From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C347C433FE for ; Fri, 24 Sep 2021 07:12:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F2FC96124C for ; Fri, 24 Sep 2021 07:12:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org F2FC96124C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 72963900002; Fri, 24 Sep 2021 03:12:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6D97E6B0071; Fri, 24 Sep 2021 03:12:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5C804900002; Fri, 24 Sep 2021 03:12:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0099.hostedemail.com [216.40.44.99]) by kanga.kvack.org (Postfix) with ESMTP id 4D5C56B006C for ; Fri, 24 Sep 2021 03:12:58 -0400 (EDT) Received: from smtpin37.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id E497632099 for ; Fri, 24 Sep 2021 07:12:57 +0000 (UTC) X-FDA: 78621599994.37.80D95D4 Received: from out30-45.freemail.mail.aliyun.com (out30-45.freemail.mail.aliyun.com [115.124.30.45]) by imf03.hostedemail.com (Postfix) with ESMTP id 63A3030000B0 for ; Fri, 24 Sep 2021 07:12:55 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R721e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04395;MF=rongwei.wang@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0UpPgYjK_1632467570; Received: from 30.240.96.158(mailfrom:rongwei.wang@linux.alibaba.com fp:SMTPD_---0UpPgYjK_1632467570) by smtp.aliyun-inc.com(127.0.0.1); Fri, 24 Sep 2021 15:12:51 +0800 Content-Type: multipart/mixed; boundary="------------dSyY0MTrLfA4xeR62xlxCVge" Message-ID: <9e41661d-9919-d556-8c49-610dae157553@linux.alibaba.com> Date: Fri, 24 Sep 2021 15:12:50 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:93.0) Gecko/20100101 Thunderbird/93.0 Subject: Re: [PATCH v2 1/2] mm, thp: check page mapping when truncating page cache Content-Language: en-US To: Andrew Morton Cc: Matthew Wilcox , Linux MM , Linux Kernel Mailing List , song@kernel.org, william.kucharski@oracle.com, Hugh Dickins References: <20210906121200.57905-1-rongwei.wang@linux.alibaba.com> <20210922070645.47345-2-rongwei.wang@linux.alibaba.com> <20210923194343.ca0f29e1c4d361170343a6f2@linux-foundation.org> From: Rongwei Wang In-Reply-To: <20210923194343.ca0f29e1c4d361170343a6f2@linux-foundation.org> X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 63A3030000B0 X-Stat-Signature: rtxwcya6ipxc4fnxj5rbmrgm4wtjwpq6 Authentication-Results: imf03.