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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 9F830C3A5A3 for ; Tue, 27 Aug 2019 23:57:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 48C80206BF for ; Tue, 27 Aug 2019 23:57:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 48C80206BF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C7FF76B0006; Tue, 27 Aug 2019 19:57:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C309B6B0008; Tue, 27 Aug 2019 19:57:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AF9226B000A; Tue, 27 Aug 2019 19:57:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0208.hostedemail.com [216.40.44.208]) by kanga.kvack.org (Postfix) with ESMTP id 8CF226B0006 for ; Tue, 27 Aug 2019 19:57:18 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 1DD98181AC9AE for ; Tue, 27 Aug 2019 23:57:18 +0000 (UTC) X-FDA: 75869871756.27.boy12_2289f92dfc439 X-HE-Tag: boy12_2289f92dfc439 X-Filterd-Recvd-Size: 4642 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Tue, 27 Aug 2019 23:57:17 +0000 (UTC) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Aug 2019 16:57:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,439,1559545200"; d="scan'208";a="192412679" Received: from orsmsx105.amr.corp.intel.com ([10.22.225.132]) by orsmga002.jf.intel.com with ESMTP; 27 Aug 2019 16:57:14 -0700 Received: from orsmsx121.amr.corp.intel.com ([169.254.10.57]) by ORSMSX105.amr.corp.intel.com ([169.254.2.66]) with mapi id 14.03.0439.000; Tue, 27 Aug 2019 16:57:14 -0700 From: "Keppel, Pardo" To: "linux-mm@kvack.org" , "mtk.manpages@gmail.com" CC: "Hansen, Dave" , "Keppel, Pardo" Subject: [patch] mremap.2: Note/clarify "partial completion" on errors Thread-Topic: [patch] mremap.2: Note/clarify "partial completion" on errors Thread-Index: AdVdMnrV5boX8JSFS+iVGVEVCto0vw== Date: Tue, 27 Aug 2019 23:57:13 +0000 Message-ID: <388C0EB820381246B2BFD2C7583B3ECBAA1EE1FA@ORSMSX121.amr.corp.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: yes X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiMGIwZDRkNDMtNmRlYy00YTE1LWEyNGUtZGE2ZWFiMDM0YTljIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiRVlOTW5pWnUzWXRLUEIxMVpTdTlVbGEydnpoS3JRZkRsQlwvR1hxZGN2MkZDMDIrKzJ5eFNoOU5vMVlqMTUyZ3EifQ== x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.2.0.6 dlp-reaction: no-action x-originating-ip: [10.22.254.138] Content-Type: multipart/mixed; boundary="_002_388C0EB820381246B2BFD2C7583B3ECBAA1EE1FAORSMSX121amrcor_" MIME-Version: 1.0 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: --_002_388C0EB820381246B2BFD2C7583B3ECBAA1EE1FAORSMSX121amrcor_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable When using mremap() with MREMAP_FIXED and bad parameters, mremap() returns EINVAL, which is expected; but it also unmaps existing regions at 'new_address', which surprised me. I had expected that on EINVAL, mappings at 'new_address' would remain unmodified. The current behavior is reasonable, but it was surprising to me, so it migh= t be surprising to others. The man page DESCRIPTION currently says: "Any previous mapping at the address range specified by new_address and new_size is unmapped." It would be clearer to me if it also said something like: "Previous mappings may be unmapped even if mremap() returns an error." And/or if ERRORS said something about this behavior. A sample patch for man2/mremap.2 is attached. --_002_388C0EB820381246B2BFD2C7583B3ECBAA1EE1FAORSMSX121amrcor_ Content-Type: application/octet-stream; name="mremap.2.patch" Content-Description: mremap.2.patch Content-Disposition: attachment; filename="mremap.2.patch"; size=788; creation-date="Tue, 27 Aug 2019 21:18:19 GMT"; modification-date="Tue, 27 Aug 2019 21:43:38 GMT" Content-Transfer-Encoding: base64 ZGlmZiAtLWdpdCBhL21hbjIvbXJlbWFwLjIgYi9tYW4yL21yZW1hcC4yCmluZGV4IGQ3M2ZiNjRm YS4uZjY0MDhhNWM5IDEwMDY0NAotLS0gYS9tYW4yL21yZW1hcC4yCisrKyBiL21hbjIvbXJlbWFw LjIKQEAgLTEyNCw2ICsxMjQsOSBAQCBBbnkgcHJldmlvdXMgbWFwcGluZyBhdCB0aGUgYWRkcmVz cyByYW5nZSBzcGVjaWZpZWQgYnkKIGFuZAogLkkgbmV3X3NpemUKIGlzIHVubWFwcGVkLgorUHJl dmlvdXMgbWFwcGluZ3MgbWF5IGJlIHVubWFwcGVkIGV2ZW4gaWYKKy5CUiBtcmVtYXAgKCkKK3Jl dHVybnMgYW4gZXJyb3IuCiBJZgogLkIgTVJFTUFQX0ZJWEVECiBpcyBzcGVjaWZpZWQsIHRoZW4K QEAgLTE0OCw2ICsxNTEsMTYgQEAgT24gZXJyb3IsIHRoZSB2YWx1ZQogKHRoYXQgaXMsIFxmSSh2 b2lkXCAqKVwgXC0xXGZQKSBpcyByZXR1cm5lZCwKIGFuZCBcZkllcnJub1xmUCBpcyBzZXQgYXBw cm9wcmlhdGVseS4KIC5TSCBFUlJPUlMKK09uIGVycm9ycywKKy5CUiBtcmVtYXAgKCkKK21heSBw ZXJmb3JtCisuSSBwYXJ0aWFsIGNvbXBsZXRpb24KK3doZXJlIHNvbWUgYnV0IG5vdCBhbGwgc2lk ZS1lZmZlY3RzIG9jY3VyLgorRm9yIGV4YW1wbGUsIHdpdGgKKy5CUiBNUkVNQVBfRklYRUQgLAor bWFwcGluZ3MgYXQKKy5CIG5ld19hZGRyZXNzCittYXkgYmUgdW5tYXBwZWQsIHdpdGggbm8gbmV3 IG1hcHBpbmdzIHRvIHJlcGxhY2UgdGhlbS4KIC5UUAogLkIgRUFHQUlOCiBUaGUgY2FsbGVyIHRy aWVkIHRvIGV4cGFuZCBhIG1lbW9yeSBzZWdtZW50IHRoYXQgaXMgbG9ja2VkLAo= --_002_388C0EB820381246B2BFD2C7583B3ECBAA1EE1FAORSMSX121amrcor_--