Re: [PATCH v2 20/20] ppc: propagate the calling conventions change down to csum_partial_copy_generic()

On Thu, Oct 15, 2020 at 12:53 AM Linus Torvalds
[off-list ref] wrote:

On Wed, Oct 14, 2020 at 3:51 PM Linus Torvalds
[off-list ref] wrote:

quoted

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).

Patch attached to make it easier to test.

NOTE! This is ENTIRELY untested. My ppc asm is so rusty that I might
be barking entirely up the wrong tree, and I just made things much
worse.

Indeed - exactly the same thing that's in my tree. Writing a commit
message for it now.

Jason