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

H. Peter Anvin
2026-03-06T20:53:29Z

On March 6, 2026 1:42:25 AM PST, "Thomas Weißschuh" <thomas.weissschuh@linutronix.de> wrote:
>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

I think I agree with you (and sadly, no, I can't point at them directly.)