Re: [PATCH 1/7] x86/vdso: Respect COMPAT_32BIT_TIME

Thomas Weißschuh
2026-03-06T09:42:39Z

On Thu, Mar 05, 2026 at 03:57:59PM -0800, H. Peter Anvin wrote:
> On 2026-03-05 01:24, Thomas Weißschuh wrote:
> >
> >> Weak references would be a way to work around the link failures.
> >
> > I am still not sure where "the link failures" should be coming from.
> > The only sense I can make out of it, is if somebody manually and directly links
> > to vdso.so. Like in the following example:

(...)

> > This actually works on glibc (not on musl). But it is highly non-standard and
> > relies on multiple implementation details. Furthermore it can fail to run on
> > systems without a vDSO, as mentioned before.
> >
> > Is this the usage pattern you have in mind?
> > Do you know of anybody doing things this way?
> >
>
> Yes, and yes, I do.

Thanks.

Do you know why it is done this way? Are these applications public and
if so, could you point me to them?
In case we stub out the vDSO functions with ENOSYS, would these
applications be able to handle that error gracefully?

Personally I am still in favor of removing these functions completely
when !COMPAT_32BIT_TIME.

Thomas