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

[Thierry Reding]

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

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