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 DC8C3C71148 for ; Fri, 13 Jun 2025 13:44:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7F9E96B00A4; Fri, 13 Jun 2025 09:44:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7D1526B00A5; Fri, 13 Jun 2025 09:44:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6E7896B00A6; Fri, 13 Jun 2025 09:44:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 50B496B00A4 for ; Fri, 13 Jun 2025 09:44:17 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 19967C0817 for ; Fri, 13 Jun 2025 13:44:17 +0000 (UTC) X-FDA: 83550496554.03.651A214 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf06.hostedemail.com (Postfix) with ESMTP id 8446E180006 for ; Fri, 13 Jun 2025 13:44:15 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf06.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1749822255; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gBxMD+vkqaTJ6lkoZPhzjIQaUSBgVv0R1o0w07xnXhM=; b=8lyMmDbtj14WmSJbshxfWkH6q1Ozf6ECZ4/09mHlOh5D+ND4FaiJOMdA0IL/2JsNKbFfM0 UEDyVMIuCb85rDIzir/0eIkF+3UHbc9lHoT9eaYcHMwNd7+yVophiKmKxiKoAf66ywv3AN 6Tinn2N1GFWX9cDxTr5l8+rsr7XMCNg= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1749822255; a=rsa-sha256; cv=none; b=dmI6Li/tq0p2yfn1FVreNYCviaT68v1GdX4lWfBryeOZOnsDd02tI8exsl4F/xO3OXlMPk ojJ/A1W2rD46StucaemxMy0VswIcFjUYKn4mp/7iPJhqmP3ILaQeANq8v6yQPNED4yeNYX NGaGpzcScXmiGimY3UNu1smqwAT/kGk= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf06.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 462562B; Fri, 13 Jun 2025 06:43:54 -0700 (PDT) Received: from MacBook-Pro.blr.arm.com (MacBook-Pro.blr.arm.com [10.164.18.48]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 07BAB3F59E; Fri, 13 Jun 2025 06:44:08 -0700 (PDT) From: Dev Jain To: akpm@linux-foundation.org, david@redhat.com, catalin.marinas@arm.com, will@kernel.org Cc: lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, suzuki.poulose@arm.com, steven.price@arm.com, gshan@redhat.com, linux-arm-kernel@lists.infradead.org, yang@os.amperecomputing.com, ryan.roberts@arm.com, anshuman.khandual@arm.com, Dev Jain Subject: [PATCH v3 2/2] arm64: pageattr: Enable huge-vmalloc permission change Date: Fri, 13 Jun 2025 19:13:52 +0530 Message-Id: <20250613134352.65994-3-dev.jain@arm.com> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20250613134352.65994-1-dev.jain@arm.com> References: <20250613134352.65994-1-dev.jain@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 8446E180006 X-Stat-Signature: s6ffync1btazztjm4tizait5eszz6985 X-Rspam-User: X-HE-Tag: 1749822255-89009 X-HE-Meta: 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 KyEkvhmz 5fZ7wwASsJhZCbi9UcGZ3IRE4FVaAylYgBhOaifaquX2e40lM6zKBY3QVygfRFpMZAC6GcMNx1K1stX4dUixaucrqEjSAaVK1D/8Z8gHyG6qxMn7F3MIBtA9qKzwfFFbQwa+FlyapyoMnPWB1vOB4Kf3RpQ== 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: Commit fcf8dda8cc48 ("arm64: pageattr: Explicitly bail out when changing permissions for vmalloc_huge mappings") disallowed changing permissions for vmalloc-huge mappings. The motivation of this was to enforce an API requirement and explicitly tell the caller that it is unsafe to change permissions for block mappings since splitting may be required, which cannot be handled safely on an arm64 system in absence of BBML2. This patch effectively partially reverts this commit, since patch 1 will now enable permission changes on kernel block mappings, thus, through change_memory_common(), enable permission changes for vmalloc-huge mappings. Any caller "misusing" the API, in the sense, calling it for a partial block mapping, will receive an error code of -EINVAL via the pagewalk callbacks, thus reverting to the behaviour of the API itself returning -EINVAL, through apply_to_page_range returning -EINVAL in case of block mappings, the difference now being, the -EINVAL is restricted to playing permission games on partial block mappings courtesy of patch 1. Signed-off-by: Dev Jain --- arch/arm64/mm/pageattr.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index cfc5279f27a2..66676f7f432a 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -195,8 +195,6 @@ static int change_memory_common(unsigned long addr, int numpages, * we are operating on does not result in such splitting. * * Let's restrict ourselves to mappings created by vmalloc (or vmap). - * Disallow VM_ALLOW_HUGE_VMAP mappings to guarantee that only page - * mappings are updated and splitting is never needed. * * So check whether the [addr, addr + size) interval is entirely * covered by precisely one VM area that has the VM_ALLOC flag set. @@ -204,7 +202,7 @@ static int change_memory_common(unsigned long addr, int numpages, area = find_vm_area((void *)addr); if (!area || end > (unsigned long)kasan_reset_tag(area->addr) + area->size || - ((area->flags & (VM_ALLOC | VM_ALLOW_HUGE_VMAP)) != VM_ALLOC)) + !(area->flags & VM_ALLOC)) return -EINVAL; if (!numpages) -- 2.30.2