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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F9FDE77179 for ; Thu, 5 Dec 2024 17:50:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8D3876B0194; Thu, 5 Dec 2024 12:50:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 885FD6B019A; Thu, 5 Dec 2024 12:50:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 687A26B019C; Thu, 5 Dec 2024 12:50:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 490DD6B0194 for ; Thu, 5 Dec 2024 12:50:15 -0500 (EST) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id E220F160D5D for ; Thu, 5 Dec 2024 17:50:14 +0000 (UTC) X-FDA: 82861643424.09.B09581B Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) by imf04.hostedemail.com (Postfix) with ESMTP id 12F3A4001A for ; Thu, 5 Dec 2024 17:49:54 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=ERSypDMw; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=xod107vZ; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=exmjsGNS; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=h9qKu0sm; spf=pass (imf04.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.131 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1733421000; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ssw4lT/FrrxkWzHPEs7J+XtZPtU95ZBUColtMR1uZsQ=; b=IGUPzR6DCWCwMLQZI2RrI2H/1PD6TF9mYlhUufUgK5DPJ3ttnnT4qyQJYmHQ2M/dBnS392 l5euXGcNXAIToMCYsbUduYG5qrO3zEBcbtI4I2q5pHHP+ISpVDMJa6QJqJOSKfpxkh1Phg hdAioNENAeyOSz9XAnAi7X5M2mbltH4= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=ERSypDMw; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=xod107vZ; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=exmjsGNS; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=h9qKu0sm; spf=pass (imf04.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.131 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1733421000; a=rsa-sha256; cv=none; b=VjpCWArAfe+s83B93WPqb+ksY54g9/l3l5PJuBanfizCiEYo/7AGymCnM9+totZm4gHpup 22E4aFTI1wiJzs5WeU8MAI1sCK4ltwyHR/97EUzbZThoE+zAJhVR5NmAERRndlv/wMWm3S ilPNkT+WNM+5MXIyYJgsbzB6AYO3mHE= Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 730EE1F38C; Thu, 5 Dec 2024 17:50:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1733421010; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=ssw4lT/FrrxkWzHPEs7J+XtZPtU95ZBUColtMR1uZsQ=; b=ERSypDMwuyGsXk0FGP5xAkbNBXrB8A4PQIM+62NXl0BY2euzFffjxspXMipYBTxdA3Oale uJRSyRburWaytFt+4XXoeDEotG7IQkBz0fCRpLJipGzCTDmmE69H7kMfcgqrx0wBMkyP74 ewN9ZTCUd5I2DR1Uzl9yS73Mwz/KFG8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1733421010; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=ssw4lT/FrrxkWzHPEs7J+XtZPtU95ZBUColtMR1uZsQ=; b=xod107vZswGRbAKz/281SoyqjpaQL8KLv75jSv6uqX8tET4LrL8BkqeI/rAeT+b9O4Q1MK yQHgwM6wJiBqgjAQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1733421009; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=ssw4lT/FrrxkWzHPEs7J+XtZPtU95ZBUColtMR1uZsQ=; b=exmjsGNS8+VGaqsu8G4X6IXv4fBDTJsURQXC3Di11QisU2zzCfEKmcnIOTGvPRfFGmzCZ9 0TBZwbXMCWgkb/C0v1EPdkZ9l8Q9vpGatwaoCw9/Aaa5wgpJI7qImTHcwYxFtofGxumCbz