[Patches] [ python-Patches-1467512 ] fix double free with tqs in standard build

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Patches item #1467512, was opened at 2006-04-09 20:26
Message generated for change (Comment added) made by nnorwitz
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Category: Core (C code)
Group: Python 2.5
>Status: Closed
Resolution: Accepted
Priority: 5
Submitted By: Neal Norwitz (nnorwitz)
Assigned to: Neal Norwitz (nnorwitz)
Summary: fix double free with tqs in standard build

Initial Comment:
Fix for
http://mail.python.org/pipermail/python-dev/2006-April/063572.html

Convert all PyMem_* to PyObject_* that way we can't
have an inconsistent use of PyMem_ and PyObject_ APIs
in the Parser.  This could even be a perf win if more
of the allocations are smaller than 256 bytes.  I don't
know if that's more common though.

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>Comment By: Neal Norwitz (nnorwitz)
Date: 2006-04-09 23:42

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The only inconsistency I could find was at line 818 of
tokenizer.c:

tok->buf = new;

new is PyMem_*, but tok->buf is PyObject_* everywhere except
this assignment.

I didn't see an easy fix other than reallocating and copying
instead of the assignment.

I undid a few of the changes in the patch.

Committed revision 45225.


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Comment By: Neal Norwitz (nnorwitz)
Date: 2006-04-09 21:40

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Heh, I'm going the opposite direction.  I'm going to
selectively move some of the known big calls back to
PyMem_*.  I also notice that there are a lot of allocs
without this patch are larger than 256 bytes.  I'm going to
research those too.  Thanks for the review.

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Comment By: Tim Peters (tim_one)
Date: 2006-04-09 21:19

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I noted some cautions on python-dev, but marked Accepted. 
In general I'm nervous about more-or-less mindless s/x/y/g
patches, but Guido's bug is proof that my time-consuming
selective approach may well not be the best approach to this
mess :-)

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Comment By: Guido van Rossum (gvanrossum)
Date: 2006-04-09 21:02

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Works for me.  Thanks for the quick fix!

I suppose Tim should review this.

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