From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from buildserver.ru.mvista.com (unknown [85.21.88.6]) by ozlabs.org (Postfix) with ESMTP id 96B7ADDE1B for ; Fri, 6 Feb 2009 02:45:32 +1100 (EST) Date: Thu, 5 Feb 2009 18:45:29 +0300 From: Anton Vorontsov To: Benjamin Herrenschmidt Subject: Re: [PATCH 2/3] powerpc: Make it possible to safely select CONFIG_FRAME_POINTER Message-ID: <20090205154529.GA20678@oksana.dev.rtsoft.ru> References: <20090204150755.GA24163@oksana.dev.rtsoft.ru> <20090204150838.GB30027@oksana.dev.rtsoft.ru> <1233793889.4612.33.camel@pasglop> <1233794154.16878.20.camel@localhost.localdomain> <1233796531.4612.35.camel@pasglop> <20090205013023.GA31417@oksana.dev.rtsoft.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 In-Reply-To: <20090205013023.GA31417@oksana.dev.rtsoft.ru> Cc: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, Steven Rostedt , Paul Mackerras , Ingo Molnar Reply-To: avorontsov@ru.mvista.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Feb 05, 2009 at 04:30:23AM +0300, Anton Vorontsov wrote: [...] > > > > > Remove -fno-omit-frame-pointer flag from CFLAGS. > > > > > Remove -fno-omit-frame-pointer workarounds. > > > > > > > > But what about -pg -requires -fno-omit-frame-pointer ? > > > > > > I don't think it requires -fno-omit-frame-pointer. It is just > > > incompatible with -fomit-frame-pointer. > > > > From a quick test, you seem to be right. > > > > Now the question of course is whether -pg will internally trigger > > the bug for which we need the workaround tho... > > According to http://marc.info/?l=linux-kernel&m=121958694215835&w=4 > just removing -fno-omit-frame-pointer solved the problem. > > But I'll double check that on the actual hardware. Confirmed. Just -pg doesn't cause any ill effects (for the test I built kernel on a ppc32 board). While simply adding -fno-omit-frame-pointer caused this during bootup: ... Waiting for /dev to be fully populated... Unable to handle kernel paging request for data at address 0x00000901 Faulting instruction address: 0xc00d9a4c Oops: Kernel access of bad area, sig: 11 [#1] MPC837x RDB Modules linked in: NIP: c00d9a4c LR: c00d9a34 CTR: c015ac7c REGS: cf197cd0 TRAP: 0300 Not tainted (2.6.29-rc3-45527-g727839a-dirty) MSR: 00009032 CR: 44084228 XER: 20000000 DAR: 00000901, DSISR: 22000000 TASK = cfa42a80[1140] 'udevd' THREAD: cf196000 GPR00: fffff000 cf197d80 cfa42a80 cf4213f0 c058e678 00000003 cf42145a 7f7f7f7f GPR08: 0000012c 00000000 c0580000 cf197d80 84084228 1002414c cf197e9c c058e7b4 GPR16: c058e678 fffffff4 c05b0000 cf197dc0 cf197db8 cf197dc8 00000000 00000000 GPR24: c00e4e30 00000000 24084222 00000001 00000901 cf197e98 cf4213f0 cf197d80 NIP [c00d9a4c] do_lookup+0x7c/0xf8 LR [c00d9a34] do_lookup+0x64/0xf8 Call Trace: [cf197d80] [c00d9a34] do_lookup+0x64/0xf8 (unreliable) [cf197db0] [c00db73c] __link_path_walk+0x180/0xdc4 [cf197e30] [c00dc3d8] path_walk+0x58/0xe0 [cf197e60] [c00dc55c] do_path_lookup+0x8c/0x164 [cf197e90] [c00dd260] user_path_at+0x64/0xac [cf197f00] [c00d3760] sys_readlinkat+0x40/0xb4 [cf197f30] [c00d380c] sys_readlink+0x38/0x50 [cf197f40] [c0018040] ret_from_syscall+0x0/0x38 --- Exception: c01 at 0xfed4754 LR = 0x10006280 Instruction dump: 80090000 2f800000 419e0028 7fa4eb78 7c0903a6 4e800421 7c7b1b79 40810040 3800f000 7fc3f378 7f9e0040 419d0018 <935c0000> 7f83e378 93dc0004 4bfffcd1 ---[ end trace 4815c47675962320 ]--- FWIW, gcc version 4.2.0. -- Anton Vorontsov email: cbouatmailru@gmail.com irc://irc.freenode.net/bd2 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Vorontsov