* [PATCH] xen: check return value of xenbus_printf
@ 2015-10-15 16:25 Insu Yun
2015-10-15 16:40 ` David Vrabel
0 siblings, 1 reply; 9+ messages in thread
From: Insu Yun @ 2015-10-15 16:25 UTC (permalink / raw)
To: dmitry.torokhov, david.vrabel, wei.liu2, julien.grall,
stefano.stabellini, huaixin.chx, linux-input, linux-kernel
Cc: taesoo, yeongjin.jang, insu, Insu Yun
Internally, xenbus_printf uses memory allocation, so it can be failed in
memory pressure.Therefore, xenbus_printf's return should be checked
and properly handled.
Signed-off-by: Insu Yun <wuninsu@gmail.com>
---
drivers/input/misc/xen-kbdfront.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index 23d0549..a3b0940 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c
@@ -129,8 +129,11 @@ static int xenkbd_probe(struct xenbus_device *dev,
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
abs = 0;
- if (abs)
- xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
+ if (abs) {
+ ret = xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
+ if (ret)
+ pr_warning("xenkbd: can't request abs-pointer");
+ }
/* keyboard */
kbd = input_allocate_device();
--
1.9.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] xen: check return value of xenbus_printf
2015-10-15 16:25 Insu Yun
@ 2015-10-15 16:40 ` David Vrabel
[not found] ` <CAGoFzNeiu0sNXUh_JtGp8_HWA+k5xq9s-D4qFqU43Vgm=bYiiA@mail.gmail.com>
0 siblings, 1 reply; 9+ messages in thread
From: David Vrabel @ 2015-10-15 16:40 UTC (permalink / raw)
To: Insu Yun, dmitry.torokhov, wei.liu2, julien.grall,
stefano.stabellini, huaixin.chx, linux-input, linux-kernel
Cc: taesoo, yeongjin.jang, insu
On 15/10/15 17:25, Insu Yun wrote:
> Internally, xenbus_printf uses memory allocation, so it can be failed in
> memory pressure.Therefore, xenbus_printf's return should be checked
> and properly handled.
[...]
> --- a/drivers/input/misc/xen-kbdfront.c
> +++ b/drivers/input/misc/xen-kbdfront.c
> @@ -129,8 +129,11 @@ static int xenkbd_probe(struct xenbus_device *dev,
>
> if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
> abs = 0;
> - if (abs)
> - xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
> + if (abs) {
> + ret = xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
> + if (ret)
> + pr_warning("xenkbd: can't request abs-pointer");
I think you want abs = 0 here or input device will be configured as
absolute but the backend will supply relative coordinates.
David
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] xen: check return value of xenbus_printf
[not found] ` <CAGoFzNeiu0sNXUh_JtGp8_HWA+k5xq9s-D4qFqU43Vgm=bYiiA@mail.gmail.com>
@ 2015-10-15 18:20 ` Julien Grall
0 siblings, 0 replies; 9+ messages in thread
From: Julien Grall @ 2015-10-15 18:20 UTC (permalink / raw)
To: Insu Yun, David Vrabel
Cc: Dmitry Torokhov, Wei Liu, Stefano Stabellini, huaixin.chx,
linux-input, linux-kernel, Taesoo Kim, Yeongjin Jang, Yun, Insu
Hi Insu,
On 15/10/15 19:12, Insu Yun wrote:
>
>
> On Thu, Oct 15, 2015 at 12:40 PM, David Vrabel <david.vrabel@citrix.com
> <mailto:david.vrabel@citrix.com>> wrote:
>
> On 15/10/15 17:25, Insu Yun wrote:
> > Internally, xenbus_printf uses memory allocation, so it can be failed in
> > memory pressure.Therefore, xenbus_printf's return should be checked
> > and properly handled.
> [...]
> > --- a/drivers/input/misc/xen-kbdfront.c
> > +++ b/drivers/input/misc/xen-kbdfront.c
> > @@ -129,8 +129,11 @@ static int xenkbd_probe(struct xenbus_device *dev,
> >
> > if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
> > abs = 0;
> > - if (abs)
> > - xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
> > + if (abs) {
> > + ret = xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
> > + if (ret)
>
> > + pr_warning("xenkbd: can't request abs-pointer");
>
>
> This error handling is from other code .
> I am not sure that it is right error handling.
>
>
>
> I think you want abs = 0 here or input device will be configured as
> absolute but the backend will supply relative coordinates.
>
>
> I cannot understand
If the frontend is not able to write the node "request-abs-pointer" in
the xenstore, the backend will always supply relative coordinates.
Although, as abs = 1, the frontend will be configured to handle absolute
coordinate. So the backend and frontend won't be able to understand each
other.
So you have to set abs to 0 if xebus_printf fails.
