* [PATCH] drivers: virtio: Use PTR_RET function
@ 2013-03-25 13:25 Alexandru Gheorghiu
2013-03-26 3:27 ` Rusty Russell
0 siblings, 1 reply; 9+ messages in thread
From: Alexandru Gheorghiu @ 2013-03-25 13:25 UTC (permalink / raw)
To: Rusty Russell
Cc: Michael S. Tsirkin, virtualization, linux-kernel,
Alexandru Gheorghiu
Used PTR_RET function instead of IS_ERR and PTR_ERR.
Patch found using coccinelle.
Signed-off-by: Alexandru Gheorghiu <gheorghiuandru@gmail.com>
---
drivers/virtio/virtio_mmio.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 1ba0d68..d1e664f 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -567,10 +567,7 @@ static int vm_cmdline_set(const char *device,
pdev = platform_device_register_resndata(&vm_cmdline_parent,
"virtio-mmio", vm_cmdline_id++,
resources, ARRAY_SIZE(resources), NULL, 0);
- if (IS_ERR(pdev))
- return PTR_ERR(pdev);
-
- return 0;
+ return PTR_RET(pdev);
}
static int vm_cmdline_get_device(struct device *dev, void *data)
--
1.7.9.5
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] drivers: virtio: Use PTR_RET function
2013-03-25 13:25 [PATCH] drivers: virtio: Use PTR_RET function Alexandru Gheorghiu
@ 2013-03-26 3:27 ` Rusty Russell
0 siblings, 0 replies; 9+ messages in thread
From: Rusty Russell @ 2013-03-26 3:27 UTC (permalink / raw)
Cc: Michael S. Tsirkin, linux-kernel, virtualization,
Alexandru Gheorghiu, Uwe Kleine-König, Andrew Morton
Alexandru Gheorghiu <gheorghiuandru@gmail.com> writes:
> Used PTR_RET function instead of IS_ERR and PTR_ERR.
> Patch found using coccinelle.
WTF is PTR_RET? PTR_RET doesn't return anything. Why is it called
that? It doesn't even make sense.
ZERO_OR_PTR_ERR() maybe.
But what problem are we solving? Insufficient churn in the tree? Code
being too readable? This isn't some hard-to-get right corner case, or a
missed optimization.
Andrew, what am I missing here?
Grumpy,
Rusty.
> Signed-off-by: Alexandru Gheorghiu <gheorghiuandru@gmail.com>
> ---
> drivers/virtio/virtio_mmio.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
> index 1ba0d68..d1e664f 100644
> --- a/drivers/virtio/virtio_mmio.c
> +++ b/drivers/virtio/virtio_mmio.c
> @@ -567,10 +567,7 @@ static int vm_cmdline_set(const char *device,
> pdev = platform_device_register_resndata(&vm_cmdline_parent,
> "virtio-mmio", vm_cmdline_id++,
> resources, ARRAY_SIZE(resources), NULL, 0);
> - if (IS_ERR(pdev))
> - return PTR_ERR(pdev);
> -
> - return 0;
> + return PTR_RET(pdev);
> }
>
> static int vm_cmdline_get_device(struct device *dev, void *data)
> --
> 1.7.9.5
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drivers: virtio: Use PTR_RET function
@ 2013-03-26 3:27 ` Rusty Russell
0 siblings, 0 replies; 9+ messages in thread
From: Rusty Russell @ 2013-03-26 3:27 UTC (permalink / raw)
To: Alexandru Gheorghiu
Cc: Michael S. Tsirkin, virtualization, linux-kernel,
Alexandru Gheorghiu, Uwe Kleine-König, Andrew Morton
Alexandru Gheorghiu <gheorghiuandru@gmail.com> writes:
> Used PTR_RET function instead of IS_ERR and PTR_ERR.
> Patch found using coccinelle.
WTF is PTR_RET? PTR_RET doesn't return anything. Why is it called
that? It doesn't even make sense.
ZERO_OR_PTR_ERR() maybe.
But what problem are we solving? Insufficient churn in the tree? Code
being too readable? This isn't some hard-to-get right corner case, or a
missed optimization.
Andrew, what am I missing here?
Grumpy,
Rusty.