Subject: Re: [PATCH 2/3] powerpc: Make it possible to safely select CONFIG_FRAME_POINTER Date: Thu, 5 Feb 2009 18:45:29 +0300 Message-ID: <20090205154529.GA20678@oksana.dev.rtsoft.ru> References: <20090204150755.GA24163@oksana.dev.rtsoft.ru> <20090204150838.GB30027@oksana.dev.rtsoft.ru> <1233793889.4612.33.camel@pasglop> <1233794154.16878.20.camel@localhost.localdomain> <1233796531.4612.35.camel@pasglop> <20090205013023.GA31417@oksana.dev.rtsoft.ru> Reply-To: avorontsov@ru.mvista.com Mime-Version: 1.0 Content-Type: text/plain; charset=utf8 Cc: Steven Rostedt , Ingo Molnar , Paul Mackerras , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org To: Benjamin Herrenschmidt Return-path: Received: from rtsoft3.corbina.net ([85.21.88.6]:63588 "EHLO buildserver.ru.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751863AbZBEPpe (ORCPT ); Thu, 5 Feb 2009 10:45:34 -0500 Content-Disposition: inline In-Reply-To: <20090205013023.GA31417@oksana.dev.rtsoft.ru> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Thu, Feb 05, 2009 at 04:30:23AM +0300, Anton Vorontsov wrote: [...] > > > > > Remove -fno-omit-frame-pointer flag from CFLAGS. > > > > > Remove -fno-omit-frame-pointer workarounds. > > > > > > > > But what about -pg -requires -fno-omit-frame-pointer ? > > > > > > I don't think it requires -fno-omit-frame-pointer. It is just > > > incompatible with -fomit-frame-pointer. > > > > From a quick test, you seem to be right. > > > > Now the question of course is whether -pg will internally trigger > > the bug for which we need the workaround tho... > > According to http://marc.info/?l=linux-kernel&m=121958694215835&w=4 > just removing -fno-omit-frame-pointer solved the problem. > > But I'll double check that on the actual hardware. Confirmed. Just -pg doesn't cause any ill effects (for the test I built kernel on a ppc32 board). While simply adding -fno-omit-frame-pointer caused this during bootup: ... Waiting for /dev to be fully populated... Unable to handle kernel paging request for data at address 0x00000901 Faulting instruction address: 0xc00d9a4c Oops: Kernel access of bad area, sig: 11 [#1] MPC837x RDB Modules linked in: NIP: c00d9a4c LR: c00d9a34 CTR: c015ac7c REGS: cf197cd0 TRAP: 0300 Not tainted (2.6.29-rc3-45527-g727839a-dirty) MSR: 00009032 CR: 44084228 XER: 20000000 DAR: 00000901, DSISR: 22000000 TASK = cfa42a80[1140] 'udevd' THREAD: cf196000 GPR00: fffff000 cf197d80 cfa42a80 cf4213f0 c058e678 00000003 cf42145a 7f7f7f7f GPR08: 0000012c 00000000 c0580000 cf197d80 84084228 1002414c cf197e9c c058e7b4 GPR16: c058e678 fffffff4 c05b0000 cf197dc0 cf197db8 cf197dc8 00000000 00000000 GPR24: c00e4e30 00000000 24084222 00000001 00000901 cf197e98 cf4213f0 cf197d80 NIP [c00d9a4c] do_lookup+0x7c/0xf8 LR [c00d9a34] do_lookup+0x64/0xf8 Call Trace: [cf197d80] [c00d9a34] do_lookup+0x64/0xf8 (unreliable) [cf197db0] [c00db73c] __link_path_walk+0x180/0xdc4 [cf197e30] [c00dc3d8] path_walk+0x58/0xe0 [cf197e60] [c00dc55c] do_path_lookup+0x8c/0x164 [cf197e90] [c00dd260] user_path_at+0x64/0xac [cf197f00] [c00d3760] sys_readlinkat+0x40/0xb4 [cf197f30] [c00d380c] sys_readlink+0x38/0x50 [cf197f40] [c0018040] ret_from_syscall+0x0/0x38 --- Exception: c01 at 0xfed4754 LR = 0x10006280 Instruction dump: 80090000 2f800000 419e0028 7fa4eb78 7c0903a6 4e800421 7c7b1b79 40810040 3800f000 7fc3f378 7f9e0040 419d0018 <935c0000> 7f83e378 93dc0004 4bfffcd1 ---[ end trace 4815c47675962320 ]--- FWIW, gcc version 4.2.0. -- Anton Vorontsov email: cbouatmailru@gmail.com irc://irc.freenode.net/bd2