add usb fix for user space libusb zero copy on some arches

2 files changed, 107 insertions, 0 deletions

diff --git a/kernel.spec b/kernel.spec
index 546109342..f0503d450 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -819,6 +819,9 @@ Patch303: ACPI-irq-Workaround-firmware-issue-on-X-Gene-based-m400.patch
 
 Patch304: ARM-tegra-usb-no-reset.patch
 
+# https://patchwork.kernel.org/patch/11527525/
+Patch305: usb-usbfs-correct-kernel-user-page-attribute-mismatch.patch
+
 # Raspberry Pi
 # https://patchwork.kernel.org/cover/11353083/
 Patch310: arm64-pinctrl-bcm2835-Add-support-for-all-BCM2711-GPIOs.patch
diff --git a/usb-usbfs-correct-kernel-user-page-attribute-mismatch.patch b/usb-usbfs-correct-kernel-user-page-attribute-mismatch.patch
new file mode 100644
index 000000000..ad65b8db6
--- /dev/null
+++ b/usb-usbfs-correct-kernel-user-page-attribute-mismatch.patch
@@ -0,0 +1,104 @@
+From patchwork Mon May  4 20:13:48 2020
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+X-Patchwork-Submitter: Jeremy Linton <jeremy.linton@arm.com>
+X-Patchwork-Id: 11527525
+Return-Path: <SRS0=7ANT=6S=vger.kernel.org=linux-usb-owner@kernel.org>
+Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org
+ [172.30.200.123])
+	by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1F74F92A
+	for <patchwork-linux-usb@patchwork.kernel.org>;
+ Mon,  4 May 2020 20:14:04 +0000 (UTC)
+Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
+	by mail.kernel.org (Postfix) with ESMTP id 11A4B20746
+	for <patchwork-linux-usb@patchwork.kernel.org>;
+ Mon,  4 May 2020 20:14:04 +0000 (UTC)
+Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
+        id S1726756AbgEDUOB (ORCPT
+        <rfc822;patchwork-linux-usb@patchwork.kernel.org>);
+        Mon, 4 May 2020 16:14:01 -0400
+Received: from foss.arm.com ([217.140.110.172]:52874 "EHLO foss.arm.com"
+        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
+        id S1726111AbgEDUOA (ORCPT <rfc822;linux-usb@vger.kernel.org>);
+        Mon, 4 May 2020 16:14:00 -0400
+Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14])
+        by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5BD30101E;
+        Mon,  4 May 2020 13:14:00 -0700 (PDT)
+Received: from mammon-tx2.austin.arm.com (mammon-tx2.austin.arm.com
+ [10.118.28.62])
+        by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id
+ 52CCC3F71F;
+        Mon,  4 May 2020 13:14:00 -0700 (PDT)
+From: Jeremy Linton <jeremy.linton@arm.com>
+To: linux-usb@vger.kernel.org
+Cc: gregkh@linuxfoundation.org, stern@rowland.harvard.edu,
+        git@thegavinli.com, jarkko.sakkinen@linux.intel.com,
+        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
+        mark.rutland@arm.com, maz@kernel.org, robin.murphy@arm.com,
+        Jeremy Linton <jeremy.linton@arm.com>
+Subject: [PATCH v2] usb: usbfs: correct kernel->user page attribute mismatch
+Date: Mon,  4 May 2020 15:13:48 -0500
+Message-Id: <20200504201348.1183246-1-jeremy.linton@arm.com>
+X-Mailer: git-send-email 2.24.1
+MIME-Version: 1.0
+Sender: linux-usb-owner@vger.kernel.org
+Precedence: bulk
+List-ID: <linux-usb.vger.kernel.org>
+X-Mailing-List: linux-usb@vger.kernel.org
+
+On some architectures (e.g. arm64) requests for
+IO coherent memory may use non-cachable attributes if
+the relevant device isn't cache coherent. If these
+pages are then remapped into userspace as cacheable,
+they may not be coherent with the non-cacheable mappings.
+
+In particular this happens with libusb, when it attempts
+to create zero-copy buffers for use by rtl-sdr
+(https://github.com/osmocom/rtl-sdr/). On low end arm
+devices with non-coherent USB ports, the application will
+be unexpectedly killed, while continuing to work fine on
+arm machines with coherent USB controllers.
+
+This bug has been discovered/reported a few times over
+the last few years. In the case of rtl-sdr a compile time
+option to enable/disable zero copy was implemented to
+work around it.
+
+Rather than relaying on application specific workarounds,
+dma_mmap_coherent() can be used instead of remap_pfn_range().
+The page cache/etc attributes will then be correctly set in
+userspace to match the kernel mapping.
+
+Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
+---
+v1->v2:
+	Update commit message and change to dma_mmap_coherent()
+	from dma_mmap_attr(,,,0) which are the same.
+
+ drivers/usb/core/devio.c | 5 ++---
+ 1 file changed, 2 insertions(+), 3 deletions(-)
+
+diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
+index 6833c918abce..b9db9812d6c5 100644
+--- a/drivers/usb/core/devio.c
++++ b/drivers/usb/core/devio.c
+@@ -217,6 +217,7 @@ static int usbdev_mmap(struct file *file, struct vm_area_struct *vma)
+ {
+ 	struct usb_memory *usbm = NULL;
+ 	struct usb_dev_state *ps = file->private_data;
++	struct usb_hcd *hcd = bus_to_hcd(ps->dev->bus);
+ 	size_t size = vma->vm_end - vma->vm_start;
+ 	void *mem;
+ 	unsigned long flags;
+@@ -250,9 +251,7 @@ static int usbdev_mmap(struct file *file, struct vm_area_struct *vma)
+ 	usbm->vma_use_count = 1;
+ 	INIT_LIST_HEAD(&usbm->memlist);
+ 
+-	if (remap_pfn_range(vma, vma->vm_start,
+-			virt_to_phys(usbm->mem) >> PAGE_SHIFT,
+-			size, vma->vm_page_prot) < 0) {
++	if (dma_mmap_coherent(hcd->self.sysdev, vma, mem, dma_handle, size)) {
+ 		dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
+ 		return -EAGAIN;
+ 	}