Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754279Ab3JXIqX (ORCPT ); Thu, 24 Oct 2013 04:46:23 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:41611 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754245Ab3JXIqU (ORCPT ); Thu, 24 Oct 2013 04:46:20 -0400 Date: Thu, 24 Oct 2013 09:45:59 +0100 From: Russell King - ARM Linux To: Rusty Russell Cc: Ming Lei , Andrew Morton , linux-kernel@vger.kernel.org, Chen Gang , linux-arm-kernel@lists.infradead.org Subject: Re: [RFC PATCH] kernel/kallsyms.c: only show legal kernel symbol Message-ID: <20131024084559.GD16735@n2100.arm.linux.org.uk> References: <1382498320-26594-1-git-send-email-tom.leiming@gmail.com> <87eh7bfoq9.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87eh7bfoq9.fsf@rustcorp.com.au> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1565 Lines: 42 On Thu, Oct 24, 2013 at 11:51:18AM +1030, 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. How do you "don't put them in the kernel at all" when they're used by the kernel internally as offsets? If you mean, just get rid of them, shall I just add these as magic numbers instead based on the values in this email? Is that really a sane solution? No, we have to keep these symbols IMHO. -- 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/