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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Mathias Nyman <mathias.nyman@linux.intel.com>,
        Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Subject: [PATCH 4.14 322/323] xhci: Do not use GFP_KERNEL in (potentially) atomic context
Date:   Thu, 20 May 2021 11:23:34 +0200
Message-Id: <20210520092131.280369939@linuxfoundation.org>
In-Reply-To: <20210520092120.115153432@linuxfoundation.org>
References: <20210520092120.115153432@linuxfoundation.org>
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From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

commit dda32c00c9a0fa103b5d54ef72c477b7aa993679 upstream.

'xhci_urb_enqueue()' is passed a 'mem_flags' argument, because "URBs may be
submitted in interrupt context" (see comment related to 'usb_submit_urb()'
in 'drivers/usb/core/urb.c')

So this flag should be used in all the calling chain.
Up to now, 'xhci_check_maxpacket()' which is only called from
'xhci_urb_enqueue()', uses GFP_KERNEL.

Be safe and pass the mem_flags to this function as well.

Fixes: ddba5cd0aeff ("xhci: Use command structures when queuing commands on the command ring")
Cc: <stable@vger.kernel.org>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210512080816.866037-4-mathias.nyman@linux.intel.com
[iwamatsu: Adjust context]
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/host/xhci.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1308,7 +1308,7 @@ static int xhci_configure_endpoint(struc
  * we need to issue an evaluate context command and wait on it.
  */
 static int xhci_check_maxpacket(struct xhci_hcd *xhci, unsigned int slot_id,
-		unsigned int ep_index, struct urb *urb)
+		unsigned int ep_index, struct urb *urb, gfp_t mem_flags)
 {
 	struct xhci_container_ctx *out_ctx;
 	struct xhci_input_control_ctx *ctrl_ctx;
@@ -1339,7 +1339,7 @@ static int xhci_check_maxpacket(struct x
 		 * changes max packet sizes.
 		 */
 
-		command = xhci_alloc_command(xhci, false, true, GFP_KERNEL);
+		command = xhci_alloc_command(xhci, false, true, mem_flags);
 		if (!command)
 			return -ENOMEM;
 
@@ -1430,7 +1430,7 @@ static int xhci_urb_enqueue(struct usb_h
 		 */
 		if (urb->dev->speed == USB_SPEED_FULL) {
 			ret = xhci_check_maxpacket(xhci, slot_id,
-					ep_index, urb);
+					ep_index, urb, mem_flags);
 			if (ret < 0) {
 				xhci_urb_free_priv(urb_priv);
 				urb->hcpriv = NULL;