Fixing the glibc adobe flash incompatibility

Chris Adams cmadams at
Thu Nov 18 03:03:02 UTC 2010

Once upon a time, Sam Varshavchik <mrsam at> said:
> Fulko Hew writes:
> >I know the definition for memcpy (on Linux) says don't use overlapping
> >regions
> No, the definition for memcpy on Linux does not say that. What says that is 
> the POSIX specification. Which is called a "standard".

Just for kicks, I pulled my K&R (ANSI edition) off the shelf, and it
says the same thing.

However, I still think that changing memcpy away from years of "it just
works" is an ABI change that should not be taken lightly and IMHO
shouldn't be done in a "stable" release of glibc.  Is memcpy called
often enough (and on large enough blocks) that this change makes a real
performance difference (not just on a synthetic memcpy benchmark)?

A change like this could even introduce security bugs in code that was
formerly working.

This is also especially annoying when the change may not really make
difference in performance (according to Linus' test).
Chris Adams <cmadams at>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.

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