Re: MIPS: bug: gettimeofday syscall broken on CI20 board

From: Maarten ter Huurne
Date: Thu Nov 28 2019 - 08:29:55 EST


On Thursday, 28 November 2019 13:33:17 CET H. Nikolaus Schaller wrote:
> Hi Vincenzo,
>
> > Am 28.11.2019 um 13:21 schrieb Vincenzo Frascino
> > <vincenzo.frascino@xxxxxxx>:>
> > [...]
> > The the lib that provides the gettimeofday() changes accordingly
> > with vdso_data. 5.4 and 4.19 have 2 different vdso libraries as
> > well.
>
> Yes, that is what I have assumed what happens. How do these libs go
> into an existing and working root-file-system with Debian Stretch?

I'm a novice when it comes to vDSO, so someone please correct me if I'm
wrong.

>From what I read vDSO is a library in the sense that it exports ELF
symbols that applications and other libraries (libc in particular) can
use, but it is not a file on disk.

As such, which rootfs you use shouldn't matter, since the vDSO is not in
the rootfs. Instead, it is contained in the kernel image. Searching for
"linux-vdso.so.1" on packages.debian.org indeed returns no hits.

There is a check in arch/mips/vdso/Makefile that disables vDSO on MIPS
when building the kernel with binutils < 2.25. I don't know if that is
in any way related to this issue.

Bye,
Maarten