* [PATCH] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all()
@ 2015-11-12 4:37 Yoshihiro Shimoda
2015-11-16 3:58 ` Vinod Koul
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Yoshihiro Shimoda @ 2015-11-12 4:37 UTC (permalink / raw)
To: linux-sh
This patch fixes an issue that list_for_each_entry() in
usb_dmac_chan_terminate_all() is possible to cause endless loop because
this will move own desc to the desc_freed. So, this driver should use
list_for_each_entry_safe() instead of list_for_each_entry().
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
drivers/dma/sh/usb-dmac.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
index ebd8a5f..16fb330 100644
--- a/drivers/dma/sh/usb-dmac.c
+++ b/drivers/dma/sh/usb-dmac.c
@@ -448,7 +448,7 @@ usb_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
static int usb_dmac_chan_terminate_all(struct dma_chan *chan)
{
struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
- struct usb_dmac_desc *desc;
+ struct usb_dmac_desc *desc, *_desc;
unsigned long flags;
LIST_HEAD(head);
LIST_HEAD(list);
@@ -459,7 +459,7 @@ static int usb_dmac_chan_terminate_all(struct dma_chan *chan)
if (uchan->desc)
uchan->desc = NULL;
list_splice_init(&uchan->desc_got, &list);
- list_for_each_entry(desc, &list, node)
+ list_for_each_entry_safe(desc, _desc, &list, node)
list_move_tail(&desc->node, &uchan->desc_freed);
spin_unlock_irqrestore(&uchan->vc.lock, flags);
vchan_dma_desc_free_list(&uchan->vc, &head);
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all()
2015-11-12 4:37 [PATCH] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all() Yoshihiro Shimoda
@ 2015-11-16 3:58 ` Vinod Koul
2015-11-16 7:13 ` Yoshihiro Shimoda
2015-12-05 8:20 ` Vinod Koul
2 siblings, 0 replies; 6+ messages in thread
From: Vinod Koul @ 2015-11-16 3:58 UTC (permalink / raw)
To: linux-sh
On Thu, Nov 12, 2015 at 01:37:40PM +0900, Yoshihiro Shimoda wrote:
> This patch fixes an issue that list_for_each_entry() in
> usb_dmac_chan_terminate_all() is possible to cause endless loop because
> this will move own desc to the desc_freed. So, this driver should use
> list_for_each_entry_safe() instead of list_for_each_entry().
Sorry this is not clear to my why this owuld have endless loop, can you
explain more
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
> drivers/dma/sh/usb-dmac.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
> index ebd8a5f..16fb330 100644
> --- a/drivers/dma/sh/usb-dmac.c
> +++ b/drivers/dma/sh/usb-dmac.c
> @@ -448,7 +448,7 @@ usb_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
> static int usb_dmac_chan_terminate_all(struct dma_chan *chan)
> {
> struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
> - struct usb_dmac_desc *desc;
> + struct usb_dmac_desc *desc, *_desc;
> unsigned long flags;
> LIST_HEAD(head);
> LIST_HEAD(list);
> @@ -459,7 +459,7 @@ static int usb_dmac_chan_terminate_all(struct dma_chan *chan)
> if (uchan->desc)
> uchan->desc = NULL;
> list_splice_init(&uchan->desc_got, &list);
> - list_for_each_entry(desc, &list, node)
> + list_for_each_entry_safe(desc, _desc, &list, node)
> list_move_tail(&desc->node, &uchan->desc_freed);
> spin_unlock_irqrestore(&uchan->vc.lock, flags);
> vchan_dma_desc_free_list(&uchan->vc, &head);
> --
> 1.9.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe dmaengine" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
~Vinod
^ permalink raw reply [flat|nested] 6+ messages in thread* RE: [PATCH] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all()
2015-11-12 4:37 [PATCH] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all() Yoshihiro Shimoda
2015-11-16 3:58 ` Vinod Koul
@ 2015-11-16 7:13 ` Yoshihiro Shimoda
2015-12-05 8:20 ` Vinod Koul
2 siblings, 0 replies; 6+ messages in thread
From: Yoshihiro Shimoda @ 2015-11-16 7:13 UTC (permalink / raw)
To: linux-sh
Hi Vinod,
> From: Vinod Koul [mailto:vinod.koul@intel.com]
> Sent: Monday, November 16, 2015 12:47 PM
>
> On Thu, Nov 12, 2015 at 01:37:40PM +0900, Yoshihiro Shimoda wrote:
> > This patch fixes an issue that list_for_each_entry() in
> > usb_dmac_chan_terminate_all() is possible to cause endless loop because
> > this will move own desc to the desc_freed. So, this driver should use
> > list_for_each_entry_safe() instead of list_for_each_entry().
