Re: [RFC][PATCH] linux-2.6.2-rc2_vsyscall-gtod_B1.patch

Andrea Arcangeli
2004-02-06T15:49:11Z

On Fri, Feb 06, 2004 at 01:23:23AM -0800, Ulrich Drepper wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Andrea Arcangeli wrote:
>
> > I don't think I was arguing against it completely, exactly because I'm
> > just saying it should be optional.
>
> And the result is that the current fast syscall handling on x86-64 is
> completely unacceptable. If it's not change security enhancements are
> not possible since the libc has to hardcode the address.

by the same argument the 2.6 i386 vsyscall is not acceptable too since
it has an hardcoded address too that is the same for all binary kernels
that you ship, and furthmore it has the sysenter or int 0x80 hardcoded
at a fixed address to jump into. In short either you claim the 2.6.2
i386 code as broken the way glibc calls into it, or x86-64 is perfectly
fine too. so your claims makes very little sense to me.