[FFmpeg-devel] TEXTRELs in fft_mmx.asm

Uoti Urpala uoti.urpala
Mon Nov 3 08:21:35 CET 2008

On Mon, 2008-11-03 at 07:42 +0100, Reinhard Tartler wrote:
> Loren Merritt <lorenm at u.washington.edu> writes:
> > If it's just to stop selinux from complaining at you, then screw it,
> > I'm not willing to spend any code on that.
> Would some configure switch sacrificing performance for avoiding
> textrels be acceptable for you?

The issue in this thread is not related to performance. Putting the
tables in the correct section should not have any negative performance
impact; apparently it's just nontrivial to implement such things right
in yasm code.

> I can understand that selinux, pax and similar security urges to severe
> compromises. However at least some users are willing to give up 20-40%
> performance if they gain some security benefit. For these users I'm
> considering building yet another variant, if it was a matter of
> selecting some switch for the configure switch. [1]

You mean specifically for x86? On AMD64 there should already be no
textrels except the tables in yasm files.

How familiar are you with the SELinux issues? Would it be possible to
reduce the risk by some alternative mechanism that allows a binary to
perform textrels when it's starting but drops those privileges before
processing any user data? (Obviously dynamic loading of a library
containing textrels would not be possible.)

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