From patchwork Thu Oct 26 20:01:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 738638 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 556003C078 for ; Thu, 26 Oct 2023 20:09:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Q6YJK2jt" X-Greylist: delayed 486 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 26 Oct 2023 13:09:31 PDT Received: from out-174.mta0.migadu.com (out-174.mta0.migadu.com [91.218.175.174]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B84EE129 for ; Thu, 26 Oct 2023 13:09:31 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1698350482; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=w9sbKYXZtIyf/ohQE3Edg07I3no4RCuR4cZPauSieZc=; b=Q6YJK2jt8aNtYlz8aXpbXEWd2kqMpPtQi5xuwpIHAqyuf9aFF60iI469yR9sXN+U5jAsl1 Mtp7c9Vc5whZ4u38LKe46DBzYaXVhRTQQCFXcC/gDZVPwZarUGe2TcuOM0l9txxgRMmVIq drqS5ay+gubC+PaR89dnjZTdhkwB61U= From: andrey.konovalov@linux.dev To: Greg Kroah-Hartman Cc: Andrey Konovalov , Alan Stern , Felipe Balbi , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/3] usb: raw-gadget: properly handle interrupted requests Date: Thu, 26 Oct 2023 22:01:12 +0200 Message-Id: <0db45b1d7cc466e3d4d1ab353f61d63c977fbbc5.1698350424.git.andreyknvl@gmail.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT From: Andrey Konovalov Currently, if a USB request that was queued by Raw Gadget is interrupted (via a signal), wait_for_completion_interruptible returns -ERESTARTSYS. Raw Gadget then attempts to propagate this value to userspace as a return value from its ioctls. However, when -ERESTARTSYS is returned by a syscall handler, the kernel internally restarts the syscall. This doesn't allow userspace applications to interrupt requests queued by Raw Gadget (which is required when the emulated device is asked to switch altsettings). It also violates the implied interface of Raw Gadget that a single ioctl must only queue a single USB request. Instead, make Raw Gadget do what GadgetFS does: check whether the request was interrupted (dequeued with status == -ECONNRESET) and report -EINTR to userspace. Fixes: f2c2e717642c ("usb: gadget: add raw-gadget interface") Signed-off-by: Andrey Konovalov --- drivers/usb/gadget/legacy/raw_gadget.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c index b9ecc55a2ce2..ce9e87f84911 100644 --- a/drivers/usb/gadget/legacy/raw_gadget.c +++ b/drivers/usb/gadget/legacy/raw_gadget.c @@ -674,12 +674,12 @@ static int raw_process_ep0_io(struct raw_dev *dev, struct usb_raw_ep_io *io, if (WARN_ON(in && dev->ep0_out_pending)) { ret = -ENODEV; dev->state = STATE_DEV_FAILED; - goto out_done; + goto out_unlock; } if (WARN_ON(!in && dev->ep0_in_pending)) { ret = -ENODEV; dev->state = STATE_DEV_FAILED; - goto out_done; + goto out_unlock; } dev->req->buf = data; @@ -694,7 +694,7 @@ static int raw_process_ep0_io(struct raw_dev *dev, struct usb_raw_ep_io *io, "fail, usb_ep_queue returned %d\n", ret); spin_lock_irqsave(&dev->lock, flags); dev->state = STATE_DEV_FAILED; - goto out_done; + goto out_queue_failed; } ret = wait_for_completion_interruptible(&dev->ep0_done); @@ -703,13 +703,16 @@ static int raw_process_ep0_io(struct raw_dev *dev, struct usb_raw_ep_io *io, usb_ep_dequeue(dev->gadget->ep0, dev->req); wait_for_completion(&dev->ep0_done); spin_lock_irqsave(&dev->lock, flags); - goto out_done; + if (dev->ep0_status == -ECONNRESET) + dev->ep0_status = -EINTR; + goto out_interrupted; } spin_lock_irqsave(&dev->lock, flags); - ret = dev->ep0_status; -out_done: +out_interrupted: + ret = dev->ep0_status; +out_queue_failed: dev->ep0_urb_queued = false; out_unlock: spin_unlock_irqrestore(&dev->lock, flags); @@ -1078,7 +1081,7 @@ static int raw_process_ep_io(struct raw_dev *dev, struct usb_raw_ep_io *io, "fail, usb_ep_queue returned %d\n", ret); spin_lock_irqsave(&dev->lock, flags); dev->state = STATE_DEV_FAILED; - goto out_done; + goto out_queue_failed; } ret = wait_for_completion_interruptible(&done); @@ -1087,13 +1090,16 @@ static int raw_process_ep_io(struct raw_dev *dev, struct usb_raw_ep_io *io, usb_ep_dequeue(ep->ep, ep->req); wait_for_completion(&done); spin_lock_irqsave(&dev->lock, flags); - goto out_done; + if (ep->status == -ECONNRESET) + ep->status = -EINTR; + goto out_interrupted; } spin_lock_irqsave(&dev->lock, flags); - ret = ep->status; -out_done: +out_interrupted: + ret = ep->status; +out_queue_failed: ep->urb_queued = false; out_unlock: spin_unlock_irqrestore(&dev->lock, flags);