Re: [PATCH v2] random: vDSO: Avoid call to memset() when zeroing reserved in __cvdso_getrandom_data()

[Nathan Chancellor]

On Sat, Sep 26, 2026 at 12:55:34PM +0200, Christophe Leroy (CS GROUP) wrote:
> Le 26/09/2026 à 12:02, Jason A. Donenfeld a écrit :
> > Apparently not on RISCV, which is what prompted this patch in the first
> > place. So I suspect Nathan's v2 here is the way to go.
> 
> 
> Don't you have -fno-builtin on RISCV like we have on powerpc ?
> 
> Or is it clang that is missing this option ?

Yes, clang has -fno-builtin but as I mention in the commit message, that
may not always stop the compiler from generating calls to memset(),
which it is allowed to do even with -ffreestanding (which implies
-fno-builtin) per GCC's documentation. -fno-builtin with GCC < 14 just
happens to avoid generating memset() for memset_inline() in all of my
tests, hence why I went with this approach as suggested by Jason.

-- 
Cheers,
Nathan