From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761135AbYGPA1j (ORCPT ); Tue, 15 Jul 2008 20:27:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758408AbYGPAZR (ORCPT ); Tue, 15 Jul 2008 20:25:17 -0400 Received: from ug-out-1314.google.com ([66.249.92.173]:8513 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757860AbYGPAZO (ORCPT ); Tue, 15 Jul 2008 20:25:14 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:to:subject:message-id:mime-version:content-type :content-disposition:user-agent:from; b=fqDiMj75VTSlBadZ2+6eqZRVS651boOjRSDAsR+tXDtgja57LLbxkU5bk5x4/O5BaO ZU1JMTdV21fVJBILUp8gPhCP71exF7hcTjf+ndwV1WD8UTiIRU92Fzbjj2xHJm9K7fCY AEGYSlux5+gNfBPDPA9CgHCa4+Y6bzWG8O5e0= Date: Wed, 16 Jul 2008 02:25:00 +0200 To: Andrew Morton , Ingo Molnar , Pekka Enberg , Peter Zijlstra , linux-kernel@vger.kernel.org Subject: [PATCH 13/13] kmemcheck: enable in the x86 Kconfig Message-ID: <20080716002500.GN12564@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) From: Vegard Nossum Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>From 443d8b28cb141b3fe8bbe6dd1daa0ef41bc21d80 Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Fri, 4 Apr 2008 00:51:41 +0200 Subject: [PATCH 13/13] kmemcheck: enable in the x86 Kconfig let it rip! Signed-off-by: Pekka Enberg Signed-off-by: Vegard Nossum --- arch/x86/Kconfig.debug | 109 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 109 insertions(+), 0 deletions(-) diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 1836337..552cf57 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -246,6 +246,115 @@ config DEFAULT_IO_DELAY_TYPE default IO_DELAY_TYPE_NONE endif +menuconfig KMEMCHECK + bool "kmemcheck: trap use of uninitialized memory" + depends on X86 + depends on !X86_USE_3DNOW + depends on SLUB || (SLAB && !DEBUG_SLAB) + depends on !CC_OPTIMIZE_FOR_SIZE + depends on !DEBUG_PAGEALLOC + select FRAME_POINTER + select STACKTRACE + default n + help + This option enables tracing of dynamically allocated kernel memory + to see if memory is used before it has been given an initial value. + Be aware that this requires half of your memory for bookkeeping and + will insert extra code at *every* read and write to tracked memory + thus slow down the kernel code (but user code is unaffected). + + The kernel may be started with kmemcheck=0 or kmemcheck=1 to disable + or enable kmemcheck at boot-time. If the kernel is started with + kmemcheck=0, the large memory and CPU overhead is not incurred. + +choice + prompt "kmemcheck: default mode at boot" + depends on KMEMCHECK + default KMEMCHECK_ONESHOT_BY_DEFAULT + help + This option controls the default behaviour of kmemcheck when the + kernel boots and no kmemcheck= parameter is given. + +config KMEMCHECK_DISABLED_BY_DEFAULT + bool "disabled" + depends on KMEMCHECK + +config KMEMCHECK_ENABLED_BY_DEFAULT + bool "enabled" + depends on KMEMCHECK + +config KMEMCHECK_ONESHOT_BY_DEFAULT + bool "one-shot" + depends on KMEMCHECK + help + In one-shot mode, only the first error detected is reported before + kmemcheck is disabled. + +endchoice + +config KMEMCHECK_USE_SMP + bool "kmemcheck: use multiple CPUs" + depends on KMEMCHECK + depends on SMP + depends on BROKEN + default n + help + This option will prevent kmemcheck from disabling all but one CPU + on boot. This means that whenever a page fault is taken, all the + other CPUs in the system are halted. This is potentially extremely + expensive, depending on the number of CPUs in the system (the more + the worse). + + The upside is that kmemcheck can be compiled into the kernel with + very little overhead by default if kmemcheck is disabled at run- + time. + + If you want to compile a kernel specifically for the purpose of + playing with kmemcheck, you should say N here. If you want a normal + kernel with the possibility of enabling kmemcheck without + recompiling, you should say Y here. + +config KMEMCHECK_QUEUE_SIZE + int "kmemcheck: error queue size" + depends on KMEMCHECK + default 64 + help + Select the maximum number of errors to store in the queue. This + queue will be emptied once every second, so this is effectively a + limit on how many reports to print in one go. Note however, that + if the number of errors occuring between two bursts is larger than + this number, the extra error reports will get lost. + +config KMEMCHECK_SHADOW_COPY_SHIFT + int "kmemcheck: shadow copy size (5 => 32 bytes, 6 => 64 bytes)" + depends on KMEMCHECK + range 2 8 + default 6 + help + Select the number of shadow bytes to save along with each entry of + the queue. These bytes indicate what parts of an allocation are + initialized, uninitialized, etc. and will be displayed when an + error is detected to help the debugging of a particular problem. + +config KMEMCHECK_PARTIAL_OK + bool "kmemcheck: allow partially uninitialized memory" + depends on KMEMCHECK + default y + help + This option works around certain GCC optimizations that produce + 32-bit reads from 16-bit variables where the upper 16 bits are + thrown away afterwards. This may of course also hide some real + bugs. + +config KMEMCHECK_BITOPS_OK + bool "kmemcheck: allow bit-field manipulation" + depends on KMEMCHECK + default n + help + This option silences warnings that would be generated for bit-field + accesses where not all the bits are initialized at the same time. + This may also hide some real bugs. + config DEBUG_BOOT_PARAMS bool "Debug boot parameters" depends on DEBUG_KERNEL -- 1.5.5.1