Re: [PATCH v6 1/3] arch: vDSO: Add a __vdso_getrandom prototype for all architectures

From: Jason A. Donenfeld
Date: Sun Sep 01 2024 - 14:13:47 EST


On Sun, Sep 01, 2024 at 08:06:51PM +0200, Christophe Leroy wrote:
>
>
> Le 01/09/2024 à 08:13, Xi Ruoyao a écrit :
> > Without a prototype, we'll have to add a prototype for each architecture
> > implementing vDSO getrandom. As most architectures will likely have the
> > vDSO getrandom implemented in a near future, and we'd like to keep the
> > declarations compatible everywhere (to ease the Glibc work), we should
> > really just have one copy of the prototype.
>
> It is a good idea but it have to handle all architectures, not only half
> of them. If you look into vdso_config.h in selftests, you can see that
> there are two names:
>
> __kernel_getrandom is used on arm64, powerpc, s390,
>
> __vdso_getrandom is used on arm, mips, sparc, x86, riscv, loongarch

I thought about this too, but actually it looks like the __vdso_* ones
are already being handled this way, while the __kernel_* ones have their
own special thing going on. See include/vdso/gettime.h. So this patch
makes __vdso_getrandom() just like the other ones in gettime.h, which is
fine with me.