Re: [PATCH/RFC] um: Preinclude include/linux/kern_levels.h

[Joe Perches <joe@perches.com>]

On Sun, 2012-09-09 at 10:33 +0200, Geert Uytterhoeven wrote:
> Ping?

Richard?  Are you going to pick up this patch?
It seems sensible.

Geert, I suggest sending it directly to Linus as a fix
if Richard doesn't respond in a few days.

> On Thu, Aug 16, 2012 at 8:15 PM, Geert Uytterhoeven
> <geert@linux-m68k.org> wrote:
> > The userspace part of UML uses the asm-offsets.h generator mechanism to
> > create definitions for UM_KERN_<LEVEL> that match the in-kernel
> > KERN_<LEVEL> constant definitions.
> >
> > As of commit 04d2c8c83d0e3ac5f78aeede51babb3236200112 ("printk: convert
> > the format for KERN_<LEVEL> to a 2 byte pattern"), KERN_<LEVEL> is no
> > longer expanded to the literal '"<LEVEL>"', but to '"\001" "LEVEL"', i.e.
> > it contains two parts.
> >
> > However, the combo of DEFINE_STR() in
> > arch/x86/um/shared/sysdep/kernel-offsets.h and sed-y in Kbuild doesn't
> > support string literals consisting of multiple parts. Hence for all
> > UM_KERN_<LEVEL> definitions, only the SOH character is retained in the actual
> > definition, while the remainder ends up in the comment. E.g. in
> > include/generated/asm-offsets.h we get
> >
> >     #define UM_KERN_INFO "\001" /* "6" KERN_INFO */
> >
> > instead of
> >
> >     #define UM_KERN_INFO "\001" "6" /* KERN_INFO */
> >
> > This causes spurious '^A' output in some kernel messages: