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 5A86B368D78; Mon, 14 Sep 2026 17:18:21 +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=1789406302; cv=none; b=AWONmy239gryeApOulMgK1UwrIJwL5M2Ayhc5n8yn7+YMYJ4p+5E+ITz4rPNMIB/amIQW1BatOkClKBl4bBYQODAwIYAgSWrZS9dc/oqFiEVDoYZGAW+0z3ZC0jHEaed/9WQeP8cx8/XbHLbViJsy06SfLFdaAGLbpJVF/+ryjI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789406302; c=relaxed/simple; bh=pauKHZWnefu0Gep+Yagb66UL066ySpulAaOVGUW/esM=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=E+3totgCV23ycw+37cWOGe8UdIyPAX2GGVkUqZ+jhXipYv3BJvMj+PnP/bVUrNdPJ40aFUXcGBBJeJiqUV3UgzPYbteeN03ZhQOzcheDccYBPiSnwFftIiIyj0Lx3AjBr3qK0bETmKZmM42oEvcAxRf7eQQDfLuiZEjlpKB9Yj0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jqegBZjG; 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="jqegBZjG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 219E01F00893; Mon, 14 Sep 2026 17:18:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789406301; bh=pauKHZWnefu0Gep+Yagb66UL066ySpulAaOVGUW/esM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=jqegBZjGFHivvTOkcrd4LsU6SjsE8bS8wg2bRQG8dmb2zUi5lEW0EoUQKKt/mVLPM R3j92zYpwoXFeJm9yoBqTTi+o+hA+S3S+Soqt2apm6sVHlfgLona+cic7xsflOyCyQ wWv8L14X10AIIUfCi9+tttmMuNTPrWTXiuX+subvlixhkxhMz1C6GdwjctkMGXUkjW B1vkJW21v8DOTs5PcgL6Pdfm2k62grfrGkl1/ewXLbSmcMBzdQV/ZGPheKIyDArAhF NfObdDplPUCHMeK1yHqjpNVRk7/vrkwnmceVPoN1FvBX40nA8kE17QCq850HUDR5BX 1g27ty4UyIF6w== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 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: "Heiko Carstens" , "Oliver Upton" , kvmarm@lists.linux.dev, kvm@vger.kernel.org, "Vasily Gorbik" , "Marc Zyngier" , linux-scsi@vger.kernel.org, linux-s390@vger.kernel.org, selinux@vger.kernel.org, linux-rdma@vger.kernel.org, "Alexander Gordeev" , linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, "Christian Borntraeger" , bpf@vger.kernel.org In-Reply-To: <20260914-b4-mmap-prepare-vma-flag-sanify-v2-10-7d9781ed5361@kernel.org> References: <20260914-b4-mmap-prepare-vma-flag-sanify-v2-0-7d9781ed5361@kernel.org> <20260914-b4-mmap-prepare-vma-flag-sanify-v2-10-7d9781ed5361@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 14 Sep 2026 17:18:19 +0000 Message-Id: <20260914171820.219E01F00893@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/20260914-b4-mmap-pr= epare-vma-flag-sanify-v2-0-7d9781ed5361@kernel.org?part=3D10