Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 14 Oct 2020 15:51:00 -0700 | Subject | Re: [PATCH v2 20/20] ppc: propagate the calling conventions change down to csum_partial_copy_generic() |
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On Wed, Oct 14, 2020 at 3:27 PM Jason A. Donenfeld <Jason@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
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