> Signed-off-by: Alexandru Gheorghiu <gheorghiuandru@gmail.com>
> ---
> drivers/virtio/virtio_mmio.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
> index 1ba0d68..d1e664f 100644
> --- a/drivers/virtio/virtio_mmio.c
> +++ b/drivers/virtio/virtio_mmio.c
> @@ -567,10 +567,7 @@ static int vm_cmdline_set(const char *device,
> pdev = platform_device_register_resndata(&vm_cmdline_parent,
> "virtio-mmio", vm_cmdline_id++,
> resources, ARRAY_SIZE(resources), NULL, 0);
> - if (IS_ERR(pdev))
> - return PTR_ERR(pdev);
> -
> - return 0;
> + return PTR_RET(pdev);
> }
>
> static int vm_cmdline_get_device(struct device *dev, void *data)
> --
> 1.7.9.5
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drivers: virtio: Use PTR_RET function
2013-03-26 3:27 ` Rusty Russell
@ 2013-03-26 5:01 ` Andrew Morton
-1 siblings, 0 replies; 9+ messages in thread
From: Andrew Morton @ 2013-03-26 5:01 UTC (permalink / raw)
To: Rusty Russell
Cc: Alexandru Gheorghiu, virtualization, Uwe Kleine-König,
linux-kernel, Michael S. Tsirkin
On Tue, 26 Mar 2013 13:57:09 +1030 Rusty Russell <rusty@rustcorp.com.au> wrote:
> Alexandru Gheorghiu <gheorghiuandru@gmail.com> writes:
>
> > Used PTR_RET function instead of IS_ERR and PTR_ERR.
> > Patch found using coccinelle.
>
> WTF is PTR_RET? PTR_RET doesn't return anything. Why is it called
> that? It doesn't even make sense.
>
> ZERO_OR_PTR_ERR() maybe.
>
> But what problem are we solving? Insufficient churn in the tree? Code
> being too readable? This isn't some hard-to-get right corner case, or a
> missed optimization.
>
> Andrew, what am I missing here?
It seemed like a good idea at the time. Merged it two years ago and
have since been keenly awaiting an opportunity to use it.
It seems that people _have_ been using it, but mainly netfilter people
and we know they're all crazy ;)
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drivers: virtio: Use PTR_RET function
@ 2013-03-26 5:01 ` Andrew Morton
0 siblings, 0 replies; 9+ messages in thread
From: Andrew Morton @ 2013-03-26 5:01 UTC (permalink / raw)
To: Rusty Russell
Cc: Alexandru Gheorghiu, Michael S. Tsirkin, virtualization,
linux-kernel, Uwe Kleine-König
On Tue, 26 Mar 2013 13:57:09 +1030 Rusty Russell <rusty@rustcorp.com.au> wrote:
> Alexandru Gheorghiu <gheorghiuandru@gmail.com> writes:
>
> > Used PTR_RET function instead of IS_ERR and PTR_ERR.
> > Patch found using coccinelle.
>
> WTF is PTR_RET? PTR_RET doesn't return anything. Why is it called
> that? It doesn't even make sense.
>
> ZERO_OR_PTR_ERR() maybe.
>
> But what problem are we solving? Insufficient churn in the tree? Code
> being too readable? This isn't some hard-to-get right corner case, or a
> missed optimization.
>
> Andrew, what am I missing here?
It seemed like a good idea at the time. Merged it two years ago and
have since been keenly awaiting an opportunity to use it.
It seems that people _have_ been using it, but mainly netfilter people
and we know they're all crazy ;)
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drivers: virtio: Use PTR_RET function
2013-03-26 5:01 ` Andrew Morton
(?)
@ 2013-03-26 7:41 ` Andru Gheorghiu
2013-03-26 10:23 ` Rusty Russell
-1 siblings, 1 reply; 9+ messages in thread
From: Andru Gheorghiu @ 2013-03-26 7:41 UTC (permalink / raw)
To: Andrew Morton
Cc: Uwe Kleine-König, virtualization, linux-kernel,
Michael S. Tsirkin
[-- Attachment #1.1: Type: text/plain, Size: 1319 bytes --]
PTR_RET does return. It's perfectly equivalent to using IS_ERR and the
returning PTR_ERR. The implementation is here [1]. The reason for using it
is this: if you have a function that does something why not call it instead
of reproducing it's behavior by explicitly writing what it does.
[1] http://lxr.free-electrons.com/source/include/linux/err.h#L55
Alexandru Gheorghiu
On Tue, Mar 26, 2013 at 7:01 AM, Andrew Morton <akpm@linux-foundation.org>wrote:
> On Tue, 26 Mar 2013 13:57:09 +1030 Rusty Russell <rusty@rustcorp.com.au>
> wrote:
>
> > Alexandru Gheorghiu <gheorghiuandru@gmail.com> writes:
> >
> > > Used PTR_RET function instead of IS_ERR and PTR_ERR.
> > > Patch found using coccinelle.
> >
> > WTF is PTR_RET? PTR_RET doesn't return anything. Why is it called
> > that? It doesn't even make sense.
> >
> > ZERO_OR_PTR_ERR() maybe.
> >
> > But what problem are we solving? Insufficient churn in the tree? Code
> > being too readable? This isn't some hard-to-get right corner case, or a
> > missed optimization.
> >
> > Andrew, what am I missing here?
