From: Simon Horman <horms@verge.net.au>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>, Ulrich Hecht <uli+renesas@fpond.eu>,
Wolfram Sang <wsa+renesas@sang-engineering.com>,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
Linux-sh list <linux-sh@vger.kernel.org>,
"open list:SERIAL DRIVERS" <linux-serial@vger.kernel.org>
Subject: Re: [PATCH v4 2/4] serial: sh-sci: Fix crash in rx_timer_fn() on PIO fallback
Date: Mon, 17 Dec 2018 15:50:44 +0100 [thread overview]
Message-ID: <20181217145043.ygw2lwtw2v5i4lpm@verge.net.au> (raw)
In-Reply-To: <CAMuHMdUHUUEd0KQ3NP4M_hiYuwcyYRMiET3BamC4Qmrc3oEBBA@mail.gmail.com>
On Mon, Dec 17, 2018 at 02:27:47PM +0100, Geert Uytterhoeven wrote:
> Hi Simon,
>
> On Mon, Dec 17, 2018 at 2:22 PM Simon Horman <horms@verge.net.au> wrote:
> > On Thu, Dec 13, 2018 at 07:44:42PM +0100, Geert Uytterhoeven wrote:
> > > When falling back to PIO, active_rx must be set to a different value
> > > than cookie_rx[i], else sci_dma_rx_find_active() will incorrectly find a
> > > match, leading to a NULL pointer dereference in rx_timer_fn() later.
> > >
> > > Use zero instead, which is the same value as after driver
> > > initialization.
> > >
> > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> >
> > This looks good so to me long as dmaengine_submit() doesn't return 0.
> > Is that the case?
>
> include/linux/dmaengine.h:
>
> /**
> * typedef dma_cookie_t - an opaque DMA cookie
> *
> * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
> */
> typedef s32 dma_cookie_t;
> #define DMA_MIN_COOKIE 1
In that case I have no objections.
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
next prev parent reply other threads:[~2018-12-17 14:50 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-13 18:44 [PATCH v4 0/4] serial: sh-sci: Fix fallback to PIO on DMA failure Geert Uytterhoeven
2018-12-13 18:44 ` [PATCH v4 1/4] serial: sh-sci: Fix locking in sci_submit_rx() Geert Uytterhoeven
2018-12-17 13:17 ` Simon Horman
2018-12-13 18:44 ` [PATCH v4 2/4] serial: sh-sci: Fix crash in rx_timer_fn() on PIO fallback Geert Uytterhoeven
2018-12-17 13:22 ` Simon Horman
2018-12-17 13:27 ` Geert Uytterhoeven
2018-12-17 14:50 ` Simon Horman [this message]
2018-12-13 18:44 ` [PATCH v4 3/4] serial: sh-sci: Resume PIO in sci_rx_interrupt() on DMA failure Geert Uytterhoeven
2018-12-14 16:14 ` Wolfram Sang
2018-12-17 13:25 ` Simon Horman
2018-12-13 18:44 ` [PATCH v4 4/4] serial: sh-sci: Fix fallback to PIO in sci_dma_rx_complete() Geert Uytterhoeven
2018-12-17 13:29 ` Simon Horman
2018-12-16 2:22 ` [PATCH v4 0/4] serial: sh-sci: Fix fallback to PIO on DMA failure Rob Landley
2018-12-16 8:27 ` Geert Uytterhoeven
2018-12-17 14:05 ` Greg Kroah-Hartman
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