On Wed, Oct 14, 2020 at 3:27 PM Jason A. Donenfeld <ja...@zx2c4.com> wrote:
>
> This patch is causing crashes in WireGuard's CI over at
> https://www.wireguard.com/build-status/ . Apparently sending a simple
> network packet winds up triggering refcount_t's warn-on-saturate code. I
Ouch.
The C parts look fairly straightforward, and I don't see how they
could cause that odd refcount issue.
So I assume it's the low-level asm code conversion that is buggy. And
it's apparently the 32-bit conversion, since your ppc64 status looks
fine.
I think it's this instruction:
addi r1,r1,16
that should be removed from the function exit, because Al removed the
- stwu r1,-16(r1)
on function entry.
So I think you end up with a corrupt stack pointer and basically
random behavior.
Mind trying that? (This is obviously all in
arch/powerpc/lib/checksum_32.S, the csum_partial_copy_generic()
function).
Linus
