From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [PATCHv2] UAS: fix alignment of scatter/gather segments From: Oliver Neukum Message-Id: <20190430102145.7423-1-oneukum@suse.com> Date: Tue, 30 Apr 2019 12:21:45 +0200 To: gregKH@linuxfoundation.org, linux-usb@vger.kernel.org Cc: Oliver Neukum List-ID: VGhpcyBpcyB0aGUgVUFTIHZlcnNpb24gb2YKCjc0NzY2OGRiYzA2MWIzZTYyYmMxOTgyNzY3YTNh MWY5ODE1ZmNmMGUKdXNiLXN0b3JhZ2U6IFNldCB2aXJ0X2JvdW5kYXJ5X21hc2sgdG8gYXZvaWQg U0cgb3ZlcmZsb3dzCgpXZSBhcmUgbm90IGFzIGxpa2VseSB0byBiZSB2dWxuZXJhYmxlIGFzIHN0 b3JhZ2UsIGFzIGl0IGlzIHVubGlrZWxpZXIKdGhhdCBVQVMgaXMgcnVuIG92ZXIgYSBjb250cm9s bGVyIHdpdGhvdXQgbmF0aXZlIHN1cHBvcnQgZm9yIFNHLApidXQgdGhlIGlzc3VlIGV4aXN0cy4K VGhlIGlzc3VlIGhhcyBiZWVuIGV4aXN0aW5nIHNpbmNlIHRoZSBpbmNlcHRpb24gb2YgdGhlIGRy aXZlci4KCkZpeGVzOiAxMTViYjFmZmE1NGFjICgiVVNCOiBBZGQgVUFTIGRyaXZlciIpClNpZ25l ZC1vZmYtYnk6IE9saXZlciBOZXVrdW0gPG9uZXVrdW1Ac3VzZS5jb20+Ci0tLQogZHJpdmVycy91 c2Ivc3RvcmFnZS91YXMuYyB8IDM1ICsrKysrKysrKysrKysrKysrKysrKystLS0tLS0tLS0tLS0t CiAxIGZpbGUgY2hhbmdlZCwgMjIgaW5zZXJ0aW9ucygrKSwgMTMgZGVsZXRpb25zKC0pCgpkaWZm IC0tZ2l0IGEvZHJpdmVycy91c2Ivc3RvcmFnZS91YXMuYyBiL2RyaXZlcnMvdXNiL3N0b3JhZ2Uv dWFzLmMKaW5kZXggNmQ3MWI4ZmZmOWRmLi4zODU2ZjM0Yjg5YjggMTAwNjQ0Ci0tLSBhL2RyaXZl cnMvdXNiL3N0b3JhZ2UvdWFzLmMKKysrIGIvZHJpdmVycy91c2Ivc3RvcmFnZS91YXMuYwpAQCAt Nzg5LDI0ICs3ODksMzMgQEAgc3RhdGljIGludCB1YXNfc2xhdmVfYWxsb2Moc3RydWN0IHNjc2lf ZGV2aWNlICpzZGV2KQogewogCXN0cnVjdCB1YXNfZGV2X2luZm8gKmRldmluZm8gPQogCQkoc3Ry dWN0IHVhc19kZXZfaW5mbyAqKXNkZXYtPmhvc3QtPmhvc3RkYXRhOworCWludCBtYXhwOwogCiAJ c2Rldi0+aG9zdGRhdGEgPSBkZXZpbmZvOwogCiAJLyoKLQkgKiBVU0IgaGFzIHVudXN1YWwgRE1B LWFsaWdubWVudCByZXF1aXJlbWVudHM6IEFsdGhvdWdoIHRoZQotCSAqIHN0YXJ0aW5nIGFkZHJl c3Mgb2YgZWFjaCBzY2F0dGVyLWdhdGhlciBlbGVtZW50IGRvZXNuJ3QgbWF0dGVyLAotCSAqIHRo ZSBsZW5ndGggb2YgZWFjaCBlbGVtZW50IGV4Y2VwdCB0aGUgbGFzdCBtdXN0IGJlIGRpdmlzaWJs ZQotCSAqIGJ5IHRoZSBCdWxrIG1heHBhY2tldCB2YWx1ZS4gIFRoZXJlJ3MgY3VycmVudGx5IG5v IHdheSB0bwotCSAqIGV4cHJlc3MgdGhpcyBieSBibG9jay1sYXllciBjb25zdHJhaW50cywgc28g d2UnbGwgY29wIG91dAotCSAqIGFuZCBzaW1wbHkgcmVxdWlyZSBhZGRyZXNzZXMgdG8gYmUgYWxp Z25lZCBhdCA1MTItYnl0ZQotCSAqIGJvdW5kYXJpZXMuICBUaGlzIGlzIG9rYXkgc2luY2UgbW9z dCBibG9jayBJL08gaW52b2x2ZXMKLQkgKiBoYXJkd2FyZSBzZWN0b3JzIHRoYXQgYXJlIG11bHRp cGxlcyBvZiA1MTIgYnl0ZXMgaW4gbGVuZ3RoLAotCSAqIGFuZCBzaW5jZSBob3N0IGNvbnRyb2xs ZXJzIHVwIHRocm91Z2ggVVNCIDIuMCBoYXZlIG1heHBhY2tldAotCSAqIHZhbHVlcyBubyBsYXJn ZXIgdGhhbiA1MTIuCisJICogV2UgaGF2ZSB0d28gcmVxdWlyZW1lbnRzIGhlcmUuIFdlIG11c3Qg c2F0aXNmeSB0aGUgcmVxdWlyZW1lbnRzCisJICogb2YgdGhlIHBoeXNpY2FsIEhDIGFuZCB0aGUg