Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758724Ab3IFD6i (ORCPT ); Thu, 5 Sep 2013 23:58:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2580 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755607Ab3IFD6h (ORCPT ); Thu, 5 Sep 2013 23:58:37 -0400 Date: Thu, 5 Sep 2013 23:58:27 -0400 From: Dave Jones To: Steven Rostedt Cc: Linux Kernel Subject: Re: ftrace 'failed to modify' bug when loading reiserfs.ko Message-ID: <20130906035827.GA13446@redhat.com> Mail-Followup-To: Dave Jones , Steven Rostedt , Linux Kernel References: <20130906011924.GA7970@redhat.com> <20130905212834.605408a4@gandalf.local.home> <20130906013455.GA10073@redhat.com> <20130905214455.101c6347@gandalf.local.home> <20130906014859.GB10073@redhat.com> <20130905215154.74c55e9a@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130905215154.74c55e9a@gandalf.local.home> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2371 Lines: 63 On Thu, Sep 05, 2013 at 09:51:54PM -0400, Steven Rostedt wrote: > On Thu, 5 Sep 2013 21:48:59 -0400 > Dave Jones wrote: > > > On Thu, Sep 05, 2013 at 09:44:55PM -0400, Steven Rostedt wrote: > > > On Thu, 5 Sep 2013 21:34:55 -0400 > > > Dave Jones wrote: > > > > > > > On Thu, Sep 05, 2013 at 09:28:34PM -0400, Steven Rostedt wrote: > > > > Did you change a config option, or update your gcc? > > > > Yeah, changed CONFIG_DEBUG_KOBJECT, which rebuilt the world. > > Still doesn't explain why it gave you that splat there. > > Do you still have that binary module, and can you show me what's at > reiserfs_init_bitmap_cache+0x0 with objdump? I didn't, but it turns out I can recreate this. A little convoluted but.. disable DEBUG_KOBJECT_RELEASE build, install and boot into kernel enable DEBUG_KOBJECT_RELEASE build kernel install -> boom 00000000000028b0 : return bh; } int reiserfs_init_bitmap_cache(struct super_block *sb) { 28b0: e8 00 00 00 00 callq 28b5 28b5: 55 push %rbp /* Don't trust REISERFS_SB(sb)->s_bmap_nr, it's a u16 * which overflows on large file systems. */ static inline __u32 reiserfs_bmap_count(struct super_block *sb) { return (SB_BLOCK_COUNT(sb) - 1) / (sb->s_blocksize * 8) + 1; 28b6: 31 d2 xor %edx,%edx 28b8: 48 89 e5 mov %rsp,%rbp 28bb: 41 54 push %r12 28bd: 53 push %rbx 28be: 48 89 fb mov %rdi,%rbx 28c1: 48 8b 87 50 07 00 00 mov 0x750(%rdi),%rax 28c8: 48 8b 77 18 mov 0x18(%rdi),%rsi 28cc: 48 8b 40 08 mov 0x8(%rax),%rax 28d0: 48 8d 0c f5 00 00 00 lea 0x0(,%rsi,8),%rcx 28d7: 00 28d8: 8b 00 mov (%rax),%eax 28da: 83 e8 01 sub $0x1,%eax 28dd: 48 f7 f1 div %rcx -- 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/