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: [PATCHv3] UAS: fix alignment of scatter/gather segments From: Oliver Neukum Message-Id: <20190430131000.9723-1-oneukum@suse.com> Date: Tue, 30 Apr 2019 15:10:00 +0200 To: gregKH@linuxfoundation.org, linux-usb@vger.kernel.org Cc: Oliver Neukum List-ID: VGhpcyBpcyB0aGUgVUFTIHZlcnNpb24gb2YKCjc0NzY2OGRiYzA2MWIzZTYyYmMxOTgyNzY3YTNh MWY5ODE1ZmNmMGUKdXNiLXN0b3JhZ2U6IFNldCB2aXJ0X2JvdW5kYXJ5X21hc2sgdG8gYXZvaWQg U0cgb3ZlcmZsb3dzCgpXZSBhcmUgbm90IGFzIGxpa2VseSB0byBiZSB2dWxuZXJhYmxlIGFzIHN0 b3JhZ2UsIGFzIGl0IGlzIHVubGlrZWxpZXIKdGhhdCBVQVMgaXMgcnVuIG92ZXIgYSBjb250cm9s bGVyIHdpdGhvdXQgbmF0aXZlIHN1cHBvcnQgZm9yIFNHLApidXQgdGhlIGlzc3VlIGV4aXN0cy4K VGhlIGlzc3VlIGhhcyBiZWVuIGV4aXN0aW5nIHNpbmNlIHRoZSBpbmNlcHRpb24gb2YgdGhlIGRy aXZlci4KCnYyOiBpbXByb3ZlZCBjb21tZW50cwp2MzogcmVtb3ZlZCB2aSBhcnRpZmFjdHMgZnJv bSBsb2cgdGV4dAoKRml4ZXM6IDExNWJiMWZmYTU0YyAoIlVTQjogQWRkIFVBUyBkcml2ZXIiKQpT aWduZWQtb2ZmLWJ5OiBPbGl2ZXIgTmV1a3VtIDxvbmV1a3VtQHN1c2UuY29tPgotLS0KIGRyaXZl cnMvdXNiL3N0b3JhZ2UvdWFzLmMgfCAzNSArKysrKysrKysrKysrKysrKysrKysrLS0tLS0tLS0t LS0tLQogMSBmaWxlIGNoYW5nZWQsIDIyIGluc2VydGlvbnMoKyksIDEzIGRlbGV0aW9ucygtKQoK ZGlmZiAtLWdpdCBhL2RyaXZlcnMvdXNiL3N0b3JhZ2UvdWFzLmMgYi9kcml2ZXJzL3VzYi9zdG9y YWdlL3Vhcy5jCmluZGV4IDZkNzFiOGZmZjlkZi4uMzg1NmYzNGI4OWI4IDEwMDY0NAotLS0gYS9k cml2ZXJzL3VzYi9zdG9yYWdlL3Vhcy5jCisrKyBiL2RyaXZlcnMvdXNiL3N0b3JhZ2UvdWFzLmMK QEAgLTc4OSwyNCArNzg5LDMzIEBAIHN0YXRpYyBpbnQgdWFzX3NsYXZlX2FsbG9jKHN0cnVjdCBz Y3NpX2RldmljZSAqc2RldikKIHsKIAlzdHJ1Y3QgdWFzX2Rldl9pbmZvICpkZXZpbmZvID0KIAkJ KHN0cnVjdCB1YXNfZGV2X2luZm8gKilzZGV2LT5ob3N0LT5ob3N0ZGF0YTsKKwlpbnQgbWF4cDsK IAogCXNkZXYtPmhvc3RkYXRhID0gZGV2aW5mbzsKIAogCS8qCi0JICogVVNCIGhhcyB1bnVzdWFs IERNQS1hbGlnbm1lbnQgcmVxdWlyZW1lbnRzOiBBbHRob3VnaCB0aGUKLQkgKiBzdGFydGluZyBh ZGRyZXNzIG9mIGVhY2ggc2NhdHRlci1nYXRoZXIgZWxlbWVudCBkb2Vzbid0IG1hdHRlciwKLQkg KiB0aGUgbGVuZ3RoIG9mIGVhY2ggZWxlbWVudCBleGNlcHQgdGhlIGxhc3QgbXVzdCBiZSBkaXZp c2libGUKLQkgKiBieSB0aGUgQnVsayBtYXhwYWNrZXQgdmFsdWUuICBUaGVyZSdzIGN1cnJlbnRs eSBubyB3YXkgdG8KLQkgKiBleHByZXNzIHRoaXMgYnkgYmxvY2stbGF5ZXIgY29uc3RyYWludHMs IHNvIHdlJ2xsIGNvcCBvdXQKLQkgKiBhbmQgc2ltcGx5IHJlcXVpcmUgYWRkcmVzc2VzIHRvIGJl IGFsaWduZWQgYXQgNTEyLWJ5dGUKLQkgKiBib3VuZGFyaWVzLiAgVGhpcyBpcyBva2F5IHNpbmNl IG1vc3QgYmxvY2sgSS9PIGludm9sdmVzCi0JICogaGFyZHdhcmUgc2VjdG9ycyB0aGF0IGFyZSBt dWx0aXBsZXMgb2YgNTEyIGJ5dGVzIGluIGxlbmd0aCwKLQkgKiBhbmQgc2luY2UgaG9zdCBjb250 cm9sbGVycyB1cCB0aHJvdWdoIFVTQiAyLjAgaGF2ZSBtYXhwYWNrZXQKLQkgKiB2YWx1ZXMgbm8g bGFyZ2VyIHRoYW4gNTEyLgorCSAqIFdlIGhhdmUgdHdvIHJlcXVpcmVtZW50cyBoZXJlLiBXZSBt dXN0IHNhdGlzZnkgdGhlIHJlcXVpcmVtZW50cworCSAqIG9mIHRoZSBwaHlzaWNhbCBIQyBhbmQg