From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10128 invoked by alias); 25 Jul 2007 06:52:53 -0000 Received: (qmail 10121 invoked by uid 22791); 25 Jul 2007 06:52:53 -0000 X-Spam-Status: No, hits=-2.0 required=5.0 tests=AWL,BAYES_00,DK_POLICY_SIGNSOME,DNS_FROM_RFC_ABUSE,SPF_PASS X-Spam-Check-By: sourceware.org Received: from ausmtp04.au.ibm.com (HELO ausmtp04.au.ibm.com) (202.81.18.152) by sourceware.org (qpsmtpd/0.31) with ESMTP; Wed, 25 Jul 2007 06:52:49 +0000 Received: from d23relay01.au.ibm.com (d23relay01.au.ibm.com [202.81.18.232]) by ausmtp04.au.ibm.com (8.13.8/8.13.8) with ESMTP id l6P7FMNu277334 for ; Wed, 25 Jul 2007 17:15:39 +1000 Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.250.244]) by d23relay01.au.ibm.com (8.13.8/8.13.8/NCO v8.4) with ESMTP id l6P6pGJ9201094 for ; Wed, 25 Jul 2007 16:51:16 +1000 Received: from d23av03.au.ibm.com (loopback [127.0.0.1]) by d23av03.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l6P6prO2031981 for ; Wed, 25 Jul 2007 16:51:53 +1000 Received: from srinivasa-laptop.in.ibm.com (srinivasa-laptop.in.ibm.com [9.124.35.39]) by d23av03.au.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id l6P6pq1W031911; Wed, 25 Jul 2007 16:51:52 +1000 From: Srinivasa Ds Organization: IBM To: linux-kernel@vger.kernel.org, Andrew Morton , ananth@in.ibm.com, prasanna@in.ibm.com, anil.s.keshavamurthy@intel.com, jkenisto@us.ibm.com, systemtap@sources.redhat.com Subject: [RFC] [PATCH] To vunmap correct address in text_poke()(kprobes) Date: Wed, 25 Jul 2007 13:01:00 -0000 User-Agent: KMail/1.9.6 Cc: suzuki@in.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707251221.49827.srinivasa@in.ibm.com> X-IsSubscribed: yes Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2007-q3/txt/msg00178.txt.bz2 When I was testing kprobes on x86_64 and I come across the below error message on latest 2.6.23-rc1 kernel. ========================================== Trying to vfree() bad address (ffffc20002233199) WARNING: at mm/vmalloc.c:330 __vunmap() Call Trace: [] sys_gettimeofday+0x0/0x62 [] text_poke+0x119/0x124 [] arch_arm_kprobe+0x1c/0x21 [] __register_kprobe+0x28a/0x2ed [] :gettimeofday:kprobe_init+0x39/0x65 [] sys_init_module+0x1626/0x1788 [] dput+0x3f/0xfa [] audit_syscall_entry+0x141/0x174 [] tracesys+0xdc/0xe1 ====================================================== This indicates that vunmap() is not receving the page-aligned address in text_poke(). So the below attached patch will address this issue. Please let me know your comments. Signed-off-by: Srinivasa DS Signed-off-by: Suzuki K P Index: linux-2.6.23-rc1/arch/i386/kernel/alternative.c =================================================================== --- linux-2.6.23-rc1.orig/arch/i386/kernel/alternative.c 2007-07-23 02:11:00.000000000 +0530 +++ linux-2.6.23-rc1/arch/i386/kernel/alternative.c 2007-07-25 11:45:53.000000000 +0530 @@ -447,5 +447,5 @@ void __kprobes text_poke(void *oaddr, un if (cpu_has_clflush) asm("clflush (%0) " :: "r" (oaddr) : "memory"); if (addr != oaddr) - vunmap(addr); + vunmap(addr-(((unsigned long)oaddr) % PAGE_SIZE)); }