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

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 14/06/2020 à 20:57, Chuck Lever a écrit :
> Hi Christophe -
> 
>> On Jun 14, 2020, at 1:07 PM, Christophe Leroy <christophe.leroy@csgroup.eu> 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@csgroup.eu>
>> ---
>> 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@csgroup.eu/

> 
> 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@intel.com>
> 
> 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