licensed under GPL: aclocal.m4 config-ml.in config.guess config.sub depcomp ltcf-c.sh ltconfig missing Are you sure? The copies of aclocal.m4 and config-ml.in both disagree with you. aclocal seems to have a completely liberal license, and config-ml has a whatever the license of the program it's building license. James aclocal.m4:: # generated automatically by aclocal 1.7.3 -*- Autoconf -*- # Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002 # Free Software Foundation, Inc. # This file is free software; the Free Software Foundation # gives unlimited permission to copy and/or distribute it, # with or without modifications, as long as this notice is preserved. # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY, to the extent permitted by law; without # even the implied warranty of MERCHANTABILITY or FITNESS FOR A # PARTICULAR PURPOSE. # libtool.m4 - Configure libtool for the host system. -*-Autoconf-*- config-ml.in:: # Configure fragment invoked in the post-target section for subdirs # wanting multilib support. # # Copyright (C) 1995, 1997, 1998, 1999, 2000, 2001, 2002, 2003 # Free Software Foundation, Inc. # # This file is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 59 Temple Place - Suite 330, # Boston, MA 02111-1307, USA. # # As a special exception to the GNU General Public License, if you # distribute this file as part of a program that contains a # configuration script generated by Autoconf, you may include it under # the same distribution terms that you use for the rest of that program. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Martin v. Löwis [EMAIL PROTECTED] writes: Guido van Rossum wrote: On 1/16/06, Thomas Heller [EMAIL PROTECTED] wrote: It looks like we need a pronouncement now. Sorry. It appeared to me that there was general agreement to using a strongly worded warning in the docs, so I tuned out of the rest of the discussion. So for the record, I'm fine with that. Ok. If Thomas checks in the code and the documentation, I'll do the Windows/setup part of it. Great. Now, I'm trying to build ctypes on OS X as the first non-windows platform. As I said, ctypes currently has its own source copy of libffi (since there are no separate releases of libffi, and the only platform that comes with libffi by default that I know is cygwin). It is built into a static non-shared library with a call to configure like this: cd build_dir src_dir/configure --disable-shared --enable-static \ --enable-multilib=no --prefix=inst_dir make install then libffi.a is linked into the _ctypes extension module. I know near to nothing about 'configure', can/should a call to os.system with the commands above be added to setup.py, or how could this be approached? Thomas ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Martin v. Löwis [EMAIL PROTECTED] writes: Guido van Rossum wrote: On the other hand it breaks one of the most fundamental Python guidelines: if you get a core dump (segfault etc.) it's a bug in Python or in a 3rd party extension, not in *your* Python code. An exception would have to be made for any code that uses ctypes, as it is usually trivial to cause core dumps with ctypes (I'd venture it's hard to avoid them ;-). I don't expect this to count against including ctypes; but I do want it to be dealt with somehow! I think the strongest point *for* ctypes is the inclusion of dl in the source distribution, which has the very same flaws as ctypes in terms of crashability. So as for dealing with it somehow: I would make ctypes a dynamically loaded module (ctypes.pyd), so administrators could remove it, and I could also make it a separate option in the Windows installer, so administrators could reject to install it. It looks like we need a pronouncement now. Thomas ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Thomas Heller [EMAIL PROTECTED] writes: It looks like we need a pronouncement now. +1 I am a lurker in this list. I maintain ctypes for Debian and I would love to see it in core python. Debian now includes ctypes for 10 Linux architectures and kFreeBSD. The only missing significant architecture is ARM because of lack of FFI support. Ganesan -- Ganesan Rajagopal (rganesan at debian.org) | GPG Key: 1024D/5D8C12EA Web: http://employees.org/~rganesan| http://rganesan.blogspot.com ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On 1/16/06, Thomas Heller [EMAIL PROTECTED] wrote: It looks like we need a pronouncement now. Sorry. It appeared to me that there was general agreement to using a strongly worded warning in the docs, so I tuned out of the rest of the discussion. So for the record, I'm fine with that. -- --Guido van Rossum (home page: http://www.python.org/~guido/) ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Guido van Rossum wrote: On 1/16/06, Thomas Heller [EMAIL PROTECTED] wrote: It looks like we need a pronouncement now. Sorry. It appeared to me that there was general agreement to using a strongly worded warning in the docs, so I tuned out of the rest of the discussion. So for the record, I'm fine with that. Ok. If Thomas checks in the