Re: [PATCH] SUNRPC: Add missing asm/cacheflush.h

[Christophe Leroy]

Le 14/06/2020 Ã 20:57, Chuck Lever a ÃcritÂ:
> Hi Christophe -
>
> > On Jun 14, 2020, at 1:07 PM, Christophe Leroy <christophe.leroy@xxxxxxxxxx> wrote:
> >
> > Even if that's only a warning, not including asm/cacheflush.h
> > leads to svc_flush_bvec() being empty allthough powerpc defines
> > ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE.
> >
> >   CC      net/sunrpc/svcsock.o
> > net/sunrpc/svcsock.c:227:5: warning: "ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE" is not defined [-Wundef]
> > #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
> >      ^
> >
> > Fixes: ca07eda33e01 ("SUNRPC: Refactor svc_recvfrom()")
> > Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> > ---
> > I detected this on linux-next on June 4th and warned Chuck. Seems like it went into mainline anyway.
>
> Thanks for your patch. I've searched my mailbox. It appears I never
> received your June 4th e-mail.

It is there: 
https://lore.kernel.org/linuxppc-dev/868915eb-8fed-0600-ea5d-31ae874457b1@xxxxxxxxxx/

> Does your patch also address:
>
>     https://marc.info/?l=linux-kernel&m=159194369128024&w=2 ?

I guess it does, yes.

> If so, then
>
>     Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> should be added to the patch description.
>
> Ideally, compilation on x86_64 should have thrown the same warning,
> but it didn't. Why would the x86_64 build behave differently than
> ppc64 or i386?

I think it depends whether you have selected CONFIG_BLOCK or not.
In my embedded config, CONFIG_BLOCK isn't selected.

When CONFIG_BLOCK is selected, there is the following inclusion chain:

  CC      net/sunrpc/svcsock.o
In file included from ./include/linux/highmem.h:12:0,
                 from ./include/linux/pagemap.h:11,
                 from ./include/linux/blkdev.h:16,
                 from ./include/linux/blk-cgroup.h:23,
                 from ./include/linux/writeback.h:14,
                 from ./include/linux/memcontrol.h:22,
                 from ./include/net/sock.h:53,
                 from ./include/net/inet_sock.h:22,
                 from ./include/linux/udp.h:16,
                 from net/sunrpc/svcsock.c:31:
./arch/powerpc/include/asm/cacheflush.h:26:2: warning: #warning Coucous 
[-Wcpp]
 #warning test

But linux/blkdev.h includes linux/pagemap.h only when CONFIG_BLOCK is 
defined.

> > net/sunrpc/svcsock.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
> > index 5c4ec9386f81..d9e99cb09aab 100644
> > --- a/net/sunrpc/svcsock.c
> > +++ b/net/sunrpc/svcsock.c
> > @@ -45,6 +45,7 @@
> > #include <net/tcp_states.h>
> > #include <linux/uaccess.h>
> > #include <asm/ioctls.h>
> > +#include <asm/cacheflush.h>
>
> Nit: Let's include <linux/highmem.h> in net/sunrpc/svcsock.h instead
> of <asm/cacheflush.h> directly.

Ok, I'll post v2.

> > #include <linux/sunrpc/types.h>
> > #include <linux/sunrpc/clnt.h>
> > --
> > 2.25.0
>
> --
> Chuck Lever

Christophe