linux-kernel - Re: [PATCH] usb: musb: Convert timers to use timer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20171030131735.GA3964@uda0271908>
Date:   Mon, 30 Oct 2017 08:17:35 -0500
From:   Bin Liu <b-liu@...com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
CC:     Kees Cook <keescook@...omium.org>, <linux-usb@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] usb: musb: Convert timers to use timer_setup()

On Mon, Oct 30, 2017 at 09:52:15AM +0100, Greg Kroah-Hartman wrote:
> On Fri, Oct 27, 2017 at 11:24:22AM -0500, Bin Liu wrote:
> > Hi,
> > 
> > On Tue, Oct 24, 2017 at 03:08:35AM -0700, Kees Cook wrote:
> > > In preparation for unconditionally passing the struct timer_list pointer to
> > > all timer callbacks, switch to using the new timer_setup() and from_timer()
> > > to pass the timer pointer explicitly.
> > > 
> > > Instead of a per-device static timer variable, a spare timer "dev_timer"
> > > is added to the musb structure for devices to use for their per-device
> > > timer.
> > > 
> > > Cc: Bin Liu <b-liu@...com>
> > > Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
> > > Cc: linux-usb@...r.kernel.org
> > > Signed-off-by: Kees Cook <keescook@...omium.org>
> > > ---
> > >  drivers/usb/musb/am35x.c     | 24 +++++++++++-------------
> > >  drivers/usb/musb/blackfin.c  | 13 ++++++-------
> > >  drivers/usb/musb/blackfin.h  |  2 --
> > >  drivers/usb/musb/da8xx.c     | 26 ++++++++++++--------------
> > >  drivers/usb/musb/davinci.c   | 20 +++++++++-----------
> > >  drivers/usb/musb/musb_core.c |  6 +++---
> > >  drivers/usb/musb/musb_core.h |  1 +
> > >  drivers/usb/musb/musb_dsps.c |  7 ++++---
> > >  drivers/usb/musb/tusb6010.c  | 20 +++++++++-----------
> > >  9 files changed, 55 insertions(+), 64 deletions(-)
> > 
> > [snip]
> > 
> > > diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
> > > index 20f4614178d9..e8573975743d 100644
> > > --- a/drivers/usb/musb/musb_core.h
> > > +++ b/drivers/usb/musb/musb_core.h
> > > @@ -345,6 +345,7 @@ struct musb {
> > >  	struct list_head	pending_list;	/* pending work list */
> > >  
> > >  	struct timer_list	otg_timer;
> > > +	struct timer_list	dev_timer;
> > 
> > Now since dev_timer is added in struct musb for glue drivers,
> > 
> > >  	struct notifier_block	nb;
> > >  
> > >  	struct dma_controller	*dma_controller;
> > > diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
> > > index f6b526606ad1..e3d0e626a5d6 100644
> > > --- a/drivers/usb/musb/musb_dsps.c
> > > +++ b/drivers/usb/musb/musb_dsps.c
> > > @@ -282,9 +282,10 @@ static int dsps_check_status(struct musb *musb, void *unused)
> > >  	return 0;
> > >  }
> > >  
> > > -static void otg_timer(unsigned long _musb)
> > > +static void otg_timer(struct timer_list *t)
> > >  {
> > > -	struct musb *musb = (void *)_musb;
> > > +	struct dsps_glue *glue = from_timer(glue, t, timer);
> > > +	struct musb *musb = platform_get_drvdata(glue->musb);
> > >  	struct device *dev = musb->controller;
> > >  	unsigned long flags;
> > >  	int err;
> > > @@ -480,7 +481,7 @@ static int dsps_musb_init(struct musb *musb)
> > >  		}
> > >  	}
> > >  
> > > -	setup_timer(&glue->timer, otg_timer, (unsigned long) musb);
> > > +	timer_setup(&glue->timer, otg_timer, 0);
> > 
> > this glue->timer is duplicate. It can be removed and use musb->dev_timer
> > instead as other glue drivers do.
> 
> I do not understand your review comments at all.  Can you do the fixup
> here to use timer_setup for the musb timer code?

I meant something like

diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
index f6b526606ad1..8a2abe50f2d4 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -119,7 +119,6 @@ struct dsps_glue {
        struct platform_device *musb;   /* child musb pdev */
        const struct dsps_musb_wrapper *wrp; /* wrapper register offsets */
        int vbus_irq;                   /* optional vbus irq */
-       struct timer_list timer;        /* otg_workaround timer */
        unsigned long last_timer;    /* last timer data for each instance */
        bool sw_babble_enabled;
        void __iomem *usbss_base;
@@ -480,7 +479,7 @@ static int dsps_musb_init(struct musb *musb)
                }
        }
 
-       setup_timer(&glue->timer, otg_timer, (unsigned long) musb);
+       timer_setup(&musb->dev_timer, otg_timer, 0);
 
        /* Reset the musb */
        musb_writel(reg_base, wrp->control, (1 << wrp->reset));

which removes the duplicated timer from dsps_glue, and uses the newly added
dev_timer in struct musb.

I will send the fixup patch after I tested it.

Thanks,
-Bin.