code and the documentation, I'll do the Windows/setup part of it. Regards, Martin ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Delaney, Timothy (Tim) [EMAIL PROTECTED] writes: Martin v. Löwis wrote: So as for dealing with it somehow: I would make ctypes a dynamically loaded module (ctypes.pyd), so administrators could remove it, and I could also make it a separate option in the Windows installer, so administrators could reject to install it. I like this solution. Of course, Thomas (author of both py2exe and ctypes) may like the ability to have ctypes built into python.dll ... It is getting offtopic, but I don't care too much about that. I requested that zlib be changed to a builtin module too allow easier bootstrapping of py2exe'd apps which have a compressed library archive. The nearly only reason for me to implement the single-file option for py2exe was that the implementation simulates a static linked Python-dll, which allows for several totally-isolated interpreters in the same process. Thomas ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Martin v. Löwis [EMAIL PROTECTED] writes: Guido van Rossum wrote: On the other hand it breaks one of the most fundamental Python guidelines: if you get a core dump (segfault etc.) it's a bug in Python or in a 3rd party extension, not in *your* Python code. An exception would have to be made for any code that uses ctypes, as it is usually trivial to cause core dumps with ctypes (I'd venture it's hard to avoid them ;-). I don't expect this to count against including ctypes; but I do want it to be dealt with somehow! I think the strongest point *for* ctypes is the inclusion of dl in the source distribution, which has the very same flaws as ctypes in terms of crashability. So as for dealing with it somehow: I would make ctypes a dynamically loaded module (ctypes.pyd), so administrators could remove it, and I could also make it a separate option in the Windows installer, so administrators could reject to install it. Sounds good, although it should be noted that ctypes is a package now, with a ctypes.wrap subpackage (contains the code generator), a ctypes.macholib subpackage (contains Bob Ippolitos macholib for OS X), and ctypes.test subpackage whcih contains several test modules. Plus the _ctypes.(dll|so) extension module. Thomas ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Thomas Heller wrote: Sounds good, although it should be noted that ctypes is a package now, with a ctypes.wrap subpackage (contains the code generator), a ctypes.macholib subpackage (contains Bob Ippolitos macholib for OS X), and ctypes.test subpackage whcih contains several test modules. Plus the _ctypes.(dll|so) extension module. Ok. The installer should then combine them all into a feature. Still, the admin could disable all of this just by removing _ctypes.dll, right? Regards, Martin ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Martin v. Löwis [EMAIL PROTECTED] writes: Thomas Heller wrote: Sounds good, although it should be noted that ctypes is a package now, with a ctypes.wrap subpackage (contains the code generator), a ctypes.macholib subpackage (contains Bob Ippolitos macholib for OS X), and ctypes.test subpackage whcih contains several test modules. Plus the _ctypes.(dll|so) extension module. Ok. The installer should then combine them all into a feature. Still, the admin could disable all of this just by removing _ctypes.dll, right? Right. Thomas ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On Wed, 2006-01-11 at 07:59 +0100, Thomas Heller wrote: Another possibility would be to emit a warning when the module (dl or ctypes, if included) is imported. warnings.warn(Incorrect usage of this module may crash Python, RuntimeWarning, stacklevel=2) BTW, although I'm pretty sure the answer is no (at least, I hope it is), is anyone aware of a situation where the mere importation of a module can cause Python to crash? -Barry signature.asc Description: This is a digitally signed message part ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On Wed, Jan 11, 2006 at 07:59:50AM -0500, Barry Warsaw wrote: BTW, although I'm pretty sure the answer is no (at least, I hope it is), is anyone aware of a situation where the mere importation of a module can cause Python to crash? Well, I assume you aren't importing any 'hostile' code, nor running in an uncontrolled environment so I guess you mean other than running out of memory, or the module you are importing actually executing one of the ways to crash Python? Or the module being an extension module that crashes on import? Or another extension module having corrupted the Python environment to a point where a simple import crashes Python? Or a non-extension module using one of the vulnerabilities (in, say, marshal, or pickle) to corrupt the Python environment? Or stuff in os.environ, like LD_* variables, that interfere with library linking? Ponder, ponder, no, can't think of any. :) The pickle vulnerability came up last year, when someone on #python was subclassing a builtin type (string or dict, I think the latter) that was using a magical invocation of (IIRC) __new__ on unpickle. The subclassed __new__ didn't handle this right, so the baseclass __new__ wasn't getting called right, and the new object's addressspace was not initialized. This lead to crashes. I don't remember the details exactly, and my continuous advice of not subclassing builtin types unless you know what you're doing solved the issue (there was no actual need to subclass, there), and I have no idea whether that specific issue was solved or not, but I'm trying to find it again :) -- Thomas Wouters [EMAIL PROTECTED] Hi! I'm a .signature virus! copy me into your .signature file to help me spread! ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On Wed, 2006-01-11 at 14:54 +0100, Thomas Wouters wrote: On Wed, Jan 11, 2006 at 07:59:50AM -0500, Barry Warsaw wrote: BTW, although I'm pretty sure the answer is no (at least, I hope it is), is anyone aware of a situation where the mere importation of a module can cause Python to crash? Well, I assume you aren't importing any 'hostile' code, nor running in an uncontrolled environment so I guess you mean other than running out of memory, or the module you are importing actually executing one of the ways to crash Python? Correct. Or the module being an extension module that crashes on import? Or another extension module having corrupted the Python environment to a point where a simple import crashes Python? Or a non-extension module using one of the vulnerabilities (in, say, marshal, or pickle) to corrupt the Python environment? Or stuff in os.environ, like LD_* variables, that interfere with library linking? Ponder, ponder, no, can't think of any. :) Let's keep it to modules in the standard library, although that includes extension modules, and let's further say that it's a controlled enough environment that you won't have stray evil modules floating around in your sys.path. The pickle vulnerability came up last year, when someone on #python was subclassing a builtin type (string or dict, I think the latter) that was using a magical invocation of (IIRC) __new__ on unpickle. The subclassed __new__ didn't handle this right, so the baseclass __new__ wasn't getting called right, and the new object's addressspace was not initialized. This lead to crashes. I don't remember the details exactly, and my continuous advice of not subclassing builtin types unless you know what you're doing solved the issue (there was no actual need to subclass, there), and I have no idea whether that specific issue was solved or not, but I'm trying to find it again :) -Barry signature.asc Description: This is a digitally signed message part ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Guido van Rossum [EMAIL PROTECTED] writes: On 1/10/06, Thomas Wouters [EMAIL PROTECTED] wrote: Sorry, I missed the point I was aiming at, I guess. I wasn't aiming for fixable bugs; I see these things as, with great effort, holding up your foot at an awkward angle so that it ends up right at the business end of your primed and lit medieval cannon. We can jump through hoops to stop those particular examples, but I'd rather spend time and effort to fix *real* bugs instead. I'm not sure what makes those particular examples less than real bugs. I think the sys.setrecursionlimit(130) one is fairly well into the terriotory of don't do that, isn't it? Cheers, mwh -- exarkun today's lesson exarkun don't strace X in an xterm -- from Twisted.Quotes ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On Wed, Jan 11, 2006 at 02:54:40PM +0100, Thomas Wouters wrote: The pickle vulnerability came up last year, when someone on #python was subclassing a builtin type (string or dict, I think the latter) that was using a magical invocation of (IIRC) __new__ on unpickle. The subclassed __new__ didn't handle this right, so the baseclass __new__ wasn't getting called right, and the new object's addressspace was not initialized. This lead to crashes. I don't remember the details exactly, and my continuous advice of not subclassing builtin types unless you know what you're doing solved the issue (there was no actual need to subclass, there), and I have no idea whether that specific issue was solved or not, but I'm trying to find it again :) Ah, found it: it was one of the datetime types. It has guards in place (some back then, python2.3, more since 2.4) so I wasn't able to figure out why it actually crashed Python, rather than produce a weird date. I couldn't find anything obviously wrong with the data's handling (although the extra guards are good.) I'll see if I can reproduce it anyway. -- Thomas Wouters [EMAIL PROTECTED] Hi! I'm a .signature virus! copy me into your .signature file to help me spread! ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On 11-jan-2006, at 7:59, Thomas Heller wrote: I'm of the opinion that having a big red warning at the top of the module documentation that this is a contributed module, and incorrect use could cause segmentation faults/crashes, etc would be sufficient. Works for me. Another possibility would be to emit a warning when the module (dl or ctypes, if included) is imported. warnings.warn(Incorrect usage of this module may crash Python, RuntimeWarning, stacklevel=2) Yuck. Just adding a warning to the documentation should be good enough. Other modules allow you to make your machine unuseable (such a fork bomb using os.fork) and those don't warn either. Ronald Thomas ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/ ronaldoussoren%40mac.com ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On Wed, Jan 11, 2006 at 07:59:03AM +0100, Thomas Heller wrote: Another possibility would be to emit a warning when the module (dl or ctypes, if included) is imported. warnings.warn(Incorrect usage of this module may crash Python, RuntimeWarning, stacklevel=2) Arrgggh! No!! Warnings are one of the things I really hate about perl and I'd hate to see them infecting python any more than they already have. I want my programming language to tell me, the programmer, about stuff not go blurting to the user behind my back. Death to warnings ;-) (Yes I know about the warnings module!) -- Nick Craig-Wood [EMAIL PROTECTED] -- http://www.craig-wood.com/nick ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Martin v. Löwis wrote: So as for dealing with it somehow: I would make ctypes a dynamically loaded module (ctypes.pyd), so administrators could remove it, and I could also make it a separate option in the Windows installer, so administrators could reject to install it. I like this solution. Of course, Thomas (author of both py2exe and ctypes) may like the ability to have ctypes built into python.dll ... Tim Delaney ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On 1/10/06, Thomas Heller [EMAIL PROTECTED] wrote: I would like to suggest to include ctypes into core Python, starting with the 2.5 release. On the one hand I agree that this is a useful module, popular, mature etc. On the other hand it breaks one of the most fundamental Python guidelines: if you get a core dump (segfault etc.) it's a bug in Python or in a 3rd party extension, not in *your* Python code. An exception would have to be made for any code that uses ctypes, as it is usually trivial to cause core dumps with ctypes (I'd venture it's hard to avoid them ;-). I don't expect this to count against including ctypes; but I do want it to be dealt with somehow! -- --Guido van Rossum (home page: http://www.python.org/~guido/) ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Guido van Rossum wrote: On 1/10/06, Thomas Heller [EMAIL PROTECTED] wrote: I would like to suggest to include ctypes into core Python, starting with the 2.5 release. On the one hand I agree that this is a useful module, popular, mature etc. On the other hand it breaks one of the most fundamental Python guidelines: if you get a core dump (segfault etc.) it's a bug in Python or in a 3rd party extension, not in *your* Python code. An exception would have to be made for any code that uses ctypes, as it is usually trivial to cause core dumps with ctypes (I'd venture it's hard to avoid them ;-). I don't expect this to count against including ctypes; but I do want it to be dealt with somehow! As was pointed out on c.l.py, the `dl` module suffers the exact same problem (I don't know myself, as I've never used it). There are no warnings about this in the `dl` module documentation. I can't see how it would be possible to guarantee that such a module could not cause crashes. I'm of the opinion that having a big red warning at the top of the module documentation that this is a contributed module, and incorrect use could cause segmentation faults/crashes, etc would be sufficient. Tim Delaney ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Delaney, Timothy (Tim) wrote: Guido van Rossum wrote: On 1/10/06, Thomas Heller [EMAIL PROTECTED] wrote: I would like to suggest to include ctypes into core Python, starting with the 2.5 release. On the one hand I agree that this is a useful module, popular, mature etc. On the other hand it breaks one of the most fundamental Python guidelines: if you get a core dump (segfault etc.) it's a bug in Python or in a 3rd party extension, not in *your* Python code. An exception would have to be made for any code that uses ctypes, as it is usually trivial to cause core dumps with ctypes (I'd venture it's hard to avoid them ;-). I don't expect this to count against including ctypes; but I do want it to be dealt with somehow! As was pointed out on c.l.py, the `dl` module suffers the exact same problem (I don't know myself, as I've never used it). There are no warnings about this in the `dl` module documentation. I can't see how it would be possible to guarantee that such a module could not cause crashes. I'm of the opinion that having a big red warning at the top of the module documentation that this is a contributed module, and incorrect use could cause segmentation faults/crashes, etc would be sufficient. +1. A warning for dl might not be the worst thing. Georg ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On 1/10/06, Delaney, Timothy (Tim) [EMAIL PROTECTED] wrote: Guido van Rossum wrote: On 1/10/06, Thomas Heller [EMAIL PROTECTED] wrote: I would like to suggest to include ctypes into core Python, starting with the 2.5 release. On the one hand I agree that this is a useful module, popular, mature etc. On the other hand it breaks one of the most fundamental Python guidelines: if you get a core dump (segfault etc.) it's a bug in Python or in a 3rd party extension, not in *your* Python code. An exception would have to be made for any code that uses ctypes, as it is usually trivial to cause core dumps with ctypes (I'd venture it's hard to avoid them ;-). I don't expect this to count against including ctypes; but I do want it to be dealt with somehow! As was pointed out on c.l.py, the `dl` module suffers the exact same problem (I don't know myself, as I've never used it). There are no warnings about this in the `dl` module documentation. Good point. I think there should be such warnings though. I can't see how it would be possible to guarantee that such a module could not cause crashes. And I'm not asking for that. I'm of the opinion that having a big red warning at the top of the module documentation that this is a contributed module, and incorrect use could cause segmentation faults/crashes, etc would be sufficient. Works for me. -- --Guido van Rossum (home page: http://www.python.org/~guido/) ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Guido van Rossum wrote: As was pointed out on c.l.py, the `dl` module suffers the exact same problem (I don't know myself, as I've never used it). There are no warnings about this in the `dl` module documentation. Good point. I think there should be such warnings though. Added documentation patch 1402224: http://sourceforge.net/tracker/index.php?func=detailaid=1402224group_i d=5470atid=305470 May need a little more work on the wording. I can't see how it would be possible to guarantee that such a module could not cause crashes. And I'm not asking for that. I'm of the opinion that having a big red warning at the top of the module documentation that this is a contributed module, and incorrect use could cause segmentation faults/crashes, etc would be sufficient. Works for me. Sounds like we agree on everything :) Maybe I should start channelling ... wink. Tim Delaney ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On Tue, Jan 10, 2006 at 01:14:13PM -0800, Guido van Rossum wrote: On the other hand it breaks one of the most fundamental Python guidelines: if you get a core dump (segfault etc.) it's a bug in Python or in a 3rd party extension, not in *your* Python code. An exception would have to be made for any code that uses ctypes, as it is usually trivial to cause core dumps with ctypes (I'd venture it's hard to avoid them ;-). Aside from 'dl', what was also pointed out in c.l.py was the crashability of Python in general, even from pure Python code: centurion:~ python . Segmentation fault [...] sys.setrecursionlimit(130) f = lambda f:f(f) f(f) Segmentation fault There's more, all from Python itself. And sure, well, don't do that then is a perfectly valid response to most of these harebrained tricks, but it does put a lie to the 'uncrashable python' idea :) Not-for-or-against-including-ctypes-anyway'ly y'rs, -- Thomas Wouters [EMAIL PROTECTED] Hi! I'm a .signature virus! copy me into your .signature file to help me spread! ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On 1/10/06, Thomas Wouters [EMAIL PROTECTED] wrote: Aside from 'dl', what was also pointed out in c.l.py was the crashability of Python in general, even from pure Python code: centurion:~ python . Segmentation fault This I think ought to be fixed; it's just (I presume) the parser stumbling over extremely invalid input. [...] sys.setrecursionlimit(130) f = lambda f:f(f) f(f) Segmentation fault OK, point taken. There's more, all from Python itself. And sure, well, don't do that then is a perfectly valid response to most of these harebrained tricks, but it does put a lie to the 'uncrashable python' idea :) I'm not saying it's uncrashable. I'm saying that if you crash it, it's a bug unless proven harebrained. -- --Guido van Rossum (home page: http://www.python.org/~guido/) ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Tim I'm of the opinion that having a big red warning at the top of the Tim module documentation ... Do we have semantic markup to support that? ducks Skip ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
