Re: [PATCH 0/5] [RFC] printk/ia64/ppc64/parisc64: let's deprecate %pF/%pf printk specifiers

From: Helge Deller
Date: Wed Sep 20 2017 - 06:21:38 EST

On 20.09.2017 10:41, David Laight wrote:
From: Helge Deller
Sent: 19 September 2017 21:08
Using 'unsigned long' for any kind of pointer is an accident
waiting do happen.
It also makes it difficult to typecheck the function calls.
Using 'void *' isn't any better.
Either a pointer to an undefined struct, or a struct containing
a single 'char' member, is likely to be safest.

David, you might be right in most cases, but in this case I'd prefer
unsigned long too. I think this will create the least amount of
typecasts here.

I've not looked at the specifics case...

Another option is using a struct with a single member and
passing it by value.

Actually, we do already have correct structs which could be referenced:
parisc: struct Elf64_Fdesc
ia64: struct fdesc
ppc64: struct ppc64_opd_entry

One could "#define platform_opd_entry" to each of those depending on the platform and use it.
It might be misleading though, because the pointer which is handed over to
dereference_function_descriptor() can be such a pointer but isn't necessary.
I'll leave it up to Sergey to decide.