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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 44EB9C88E72 for ; Thu, 17 Sep 2026 17:29:31 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 627DE10E77D; Thu, 17 Sep 2026 17:29:30 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="UKAaiMyJ"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id B275D10E77D for ; Thu, 17 Sep 2026 17:29:28 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 292BE60202; Thu, 17 Sep 2026 17:29:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B5541F000FF; Thu, 17 Sep 2026 17:29:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789666167; bh=5TE3qraq7GClwJXcdkSpAaHBNVCfGvz6TieZ+P6h8cg=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=UKAaiMyJRcTTdjILjPZhFLx1ia0R5fr4Q2L4BO0353r2fHbr9EF1yru36ZCwTtLlh 7Mel+t/Jb29foIL+qi6vxSgiWhm+5E5yz6aDl6WQmGe9zplkKlWjaFLRDqB0G8hWWT 8fRf3FQGtQKshwcyoTEO+mK2tK03P8xgqXqxwHqL6Uo7wzLSxmNzTSPRoP9NqqKQED MwsidzL62y6qNQOvUXoggTkbT12zrEFTaoDMdh0tlRZDMykWtZ0WnPNrdeQgwg9Fip +FeLaYP7JEps7CjaHcZR63cvj3lG5q1KDBv7/UQ8Bg+fCKWPLyti1hMPYvkrWIio10 1pyrMuSbMcVAw== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 10/40] drivers/usb/mon: update to use mmap_prepare + map kernel pages To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: linux-rdma@vger.kernel.org, "Marc Zyngier" , dri-devel@lists.freedesktop.org, "Heiko Carstens" , selinux@vger.kernel.org, kvmarm@lists.linux.dev, linux-scsi@vger.kernel.org, linux-s390@vger.kernel.org, "Oliver Upton" , kvm@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, "Vasily Gorbik" , "Christian Borntraeger" , linux-trace-kernel@vger.kernel.org, "Alexander Gordeev" In-Reply-To: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-10-4583d8a23bca@kernel.org> References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> <20260917-b4-mmap-prepare-vma-flag-sanify-v3-10-4583d8a23bca@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 17 Sep 2026 17:29:26 +0000 Message-Id: <20260917172927.0B5541F000FF@smtp.kernel.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" > Replace the deprecated .mmap hook with its replacement .mmap_prepare. As > part of this change, additionally take the approach of mapping pages upon > mmap rather than providing a fault handler. >=20 > The page span cannot be mutated when an mmap mapping is in place, so this > is safe to do in advance (the MON_IOCT_RING_SIZE ioctl operation exits > -EBUSY if it's attempted, gated by the rp->mmap_active reference count). >=20 > Utilise the newly introduced mmap_action_map_discontig_kernel_pages() to = do > this, which allows for iteration over pages in mon_bin_discontig_get(). >=20 > mon_bin_discontig_init() increments the rp->mmap_active reference count to > stabilise page spans. Should an error arise the core unmaps the VMA and > mon_bin_vma_close() drops the reference again. >=20 > [ ... ] > page discarded with MADV_DONTNEED is not repopulated and a subsequent > access raises SIGBUS, as with other pre-populated kernel mappings. >=20 > Acked-by: Greg Kroah-Hartman > Signed-off-by: Lorenzo Stoakes (ARM) Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260917-b4-mmap-pr= epare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org?part=3D10