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf03.hostedemail.com: domain of rongwei.wang@linux.alibaba.com designates 115.124.30.45 as permitted sender) smtp.mailfrom=rongwei.wang@linux.alibaba.com X-HE-Tag: 1632467575-661750 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: This is a multi-part message in MIME format. --------------dSyY0MTrLfA4xeR62xlxCVge Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable On 9/24/21 10:43 AM, Andrew Morton wrote: > On Thu, 23 Sep 2021 01:04:54 +0800 Rongwei Wang wrote: >=20 >> >> >>> On Sep 22, 2021, at 7:37 PM, Matthew Wilcox wro= te: >>> >>> On Wed, Sep 22, 2021 at 03:06:44PM +0800, Rongwei Wang wrote: >>>> Transparent huge page has supported read-only non-shmem files. The f= ile- >>>> backed THP is collapsed by khugepaged and truncated when written (fo= r >>>> shared libraries). >>>> >>>> However, there is race in two possible places. >>>> >>>> 1) multiple writers truncate the same page cache concurrently; >>>> 2) collapse_file rolls back when writer truncates the page cache; >>> >>> As I've said before, the bug here is that somehow there is a writable= fd >>> to a file with THPs. That's what we need to track down and fix. >> Hi, Matthew >> I am not sure get your means. We know =E2=80=9Cmm, thp: relax the VM_D= ENYWRITE constraint on file-backed THPs" >> Introduced file-backed THPs for DSO. It is possible {very rarely} for = DSO to be opened in writeable way. >> >> ... >> >>> https://lore.kernel.org/linux-mm/YUdL3lFLFHzC80Wt@casper.infradead.or= g/ >> All in all, what you mean is that we should solve this race at the sou= rce? >=20 > Matthew is being pretty clear here: we shouldn't be permitting > userspace to get a writeable fd for a thp-backed file. >=20 > Why are we permitting the DSO to be opened writeably? If there's a > legitimate case for doing this then presumably "mm, thp: relax