dGhlIGRlbWFuZHMgb2YgdGhlIHByb3RvY29sLCBhcyB3ZQorCSAqIGRlZmluaXRlbHkgd2FudCBu byBhZGRpdGlvbmFsIG1lbW9yeSBhbGxvY2F0aW9uIGluIHRoaXMgcGF0aAorCSAqIHJ1bGluZyBv dXQgdXNpbmcgYm91bmNlIGJ1ZmZlcnMuCiAJICoKLQkgKiBCdXQgaXQgZG9lc24ndCBzdWZmaWNl IGZvciBXaXJlbGVzcyBVU0IsIHdoZXJlIEJ1bGsgbWF4cGFja2V0Ci0JICogdmFsdWVzIGNhbiBi ZSBhcyBsYXJnZSBhcyAyMDQ4LiAgVG8gbWFrZSB0aGF0IHdvcmsgcHJvcGVybHkKLQkgKiB3aWxs IHJlcXVpcmUgY2hhbmdlcyB0byB0aGUgYmxvY2sgbGF5ZXIuCisJICogRm9yIGEgdHJhbnNtaXNz aW9uIG9uIFVTQiB0byBjb250aW51ZSB3ZSBtdXN0IG5ldmVyIHNlbmQKKwkgKiBhIHBhY2thZ2Ug dGhhdCBpcyBzbWFsbGVyIHRoYW4gbWF4cGFja2V0LiBIZW5jZSB0aGUgbGVuZ3RoIG9mIGVhY2gK KyAgICAgICAgICogc2NhdHRlcmxpc3QgZWxlbWVudCBleGNlcHQgdGhlIGxhc3QgbXVzdCBiZSBk aXZpc2libGUgYnkgdGhlCisgICAgICAgICAqIEJ1bGsgbWF4cGFja2V0IHZhbHVlLgorCSAqIElm IHRoZSBIQyBkb2VzIG5vdCBlbnN1cmUgdGhhdCB0aHJvdWdoIFNHLAorCSAqIHRoZSB1cHBlciBs YXllciBtdXN0IGRvIHRoYXQuIFdlIG11c3QgYXNzdW1lIG5vdGhpbmcKKwkgKiBhYm91dCB0aGUg Y2FwYWJpbGl0aWVzIG9mZiB0aGUgSEMsIHNvIHdlIHVzZSB0aGUgbW9zdAorCSAqIHBlc3NpbWlz dGljIHJlcXVpcmVtZW50LgorCSAqLworCisJbWF4cCA9IHVzYl9tYXhwYWNrZXQoZGV2aW5mby0+ dWRldiwgZGV2aW5mby0+ZGF0YV9pbl9waXBlLCAwKTsKKwlibGtfcXVldWVfdmlydF9ib3VuZGFy eShzZGV2LT5yZXF1ZXN0X3F1ZXVlLCBtYXhwIC0gMSk7CisKKwkvKgorCSAqIFRoZSBwcm90b2Nv bCBoYXMgbm8gcmVxdWlyZW1lbnRzIG9uIGFsaWdubWVudCBpbiB0aGUgc3RyaWN0IHNlbnNlLgor CSAqIENvbnRyb2xsZXJzIG1heSBvciBtYXkgbm90IGhhdmUgYWxpZ25tZW50IHJlc3RyaWN0aW9u cy4KKwkgKiBBcyB0aGlzIGlzIG5vdCBleHBvcnRlZCwgd2UgdXNlIGFuIGV4dHJlbWVseSBjb25z ZXJ2YXRpdmUgZ3Vlc3MuCiAJICovCiAJYmxrX3F1ZXVlX3VwZGF0ZV9kbWFfYWxpZ25tZW50KHNk ZXYtPnJlcXVlc3RfcXVldWUsICg1MTIgLSAxKSk7CiAK 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 3BB4DC43219 for ; Tue, 30 Apr 2019 13:10:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16BD420835 for ; Tue, 30 Apr 2019 13:10:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726614AbfD3NKV (ORCPT ); Tue, 30 Apr 2019 09:10:21 -0400 Received: from mx2.suse.de ([195.135.220.15]:34492 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726264AbfD3NKV (ORCPT ); Tue, 30 Apr 2019 09:10:21 -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 5F1CCADD4; Tue, 30 Apr 2019 13:10:20 +0000 (UTC) From: Oliver Neukum To: gregKH@linuxfoundation.org, linux-usb@vger.kernel.org Cc: Oliver Neukum Subject: [PATCHv3] UAS: fix alignment of scatter/gather segments Date: Tue, 30 Apr 2019 15:10:00 +0200 Message-Id: <20190430131000.9723-1-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: <20190430131000.GGfnh6w2QOftJ_LlbY7vgkgFukyC5_EwJD8K-lYshoA@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. v2: improved comments v3: removed vi artifacts from log text Fixes: 115bb1ffa54c ("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