From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932427AbYEFQJl (ORCPT ); Tue, 6 May 2008 12:09:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1764154AbYEFQJ0 (ORCPT ); Tue, 6 May 2008 12:09:26 -0400 Received: from rv-out-0506.google.com ([209.85.198.228]:63798 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761661AbYEFQJY (ORCPT ); Tue, 6 May 2008 12:09:24 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:mime-version:content-type:content-transfer-encoding:content-disposition; b=RnXf0c3hrhp9SZHSSDMW4u3Afn45Qobm9fqE7mglYy/i1kthb5gn8PiZvfhyXTCIrWt1P6Hnv2lUiGaNYDlTwXYGYEAxJUZnL+by3LfNh72/18DYKxMRJ2WNkypZ/fTUj6kpcVXqAUJh4VA7UrHB2oHGHlJ4ZqoMcdchqxWT6No= Message-ID: <19f34abd0805060909q635d2d43j9414e5f179c9e22f@mail.gmail.com> Date: Tue, 6 May 2008 18:09:21 +0200 From: "Vegard Nossum" To: "Lin Ming" , "Bob Moore" , "Alexey Starikovskiy" , "Len Brown" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: ACPI: kmemcheck: Caught 16-bit read from freed memory (f7c12ec6) Cc: "Pekka Enberg" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Running kmemcheck on top of v2.6.26-rc1 gives the following (never before seen) warning: Linux Plug and Play Support v0.97 (c) Adam Belay pnp: PnP ACPI init ACPI: bus type pnp registered kmemcheck: Caught 16-bit read from freed memory (f7c12ec6) Pid: 1, comm: swapper Not tainted (2.6.26-rc1-00010-g7966e04 #2) EIP: 0060:[] EFLAGS: 00010286 CPU: 0 EIP is at acpi_ps_get_next_arg+0x1b8/0x262 EAX: f7c12ec0 EBX: f7d20428 ECX: f7ca1b00 EDX: 00000001 ESI: 00000049 EDI: f7d20400 EBP: f7c61e38 ESP: c06c9dc8 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 CR0: 8005003b CR2: f7c46456 CR3: 006ba000 CR4: 000006c0 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 DR6: ffff4ff0 DR7: 00000400 [] kmemcheck_read+0xe2/0x140 [] kmemcheck_access+0x136/0x1a0 [] do_page_fault+0x5e6/0x690 [] error_code+0x72/0x78 [] acpi_ps_parse_loop+0x4dd/0x7f8 [] acpi_ps_parse_aml+0xb4/0x332 [] acpi_ps_execute_method+0x13d/0x20d [] acpi_ns_evaluate+0x10e/0x1b0 [] acpi_ut_evaluate_object+0x51/0x18d [] acpi_ut_execute_STA+0x22/0x7b [] acpi_ns_get_device_callback+0x5a/0x121 [] acpi_ns_walk_namespace+0xf0/0x10c [] acpi_get_devices+0x47/0x5d [] pnpacpi_init+0x65/0xa0 [] kernel_init+0x127/0x290 [] kernel_thread_helper+0x7/0x10 [] 0xffffffff pnp: PnP ACPI: found 17 devices ACPI: ACPI bus type pnp unregistered This faulting instruction comes from $ addr2line -e vmlinux -i c027ecaa drivers/acpi/parser/psargs.c:694 Which was changed/introduced in commit bc7a36ab74e09da7bb63e2477b0740ac992b290e Author: Lin Ming Date: Thu Apr 10 19:06:42 2008 +0400 ACPICA: Fixes for Unload and DDBHandles Implemented support for the use of DDBHandles as an Indexed Reference, as per the ACPI spec. http://www.acpica.org/bugzilla/show_bug.cgi?id=486. Implemented support for UserTerm (Method invocation) for the Unload operator as per the ACPI spec. http://www.acpica.org/bugzilla/show_bug.cgi?id=580 Signed-off-by: Bob Moore Signed-off-by: Alexey Starikovskiy Signed-off-by: Len Brown I've tried reverting this particular commit and the warning does indeed go away. Now, please keep in mind that kmemcheck is a work in progress and may produce false positives :-) I think it might be worth looking at, though. Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036