[issue9530] integer undefined behaviors
Mark Dickinson added the comment: It looks as though all the issues found by John's tool have now been fixed, with the exception of the ctypes issue. There's a separate issue open for that, so I'm closing this issue as fixed. -- resolution: - fixed status: open - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: Thanks. It looks like that = report has uncovered a bug in the way that ctypes lays out bitfields: in the following, BITS.M should (I believe) look like: Field type=c_short, ofs=4:0, bits=1. Instead, ctypes is trying to store a bitfield starting at bit position 17 of a short, which doesn't make much sense. iwasawa:cpython mdickinson$ ./python.exe Python 3.3.0a4+ (default:2035c5ad4239+, Jun 21 2012, 08:30:36) [GCC 4.2.1 (Apple Inc. build 5664)] on darwin Type help, copyright, credits or license for more information. from ctypes import Structure, c_int, c_short class BITS(Structure): ... _fields_ = [(A, c_int, 17), (M, c_short, 1)] ... BITS.M Field type=c_short, ofs=2:17, bits=1 -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: Meador: I see that you've been working on some ctypes issues; does the ctypes bitfield problem above fall under any of the existing issues, or should I open a new one? -- nosy: +meador.inge ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Amaury Forgeot d'Arc amaur...@gmail.com added the comment: Issue3547 looks similar. -- nosy: +amaury.forgeotdarc ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: Thanks, Amaury. I see a whole bunch of related issues, but none of them quite seems to capture this exact issue. So I've opened a new bug report: see issue 15119. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
John Regehr reg...@cs.utah.edu added the comment: I the tests for today's cpython using IOC and got only the issues below. The on-purpose divide by zero should be OK but the shift by -2 probably wants to be fixed. ARITHMETIC UNDEFINED at /home/regehr/tmp/cpython/Modules/_ctypes/cfield.c, (589:5) : Op: =, Reason : Signed Left Shift: Right operand is negative or is greater than or equal to the width of the promoted left operand, BINARY OPERATION: left (int32): 0 right (int32): -2 ARITHMETIC UNDEFINED at ./Modules/faulthandler.c, (844:11) : Op: /, Reason : Signed Division: Divisor is 0 || divident is INT_MIN, divisor is -1, BINARY OPERATION: left (int32): 1 right (int32): 0 version info: regehr@home:~/tmp/cpython$ ./python Python 3.3.0a4+ (default:24369f6c4a22+, Jun 20 2012, 16:41:04) [GCC 4.2.1 Compatible Clang 3.1 ((branches/release_31))] on linux Type help, copyright, credits or license for more information. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Roundup Robot devn...@psf.upfronthosting.co.za added the comment: New changeset c9c2031cf16d by Mark Dickinson in branch 'default': Add John Regehr to Misc/ACKS for his help with finding integer overflows (issue #9530). http://hg.python.org/cpython/rev/c9c2031cf16d -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Changes by Chris Rebert pyb...@rebertia.com: -- nosy: +cvrebert ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: Alternatively, I can re-run the Python test suite on a Python compiled using our tool. Let me know if this would be helpful. Definitely helpful if you have the time! Yes, please. Though I do intend to try out the tool for myself at some point. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Changes by Mark Dickinson dicki...@gmail.com: -- dependencies: +Integer overflow in classic string formatting ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
John Regehr reg...@cs.utah.edu added the comment: Hi folks, I realize it was a long time ago that I reported this issue! Since then our tool has been made available: http://embed.cs.utah.edu/ioc/ In particular, that web page contains a pre-compiled version of the tool for recent Ubuntu on x86-64, that should be pretty easy to use. Alternatively, I can re-run the Python test suite on a Python compiled using our tool. Let me know if this would be helpful. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Changes by Stefan Krah stefan-use...@bytereef.org: -- nosy: +skrah ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: See also issue #13496. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Roundup Robot devn...@psf.upfronthosting.co.za added the comment: New changeset 7e37598a25a6 by Mark Dickinson in branch 'default': Issue #9530: Fix undefined behaviour due to signed overflow in Python/formatter_unicode.c. http://hg.python.org/cpython/rev/7e37598a25a6 -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: I'd be happy to re-run the tests sometime. Yes, please! Alternatively, if there are easy instructions for us to re-run these tests, that would be valuable, too. Do I understand correctly that you have a publicly available extension to LLVM for this? Basically it'll act as a more powerful -ftrapv, and the error message will be much better than aborted. Indeed---there were a number of places where tracking down the exact cause of the error using a combination of -ftrapv and gdb was painful. :-) I'm aware of two current issues: one in Python/formatter_unicode.c, and one in Modules/timemodule.c. I'll try to fix these shortly. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