>
> Sorry this is not clear to my why this owuld have endless loop, can you
> explain more
This issue will happens if &uchan->desc_got has one or more lists.
(In other words, there was a potential problem from the first commit of this driver...)
This is because that this driver use "desc" for list_move_tail() as the first
argument, and the list_move_tail() calls __list_del_entry(). So, the desc may be
wrong list_head for list_next_entry().
static int usb_dmac_chan_terminate_all(struct dma_chan *chan)
{
<snip>
list_splice_init(&uchan->desc_got, &list);
list_for_each_entry(desc, &list, node)
list_move_tail(&desc->node, &uchan->desc_freed);
< in include/linux/list.h >
static inline void list_move_tail(struct list_head *list,
struct list_head *head)
{
__list_del_entry(list);
list_add_tail(list, head);
}
If I enabled CONFIG_DEBUG_LIST, the following WARNING happened:
------------[ cut here ]------------
WARNING: CPU: 2 PID: 2477 at lib/list_debug.c:33 __list_add+0x64/0xb0()
list_add corruption. prev->next should be next (edca6098), but was ee936e00. (prevî936ec0).
Modules linked in: g_mass_storage(-) usb_f_mass_storage libcomposite
CPU: 2 PID: 2477 Comm: file-storage Not tainted 4.3.0-rc1-00002-g4d15d22 #27
Hardware name: Generic R8A7790 (Flattened Device Tree)
Backtrace:
[<c00137a0>] (dump_backtrace) from [<c0013998>] (show_stack+0x18/0x1c)
r7:c05d2664 r6:ee92e140 r5:00000009 r4:00000000
[<c0013980>] (show_stack) from [<c01be7d0>] (dump_stack+0x78/0x94)
[<c01be758>] (dump_stack) from [<c0025224>] (warn_slowpath_common+0x8c/0xb8)
r5:00000009 r4:ee22bd90
[<c0025198>] (warn_slowpath_common) from [<c0025288>] (warn_slowpath_fmt+0x38/0x40)
r9:edca6098 r8:a0000093 r7:edca605c r6:edca6098 r5:edca6098 r4:ee936ec0
[<c0025254>] (warn_slowpath_fmt) from [<c01d49b8>] (__list_add+0x64/0xb0)
r3:edca6098 r2:c05d2675
[<c01d4954>] (__list_add) from [<c0202e5c>] (usb_dmac_chan_terminate_all+0x14c/0x17c)
r6:ee22bde0 r5:edca6058 r4:edca6010
[<c0202d10>] (usb_dmac_chan_terminate_all) from [<c02e84b0>] (usbhs_pkt_pop+0xa0/0xf4)
< snip >
Best regards,
Yoshihiro Shimoda
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > ---
> > drivers/dma/sh/usb-dmac.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
> > index ebd8a5f..16fb330 100644
> > --- a/drivers/dma/sh/usb-dmac.c
> > +++ b/drivers/dma/sh/usb-dmac.c
> > @@ -448,7 +448,7 @@ usb_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
> > static int usb_dmac_chan_terminate_all(struct dma_chan *chan)
> > {
> > struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
> > - struct usb_dmac_desc *desc;
> > + struct usb_dmac_desc *desc, *_desc;
> > unsigned long flags;
> > LIST_HEAD(head);
> > LIST_HEAD(list);
> > @@ -459,7 +459,7 @@ static int usb_dmac_chan_terminate_all(struct dma_chan *chan)
> > if (uchan->desc)
> > uchan->desc = NULL;
> > list_splice_init(&uchan->desc_got, &list);
> > - list_for_each_entry(desc, &list, node)
> > + list_for_each_entry_safe(desc, _desc, &list, node)
> > list_move_tail(&desc->node, &uchan->desc_freed);
> > spin_unlock_irqrestore(&uchan->vc.lock, flags);
> > vchan_dma_desc_free_list(&uchan->vc, &head);
> > --
> > 1.9.1
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe dmaengine" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> --
> ~Vinod
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all()
2015-11-12 4:37 [PATCH] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all() Yoshihiro Shimoda
2015-11-16 3:58 ` Vinod Koul
2015-11-16 7:13 ` Yoshihiro Shimoda
@ 2015-12-05 8:20 ` Vinod Koul
2 siblings, 0 replies; 6+ messages in thread
From: Vinod Koul @ 2015-12-05 8:20 UTC (permalink / raw)
To: linux-sh
On Thu, Nov 12, 2015 at 01:37:40PM +0900, Yoshihiro Shimoda wrote:
> This patch fixes an issue that list_for_each_entry() in
> usb_dmac_chan_terminate_all() is possible to cause endless loop because
> this will move own desc to the desc_freed. So, this driver should use
> list_for_each_entry_safe() instead of list_for_each_entry().
