Re: rmk build: 54 warnings 0 failures (rmk/v5.8-rc3-11-g48b8eed3a337d)

Re: rmk build: 54 warnings 0 failures (rmk/v5.8-rc3-11-g48b8eed3a337d)

[Russell King - ARM Linux admin]

A build of my tree by Olof's autobuilder revealed a problem concerning
a couple of platforms - this is based on v5.8-rc3:

On Tue, Jul 21, 2020 at 07:36:48AM -0700, Olof's autobuilder wrote:
> 	arm.mps2_defconfig:
> net/sunrpc/svcsock.c:226:5: warning: "ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE" is not defined, evaluates to 0 [-Wundef]
> 
> 	arm.xcep_defconfig:
> net/sunrpc/svcsock.c:226:5: warning: "ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE" is not defined, evaluates to 0 [-Wundef]
> net/sunrpc/svcsock.c:226:5: warning: "ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE" is not defined, evaluates to 0 [-Wundef]

The issue is that as the #if concerned is used to determine whether
code that calls flush_dcache_page() (and therefore ensures data
integrity) is omitted - and in the above cases it will be omitted.

On ARM, we define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE to 1 in
asm/cacheflush.h, but for some reason, it seems that
net/sunrpc/svcsock.c is not seeing that.

Maybe net/sunrpc/svcsock.c needs to include asm/cacheflush.h to
ensure it picks up the definition of this preprocessor symbol?

It looks like this was introduced by:

commit ca07eda33e01eafa7a26ec06974f7eacee6a89c8
Author: Chuck Lever <chuck.lever@oracle.com>
Date:   Wed May 20 17:30:12 2020 -0400

    SUNRPC: Refactor svc_recvfrom()

Thanks.

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Re: rmk build: 54 warnings 0 failures (rmk/v5.8-rc3-11-g48b8eed3a337d)

[Chuck Lever]

Hi Russell-

> On Jul 21, 2020, at 11:14 AM, Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote:
> 
> A build of my tree by Olof's autobuilder revealed a problem concerning
> a couple of platforms - this is based on v5.8-rc3:
> 
> On Tue, Jul 21, 2020 at 07:36:48AM -0700, Olof's autobuilder wrote:
>> 	arm.mps2_defconfig:
>> net/sunrpc/svcsock.c:226:5: warning: "ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE" is not defined, evaluates to 0 [-Wundef]
>> 
>> 	arm.xcep_defconfig:
>> net/sunrpc/svcsock.c:226:5: warning: "ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE" is not defined, evaluates to 0 [-Wundef]
>> net/sunrpc/svcsock.c:226:5: warning: "ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE" is not defined, evaluates to 0 [-Wundef]
> 
> The issue is that as the #if concerned is used to determine whether
> code that calls flush_dcache_page() (and therefore ensures data
> integrity) is omitted - and in the above cases it will be omitted.
> 
> On ARM, we define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE to 1 in
> asm/cacheflush.h, but for some reason, it seems that
> net/sunrpc/svcsock.c is not seeing that.
> 
> Maybe net/sunrpc/svcsock.c needs to include asm/cacheflush.h to
> ensure it picks up the definition of this preprocessor symbol?
> 
> It looks like this was introduced by:
> 
> commit ca07eda33e01eafa7a26ec06974f7eacee6a89c8
> Author: Chuck Lever <chuck.lever@oracle.com>
> Date:   Wed May 20 17:30:12 2020 -0400
> 
>    SUNRPC: Refactor svc_recvfrom()
> 
> Thanks.

This should be addressed by

becd2014923f ("SUNRPC: Add missing definition of ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE")

which was merged in v5.8-rc4.

--
Chuck Lever