From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758754Ab3HMQcD (ORCPT ); Tue, 13 Aug 2013 12:32:03 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:4213 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757927Ab3HMQ0v (ORCPT ); Tue, 13 Aug 2013 12:26:51 -0400 X-Authority-Analysis: v=2.0 cv=P6i4d18u c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=Ciwy3NGCPMMA:10 a=gxkWszt2KDgA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=YJrJ-TgkFjwA:10 a=VwQbUJbxAAAA:8 a=lMwjtec1AAAA:8 a=sozttTNsAAAA:8 a=UqXsq3LT7gkJoKoG_8QA:9 a=6gwatna_2BgA:10 a=x2szoZtqnggA:10 a=jeBq3FmKZ4MA:10 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Message-Id: <20130813155834.357308902@goodmis.org> User-Agent: quilt/0.60-1 Date: Tue, 13 Aug 2013 11:58:02 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: UCHINO Satoshi , Michal Nazarewicz , Felipe Balbi Subject: [68/88] usb: gadget: f_mass_storage: add missing memory barrier for thread_wakeup_needed References: <20130813155654.069291373@goodmis.org> Content-Disposition: inline; filename=0068-usb-gadget-f_mass_storage-add-missing-memory-barrier.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.6.11.7-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: UCHINO Satoshi [ Upstream commit d68c277b501889b3a50c179d1c3d704db7947b83 ] Without this memory barrier, the file-storage thread may fail to escape from the following while loop, because it may observe new common->thread_wakeup_needed and old bh->state which are updated by the callback functions. /* Wait for the CBW to arrive */ while (bh->state != BUF_STATE_FULL) { rc = sleep_thread(common); if (rc) return rc; } Cc: stable@vger.kernel.org Signed-off-by: UCHINO Satoshi Acked-by: Michal Nazarewicz Signed-off-by: Felipe Balbi Signed-off-by: Steven Rostedt --- drivers/usb/gadget/f_mass_storage.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c index 4f1142e..4d60ad3 100644 --- a/drivers/usb/gadget/f_mass_storage.c +++ b/drivers/usb/gadget/f_mass_storage.c @@ -433,6 +433,7 @@ static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep) /* Caller must hold fsg->lock */ static void wakeup_thread(struct fsg_common *common) { + smp_wmb(); /* ensure the write of bh->state is complete */ /* Tell the main thread that something has happened */ common->thread_wakeup_needed = 1; if (common->thread_task) @@ -652,6 +653,7 @@ static int sleep_thread(struct fsg_common *common) } __set_current_state(TASK_RUNNING); common->thread_wakeup_needed = 0; + smp_rmb(); /* ensure the latest bh->state is visible */ return rc; } -- 1.7.10.4