Applied now, thanks
--
~Vinod
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH ] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all()
@ 2018-05-31 8:48 Biju Das
2018-06-02 13:19 ` Greg Kroah-Hartman
0 siblings, 1 reply; 6+ messages in thread
From: Biju Das @ 2018-05-31 8:48 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Vinod Koul, Yoshihiro Shimoda, Simon Horman, Chris Paterson,
Fabrizio Castro, stable, Ben Hutchings, Biju Das
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
commit d9f5efade2cfd729138a7cafb46d01044da40f5e upstream
This patch fixes an issue that list_for_each_entry() in
usb_dmac_chan_terminate_all() is possible to cause endless loop because
this will move own desc to the desc_freed. So, this driver should use
list_for_each_entry_safe() instead of list_for_each_entry().
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
[biju: cherry-pick to 4.4]
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
---
Hello Greg,
I have observed a CPU lock condition with USB DMAC driver on koelsch platform.
This patch fixes the issue on 4.4 stable. It is reproducible with ethernet(RNDIS/ECM)
gadget configuration.
regards,
Biju
drivers/dma/sh/usb-dmac.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
index 56410ea..6682b3e 100644
--- a/drivers/dma/sh/usb-dmac.c
+++ b/drivers/dma/sh/usb-dmac.c
@@ -448,7 +448,7 @@ usb_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
static int usb_dmac_chan_terminate_all(struct dma_chan *chan)
{
struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
- struct usb_dmac_desc *desc;
+ struct usb_dmac_desc *desc, *_desc;
unsigned long flags;
LIST_HEAD(head);
LIST_HEAD(list);
@@ -459,7 +459,7 @@ static int usb_dmac_chan_terminate_all(struct dma_chan *chan)
if (uchan->desc)
uchan->desc = NULL;
list_splice_init(&uchan->desc_got, &list);
- list_for_each_entry(desc, &list, node)
+ list_for_each_entry_safe(desc, _desc, &list, node)
list_move_tail(&desc->node, &uchan->desc_freed);
spin_unlock_irqrestore(&uchan->vc.lock, flags);
vchan_dma_desc_free_list(&uchan->vc, &head);
--
2.7.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH ] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all()
2018-05-31 8:48 [PATCH ] " Biju Das
@ 2018-06-02 13:19 ` Greg Kroah-Hartman
0 siblings, 0 replies; 6+ messages in thread
From: Greg Kroah-Hartman @ 2018-06-02 13:19 UTC (permalink / raw)
To: Biju Das
Cc: Vinod Koul, Yoshihiro Shimoda, Simon Horman, Chris Paterson,
Fabrizio Castro, stable, Ben Hutchings
On Thu, May 31, 2018 at 09:48:24AM +0100, Biju Das wrote:
> From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
>
> commit d9f5efade2cfd729138a7cafb46d01044da40f5e upstream
>
> This patch fixes an issue that list_for_each_entry() in
> usb_dmac_chan_terminate_all() is possible to cause endless loop because
> this will move own desc to the desc_freed. So, this driver should use
> list_for_each_entry_safe() instead of list_for_each_entry().
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
> [biju: cherry-pick to 4.4]
> Signed-off-by: Biju Das <biju.das@bp.renesas.com>
> ---
> Hello Greg,
>
> I have observed a CPU lock condition with USB DMAC driver on koelsch platform.
> This patch fixes the issue on 4.4 stable. It is reproducible with ethernet(RNDIS/ECM)
> gadget configuration.
Now applied, thanks.
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-06-02 13:20 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2015-11-12 4:37 [PATCH] dmaengine: usb-dmac: fix endless loop in usb_dmac_chan_terminate_all() Yoshihiro Shimoda
2015-11-16 3:58 ` Vinod Koul
2015-11-16 7:13 ` Yoshihiro Shimoda
2015-12-05 8:20 ` Vinod Koul
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2018-05-31 8:48 [PATCH ] " Biju Das
2018-06-02 13:19 ` Greg Kroah-Hartman
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