Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755440AbZCTFD6 (ORCPT ); Fri, 20 Mar 2009 01:03:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751514AbZCTFDr (ORCPT ); Fri, 20 Mar 2009 01:03:47 -0400 Received: from mga02.intel.com ([134.134.136.20]:29243 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750999AbZCTFDp (ORCPT ); Fri, 20 Mar 2009 01:03:45 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.38,393,1233561600"; d="scan'208";a="396059204" Subject: Re: 2.6.29 acpi regression: acpi_ex_extract_from_field -- div by zero From: Lin Ming To: Jiri Slaby Cc: "Moore, Robert" , "lenb@kernel.org" , "linux-acpi@vger.kernel.org" , "Rafael J. Wysocki" , linux-kernel , "torvalds@linux-foundation.org" In-Reply-To: <49C26D91.3010904@gmail.com> References: <49BCDCAA.8040309@gmail.com> <1237174943.4193.37.camel@minggr.sh.intel.com> <49BE7EE6.3070107@gmail.com> <49C0AC13.7040107@gmail.com> <49C26D91.3010904@gmail.com> Content-Type: text/plain Date: Fri, 20 Mar 2009 12:53:30 +0800 Message-Id: <1237524810.879.19.camel@minggr> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 (2.24.1-2.fc10) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4516 Lines: 129 On Fri, 2009-03-20 at 00:06 +0800, Jiri Slaby wrote: > On 18.3.2009 09:08, Jiri Slaby wrote: > > On 16.3.2009 17:31, Jiri Slaby wrote: > >> On 16.3.2009 04:42, Lin Ming wrote: > >>>> sometimes, when booting up/resuming from disk, I get an oops[1]. > >>>> > >>>> obj_desc->common_field.access_bit_width is zero, but even after the > >>>> loop. Division before the loop is apparently OK. > >>> > >>> Would please try below debug patch to see which region filed is > >>> accessed? > > > > I'm confused, but keep trying. > > Got it again. obj_desc->common_field.node is martian too (0x4000000), so > the added acpi_get_name dies: > http://www.fi.muni.cz/~xslaby/sklad/panics/acpi_oops1.png > > Whole common_field seems to be mangled. Ideas? I should save the field object and node path name at the entry of acpi_ex_extract_from_field. Would you please try below debug patch? I also add a return statement before the fault to disallow the oops to flood screen. Thanks. diff --git a/drivers/acpi/acpica/exfldio.c b/drivers/acpi/acpica/exfldio.c index ef58ac4..5109f5b 100644 --- a/drivers/acpi/acpica/exfldio.c +++ b/drivers/acpi/acpica/exfldio.c @@ -670,6 +670,34 @@ acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc, * ******************************************************************************/ +void debug_dump_field(union acpi_operand_object *obj_desc) +{ + struct acpi_object_field_common *obj_field; + + if (!obj_desc) { + printk(KERN_DEBUG "ACPI Debug: NULL field object\n"); + return; + } + + printk(KERN_DEBUG "next_object: %p\n", obj_desc->common.next_object); + printk(KERN_DEBUG "descriptor_type: %x\n", obj_desc->common.descriptor_type); + printk(KERN_DEBUG "type: %x\n", obj_desc->common.type); + printk(KERN_DEBUG "reference_count: %x\n", obj_desc->common.reference_count); + printk(KERN_DEBUG "flags: %x\n", obj_desc->common.flags); + + obj_field = &obj_desc->common_field; + + printk(KERN_DEBUG "field_flags: %x\n", obj_field->field_flags); + printk(KERN_DEBUG "attribute: %x\n", obj_field->attribute); + printk(KERN_DEBUG "access_byte_width: %x\n", obj_field->access_byte_width); + printk(KERN_DEBUG "node: %p\n", obj_field->node); + printk(KERN_DEBUG "bit_length: %x\n", obj_field->bit_length); + printk(KERN_DEBUG "base_byte_offset: %x\n", obj_field->base_byte_offset); + printk(KERN_DEBUG "value: %x\n", obj_field->value); + printk(KERN_DEBUG "start_field_bit_offset: %x\n", obj_field->start_field_bit_offset); + printk(KERN_DEBUG "access_bit_width: %x\n", obj_field->access_bit_width); +} + acpi_status acpi_ex_extract_from_field(union acpi_operand_object *obj_desc, void *buffer, u32 buffer_length) @@ -683,9 +711,24 @@ acpi_ex_extract_from_field(union acpi_operand_object *obj_desc, u32 datum_count; u32 field_datum_count; u32 i; + struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_operand_object backup_obj; ACPI_FUNCTION_TRACE(ex_extract_from_field); + /* backup the object */ + memcpy(&backup_obj, obj_desc, sizeof(*obj_desc)); + + name_buffer.pointer = NULL; + if (obj_desc->common_field.node) { + status = acpi_get_name(obj_desc->common_field.node, + ACPI_FULL_PATHNAME, &name_buffer); + if (ACPI_FAILURE(status)) { + printk(KERN_DEBUG "ACPI Debug: %s\n", + acpi_format_exception(status)); + } + } + /* Validate target buffer and clear it */ if (buffer_length < @@ -765,6 +808,29 @@ acpi_ex_extract_from_field(union acpi_operand_object *obj_desc, raw_datum >> obj_desc->common_field.start_field_bit_offset; } + if (obj_desc->common_field.bit_length == 0 || + obj_desc->common_field.access_bit_width == 0) { + + /* oops, dump the object */ + if (name_buffer.pointer) { + printk(KERN_DEBUG "ACPI Debug: field node path: %s\n", + (char *) name_buffer.pointer); + } + + printk(KERN_DEBUG "ACPI Debug: The original object:\n"); + debug_dump_field(&backup_obj); + + printk(KERN_DEBUG "ACPI Debug: The bad object:\n"); + debug_dump_field(obj_desc); + + kfree(name_buffer.pointer); + + /* we return here to disallow the oops to flood screen */ + return_ACPI_STATUS(AE_ERROR); + } + + kfree(name_buffer.pointer); + /* Mask off any extra bits in the last datum */ buffer_tail_bits = obj_desc->common_field.bit_length % -- 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/