Re: [PATCH mm] kfence: fix printk format for ptrdiff_t

From: Segher Boessenkool
Date: Fri Mar 19 2021 - 07:42:47 EST

On Thu, Mar 18, 2021 at 10:38:43AM +0100, Christophe Leroy wrote:
> Yes it seems to be wrong. It was changed by commit d27dfd3887 ("Import
> pre2.0.8"), so that's long time ago. Before that it was an 'int' for ppc32.
> gcc provides ptrdiff_t in stddef.h via __PTRDIFF_TYPE__
> gcc defined __PTRDIFF_TYPE__ as 'int' at build time.

(On 32-bit PowerPC Linux.)

> Should we fix it in arch/powerpc/include/uapi/asm/posix_types.h ?

I think so, yes.

> Anyway
> 'long' and 'int' makes no functionnal difference on 32 bits so there should
> be no impact for users if any.

Except that long and int are different types, which causes errors like
what you have here. There may be similar fallout from changing it back.