Re: [RFC][PATCH] linux-2.5.34_vsyscall_A0

[Manfred Spraul <manfred@colorfullife.com>]

On Fri, 2002-10-18 at 04:14, Andrea Arcangeli wrote:
> the main reason it wasn't backported to i386 is that if glibc start
> using the vgettimeofday instead of sys_gettimeofday, you won't be able
> to downgrade kernel anymore to say 2.4 (oh yeah, I would then backport
> it to my tree or Marcelo could apply the patches too to 2.4 but then 2.2
> would be left uncovered, new glibc would segfault on the old kernels).

Does that problem actually exist?

http://marc.theaimsgroup.com/?l=linux-kernel&m=103253890431473&w=2

Jakub Jelinek <jakub@redhat.com> wrote on 2002-09-20 16:15:25

> glibc supports .note.ABI-tag notes for libraries, so there is no problem
> with having NPTL libpthread.so.0 --enable-kernel=2.5.36 in say
> /lib/i686/libpthread.so.0 and linuxthreads --enable-kernel=2.2.1 in
> /lib/libpthread.so.0. The dynamic linker will then choose based
> on currently running kernel.
> (well, ATM because of libc tsd DL_ERROR --without-tls ld.so cannot be used
> with --with-tls libs and vice versa, but that is beeing worked on).
> 

It should be possible to have one library that supports both syscall 
interfaces for gettimeofday().

--
	Manfred