[Guido] I'm not saying it's uncrashable. I'm saying that if you crash it, it's a bug unless proven harebrained. +1 QOTW ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Thomas Wouters [EMAIL PROTECTED] wrote: centurion:~ python . Segmentation fault [...] sys.setrecursionlimit(130) f = lambda f:f(f) f(f) Segmentation fault There's more, all from Python itself. And sure, well, don't do that then is a perfectly valid response to most of these harebrained tricks, but it does put a lie to the 'uncrashable python' idea :) Many of the segfaulting Python issues are platform specific. On a platform with a sane malloc, you get a MemoryError for the recursion. On a platform which doesn't see the current path as a readable file, you get Access is denied. on the redirection attempt. As always, I'm sure that reasonable patches which work around such segfaulting cases will be acceptable, though remember that it may not be clear how to work around them. - Josiah ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On Tue, Jan 10, 2006 at 03:57:28PM -0800, Josiah Carlson wrote: As always, I'm sure that reasonable patches which work around such segfaulting cases will be acceptable, though remember that it may not be clear how to work around them. Sorry, I missed the point I was aiming at, I guess. I wasn't aiming for fixable bugs; I see these things as, with great effort, holding up your foot at an awkward angle so that it ends up right at the business end of your primed and lit medieval cannon. We can jump through hoops to stop those particular examples, but I'd rather spend time and effort to fix *real* bugs instead. I was just showing that if you want to crash Python, you need neither 'ctypes' nor 'dl'. I do agree a warning is suitable to both of those modules, though if anyone wants to nitpick, similar modules might be added to marshal and cPickle (and pickle, too!), when feeding invalid input. Those modules are more in the awkward-foot-angle terrain for me, though. -- Thomas Wouters [EMAIL PROTECTED] Hi! I'm a .signature virus! copy me into your .signature file to help me spread! ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On 11-jan-2006, at 0:57, Josiah Carlson wrote: On a platform which doesn't see the current path as a readable file, you get Access is denied. on the redirection attempt. On my osx box using python 2.4.2: $ cat . cat: stdin: Is a directory $ python . Bus error And finally: $ python -c 'execfile(.)' Traceback (most recent call last): File string, line 1, in ? IOError: [Errno 21] Is a directory: '.' It seems there is a bug somewhere. Annoyingly 'gdb -tty=. python' doesn't crash. Ronald As always, I'm sure that reasonable patches which work around such segfaulting cases will be acceptable, though remember that it may not be clear how to work around them. - Josiah ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/ ronaldoussoren%40mac.com ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Guido van Rossum [EMAIL PROTECTED] writes: On 1/10/06, Delaney, Timothy (Tim) [EMAIL PROTECTED] wrote: Guido van Rossum wrote: On 1/10/06, Thomas Heller [EMAIL PROTECTED] wrote: I would like to suggest to include ctypes into core Python, starting with the 2.5 release. On the one hand I agree that this is a useful module, popular, mature etc. On the other hand it breaks one of the most fundamental Python guidelines: if you get a core dump (segfault etc.) it's a bug in Python or in a 3rd party extension, not in *your* Python code. An exception would have to be made for any code that uses ctypes, as it is usually trivial to cause core dumps with ctypes (I'd venture it's hard to avoid them ;-). I don't expect this to count against including ctypes; but I do want it to be dealt with somehow! As was pointed out on c.l.py, the `dl` module suffers the exact same problem (I don't know myself, as I've never used it). There are no warnings about this in the `dl` module documentation. Good point. I think there should be such warnings though. I can't see how it would be possible to guarantee that such a module could not cause crashes. And I'm not asking for that. I'm of the opinion that having a big red warning at the top of the module documentation that this is a contributed module, and incorrect use could cause segmentation faults/crashes, etc would be sufficient. Works for me. Another possibility would be to emit a warning when the module (dl or ctypes, if included) is imported. warnings.warn(Incorrect usage of this module may crash Python, RuntimeWarning, stacklevel=2) Thomas ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
Won't ctypes completely replace dl? dl provides only a small subset of the functionality of ctypes and is very restricted in the set of argument types allowed. Neil ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Include ctypes into core Python?
On 1/10/06, Thomas Wouters [EMAIL PROTECTED] wrote: centurion:~ python . Segmentation fault I fixed that in Oct in head and 2.4 branch. Although Skip filed a bug since Py_FatalError() is called which generates a core dump in debug builds at least. http://python.org/sf/1353504 I'm not sure what else can be done except perhaps just print to stderr and exit() rather than abort(). sys.setrecursionlimit(130) f = lambda f:f(f) f(f) Segmentation fault Added as Lib/test/crashers/recursive_call.py I'm sure there are many more similar to this one though. There's more, all from Python itself. We should at least try to clearly document limitations such as these. That's why I added the crashers directory. Maybe we can even find volunteers to fix these. n ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