the There is a use case to stress file-backed THP within attachment. I test this case in a system which has enabled CONFIG_READ_ONLY_THP_FOR_F= S: $ gcc -Wall -g -o stress_madvise_dso stress_madvise_dso.c $ ulimit -s unlimited $ ./stress_madvise_dso 10000 the meaning of above parameters: 10000: the max test time; : the DSO that will been mapped into file-backed THP by=20 madvise. It recommended that the text segment of DSO to be tested is=20 greater than 2M. The crash will been triggered at once in the latest kernel. And this case also can used to trigger the bug that mentioned in our another patch= . > VM_DENYWRITE constraint on file-backed THPs: should be fixed or > reverted. >=20 > If there is no legitimate use case for returning a writeable fd for a > thp-backed file then we should fail such an attempt at open(). This > approach has back-compatibility issues which need to be thought about. > Perhaps we should permit the open-writeably attempt to appear to > succeed, but to really return a read-only fd? >=20 --------------dSyY0MTrLfA4xeR62xlxCVge Content-Type: text/plain; charset=UTF-8; name="stress_madvise_dso.c" Content-Disposition: attachment; filename="stress_madvise_dso.c" Content-Transfer-Encoding: base64 LyoKICogY2FzZTogc3RyZXNzIGZpbGUtYmFja2VkIFRIUAogKi8KI2lmbmRlZiBfR05VX1NP VVJDRQojZGVmaW5lIF9HTlVfU09VUkNFCiNlbmRpZgoKI2luY2x1ZGUgPGFzc2VydC5oPgoj aW5jbHVkZSA8ZmNudGwuaD4KI2luY2x1ZGUgPHN0ZGlvLmg+CiNpbmNsdWRlIDxzdGRsaWIu aD4KI2luY2x1ZGUgPHN0ZGludC5oPgojaW5jbHVkZSA8c2NoZWQuaD4KI2luY2x1ZGUgPHRp bWUuaD4KI2luY2x1ZGUgPHN0cmluZy5oPgojaW5jbHVkZSA8ZmNudGwuaD4KI2luY2x1ZGUg PHNpZ25hbC5oPiAvKiBmb3Igc2lnbmFsICovCiNpbmNsdWRlIDxzeXMvbW1hbi5oPgojaW5j bHVkZSA8c3lzL3RpbWUuaD4KI2luY2x1ZGUgPHN5cy90eXBlcy5oPgojaW5jbHVkZSA8c3lz L3dhaXQuaD4KI2luY2x1ZGUgPHVuaXN0ZC5oPgojaW5jbHVkZSA8ZXJybm8uaD4KCiNkZWZp bmUgUEFUSF9NQVgJMTAyNAojZGVmaW5lIEJVRkZfTUFYCTEwMjQKI2RlZmluZSBUSU1FX0RG TAkxODAJLyogc2Vjb25kcyAqLwoKdm9pZCBzaWduYWxfaGFuZGxlcihpbnQgc2lnbm8pCnsK CS8qIFJlc3RvcmUgZW52ICovCglzeXN0ZW0oImVjaG8gbmV2ZXIgPiAvc3lzL2tlcm5lbC9t bS90cmFuc3BhcmVudF9odWdlcGFnZS9lbmFibGVkIik7CglzeXN0ZW0oImVjaG8gMTAwMDAg