Regards,
--
Julien Grall
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] xen: check return value of xenbus_printf
@ 2015-10-15 18:40 Insu Yun
2015-10-16 0:01 ` Dmitry Torokhov
0 siblings, 1 reply; 9+ messages in thread
From: Insu Yun @ 2015-10-15 18:40 UTC (permalink / raw)
To: dmitry.torokhov, david.vrabel, wei.liu2, julien.grall,
stefano.stabellini, huaixin.chx, linux-input, linux-kernel
Cc: taesoo, yeongjin.jang, insu, Insu Yun
Signed-off-by: Insu Yun <wuninsu@gmail.com>
---
drivers/input/misc/xen-kbdfront.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index 23d0549..9d465d7 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c
@@ -129,8 +129,14 @@ static int xenkbd_probe(struct xenbus_device *dev,
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
abs = 0;
- if (abs)
- xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
+ if (abs) {
+ ret = xenbus_printf(XBT_NIL, dev->nodename,
+ "request-abs-pointer", "1");
+ if (ret) {
+ pr_warning("xenkbd: can't request abs-pointer");
+ abs = 0;
+ }
+ }
/* keyboard */
kbd = input_allocate_device();
--
1.9.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] xen: check return value of xenbus_printf
2015-10-15 18:40 Insu Yun
@ 2015-10-16 0:01 ` Dmitry Torokhov
0 siblings, 0 replies; 9+ messages in thread
From: Dmitry Torokhov @ 2015-10-16 0:01 UTC (permalink / raw)
To: Insu Yun
Cc: david.vrabel, wei.liu2, julien.grall, stefano.stabellini,
huaixin.chx, linux-input, linux-kernel, taesoo, yeongjin.jang,
insu
Hi Insu,
On Thu, Oct 15, 2015 at 06:40:12PM +0000, Insu Yun wrote:
> Signed-off-by: Insu Yun <wuninsu@gmail.com>
It looks lik eyou lost your patch description when respinning.
Thanks.
> ---
> drivers/input/misc/xen-kbdfront.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
> index 23d0549..9d465d7 100644
> --- a/drivers/input/misc/xen-kbdfront.c
> +++ b/drivers/input/misc/xen-kbdfront.c
> @@ -129,8 +129,14 @@ static int xenkbd_probe(struct xenbus_device *dev,
>
> if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
> abs = 0;
> - if (abs)
> - xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
> + if (abs) {
> + ret = xenbus_printf(XBT_NIL, dev->nodename,
> + "request-abs-pointer", "1");
> + if (ret) {
> + pr_warning("xenkbd: can't request abs-pointer");
> + abs = 0;
> + }
> + }
>
> /* keyboard */
> kbd = input_allocate_device();
> --
> 1.9.1
>
--
Dmitry
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] xen: check return value of xenbus_printf
@ 2015-10-19 14:10 Insu Yun
2015-10-19 14:30 ` Julien Grall
0 siblings, 1 reply; 9+ messages in thread
From: Insu Yun @ 2015-10-19 14:10 UTC (permalink / raw)
To: dmitry.torokhov, stefano.stabellini, david.vrabel, wei.liu2,
julien.grall, linux-input, linux-kernel
Cc: taesoo, yeongjin.jang, insu, changwoo, Insu Yun
Internally, xenbus_printf uses memory allocation, so it can be failed in
memory pressure.Therefore, xenbus_printf's return should be checked
and properly handled.
Signed-off-by: Insu Yun <wuninsu@gmail.com>
---
drivers/input/misc/xen-kbdfront.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index 23d0549..9d465d7 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c
@@ -129,8 +129,14 @@ static int xenkbd_probe(struct xenbus_device *dev,
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
abs = 0;
- if (abs)
- xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
+ if (abs) {
+ ret = xenbus_printf(XBT_NIL, dev->nodename,
+ "request-abs-pointer", "1");
+ if (ret) {
+ pr_warning("xenkbd: can't request abs-pointer");
+ abs = 0;
+ }
+ }
/* keyboard */
kbd = input_allocate_device();
--
1.9.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] xen: check return value of xenbus_printf
2015-10-19 14:10 [PATCH] xen: check return value of xenbus_printf Insu Yun
@ 2015-10-19 14:30 ` Julien Grall
0 siblings, 0 replies; 9+ messages in thread
From: Julien Grall @ 2015-10-19 14:30 UTC (permalink / raw)
To: Insu Yun, dmitry.torokhov, stefano.stabellini, david.vrabel,
wei.liu2, linux-input, linux-kernel
Cc: taesoo, yeongjin.jang, insu, changwoo
Hi,
On 19/10/15 15:10, Insu Yun wrote:
> Internally, xenbus_printf uses memory allocation, so it can be failed in
> memory pressure.Therefore, xenbus_printf's return should be checked
> and properly handled.
