linux-kernel - Re: [PATCH 1/1] Kernel compile bug in 2.6.22.6/7 {maybe more} ARM/StrongARM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20070926205314.GB25747@redhat.com>
Date:	Wed, 26 Sep 2007 16:53:14 -0400
From:	Dave Jones <davej@...hat.com>
To:	Russell King <rmk+lkml@....linux.org.uk>,
	Greg.Chandler@...lsfargo.com, cpufreq@...ts.linux.org.uk,
	linux-kernel@...r.kernel.org, dan.j.williams@...el.com,
	Andrew Morton <akpm@...ux-foundation.org>,
	Andi Kleen <ak@...e.de>,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH 1/1] Kernel compile bug in 2.6.22.6/7 {maybe more}
	ARM/StrongARM

On Tue, Sep 25, 2007 at 10:36:51AM -0400, Dave Jones wrote:
 > On Tue, Sep 25, 2007 at 08:31:32AM +0100, Russell King wrote:
 >  > On Mon, Sep 24, 2007 at 05:53:57PM -0500, Greg.Chandler@...lsfargo.com wrote:
 >  > > I was building a kernel for an iPaq {SA1110} and ran into this.
 >  > > 
 >  > > linux-2.6.22.7/arch/arm/mach-sa1100/generic.c:
 >  > > Has a: #include <linux/cpufreq.h>
 >  > > Then afterwards there is a: #if defined(CONFIG_CPU_FREQ_SA1100) ||
 >  > > defined(CONFIG_CPU_FREQ_SA1110)
 >  > > who's else section redefines the cpufreq_get function inhereited from
 >  > > the header....
 >  > > 
 >  > > I'm guessing no one ever ended up in the "else" section until now, and
 >  > > that the header was added some time ago and no one caught this.
 >  > > This patch worked for me to get rid of the compile time problems.  I'm
 >  > > having issues with the kernel, but as far as I can tell they are form
 >  > > the Frame buffer and not because of this.  If this assessment is correct
 >  > > {the not needing this code anymore} then please pass this along so it
 >  > > makes it into an upcoming release.
 >  > > 
 >  > > --- linux-2.6.22.7/arch/arm/mach-sa1100/generic.c.orig  2007-09-24
 >  > > 17:36:21.000000000 -0500
 >  > > +++ linux-2.6.22.7/arch/arm/mach-sa1100/generic.c       2007-09-24
 >  > > 17:40:02.000000000 -0500
 >  > > @@ -107,15 +107,6 @@ unsigned int sa11x0_getspeed(unsigned in
 >  > >         return cclk_frequency_100khz[PPCR & 0xf] * 100;
 >  > >  }
 >  > > 
 >  > > -#else
 >  > > -/*
 >  > > - * We still need to provide this so building without cpufreq works.
 >  > > - */
 >  > > -unsigned int cpufreq_get(unsigned int cpu)
 >  > > -{
 >  > > -       return cclk_frequency_100khz[PPCR & 0xf] * 100;
 >  > > -}
 >  > > -EXPORT_SYMBOL(cpufreq_get);
 >  > >  #endif
 >  > > 
 >  > >  /*
 >  > 
 >  > No.  That code is required - the StrongARM 1100 framebuffer driver
 >  > *needs* to know what the CPU frequency is so it can set the pixel
 >  > clock divisor.
 >  > 
 >  > The real problem is the silly people who added this to cpufreq.h:
 >  > 
 >  > #ifdef CONFIG_CPU_FREQ
 >  > unsigned int cpufreq_quick_get(unsigned int cpu);
 >  > unsigned int cpufreq_get(unsigned int cpu);
 >  > #else
 >  > static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 >  > {
 >  >         return 0;
 >  > }
 >  > static inline unsigned int cpufreq_get(unsigned int cpu)
 >  > {
 >  >         return 0;
 >  > }
 >  > #endif
 >  > 
 >  > which utterly bogus.
 > 
 > Which came from ...
 > 
 > commit 184c44d2049c4db7ef6ec65794546954da2c6a0e
 > Author: Andrew Morton <akpm@...ux-foundation.org>
 > Date:   Wed May 2 19:27:08 2007 +0200
 > 
 >     [PATCH] x86-64: fix x86_64-mm-sched-clock-share
 >     
 >     Fix for the following patch. Provide dummy cpufreq functions when
 >     CPUFREQ is not compiled in.
 >     
 >     Cc: Andi Kleen <ak@...e.de>
 >     Cc: Dave Jones <davej@...emonkey.org.uk>
 >     Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
 >     Signed-off-by: Andi Kleen <ak@...e.de>
 > 

Following up on this from yesterday, Linus please revert the above cset.
It doesn't seem to be necessary (it was added to fix a miscompile in
'make allnoconfig' which doesn't seem to be repeatable with it reverted)
and actively breaks the ARM SA1100 framebuffer driver.

(If you'd prefer a patch reverting it, I'll send one, but I'm
 hoping that git-revert will just dtrt).

Thanks,

	Dave

-- 
http://www.codemonkey.org.uk
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/