[asterisk-dev] [Code Review]: MALLOC_DEBUG enhancements.

[rmudgett]

> On Nov. 7, 2012, 10:45 a.m., David Lee wrote:
> > /branches/1.8/main/astmm.c, line 201
> > <https://reviewboard.asterisk.org/r/2182/diff/1/?file=32113#file32113line201>
> >
> >     If reg-> len isn't a multiple of sizeof(unsigned int), won't this overwrite the allocated memory by a few bytes? For region size 1, on 64 bit, it will allocate 141 bytes, but this writes 144.

Fixed


- rmudgett


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On Nov. 7, 2012, 2:48 p.m., rmudgett wrote:
> 
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> This is an automatically generated e-mail. To reply, visit:
> https://reviewboard.asterisk.org/r/2182/
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> 
> (Updated Nov. 7, 2012, 2:48 p.m.)
> 
> 
> Review request for Asterisk Developers.
> 
> 
> Summary
> -------
> 
> MALLOC_DEBUG enhancements.
> 
> * Makes malloc() behave like calloc().  It will return a memory block
> filled with 0x55.  A nonzero value.
> 
> * Makes free() fill the released memory block and boundary fence's with
> 0xdeaddead.  Any pointer use after free is going to have a pointer
> pointing to 0xdeaddead.  The 0xdeaddead pointer is usually an invalid
> memory address so a crash is expected.
> 
> * Puts the freed memory block into a circular array so it is not reused
> immediately.
> 
> * When the circular array rotates out a memory block to the heap it checks
> that the memory has not been altered from 0xdeaddead.
> 
> * Made the astmm_log message wording better.
> 
> * Made crash if the DO_CRASH menuselect option is enabled and something is
> found.
> 
> 
> Diffs
> -----
> 
>   /branches/1.8/include/asterisk/astmm.h 376023 
>   /branches/1.8/include/asterisk/utils.h 376023 
>   /branches/1.8/main/asterisk.c 376023 
>   /branches/1.8/main/astmm.c 376023 
>   /branches/1.8/main/utils.c 376023 
> 
> Diff: https://reviewboard.asterisk.org/r/2182/diff
> 
> 
> Testing
> -------
> 
> The MALLOC_DEBUG enhancements were instrumental in pointing out a memory corruption problem.
> 
> 
> Thanks,
> 
> rmudgett
> 
>

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