PiAvc3lzL2tlcm5lbC9tbS90cmFuc3BhcmVudF9odWdlcGFnZS9raHVnZXBhZ2VkL3NjYW5f c2xlZXBfbWlsbGlzZWNzIik7CgoJcHJpbnRmKCJcbnJlc3RvcmUgZW52OlxuIik7Cglwcmlu dGYoIgllY2hvIG5ldmVyID4gL3N5cy9rZXJuZWwvbW0vdHJhbnNwYXJlbnRfaHVnZXBhZ2Uv ZW5hYmxlZFxuIik7CglwcmludGYoIgllY2hvIDEwMDAwID4gL3N5cy9rZXJuZWwvbW0vdHJh bnNwYXJlbnRfaHVnZXBhZ2Uva2h1Z2VwYWdlZC9zY2FuX3NsZWVwX21pbGxpc2Vjc1xuIik7 CglleGl0KC0xKTsKfQoKLyogaW4gS0IgKi8KI2RlZmluZSB0ZXh0X3NpemUJKDE0VUwgPDwg MTApCgojZGVmaW5lIFBST0NNQVBfU1oJOApzdHJ1Y3QgcHJvY21hcCB7Cgl1aW50NjRfdCB2 bV9zdGFydDsKCXVpbnQ2NF90IHZtX2VuZDsKCXVpbnQ2NF90IHBnb2ZmOwoJdWludDMyX3Qg bWFqOwoJdWludDMyX3QgbWluOwoJdWludDMyX3QgaW5vOwojZGVmaW5lIFBST1RfU1oJCTUK CWNoYXIgICAgIHByb3RbUFJPVF9TWl07CgljaGFyICAgICBmbmFtZVtQQVRIX01BWF07Cn07 Cgp1bnNpZ25lZCBsb25nIHNsZWVwX3NlY3MgPSAwOwoKLyoKICogUm91dGluZXMgb2YgcHJv Y21hcCwgaS5lLiwgL3Byb2MvcGlkLyhzKW1hcHMKICovCnN0YXRpYyBpbnQgZ2V0X21lbW9y eV9tYXAocGlkX3QgcGlkLCBzdHJ1Y3QgcHJvY21hcCAqcHJvY21hcCwKCQljb25zdCBjaGFy ICpmbmFtZSkKewoJY2hhciBwYXRoW1BBVEhfTUFYXTsKCWNoYXIgbGluZVtCVUZGX01BWF07 CglGSUxFICpmcCA9IE5VTEw7CgljaGFyICplbmQgPSBOVUxMOwoJY2hhciAqcG9zLCAqc3Ag PSBOVUxMLCAqaW5bUFJPQ01BUF9TWl07CgljaGFyIGRsbVtdID0gIi0gICA6ICAgIjsKCXVp bnQ2NF90IGNvdW50ZXI7CglpbnQgaTsKCglzbnByaW50ZihwYXRoLCBQQVRIX01BWCwgIi9w cm9jLyV1L21hcHMiLCBwaWQpOwoKCWZwID0gZm9wZW4ocGF0aCwgInIiKTsKCWlmIChmcCA9 PSBOVUxMKSB7CgkJcHJpbnRmKCJmb3BlbjogJXM6ICVzXG4iLCBwYXRoLCBzdHJlcnJvcihl cnJubykpOwoJCXJldHVybiAtMTsKCX0KCglpZiAocHJvY21hcCA9PSBOVUxMIHx8IGZuYW1l ID09IE5VTEwpIHsKCQlwZXJyb3IoImZhaWw6IHByb2NtYXAgb3IgZm5hbWUgaXMgTlVMTCIp OwoJCWdvdG8gZmFpbGVkOwoJfQoKCXdoaWxlIChmZ2V0cyhsaW5lLCBCVUZGX01BWCwgZnAp KSB7CgkJLyogU3BsaXQgbGluZSBpbnRvIGZpZWxkcyAqLwoJCXBvcyA9IGxpbmU7CgkJZm9y IChpID0gMDsgaSA8IFBST0NNQVBfU1o7IGkrKykgewoJCQlpbltpXSA9IHN0cnRva19yKHBv cywgJmRsbVtpXSwgJnNwKTsKCQkJaWYgKGluW2ldID09IE5VTEwpCgkJCQlicmVhazsKCQkJ cG9zID0gTlVMTDsKCQl9CgoJCS8qIENoZWNrIHRoaXMgbGluZSBpcyBwcm9jbWFwIGl0ZW0g aGVhZGVyICovCgkJaWYgKGkgIT0gUFJPQ01BUF9TWikKCQkJY29udGludWU7CgoJCW1lbWNw eShwcm9jbWFwLT5wcm90LCBpblsyXSwgUFJPVF9TWik7CgkJbWVtY3B5KHByb2NtYXAtPmZu YW1lLCBpbls3XSwgUEFUSF9NQVgpOwoKCQkvKiBGaW5kIHRoZSB0YXJnZXQgZW50cnkgKi8K CQlpZiAoc3RyY21wKHByb2NtYXAtPnByb3QsICJyLXhwIikgfHwKCQkJCSFzdHJzdHIocHJv