Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755548AbaLVUm1 (ORCPT ); Mon, 22 Dec 2014 15:42:27 -0500 Received: from out01.mta.xmission.com ([166.70.13.231]:56703 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755471AbaLVUmZ (ORCPT ); Mon, 22 Dec 2014 15:42:25 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Sasha Levin Cc: Andrey Ryabinin , LKML , linux-fsdevel , Al Viro , "davej \@mail.xmission.com\>\> Dave Jones" References: <54982C98.9070806@oracle.com> <87oaqvd6ni.fsf@x220.int.ebiederm.org> <54985F05.2040603@oracle.com> Date: Mon, 22 Dec 2014 14:39:54 -0600 In-Reply-To: <54985F05.2040603@oracle.com> (Sasha Levin's message of "Mon, 22 Dec 2014 13:12:21 -0500") Message-ID: <87sig7beqt.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-AID: U2FsdGVkX1+PdJ8BTqZMfO2+E49Af5kw8QXyX9sgz5E= X-SA-Exim-Connect-IP: 97.121.85.189 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 TVD_RCVD_IP Message was received from an IP address * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4550] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa06 1397; Body=1 Fuz1=1 Fuz2=1] * 1.0 T_XMDrugObfuBody_12 obfuscated drug references X-Spam-DCC: XMission; sa06 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Sasha Levin X-Spam-Relay-Country: X-Spam-Timing: total 259 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 3.1 (1.2%), b_tie_ro: 2.0 (0.8%), parse: 1.15 (0.4%), extract_message_metadata: 19 (7.2%), get_uri_detail_list: 1.78 (0.7%), tests_pri_-1000: 8 (3.0%), tests_pri_-950: 1.38 (0.5%), tests_pri_-900: 1.21 (0.5%), tests_pri_-400: 22 (8.7%), check_bayes: 21 (8.1%), b_tokenize: 8 (2.9%), b_tok_get_all: 6 (2.5%), b_comp_prob: 2.8 (1.1%), b_tok_touch_all: 2.1 (0.8%), b_finish: 0.67 (0.3%), tests_pri_0: 193 (74.7%), tests_pri_500: 6 (2.2%), rewrite_mail: 0.00 (0.0%) Subject: Re: fs: proc: gpf in find_entry X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Wed, 24 Sep 2014 11:00:52 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sasha Levin writes: > On 12/22/2014 12:52 PM, Andrey Ryabinin wrote: >> 2014-12-22 18:51 GMT+03:00 Eric W. Biederman : >>> These two instructions: >>>>> 11: 4d 85 ff test %r15,%r15 >>>>> 14: 0f 84 de 01 00 00 je 0x1f8 >>> >>> Should prevent a NULL %r15 value from ever reaching the trapping >>> instruction. >> >> If they were executed, then yes. But I think there was jump from somewhere >> to the instructions below those two. > > There is indeed a jump direct to that point, which avoids the %r15 > check. Where do you see that direct jump, that certainly has not been posted in this thread? There are certainly no such code paths I in the source code. There is only one NULL pointer check in find_entry and it is executed every time the loop executes. So at this point all I know is some set of tools has totally destroyed the code and made what Sasha Levin's is testing so far from the source code that this is a useless bug report. I have no reason to even suspect this bug is actually in the upstream kernel. This appears to be a kind of testing that slows development and wastes peoples time. Can someone give me a patch that sets the TAINTED flag when KASAN is loaded? Eric -- 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/