RFC: bug in combine

[James E Wilson]

Dale Johannesen wrote:
> This is wrong, because 4 bytes starting at 73 goes outside the original
> object and can
> cause a page fault.

FYI You can write a testcase for this by using mmap to allocate a page
of memory, putting a copy of the structure 76 bytes from the end of the
mmapped region, and then trying to access the field b.  Having a
testcase will help ensure that the bug is fixed and stays fixed.

There is a existing similar testcase in gcc.dg/20030711-1.c that you can
use as a model.

I haven't tried looking at the bug yet.
-- 
Jim Wilson, GNU Tools Support, http://www.specifix.com