From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0E7554FD78B; Thu, 17 Sep 2026 17:29:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789666169; cv=none; b=MQgow1uzdk61GGV9WxRX6yUdnUMNsQcfdFTzxINfEu1t/Jp/rwnwFnzriQDqtOfW0hboF+yAAhHttjkdhbq9aC22wki+A8tXSSHjwkM5YEUvq7zA035ZgUT7ZSvTm9nOIqnSHQtqulyrhWLwJroiVaiNzH6A9UvsiVF0WDFUJvo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789666169; c=relaxed/simple; bh=5TE3qraq7GClwJXcdkSpAaHBNVCfGvz6TieZ+P6h8cg=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=tTv91lWa6e6N6G1nI1JwAdfBec0BRpWGNAaVjTbVrgUia896Fx3Wyqmp3QRScNVJjuY11yMvE+FEs4G27jSnJSy6jEkXuunEBRyVHiT+IeCfNhYJNKyMoBzQifXDaQfsTInaWh531rxXdoqNdZV9fF/9CCsCA+BAOekTUhZFMXg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UKAaiMyJ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UKAaiMyJ" 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 Reply-To: sashiko-reviews@lists.linux.dev 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> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > 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