Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751400AbaAGOdq (ORCPT ); Tue, 7 Jan 2014 09:33:46 -0500 Received: from mail-qa0-f48.google.com ([209.85.216.48]:49035 "EHLO mail-qa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750894AbaAGOd1 (ORCPT ); Tue, 7 Jan 2014 09:33:27 -0500 MIME-Version: 1.0 In-Reply-To: <201401071512.34016.arnd@arndb.de> References: <1382975339-25831-1-git-send-email-tom.leiming@gmail.com> <201401071512.34016.arnd@arndb.de> Date: Tue, 7 Jan 2014 22:33:24 +0800 Message-ID: Subject: Re: [PATCH] scripts/kallsyms: filter symbols not in kernel address space From: Ming Lei To: Arnd Bergmann Cc: linux-arm-kernel , Andrew Morton , Linux Kernel Mailing List , Michal Marek , Rusty Russell , Russell King Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Arnd, On Tue, Jan 7, 2014 at 10:12 PM, Arnd Bergmann wrote: > On Monday 28 October 2013, Ming Lei wrote: >> This patch uses CONFIG_PAGE_OFFSET to filter symbols which >> are not in kernel address space because these symbols are >> generally for generating code purpose and can't be run at >> kernel mode, so we needn't keep them in /proc/kallsyms. >> >> For example, on ARM there are some symbols which are >> linked in relocatable code section, then perf can't parse >> symbols any more from /proc/kallsyms, and this patch fixes >> the problem. >> >> Cc: Russell King >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: Michal Marek >> Acked-by: Rusty Russell >> Signed-off-by: Ming Lei > > Sorry for the late report, but I seem to have encountered a problem with this > patch, now that it has made it into all stable kernels. > > When linking an ARM nommu kernel, I get the output "No valid symbol." twice, > from scripts/kallsyms. The problem evidently is that PAGE_OFFSET is still > set to 0xC0000000 on ARM NOMMU builds but the kernel is linked to start at > PLAT_PHYS_OFFSET instead, which may be elsehwere. For most platforms, > this is defined in Kconfig these days, so we could get away with > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index d1e4098..c477a7c 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1592,6 +1592,7 @@ endchoice > > config PAGE_OFFSET > hex > + default PHYS_OFFSET if !MMU > default 0x40000000 if VMSPLIT_1G > default 0x80000000 if VMSPLIT_2G > default 0xC0000000 > > but there are still a few ARM platforms that define their own PLAT_PHYS_OFFSET > in memory.h, and it wouldn't help on non-ARM systems that might have the same > problem. We had posted two patches to address the problem, see below link: http://lists.scusting.com/index.php?t=msg&goto=1726509&S=Google Thanks, -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/