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Created on 2006-07-04 16:39 by collinwinter, last changed 2022-04-11 14:56 by admin. This issue is now closed.
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| File name | Uploaded | Description | Edit | |
| fix_gc_inspection.patch | collinwinter, 2006-07-04 16:39 | Fix for crashers/gc_inspection.py, against r47225 | ||
| Messages (7) | |||
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| msg50600 - (view) | Author: Collin Winter (collinwinter) *  |
Date: 2006-07-04 16:39 | |
The attached patch fixes the bug pointed out in crashers/gc_inspection.py, namely that gc.get_referrers() can be used to see objects (in this case tuples) before their built, leading to segfaults. The patch works by modifying Objects/abstract.c:PySequence_AsTuple, wrapping the call to PyIter_Next() with _PyObject_GC_TRACK/UNTRACK calls. This has the effect of hiding the being-created tuple from gc.get_referrers() while fetching the next item from the iterator. Also attached is a patch to crashers/gc_inspection.py itself, which allows the test to actually pass (the previous version would raise IndexErrors in the event the test passed). |
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| msg50601 - (view) | Author: Collin Winter (collinwinter) * |
Date: 2006-07-05 17:36 | |
Logged In: YES user_id=1344176 The improve_gc_inspection.patch file has been superseded by a patch attached to bug #1517663. The bug details another interpreter crash in the same vein as the one fix in tuple() by this patch. |
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| msg50602 - (view) | Author: Raymond Hettinger (rhettinger) * |
Date: 2006-07-05 22:31 | |
Logged In: YES user_id=80475 Crashers based on gc.get_referrers() should not be considered real bugs. It is certainly not worth complexifying the code or slowing it down just to preclude these little perverse safe-cracking exercises. Also, it is not worth the risk of introducing a real bug when the code was working fine. That being said, if the code is genuinely defective and has potential to cause real-world problems, then it should be fixed. I would think that if there were a long- standing problem with tuples, it would have manifested itself long ago. |
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| msg50603 - (view) | Author: Neal Norwitz (nnorwitz) * |
Date: 2006-07-06 06:28 | |
Logged In: YES user_id=33168 Note that the declaration of item needs to be moved to the top of the scope so it can compile with C89. |
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| msg50604 - (view) | Author: Armin Rigo (arigo) * |
Date: 2006-07-25 18:08 | |
Logged In: YES user_id=4771 This patch is pointless. I recommend rejecting it. The crashers/gc_inspection.py was just one example among many of crashing Python with gc.get_referrers(). I don't see why we should care to fix just this specific way. What would be needed is a complete review, possibly with an API change to decouple object creation and GC registration, and appropriate documentation for extension module writers. I don't think it's likely to happen though. |
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| msg50605 - (view) | Author: Michael Hudson (mwh) |
Date: 2006-08-04 09:19 | |
Logged In: YES user_id=6656 I agree with arigo. Assigning to Neal so he can see this and get it off his "things to do for 2.5" list. |
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| msg50606 - (view) | Author: Georg Brandl (georg.brandl) * |
Date: 2006-10-12 13:02 | |
Logged In: YES user_id=849994 Closing as well as bug #1517663. |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2022-04-11 14:56:18 | admin | set | github: 43611 |
| 2006-07-04 16:39:01 | collinwinter | create | |