yqwsCcSjjKw0NG+ujzdV7XFDKWc4pfk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1733421009; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=ssw4lT/FrrxkWzHPEs7J+XtZPtU95ZBUColtMR1uZsQ=; b=h9qKu0smN9uUeXyyIaPKTJuM2sm/qHjmZNqMQfm744ioVpEjLtW2YzJryPohr/TuLV8wXM 0KjH0vGP3FaISUCA== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 5E34B138A5; Thu, 5 Dec 2024 17:50:09 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 4CyKFtHnUWcTJgAAD6G6ig (envelope-from ); Thu, 05 Dec 2024 17:50:09 +0000 Message-ID: Date: Thu, 5 Dec 2024 18:50:09 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH man-pages v4] madvise.2: add MADV_GUARD_INSTALL, MADV_GUARD_REMOVE description Content-Language: en-US To: Lorenzo Stoakes , Alejandro Colomar Cc: linux-man@vger.kernel.org, Suren Baghdasaryan , "Liam R . Howlett" , Matthew Wilcox , Jann Horn , linux-mm@kvack.org References: <20241205104125.67518-1-lorenzo.stoakes@oracle.com> From: Vlastimil Babka Autocrypt: addr=vbabka@suse.cz; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSBWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBzdXNlLmN6PsLBlAQTAQoAPgIbAwULCQgHAwUVCgkICwUWAgMBAAIe AQIXgBYhBKlA1DSZLC6OmRA9UCJPp+fMgqZkBQJkBREIBQkRadznAAoJECJPp+fMgqZkNxIQ ALZRqwdUGzqL2aeSavbum/VF/+td+nZfuH0xeWiO2w8mG0+nPd5j9ujYeHcUP1edE7uQrjOC Gs9sm8+W1xYnbClMJTsXiAV88D2btFUdU1mCXURAL9wWZ8Jsmz5ZH2V6AUszvNezsS/VIT87 AmTtj31TLDGwdxaZTSYLwAOOOtyqafOEq+gJB30RxTRE3h3G1zpO7OM9K6ysLdAlwAGYWgJJ V4JqGsQ/lyEtxxFpUCjb5Pztp7cQxhlkil0oBYHkudiG8j1U3DG8iC6rnB4yJaLphKx57NuQ PIY0Bccg+r9gIQ4XeSK2PQhdXdy3UWBr913ZQ9AI2usid3s5vabo4iBvpJNFLgUmxFnr73SJ KsRh/2OBsg1XXF/wRQGBO9vRuJUAbnaIVcmGOUogdBVS9Sun/Sy4GNA++KtFZK95U7J417/J Hub2xV6Ehc7UGW6fIvIQmzJ3zaTEfuriU1P8ayfddrAgZb25JnOW7L1zdYL8rXiezOyYZ8Fm ZyXjzWdO0RpxcUEp6GsJr11Bc4F3aae9OZtwtLL/jxc7y6pUugB00PodgnQ6CMcfR/HjXlae h2VS3zl9+tQWHu6s1R58t5BuMS2FNA58wU/IazImc/ZQA+slDBfhRDGYlExjg19UXWe/gMcl De3P1kxYPgZdGE2eZpRLIbt+rYnqQKy8UxlszsBNBFsZNTUBCACfQfpSsWJZyi+SHoRdVyX5 J6rI7okc4+b571a7RXD5UhS9dlVRVVAtrU9ANSLqPTQKGVxHrqD39XSw8hxK61pw8p90pg4G /N3iuWEvyt+t0SxDDkClnGsDyRhlUyEWYFEoBrrCizbmahOUwqkJbNMfzj5Y7n7OIJOxNRkB IBOjPdF26dMP69BwePQao1M8Acrrex9sAHYjQGyVmReRjVEtv9iG4DoTsnIR3amKVk6si4Ea X/mrapJqSCcBUVYUFH8M7bsm4CSxier5ofy8jTEa/CfvkqpKThTMCQPNZKY7hke5qEq1CBk2 wxhX48ZrJEFf1v3NuV3OimgsF2odzieNABEBAAHCwXwEGAEKACYCGwwWIQSpQNQ0mSwujpkQ PVAiT6fnzIKmZAUCZAUSmwUJDK5EZgAKCRAiT6fnzIKmZOJGEACOKABgo9wJXsbWhGWYO7mD 8R8mUyJHqbvaz+yTLnvRwfe/VwafFfDMx5GYVYzMY9TWpA8psFTKTUIIQmx2scYsRBUwm5VI EurRWKqENcDRjyo+ol59j0FViYysjQQeobXBDDE31t5SBg++veI6tXfpco/UiKEsDswL1WAr tEAZaruo7254TyH+gydURl2wJuzo/aZ7Y7PpqaODbYv727Dvm5eX64HCyyAH0s6sOCyGF5/p eIhrOn24oBf67KtdAN3H9JoFNUVTYJc1VJU3R1JtVdgwEdr+NEciEfYl0O19VpLE/PZxP4wX PWnhf5WjdoNI1Xec+RcJ5p/pSel0jnvBX8L2cmniYnmI883NhtGZsEWj++wyKiS4NranDFlA HdDM3b4lUth1pTtABKQ1YuTvehj7EfoWD3bv9kuGZGPrAeFNiHPdOT7DaXKeHpW9homgtBxj 8aX/UkSvEGJKUEbFL9cVa5tzyialGkSiZJNkWgeHe+jEcfRT6pJZOJidSCdzvJpbdJmm+eED w9XOLH1IIWh7RURU7G1iOfEfmImFeC3cbbS73LQEFGe1urxvIH5K/7vX+FkNcr9ujwWuPE9b 1C2o4i/yZPLXIVy387EjA6GZMqvQUFuSTs/GeBcv0NjIQi8867H3uLjz+mQy63fAitsDwLmR EP+ylKVEKb0Q2A== In-Reply-To: <20241205104125.67518-1-lorenzo.stoakes@oracle.