Y21hcC0+Zm5hbWUsIGZuYW1lKSkKCQkJY29udGludWU7CgoJCS8qIENvbnZlcnQvQ29weSBl YWNoIGZpZWxkIGFzIG5lZWRlZCAqLwoJCWVycm5vID0gMDsKCQlwcm9jbWFwLT52bV9zdGFy dCA9IHN0cnRvdWxsKGluWzBdLCAmZW5kLCAxNik7CgkJaWYgKChpblswXSA9PSAnXDAnKSB8 fCAoZW5kID09IE5VTEwpIHx8ICgqZW5kICE9ICdcMCcpIHx8CgkJCQkoZXJybm8gIT0gMCkp CgkJCWdvdG8gZmFpbGVkOwoKCQlwcm9jbWFwLT52bV9lbmQgPSBzdHJ0b3VsbChpblsxXSwg JmVuZCwgMTYpOwoJCWlmICgoaW5bMV0gPT0gJ1wwJykgfHwgKGVuZCA9PSBOVUxMKSB8fCAo KmVuZCAhPSAnXDAnKSB8fAoJCQkJKGVycm5vICE9IDApKQoJCQlnb3RvIGZhaWxlZDsKCgkJ cHJvY21hcC0+cGdvZmYgPSBzdHJ0b3VsbChpblszXSwgJmVuZCwgMTYpOwoJCWlmICgoaW5b M10gPT0gJ1wwJykgfHwgKGVuZCA9PSBOVUxMKSB8fCAoKmVuZCAhPSAnXDAnKSB8fAoJCQkJ KGVycm5vICE9IDApKQoJCQlnb3RvIGZhaWxlZDsKCgkJcHJvY21hcC0+aW5vID0gc3RydG91 bChpbls2XSwgJmVuZCwgMTYpOwoJCWlmICgoaW5bNl0gPT0gJ1wwJykgfHwgKGVuZCA9PSBO VUxMKSB8fCAoKmVuZCAhPSAnXDAnKSB8fAoJCQkJKGVycm5vICE9IDApKQoJCQlnb3RvIGZh aWxlZDsKCX0KCglpZiAoZnApCgkJZmNsb3NlKGZwKTsKCXJldHVybiAwOwoKZmFpbGVkOgoJ aWYgKGZwKQoJCWZjbG9zZShmcCk7CglwcmludGYoImZhaWw6IGV4aXRcbiIpOwoKCXJldHVy biAtMTsKfQoKI2RlZmluZSBOUl9DUFUgMzIKdWludDY0X3QgZ2V0dGltZW9mZGF5X3NlYyh2 b2lkKTsKaW5saW5lIHVpbnQ2NF90IGdldHRpbWVvZmRheV9zZWModm9pZCkKewoJc3RydWN0 IHRpbWV2YWwgdHY7CgoJZ2V0dGltZW9mZGF5KCZ0diwgTlVMTCk7CglyZXR1cm4gdHYudHZf c2VjOwp9Cgp2b2lkIHRocmVhZF9yZWFkKGludCBjcHUsIGNoYXIgKmFyZ3MpCnsKCWludCBm ZDsKCWNoYXIgKmRzb19wYXRoID0gYXJnczsKCWNoYXIgYnVmWzB4ODAwMDAwXTsKCXN0cnVj dCBwcm9jbWFwIG1hcHM7CglwaWRfdCBwaWQgPSBnZXRwaWQoKTsKCgljcHVfc2V0X3QgbWFz azsKCUNQVV9aRVJPKCZtYXNrKTsKCUNQVV9TRVQoY3B1LCAmbWFzayk7CglpZiAoc2NoZWRf c2V0YWZmaW5pdHkoMCwgc2l6ZW9mKGNwdV9zZXRfdCksICZtYXNrKSA9PSAtMSkgewoJCXBy aW50Zigid2FybmluZzogY2FuIG5vdCBzZXQgQ1BVIGFmZmluaXR5XG4iKTsKCX0KCglwcmlu dGYoInJlYWQgJXNcbiIsIGRzb19wYXRoKTsKCWZkID0gb3Blbihkc29fcGF0aCwgT19SRE9O TFkpOwoJLyogVGhlIHN0YXJ0IGFkZHIgbXVzdCBiZSBhbGlnbm1lbnQgd2l0aCAyTSAqLwoJ dm9pZCAqcCA9IG1tYXAoKHZvaWQgKikweDQwMDAwZGMwMDAwMFVMLCAweDgwMDAwMCwgUFJP VF9SRUFEIHwgUFJPVF9FWEVDLAoJCQlNQVBfUFJJVkFURSwgZmQsIDApOwoJaWYgKHAgPT0g TUFQX0ZBSUxFRCkgewoJCXBlcnJvcigibW1hcCIpOwoJCWdvdG8gb3V0OwoJfQoKCS8qIGdl dCB0aGUgbWFwcGluZyBhZGRyZXNzIChPTkxZIHIteHApIG9mIHRoZSBEU08gKi8KCWdldF9t