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From:   Ben Dooks <ben.dooks@codethink.co.uk>
To:     linux-kernel@lists.codethink.co.uk
Cc:     Ben Dooks <ben.dooks@codethink.co.uk>,
        Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
        Christoph Lameter <cl@linux.com>, linux-kernel@vger.kernel.org
Subject: [PATCH] percpu: add __percpu to SHIFT_PERCPU_PTR
Date:   Tue, 15 Oct 2019 11:26:15 +0100
Message-Id: <20191015102615.11430-1-ben.dooks@codethink.co.uk>
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Sender: linux-kernel-owner@vger.kernel.org
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The SHIFT_PERCPU_PTR() returns a pointer used by a number
of functions that expect the pointer to be __percpu annotated
(sparse address space 3). Adding __percpu to this makes the
following sparse warnings go away.

Note, this then creates the problem the __percup is marked
as noderef, which may need removing for some of the internal
functions, or to remove other warnings.

mm/vmstat.c:385:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:385:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:385:13:    got signed char *
mm/vmstat.c:385:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:385:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:385:13:    got signed char *
mm/vmstat.c:385:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:385:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:385:13:    got signed char *
mm/vmstat.c:385:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:385:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:385:13:    got signed char *
mm/vmstat.c:401:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:401:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:401:13:    got signed char *
mm/vmstat.c:401:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:401:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:401:13:    got signed char *
mm/vmstat.c:401:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:401:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:401:13:    got signed char *
mm/vmstat.c:401:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:401:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:401:13:    got signed char *
mm/vmstat.c:429:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:429:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:429:13:    got signed char *
mm/vmstat.c:429:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:429:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:429:13:    got signed char *
mm/vmstat.c:429:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:429:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:429:13:    got signed char *
mm/vmstat.c:429:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:429:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:429:13:    got signed char *
mm/vmstat.c:445:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:445:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:445:13:    got signed char *
mm/vmstat.c:445:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:445:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:445:13:    got signed char *
mm/vmstat.c:445:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:445:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:445:13:    got signed char *
mm/vmstat.c:445:13: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:445:13:    expected signed char [noderef] [usertype] <asn:3> *__p
mm/vmstat.c:445:13:    got signed char *
mm/vmstat.c:763:29: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:763:29:    expected signed char [noderef] <asn:3> *__p
mm/vmstat.c:763:29:    got signed char *
mm/vmstat.c:763:29: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:763:29:    expected signed char [noderef] <asn:3> *__p
mm/vmstat.c:763:29:    got signed char *
mm/vmstat.c:763:29: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:763:29:    expected signed char [noderef] <asn:3> *__p
mm/vmstat.c:763:29:    got signed char *
mm/vmstat.c:763:29: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:763:29:    expected signed char [noderef] <asn:3> *__p
mm/vmstat.c:763:29:    got signed char *
mm/vmstat.c:825:29: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:825:29:    expected signed char [noderef] <asn:3> *__p
mm/vmstat.c:825:29:    got signed char *
mm/vmstat.c:825:29: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:825:29:    expected signed char [noderef] <asn:3> *__p
mm/vmstat.c:825:29:    got signed char *
mm/vmstat.c:825:29: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:825:29:    expected signed char [noderef] <asn:3> *__p
mm/vmstat.c:825:29:    got signed char *
mm/vmstat.c:825:29: warning: incorrect type in initializer (different address spaces)
mm/vmstat.c:825:29:    expected signed char [noderef] <asn:3> *__p
mm/vmstat.c:825:29:    got signed char *

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
---
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: linux-kernel@vger.kernel.org
---
 include/linux/percpu-defs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index a6fabd865211..a49b6c702598 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -229,7 +229,7 @@ do {									\
  * pointer value.  The weird cast keeps both GCC and sparse happy.
  */
 #define SHIFT_PERCPU_PTR(__p, __offset)					\
-	RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset))
+	RELOC_HIDE((typeof(*(__p)) __kernel __percpu __force *)(__p), (__offset))
 
 #define per_cpu_ptr(ptr, cpu)						\
 ({									\
-- 
2.23.0