>
> Signed-off-by: Insu Yun <wuninsu@gmail.com>
> ---
> drivers/input/misc/xen-kbdfront.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
> index 23d0549..9d465d7 100644
> --- a/drivers/input/misc/xen-kbdfront.c
> +++ b/drivers/input/misc/xen-kbdfront.c
> @@ -129,8 +129,14 @@ static int xenkbd_probe(struct xenbus_device *dev,
>
> if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
> abs = 0;
> - if (abs)
> - xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
> + if (abs) {
> + ret = xenbus_printf(XBT_NIL, dev->nodename,
> + "request-abs-pointer", "1");
The second line of arguments should be aligned to the first parameter. I.e:
xenbus_printf(XBT_NIL, dev->nodename,
"request-abs-pointer", "1");
See an example in xenkbd_backend_changed.
With that fixed:
Reviewed-by: Julien Grall <julien.grall@citrix.com>
> + if (ret) {
> + pr_warning("xenkbd: can't request abs-pointer");
Note that checkpatch.pl will print a warning here:
WARNING: Prefer pr_warn(... to pr_warning(...
#27: FILE: drivers/input/misc/xen-kbdfront.c:136:
+ pr_warning("xenkbd: can't request abs-pointer");
Although, I'm fine if you don't fix this one.
> + abs = 0;
> + }
> + }
>
> /* keyboard */
> kbd = input_allocate_device();
>
Regards,
--
Julien Grall
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] xen: check return value of xenbus_printf
@ 2015-10-19 16:02 Insu Yun
2015-10-19 16:46 ` Dmitry Torokhov
0 siblings, 1 reply; 9+ messages in thread
From: Insu Yun @ 2015-10-19 16:02 UTC (permalink / raw)
To: dmitry.torokhov, wei.liu2, david.vrabel, stefano.stabellini,
julien.grall, linux-input, linux-kernel
Cc: taesoo, yeongjin.jang, insu, changwoo, Insu Yun
Signed-off-by: Insu Yun <wuninsu@gmail.com>
---
drivers/input/misc/xen-kbdfront.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index 23d0549..0a9ad2cf 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c
@@ -129,8 +129,14 @@ static int xenkbd_probe(struct xenbus_device *dev,
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
abs = 0;
- if (abs)
- xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
+ if (abs) {
+ ret = xenbus_printf(XBT_NIL, dev->nodename,
+ "request-abs-pointer", "1");
+ if (ret) {
+ pr_warning("xenkbd: can't request abs-pointer");
+ abs = 0;
+ }
+ }
/* keyboard */
kbd = input_allocate_device();
--
1.9.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] xen: check return value of xenbus_printf
2015-10-19 16:02 Insu Yun
@ 2015-10-19 16:46 ` Dmitry Torokhov
0 siblings, 0 replies; 9+ messages in thread
From: Dmitry Torokhov @ 2015-10-19 16:46 UTC (permalink / raw)
To: Insu Yun
Cc: wei.liu2, david.vrabel, stefano.stabellini, julien.grall,
linux-input, linux-kernel, taesoo, yeongjin.jang, insu, changwoo
On Mon, Oct 19, 2015 at 04:02:51PM +0000, Insu Yun wrote:
> Signed-off-by: Insu Yun <wuninsu@gmail.com>
Applied, thank you. However you still are missing the commit description
on this version of the patch; I had to fish it from your original
posting.
Thanks.
> ---
> drivers/input/misc/xen-kbdfront.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
> index 23d0549..0a9ad2cf 100644
> --- a/drivers/input/misc/xen-kbdfront.c
> +++ b/drivers/input/misc/xen-kbdfront.c
> @@ -129,8 +129,14 @@ static int xenkbd_probe(struct xenbus_device *dev,
>
> if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
> abs = 0;
> - if (abs)
> - xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
> + if (abs) {
> + ret = xenbus_printf(XBT_NIL, dev->nodename,
> + "request-abs-pointer", "1");
> + if (ret) {
> + pr_warning("xenkbd: can't request abs-pointer");
> + abs = 0;
> + }
> + }
>
> /* keyboard */
> kbd = input_allocate_device();
> --
> 1.9.1
>
--
Dmitry
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2015-10-19 16:46 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
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2015-10-19 14:10 [PATCH] xen: check return value of xenbus_printf Insu Yun
2015-10-19 14:30 ` Julien Grall
-- strict thread matches above, loose matches on Subject: below --
2015-10-19 16:02 Insu Yun
2015-10-19 16:46 ` Dmitry Torokhov
2015-10-15 18:40 Insu Yun
2015-10-16 0:01 ` Dmitry Torokhov
2015-10-15 16:25 Insu Yun
2015-10-15 16:40 ` David Vrabel
[not found] ` <CAGoFzNeiu0sNXUh_JtGp8_HWA+k5xq9s-D4qFqU43Vgm=bYiiA@mail.gmail.com>
2015-10-15 18:20 ` Julien Grall
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