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Action: no action X-Rspamd-Queue-Id: 12F3A4001A X-Rspamd-Server: rspam12 X-Stat-Signature: 44hgq4sdhc89smuqyk1tyamsoj5ehrkh X-Rspam-User: X-HE-Tag: 1733420994-715118 X-HE-Meta: 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 kSMPPugx lS6GbzATlFFN38bbmw4NiXl7TRSsPJkVsmEKkp/fRiz0v877Ew0YzuHKd44q5dG28bRCB8F0HXyhkv9ynil6tBXsEqsncb/sqDdWLU9B484RoIGtxg1GVzB8G0rNsn7hyKreM0lm16X32HFS9Rb1cs21GuwuHZhnfpgdbwR2WCdX6LqerOgcK4aWOt5Tj3TTHf9SdCeAGk8oQZEedd6k27yKVGCERRHzk4mlY/KxAoC8ExH3k8O9c7PNXHLig9Q52qm85ciZ/x/f7vw9svB2xrOMXoukyirtJYzmxnj/KX34LTc9TZeCxc1Whp77eV3XyC0j9kQ7ZtOn9s/2arqErUMpxXnqrXFOPxqrDzCLmuGyOTNF+ZlKvmUnq2O00d0G1rszG4CzM7LvGF/OCq9uCa4zJSg== 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: List-Subscribe: List-Unsubscribe: On 12/5/24 11:41, Lorenzo Stoakes wrote: > Lightweight guard region support has been added to Linux 6.13, which adds > MADV_GUARD_INSTALL and MADV_GUARD_REMOVE flags to the madvise() system > call. Therefore, update the manpage for madvise() and describe these > operations. > > Reviewed-by: Jann Horn > Signed-off-by: Lorenzo Stoakes > --- > v4: > * Reference function chapters as per Alejandro. > * Minor rewording as per Alejandro. > > v3: > * Don't describe SIGSEGV as a fatal signal as per Jann. > https://lore.kernel.org/all/20241202165829.72121-1-lorenzo.stoakes@oracle.com > > v2: > * Updated to use semantic newlines as suggested by Alejandro. > * Avoided emboldening parens as suggested by Alejandro. > * One very minor grammatical fix. > https://lore.kernel.org/all/20241129155943.85215-1-lorenzo.stoakes@oracle.com > > v1: > https://lore.kernel.org/all/20241129093205.8664-1-lorenzo.stoakes@oracle.com > > man/man2/madvise.2 | 93 ++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 93 insertions(+) > > diff --git a/man/man2/madvise.2 b/man/man2/madvise.2 > index 4f2210ee2..7d682fa40 100644 > --- a/man/man2/madvise.2 > +++ b/man/man2/madvise.2 > @@ -676,6 +676,91 @@ or secret memory regions created using > Note that with > .BR MADV_POPULATE_WRITE , > the process can be killed at any moment when the system runs out of memory. > +.TP > +.BR MADV_GUARD_INSTALL " (since Linux 6.13)" > +Install a lightweight guard region into the range specified by > +.I addr > +and > +.IR size , > +causing any read or write in the range to result in a > +.B SIGSEGV > +signal being raised. > +.IP > +If the region maps memory pages they will be cleared as part of the operation, > +though if Hm this reads a bit ambiguous. One could read it as the memory pages are being cleared, but it's the page tables. > +.B MADV_GUARD_INSTALL > +is applied to regions containing pre-existing lightweight guard regions, > +they are left in place. > +.IP > +This operation is only supported for writable anonymous private mappings which > +have not been mlock'd. Not sure if "mlock'd" is the canonical term, I think I've seen "locked" used before, which I don't think it's great. Maybe Alejandro knows better. (there's also another "mlock'd" later in the patch)