>
> It seemed like a good idea at the time. Merged it two years ago and
> have since been keenly awaiting an opportunity to use it.
>
> It seems that people _have_ been using it, but mainly netfilter people
> and we know they're all crazy ;)
>
>
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[-- Attachment #2: Type: text/plain, Size: 183 bytes --]
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drivers: virtio: Use PTR_RET function
2013-03-26 7:41 ` Andru Gheorghiu
@ 2013-03-26 10:23 ` Rusty Russell
0 siblings, 0 replies; 9+ messages in thread
From: Rusty Russell @ 2013-03-26 10:23 UTC (permalink / raw)
To: Andru Gheorghiu, Andrew Morton
Cc: Uwe Kleine-König, virtualization, linux-kernel,
Michael S. Tsirkin
Andru Gheorghiu <gheorghiuandru@gmail.com> writes:
> PTR_RET does return. It's perfectly equivalent to using IS_ERR and the
> returning PTR_ERR. The implementation is here [1].
Um, I read the implementation, thanks.
> The reason for using it is this: if you have a function that does
> something why not call it instead of reproducing it's behavior by
> explicitly writing what it does.
Because clarity matters, and this function makes callers less clear.
It's the most breathtakingly bad name since BUILD_BUG_ON_ZERO().
Why not change PTR_ERR to return 0 if !IS_ERR()? Noone breaks, gcc
probably produces the same code, and noone needs to learn your weird
new kernel meme.
In fact, as gcc will produce the same code for "if (PTR_ERR(p))" as it
does for "if (IS_ERR(p))", you get to be one of the very, very few
people who have ever *reduced* the complexity of a kernel interface.
Cheers,
Rusty.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] drivers: virtio: Use PTR_RET function
@ 2013-03-26 10:23 ` Rusty Russell
0 siblings, 0 replies; 9+ messages in thread
From: Rusty Russell @ 2013-03-26 10:23 UTC (permalink / raw)
To: Andru Gheorghiu, Andrew Morton
Cc: Michael S. Tsirkin, virtualization, linux-kernel,
Uwe Kleine-König
Andru Gheorghiu <gheorghiuandru@gmail.com> writes:
> PTR_RET does return. It's perfectly equivalent to using IS_ERR and the
> returning PTR_ERR. The implementation is here [1].
Um, I read the implementation, thanks.
> The reason for using it is this: if you have a function that does
> something why not call it instead of reproducing it's behavior by
> explicitly writing what it does.
Because clarity matters, and this function makes callers less clear.
It's the most breathtakingly bad name since BUILD_BUG_ON_ZERO().
Why not change PTR_ERR to return 0 if !IS_ERR()? Noone breaks, gcc
probably produces the same code, and noone needs to learn your weird
new kernel meme.
In fact, as gcc will produce the same code for "if (PTR_ERR(p))" as it
does for "if (IS_ERR(p))", you get to be one of the very, very few
people who have ever *reduced* the complexity of a kernel interface.
Cheers,
Rusty.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] drivers: virtio: Use PTR_RET function
@ 2013-03-25 13:25 Alexandru Gheorghiu
0 siblings, 0 replies; 9+ messages in thread
From: Alexandru Gheorghiu @ 2013-03-25 13:25 UTC (permalink / raw)
To: Rusty Russell
Cc: Alexandru Gheorghiu, virtualization, linux-kernel,
Michael S. Tsirkin
Used PTR_RET function instead of IS_ERR and PTR_ERR.
Patch found using coccinelle.
Signed-off-by: Alexandru Gheorghiu <gheorghiuandru@gmail.com>
---
drivers/virtio/virtio_mmio.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 1ba0d68..d1e664f 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -567,10 +567,7 @@ static int vm_cmdline_set(const char *device,
pdev = platform_device_register_resndata(&vm_cmdline_parent,
"virtio-mmio", vm_cmdline_id++,
resources, ARRAY_SIZE(resources), NULL, 0);
- if (IS_ERR(pdev))
- return PTR_ERR(pdev);
-
- return 0;
+ return PTR_RET(pdev);
}
static int vm_cmdline_get_device(struct device *dev, void *data)
--
1.7.9.5
^ permalink raw reply related [flat|nested] 9+ messages in thread
end of thread, other threads:[~2013-03-26 22:51 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
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2013-03-25 13:25 [PATCH] drivers: virtio: Use PTR_RET function Alexandru Gheorghiu
2013-03-26 3:27 ` Rusty Russell
2013-03-26 3:27 ` Rusty Russell
2013-03-26 5:01 ` Andrew Morton
2013-03-26 5:01 ` Andrew Morton
2013-03-26 7:41 ` Andru Gheorghiu
2013-03-26 10:23 ` Rusty Russell
2013-03-26 10:23 ` Rusty Russell
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2013-03-25 13:25 Alexandru Gheorghiu
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