John Regehr reg...@cs.utah.edu added the comment: Hi Mark, yes you can run the overflow checker but easy instructions depends on whether you feel like building your own LLVM. It is not at all difficult, but it's certainly not as easy as apt-get install Patch and instructions are here: http://embed.cs.utah.edu/ioc/ If/when we get this into LLVM (the earliest possible release containing IOC will be 3.1), I'll let you know. Thanks again. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: Status update: all the reported errors from the Objects/ directory have been fixed in the default branch (many of these were fixed recently as part of making sure that the test-suite runs under Clang's -ftrapv option), or are out of date. I haven't checked the reports for the extension Modules. -- versions: +Python 3.3 -Python 3.2 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: See also issue #1621. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: The issues reported for the datetime, array, itertools and math modules are also already fixed. That just leaves the following two of the reported issues outstanding: /home/regehr/z/python/Modules/_ctypes/cfield.c, (590:5) : Op: =, Reason : Signed Left Shift Error: Right operand is negative or is greater than or equal to the width of the promoted left operand, BINARY OPERATION: left (int32): 0 right (int32): -2 and /home/regehr/z/python/Modules/testcapi_long.h, (37:47) : Op: -, Reason : Signed Subtraction Overflow, UNARY OPERATION: left (int32): 0 right (int32): -2147483648 I'm using r63764 as the revision that the line numbers relate to; not sure whether this exactly right, but it seems to be close enough. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
John Regehr reg...@cs.utah.edu added the comment: This is great. I'd be happy to re-run the tests sometime, and also we're talking with the LLVM folks about getting our patches into the main LLMM tree. Basically it'll act as a more powerful -ftrapv, and the error message will be much better than aborted. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Roundup Robot devn...@psf.upfronthosting.co.za added the comment: New changeset 71100ef4f7a2 by Mark Dickinson in branch 'default': Issue #9530: Fix undefined behaviour due to signed overflow in testcapi_long.h. http://hg.python.org/cpython/rev/71100ef4f7a2 -- nosy: +python-dev ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Changes by Jesús Cea Avión j...@jcea.es: -- nosy: +jcea ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: Applied issue9530_1.patch in r83936. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
New submission from John Regehr reg...@cs.utah.edu: I ran make test for today's Python3k snapshot under a tool which detects math operations that the C language considers to have undefined behavior. This was on x86 Linux. The list of undefined behaviors is attached. Hopefully they are self-explanatory, but please let me know if more details are needed. -- files: python-errors.txt messages: 113079 nosy: regehr priority: normal severity: normal status: open title: integer undefined behaviors type: behavior versions: Python 3.3 Added file: http://bugs.python.org/file18412/python-errors.txt ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: This is good stuff! Thank you! I'll look through these. Is the tool you used publicly available? -- assignee: - mark.dickinson nosy: +mark.dickinson ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Changes by Eric Smith e...@trueblade.com: -- nosy: +eric.smith ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: Here are some fixes for Objects/bytesobject.c and Objects/bytearrayobject.c. More to come. -- keywords: +patch versions: +Python 3.2 -Python 3.3 Added file: http://bugs.python.org/file18415/issue9530_1.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
John Regehr reg...@cs.utah.edu added the comment: Hi Mark-- Glad it's useful! We plan to release this tool but haven't done so yet, it still has rough edges. It's LLVM-based and it seems likely they will take our patches. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue9530] integer undefined behaviors
Mark Dickinson dicki...@gmail.com added the comment: Fixed two more bytearray problems in r83768. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue9530 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
