linux-kernel - Re: linux-next: Tree for September 16 (cpustr.h)

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Date:	Tue, 16 Sep 2008 13:48:25 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	"Randy.Dunlap" <rdunlap@...otime.net>
CC:	Stephen Rothwell <sfr@...b.auug.org.au>,
	linux-next@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>,
	x86@...nel.org
Subject: Re: linux-next: Tree for September 16 (cpustr.h)

Randy.Dunlap wrote:
> I'm seeing lots of gcc warnings from the generated cpustr.h file, like so:
> 
>   arch/x86/boot/mkcpustr > arch/x86/boot/cpustr.h
>   gcc -Wp,-MD,arch/x86/boot/.cpu.o.d  -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.1.1/include -D__KERNEL__ -Iinclude -Iinclude2 -I/home/rdunlap/linsrc/linux-next-20080916/include -I/home/rdunlap/linsrc/linux-next-20080916/arch/x86/include -include include/linux/autoconf.h -I/home/rdunlap/linsrc/linux-next-20080916/arch/x86/boot -Iarch/x86/boot -I/home/rdunlap/linsrc/linux-next-20080916/include -Iinclude -I/home/rdunlap/linsrc/linux-next-20080916/include2 -Iinclude2  -I/home/rdunlap/linsrc/linux-next-20080916/include  -I/home/rdunlap/linsrc/linux-next-20080916/arch/x86/include -include include/linux/autoconf.h -g -Os -D_SETUP -D__KERNEL__ -Wall -Wstrict-prototypes -march=i386 -mregparm=3 -include /home/rdunlap/linsrc/linux-next-20080916/arch/x86/boot/code16gcc.h -fno-strict-aliasing -fomit-frame-pointer -ffreestanding -fno-unit-at-a-time -fno-stack-protector -mpreferred-stack-boundary=2 -m32 -D__BIG_KERNEL__  -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(cpu)"
  -D"KBUILD_MODNAME=KBUILD_STR(cpu)" -D"DEBUG_HASH=3" -D"DEBUG_HASH2=23" -c -o arch/x86/boot/cpu.o /home/rdunlap/linsrc/linux-next-20080916/arch/x86/boot/cpu.c
> cc1: warning: hex escape sequence out of range
> 
> 
> The ending lines of cpustr.h include hex strings like "\x111".
> gcc complains about these.  If I change them to "\x011" (e.g.), there
> is no warning.
> 

Yes, there is a patch that adds a 9th cpuflags word, which this code 
doesn't handle.  The warning is real, there is an #error in mkcpustr.c 
which is supposed to trigger, but doesn't because of a typo:

#if NCAPFLAGS > 8
# error "Need to adjust the boot code handling of CPUID strings"
#endif

(The actual variable is called NCAPINTS.)

Attached is a completely untested patch for this problem.

	-hpa

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