ZW1vcnlfbWFwKHBpZCwgJm1hcHMsIGRzb19wYXRoKTsKCXByaW50ZigicGlkOiAlZFxuIiwg cGlkKTsKCXByaW50ZigidGV4dCB2bV9zdGFydDogMHglbHhcbiIsIG1hcHMudm1fc3RhcnQp OwoJcHJpbnRmKCJ0ZXh0IHZtX2VuZDogMHglbHhcbiIsIG1hcHMudm1fZW5kKTsKCW1hZHZp c2UoKHZvaWQgKiltYXBzLnZtX3N0YXJ0LCBtYXBzLnZtX2VuZCAtIG1hcHMudm1fc3RhcnQs IE1BRFZfSFVHRVBBR0UpOwoJbHNlZWsoZmQsIDAsIFNFRUtfU0VUKTsKCWZvcig7OykgewoJ CW1lbWNweShidWYsIHAsIDB4ODAwMDAwIC0gMSk7CgkJc2xlZXAoMSk7Cgl9CgoJc2xlZXAo MTAwKTsKCm91dDoKCS8qIFJlc3RvcmUgZW52ICovCglzeXN0ZW0oImVjaG8gbmV2ZXIgPiAv c3lzL2tlcm5lbC9tbS90cmFuc3BhcmVudF9odWdlcGFnZS9lbmFibGVkIik7CglzeXN0ZW0o ImVjaG8gMTAwMDAgPiAvc3lzL2tlcm5lbC9tbS90cmFuc3BhcmVudF9odWdlcGFnZS9raHVn ZXBhZ2VkL3NjYW5fc2xlZXBfbWlsbGlzZWNzIik7CgoJcHJpbnRmKCJyZWFkIGV4aXQgJXNc biIsIGRzb19wYXRoKTsKfQoKdm9pZCB0aHJlYWRfd3JpdGUoaW50IGNwdSwgY2hhciAqYXJn cykKewoJdm9pZCAqcCA9IE5VTEw7CgljaGFyIGJ1ZlszMl07Cgl1aW50NjRfdCBzZWMgPSAx OwoJdWludDY0X3QgY291bnQgPSAwOwoJY2hhciAqZHNvX3BhdGggPSBhcmdzOwoKCWNwdV9z ZXRfdCBtYXNrOwoJQ1BVX1pFUk8oJm1hc2spOwoJQ1BVX1NFVChjcHUsICZtYXNrKTsKCWlm IChzY2hlZF9zZXRhZmZpbml0eSgwLCBzaXplb2YoY3B1X3NldF90KSwgJm1hc2spID09IC0x KSB7CgkJcHJpbnRmKCJ3YXJuaW5nOiBjYW4gbm90IHNldCBDUFUgYWZmaW5pdHlcbiIpOwoJ fQoKCXNsZWVwKDMpOwoJcHJpbnRmKCJ3cml0ZSAlc1xuIiwgZHNvX3BhdGgpOwoJZm9yICg7 OykgewoJCXNlYyA9IGdldHRpbWVvZmRheV9zZWMoKTsKCQl3aGlsZSAoKHNlYyAlIDEwKSA+ PSAzKSB7CgkJCXNlYyA9IGdldHRpbWVvZmRheV9zZWMoKTsKCQl9CgoJCWludCBmZCA9IG9w ZW4oZHNvX3BhdGgsIE9fUkRXUik7CgkJcCA9IG1tYXAoTlVMTCwgMHg4MDAwMDAsIFBST1Rf UkVBRCB8IFBST1RfV1JJVEUsIE1BUF9TSEFSRUQsIGZkLCAwKTsKCQlpZiAocCA9PSBNQVBf RkFJTEVEKSB7CgkJCXBlcnJvcigibW1hcCIpOwoJCQlnb3RvIG91dDsgLyogZmFpbCAqLwoJ CX0KCgkJbHNlZWsoZmQsIDB4MTYwMCwgU0VFS19TRVQpOwoJCWZvcihsb25nIGk9MTsgaSA8 PSAyOyBpKyspewoJCQltZW1jcHkocCArIDB4MTAsIGJ1ZiwgMTYpOwoJCX0KCgkJbXVubWFw KHAsIDB4ODAwMDAwKTsKCQljbG9zZShmZCk7CgoJCXNsZWVwKDIpOwoJCWNvdW50Kys7CgkJ aWYgKGNvdW50ID49IHNsZWVwX3NlY3MpIHsKCQkJcHJpbnRmKCJ0ZXN0IGZpbmlzaDogJWxk XG4iLCBjb3VudCk7CgkJCWJyZWFrOwoJCX0KCX0gLyogZW5kIGZvciAqLwoKb3V0OgoJcHJp bnRmKCJ3cml0ZSBleGl0ICVzXG4iLCBkc29fcGF0aCk7Cn0KCi8qCiAqIHVzYWdlOgogKgkJ c3RyZXNzX21hZHZpc2VfZHNvIDx0ZXN0IHRpbWU+IDxsaWJ0ZXN0LnNvPgogKi8KaW50IG1h