ZGVtYW5kcyBvZiB0aGUgcHJvdG9jb2wsIGFzIHdlCisJICogZGVmaW5pdGVseSB3YW50IG5vIGFk ZGl0aW9uYWwgbWVtb3J5IGFsbG9jYXRpb24gaW4gdGhpcyBwYXRoCisJICogcnVsaW5nIG91dCB1 c2luZyBib3VuY2UgYnVmZmVycy4KIAkgKgotCSAqIEJ1dCBpdCBkb2Vzbid0IHN1ZmZpY2UgZm9y IFdpcmVsZXNzIFVTQiwgd2hlcmUgQnVsayBtYXhwYWNrZXQKLQkgKiB2YWx1ZXMgY2FuIGJlIGFz IGxhcmdlIGFzIDIwNDguICBUbyBtYWtlIHRoYXQgd29yayBwcm9wZXJseQotCSAqIHdpbGwgcmVx dWlyZSBjaGFuZ2VzIHRvIHRoZSBibG9jayBsYXllci4KKwkgKiBGb3IgYSB0cmFuc21pc3Npb24g b24gVVNCIHRvIGNvbnRpbnVlIHdlIG11c3QgbmV2ZXIgc2VuZAorCSAqIGEgcGFja2FnZSB0aGF0 IGlzIHNtYWxsZXIgdGhhbiBtYXhwYWNrZXQuIEhlbmNlIHRoZSBsZW5ndGggb2YgZWFjaAorICAg ICAgICAgKiBzY2F0dGVybGlzdCBlbGVtZW50IGV4Y2VwdCB0aGUgbGFzdCBtdXN0IGJlIGRpdmlz aWJsZSBieSB0aGUKKyAgICAgICAgICogQnVsayBtYXhwYWNrZXQgdmFsdWUuCisJICogSWYgdGhl IEhDIGRvZXMgbm90IGVuc3VyZSB0aGF0IHRocm91Z2ggU0csCisJICogdGhlIHVwcGVyIGxheWVy IG11c3QgZG8gdGhhdC4gV2UgbXVzdCBhc3N1bWUgbm90aGluZworCSAqIGFib3V0IHRoZSBjYXBh YmlsaXRpZXMgb2ZmIHRoZSBIQywgc28gd2UgdXNlIHRoZSBtb3N0CisJICogcGVzc2ltaXN0aWMg cmVxdWlyZW1lbnQuCisJICovCisKKwltYXhwID0gdXNiX21heHBhY2tldChkZXZpbmZvLT51ZGV2 LCBkZXZpbmZvLT5kYXRhX2luX3BpcGUsIDApOworCWJsa19xdWV1ZV92aXJ0X2JvdW5kYXJ5KHNk ZXYtPnJlcXVlc3RfcXVldWUsIG1heHAgLSAxKTsKKworCS8qCisJICogVGhlIHByb3RvY29sIGhh cyBubyByZXF1aXJlbWVudHMgb24gYWxpZ25tZW50IGluIHRoZSBzdHJpY3Qgc2Vuc2UuCisJICog Q29udHJvbGxlcnMgbWF5IG9yIG1heSBub3QgaGF2ZSBhbGlnbm1lbnQgcmVzdHJpY3Rpb25zLgor CSAqIEFzIHRoaXMgaXMgbm90IGV4cG9ydGVkLCB3ZSB1c2UgYW4gZXh0cmVtZWx5IGNvbnNlcnZh dGl2ZSBndWVzcy4KIAkgKi8KIAlibGtfcXVldWVfdXBkYXRlX2RtYV9hbGlnbm1lbnQoc2Rldi0+ cmVxdWVzdF9xdWV1ZSwgKDUxMiAtIDEpKTsKIAo= 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 X-Spam-Level: X-Spam-Status: No, score=-8.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DDE0EC43219 for ; Tue, 30 Apr 2019 10:22:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0B2621670 for ; Tue, 30 Apr 2019 10:22:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726262AbfD3KWH (ORCPT ); Tue, 30 Apr 2019 06:22:07 -0400 Received: from mx2.suse.de ([195.135.220.15]:51012 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726129AbfD3KWH (ORCPT ); Tue, 30 Apr 2019 06:22:07 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 5544EAD64; Tue, 30 Apr 2019 10:22:06 +0000 (UTC) From: Oliver Neukum To: gregKH@linuxfoundation.org, linux-usb@vger.kernel.org Cc: Oliver Neukum Subject: [PATCHv2] UAS: fix alignment of scatter/gather segments Date: Tue, 30 Apr 2019 12:21:45 +0200 Message-Id: <20190430102145.7423-1-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Message-ID: <20190430102145.WOboyrLEbKTOLXfS-3oZunR1akYCn2x4sr1Ug9lZhzM@z> This is the UAS version