Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753659Ab3JXFmS (ORCPT ); Thu, 24 Oct 2013 01:42:18 -0400 Received: from mail-ve0-f180.google.com ([209.85.128.180]:35690 "EHLO mail-ve0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751355Ab3JXFmQ (ORCPT ); Thu, 24 Oct 2013 01:42:16 -0400 MIME-Version: 1.0 In-Reply-To: <87eh7bfoq9.fsf@rustcorp.com.au> References: <1382498320-26594-1-git-send-email-tom.leiming@gmail.com> <87eh7bfoq9.fsf@rustcorp.com.au> Date: Thu, 24 Oct 2013 13:42:14 +0800 Message-ID: Subject: Re: [RFC PATCH] kernel/kallsyms.c: only show legal kernel symbol From: Ming Lei To: Rusty Russell Cc: Andrew Morton , Linux Kernel Mailing List , Russell King , linux-arm-kernel , Chen Gang 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 Content-Length: 1710 Lines: 49 On Thu, Oct 24, 2013 at 9:21 AM, Rusty Russell wrote: > Ming Lei writes: >> Address of non-module kernel symbol should always be located >> from CONFIG_PAGE_OFFSET on, so only show these legal kernel >> symbols in /proc/kallsyms. >> >> On ARM, some symbols(see below) may drop in relocatable code, so >> perf can't parse kernel symbols any more from /proc/kallsyms, this >> patch fixes the problem. >> >> 00000000 t __vectors_start >> 00000020 A cpu_v7_suspend_size >> 00001000 t __stubs_start >> 00001004 t vector_rst >> 00001020 t vector_irq >> 000010a0 t vector_dabt >> 00001120 t vector_pabt >> 000011a0 t vector_und >> 00001220 t vector_addrexcptn >> 00001224 t vector_fiq >> 00001224 T vector_fiq_offset >> >> The issue can be fixed in scripts/kallsyms.c too, but looks this >> approach is easier. > > This fix looks hacky; if these symbols are not available, don't just > remove them from /proc/kallsyms, but don't put them in the kernel at > all. > > That way, they won't interfere with other kallsyms uses (eg. backtrace). Yes, I agree. > Or, better, figure out a smart way of excluding them by knowing why > these symbol addresses are wrong. Actually the problem is caused by commit b9b32bf70f2(ARM: use linker magic for vectors and vector stubs), maybe Russell can figure out a smart way to exclude these symbols. 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/