From: Christian Borntraeger borntraeger@de.ibm.com
commit 467d12f5c7842896d2de3ced74e4147ee29e97c8 upstream.
QEMU has a funny new build error message when I use the upstream kernel headers:
CC block/file-posix.o In file included from /home/cborntra/REPOS/qemu/include/qemu/timer.h:4, from /home/cborntra/REPOS/qemu/include/qemu/timed-average.h:29, from /home/cborntra/REPOS/qemu/include/block/accounting.h:28, from /home/cborntra/REPOS/qemu/include/block/block_int.h:27, from /home/cborntra/REPOS/qemu/block/file-posix.c:30: /usr/include/linux/swab.h: In function `__swab': /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:34: error: "sizeof" is not defined, evaluates to 0 [-Werror=undef] 20 | #define BITS_PER_LONG (sizeof (unsigned long) * BITS_PER_BYTE) | ^~~~~~ /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:41: error: missing binary operator before token "(" 20 | #define BITS_PER_LONG (sizeof (unsigned long) * BITS_PER_BYTE) | ^ cc1: all warnings being treated as errors make: *** [/home/cborntra/REPOS/qemu/rules.mak:69: block/file-posix.o] Error 1 rm tests/qemu-iotests/socket_scm_helper.o
This was triggered by commit d5767057c9a ("uapi: rename ext2_swab() to swab() and share globally in swab.h"). That patch is doing
#include <asm/bitsperlong.h>
but it uses BITS_PER_LONG.
The kernel file asm/bitsperlong.h provide only __BITS_PER_LONG.
Let us use the __ variant in swap.h
Link: http://lkml.kernel.org/r/20200213142147.17604-1-borntraeger@de.ibm.com Fixes: d5767057c9a ("uapi: rename ext2_swab() to swab() and share globally in swab.h") Signed-off-by: Christian Borntraeger borntraeger@de.ibm.com Cc: Yury Norov yury.norov@gmail.com Cc: Allison Randal allison@lohutok.net Cc: Joe Perches joe@perches.com Cc: Thomas Gleixner tglx@linutronix.de Cc: William Breathitt Gray vilhelm.gray@gmail.com Cc: Torsten Hilbrich torsten.hilbrich@secunet.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- include/uapi/linux/swab.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/include/uapi/linux/swab.h +++ b/include/uapi/linux/swab.h @@ -135,9 +135,9 @@ static inline __attribute_const__ __u32
static __always_inline unsigned long __swab(const unsigned long y) { -#if BITS_PER_LONG == 64 +#if __BITS_PER_LONG == 64 return __swab64(y); -#else /* BITS_PER_LONG == 32 */ +#else /* __BITS_PER_LONG == 32 */ return __swab32(y); #endif }