Re: [RFC: PATCH] err.h: silence warning when using IS_ERR on void__iomem *

From: Dan Carpenter
Date: Mon Jun 17 2013 - 03:59:53 EST


On Thu, Jun 13, 2013 at 11:39:25PM +0200, Thierry Reding wrote:
> On Thu, Jun 13, 2013 at 01:14:15PM -0700, Andrew Morton wrote:
> > On Thu, 13 Jun 2013 20:24:48 +0200 Thierry Reding <thierry.reding@xxxxxxxxx> wrote:
> >
> > > On Thu, Jun 13, 2013 at 10:55:17AM +0530, Sachin Kamat wrote:
> > > > On 13 June 2013 03:01, Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote:
> > > > > Commit 75096579c3ac ("lib: devres: Introduce devm_ioremap_resource()")
> > > > > introduced devm_ioremap_resource() and encourage to check its return value with
> > > > > IS_ERR(). This however leads to the following sparse warnings, as
> > > > > devm_ioremap_resource() returns a void __iomem pointer:
> > > > >
> > > > > drivers/net/can/c_can/c_can_platform.c:205:32: warning: incorrect type in argument 1 (different address spaces)
> > > > > drivers/net/can/c_can/c_can_platform.c:205:32: expected void const *ptr
> > > > > drivers/net/can/c_can/c_can_platform.c:205:32: got unsigned int [noderef] [usertype] <asn:2>*raminit_ctrlreg
> > > >
> > > > CC ing Thierry who has solved this issue some time back.
> > >
> > > I had sent two patches, one against sparse, the other against the
> > > kernel, but none were picked up yet.
> >
> > I didn't know that.
> >
> > On May 8 I queued
> > http://ozlabs.org/~akpm/mmots/broken-out/errh-is_err-can-accept-__user-pointers.patch.
> > Dan says that sparse v0.4.5-rc1 or later is also required.
>
> So maybe latest sparse does have the patch. I didn't find it looking at
> the logs. But looking again it seems like an equivalent patch made it in
> recently. Also the above patch looks very much like what I posted back
> at the time. Shame that work was duplicated, maybe I should have pushed
> harder when I didn't get a response.
>
> Thierry

Sorry about that. I didn't mean to steal anyone's patch.

regards,
dan carpenter
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