aW4oaW50IGFyZ2MsIGNoYXIgKmFyZ3ZbXSkKewoJc3RydWN0IHRpbWV2YWwgc3RhcnQsIGVu ZDsKCWNoYXIgZHNvX3BhdGhbODBdOwoJaW50IHJldCA9IDA7CglwaWRfdCBwaWQ7CgoJaWYg KGFyZ2MgPiAyKSB7CgkJc2xlZXBfc2VjcyA9IHN0cnRvdWwoYXJndlsxXSwgTlVMTCwgMTAp OwoJCXJlYWxwYXRoKGFyZ3ZbMl0sIGRzb19wYXRoKTsKCX0KCWVsc2UgewoJCXByaW50Zigi dXNhZ2UgZXJyb3I6XG4iXAoJCQkJIglzdHJlc3NfbWFkdmlzZV9kc28gPHRlc3QgdGltZT4g PGxpYnRlc3Quc28+XG4iXAoJCQkJIgllLmcuIHN0cmVzc19tYWR2aXNlX2RzbyAxMDAwMCBs aWJ0ZXN0LnNvXG4iKTsKCQlleGl0KC0xKTsKCX0KCgkvKiBTZXQgZW52ICovCglzeXN0ZW0o InVsaW1pdCAtcyB1bmxpbWl0ZWQiKTsKCXN5c3RlbSgiZWNobyBtYWR2aXNlID4gL3N5cy9r ZXJuZWwvbW0vdHJhbnNwYXJlbnRfaHVnZXBhZ2UvZW5hYmxlZCIpOwoJc3lzdGVtKCJlY2hv IDEwMDAgPiAvc3lzL2tlcm5lbC9tbS90cmFuc3BhcmVudF9odWdlcGFnZS9raHVnZXBhZ2Vk L3NjYW5fc2xlZXBfbWlsbGlzZWNzIik7CgoJZ2V0dGltZW9mZGF5KCZzdGFydCwgTlVMTCk7 CgoJLyoKCSAqIGZvcmsgMzIgdGFzayB0byByZWFkIGFuZCB3cml0ZSB0aGUgc2FtZSBEU086 CgkgKgkJdGFzayAwOiByZWFkIGRzbzsKCSAqCQl0YXNrIDEgLSAzMTogd3JpdGUgZHNvOwoJ ICovCglmb3IgKGludCBpID0gMDsgaSA8IE5SX0NQVTsgKytpKSB7CgkJcGlkID0gZm9yaygp OwoJCWlmIChwaWQgPT0gMCkgewoJCQlpZiAoaSA9PSAwKQoJCQkJdGhyZWFkX3JlYWQoaSwg ZHNvX3BhdGgpOwoJCQllbHNlCgkJCQl0aHJlYWRfd3JpdGUoaSwgZHNvX3BhdGgpOwoJCQli cmVhazsgLyogZm9yYmlkIGNoaWxkIGZvcmsgKi8KCQl9CgkJZWxzZSB7CgkJCS8qIHBhcmVu dCAqLwoJCX0KCX0KCglpZiAocGlkICE9IDApIHsKCQlzaWduYWwoU0lHSU5ULCBzaWduYWxf aGFuZGxlcik7CgkJc2lnbmFsKFNJR1NFR1YsIHNpZ25hbF9oYW5kbGVyKTsKCQlzaWduYWwo U0lHQUJSVCwgc2lnbmFsX2hhbmRsZXIpOwoJCS8qIHdhaXQgKi8KCQl3aGlsZSAoMSkgewoJ CQlpbnQgc3RhdHVzOwoKCQkJcGlkX3QgZG9uZSA9IHdhaXQoJnN0YXR1cyk7CgkJCWlmIChk b25lID09IC0xKSB7CgkJCQlpZiAoZXJybm8gPT0gRUNISUxEKQoJCQkJCWJyZWFrOyAvKiBO byBtb3JlIGNoaWxkIHByb2Nlc3NlcyAqLwoJCQl9IGVsc2UgewoJCQkJaWYgKCFXSUZFWElU RUQoc3RhdHVzKSB8fCBXRVhJVFNUQVRVUyhzdGF0dXMpICE9IDApIHsKCQkJCQlwcmludGYo IlBpZDolZCBmYWlsZWRcbiIsIGRvbmUpOwoJCQkJCWdvdG8gb3V0OwoJCQkJfQoJCQl9CgkJ fQoJfQoKb3V0OgoJaWYgKHJldCA9PSAwKSB7CgkJZ2V0dGltZW9mZGF5KCZlbmQsIE5VTEwp OwoJCXByaW50ZigidGltZSB0byBjb2xsYXBzZSBmaWxlIHRocDogJWxkIG1zXG4iLAoJCQkJ MTAwMCAqIChlbmQudHZfc2VjIC0gc3RhcnQudHZfc2VjKSArCgkJCQkoZW5kLnR2X3VzZWMg LSBzdGFydC50dl91c2VjKSAvIDEwMDApOwoJfQoKCXJldHVybiByZXQ7Cn0K --------------dSyY0MTrLfA4xeR62xlxCVge--