[PATCH 3.16 265/370] parisc: Don't use BITS_PER_LONG in userspace-exported swab.h header

From: Ben Hutchings
Date: Fri Mar 10 2017 - 08:49:14 EST


3.16.42-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Helge Deller <deller@xxxxxx>

commit 2ad5d52d42810bed95100a3d912679d8864421ec upstream.

In swab.h the "#if BITS_PER_LONG > 32" breaks compiling userspace programs if
BITS_PER_LONG is #defined by userspace with the sizeof() compiler builtin.

Solve this problem by using __BITS_PER_LONG instead. Since we now
#include asm/bitsperlong.h avoid further potential userspace pollution
by moving the #define of SHIFT_PER_LONG to bitops.h which is not
exported to userspace.

This patch unbreaks compiling qemu on hppa/parisc.

Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
arch/parisc/include/asm/bitops.h | 8 +++++++-
arch/parisc/include/uapi/asm/bitsperlong.h | 2 --
arch/parisc/include/uapi/asm/swab.h | 5 +++--
3 files changed, 10 insertions(+), 5 deletions(-)

--- a/arch/parisc/include/asm/bitops.h
+++ b/arch/parisc/include/asm/bitops.h
@@ -6,7 +6,7 @@
#endif

#include <linux/compiler.h>
-#include <asm/types.h> /* for BITS_PER_LONG/SHIFT_PER_LONG */
+#include <asm/types.h>
#include <asm/byteorder.h>
#include <asm/barrier.h>
#include <linux/atomic.h>
@@ -17,6 +17,12 @@
* to include/asm-i386/bitops.h or kerneldoc
*/

+#if __BITS_PER_LONG == 64
+#define SHIFT_PER_LONG 6
+#else
+#define SHIFT_PER_LONG 5
+#endif
+
#define CHOP_SHIFTCOUNT(x) (((unsigned long) (x)) & (BITS_PER_LONG - 1))


--- a/arch/parisc/include/uapi/asm/bitsperlong.h
+++ b/arch/parisc/include/uapi/asm/bitsperlong.h
@@ -9,10 +9,8 @@
*/
#if (defined(__KERNEL__) && defined(CONFIG_64BIT)) || defined (__LP64__)
#define __BITS_PER_LONG 64
-#define SHIFT_PER_LONG 6
#else
#define __BITS_PER_LONG 32
-#define SHIFT_PER_LONG 5
#endif

#include <asm-generic/bitsperlong.h>
--- a/arch/parisc/include/uapi/asm/swab.h
+++ b/arch/parisc/include/uapi/asm/swab.h
@@ -1,6 +1,7 @@
#ifndef _PARISC_SWAB_H
#define _PARISC_SWAB_H

+#include <asm/bitsperlong.h>
#include <linux/types.h>
#include <linux/compiler.h>

@@ -38,7 +39,7 @@ static inline __attribute_const__ __u32
}
#define __arch_swab32 __arch_swab32

-#if BITS_PER_LONG > 32
+#if __BITS_PER_LONG > 32
/*
** From "PA-RISC 2.0 Architecture", HP Professional Books.
** See Appendix I page 8 , "Endian Byte Swapping".
@@ -61,6 +62,6 @@ static inline __attribute_const__ __u64
return x;
}
#define __arch_swab64 __arch_swab64
-#endif /* BITS_PER_LONG > 32 */
+#endif /* __BITS_PER_LONG > 32 */

#endif /* _PARISC_SWAB_H */