of 747668dbc061b3e62bc1982767a3a1f9815fcf0e usb-storage: Set virt_boundary_mask to avoid SG overflows We are not as likely to be vulnerable as storage, as it is unlikelier that UAS is run over a controller without native support for SG, but the issue exists. The issue has been existing since the inception of the driver. Fixes: 115bb1ffa54ac ("USB: Add UAS driver") Signed-off-by: Oliver Neukum --- drivers/usb/storage/uas.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index 6d71b8fff9df..3856f34b89b8 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -789,24 +789,33 @@ static int uas_slave_alloc(struct scsi_device *sdev) { struct uas_dev_info *devinfo = (struct uas_dev_info *)sdev->host->hostdata; + int maxp; sdev->hostdata = devinfo; /* - * USB has unusual DMA-alignment requirements: Although the - * starting address of each scatter-gather element doesn't matter, - * the length of each element except the last must be divisible - * by the Bulk maxpacket value. There's currently no way to - * express this by block-layer constraints, so we'll cop out - * and simply require addresses to be aligned at 512-byte - * boundaries. This is okay since most block I/O involves - * hardware sectors that are multiples of 512 bytes in length, - * and since host controllers up through USB 2.0 have maxpacket - * values no larger than 512. + * We have two requirements here. We must satisfy the requirements + * of the physical HC and the demands of the protocol, as we + * definitely want no additional memory allocation in this path + * ruling out using bounce buffers. * - * But it doesn't suffice for Wireless USB, where Bulk maxpacket - * values can be as large as 2048. To make that work properly - * will require changes to the block layer. + * For a transmission on USB to continue we must never send + * a package that is smaller than maxpacket. Hence the length of each + * scatterlist element except the last must be divisible by the + * Bulk maxpacket value. + * If the HC does not ensure that through SG, + * the upper layer must do that. We must assume nothing + * about the capabilities off the HC, so we use the most + * pessimistic requirement. + */ + + maxp = usb_maxpacket(devinfo->udev, devinfo->data_in_pipe, 0); + blk_queue_virt_boundary(sdev->request_queue, maxp - 1); + + /* + * The protocol has no requirements on alignment in the strict sense. + * Controllers may or may not have alignment restrictions. + * As this is not exported, we use an extremely conservative guess. */ blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1)); -- 2.16.4