Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753830Ab1C0Ph5 (ORCPT ); Sun, 27 Mar 2011 11:37:57 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:58633 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753766Ab1C0Ph4 convert rfc822-to-8bit (ORCPT ); Sun, 27 Mar 2011 11:37:56 -0400 MIME-Version: 1.0 In-Reply-To: References: From: Linus Torvalds Date: Sun, 27 Mar 2011 08:37:24 -0700 Message-ID: Subject: Re: BUG: unable to handle kernel paging request To: Anca Emanuel , Al Viro Cc: LKML Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1763 Lines: 48 Al, this smells like your /proc cleanups/fixes... On Sun, Mar 27, 2011 at 2:16 AM, Anca Emanuel wrote: > Hi, I'm using latest kernel git. > > > [15117.080119] BUG: unable to handle kernel paging request at fffffffffffffff3 That's "-13" (possibly -EACCES) > [15117.080152] IP: [] vma_stop+0x19/0x40 .. and the code disassembles to 0: 55 push %rbp 1: 48 89 e5 mov %rsp,%rbp 4: 53 push %rbx 5: 48 83 ec 08 sub $0x8,%rsp 9: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) e: 48 85 f6 test %rsi,%rsi 11: 74 1a je 0x2d 13: 48 39 77 10 cmp %rsi,0x10(%rdi) 17: 74 14 je 0x2d 19: 8b 1e mov (%rsi),%ebx 1b: 48 8d 7b 60 lea 0x60(%rbx),%rdi 1f: e8 eb 2f ed ff callq up_read where that instruction at 0x19 is the access "mm = vma->vm_mm". So it's vma that is -EPERM. I bet it's due to commit ec6fd8a4355c ("report errors in /proc/*/*map* sanely"), which replaces NULL with various ERR_PTR() cases. > [15117.080660] Call Trace: > [15117.080671] ?[] m_stop+0x1a/0x40 > [15117.080685] ?[] seq_read+0x1e1/0x420 > [15117.080698] ?[] vfs_read+0xc5/0x190 > [15117.080711] ?[] sys_read+0x51/0x90 > [15117.080724] ?[] system_call_fastpath+0x16/0x1b Al? Linus -- 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/