On Thursday 07 April 2022 11:54:55 Miquel Raynal wrote: > Hi Pali, > > p...@kernel.org wrote on Thu, 7 Apr 2022 11:41:59 +0200: > > > On Thursday 07 April 2022 09:54:21 Miquel Raynal wrote: > > > Hi Pali, > > > > > > p...@kernel.org wrote on Wed, 6 Apr 2022 23:31:53 +0200: > > > > > > Would you mind explaining a little bit how this change fixes it? It > > > does not look straightforward to me. > > > > Yes! I though that it is straightforward this change... > > byteorder/little_endian.h defines cpu_to_le* macros for Little Endian > > systems and byteorder/big_endian.h for Big Endian systems. > > > > File asm/byteorder.h is then ARCH-specific and implements macros for the > > current architecture (by including the correct header file). > > > > So currently if you try to compile squashfs for big endian systems you > > get compile error: > > > > In file included from ./arch/powerpc/include/asm/byteorder.h:82, > > from include/linux/unaligned/access_ok.h:4, > > from ./arch/powerpc/include/asm/unaligned.h:9, > > from fs/squashfs/sqfs_filesystem.h:11, > > from fs/squashfs/sqfs_dir.c:16: > > include/linux/byteorder/big_endian.h:34: warning: "__cpu_to_le32" > > redefined > > #define __cpu_to_le32(x) ((__force __le32)__swab32((x))) > > > > In file included from fs/squashfs/sqfs_dir.c:10: > > include/linux/byteorder/little_endian.h:34: note: this is the location of > > the previous definition > > #define __cpu_to_le32(x) ((__force __le32)(__u32)(x)) > > > > Or: > > > > In file included from fs/squashfs/sqfs.c:14: > > include/linux/byteorder/little_endian.h:89:21: error: redefinition of > > ‘__be16_to_cpup’ > > static inline __u16 __be16_to_cpup(const __be16 *p) > > ^~~~~~~~~~~~~~ > > In file included from ./arch/powerpc/include/asm/byteorder.h:82, > > from include/linux/unaligned/access_ok.h:4, > > from ./arch/powerpc/include/asm/unaligned.h:9, > > from fs/squashfs/sqfs.c:10: > > include/linux/byteorder/big_endian.h:89:21: note: previous definition of > > ‘__be16_to_cpup’ was here > > static inline __u16 __be16_to_cpup(const __be16 *p) > > ^~~~~~~~~~~~~~ > > > > As some header files include correct asm/byteorder.h file and this > > squashfs includes additional little_endian.h. > > Great, thanks for the thorough explanation. Based on what you said, > wouldn't it be cleaner to just get rid of the little_endian.h include > rather than also use the ARCH specific byteorder.h header?
I think that this is not possible. squashfs code uses le16_to_cpu() macro and its correct definition is provided only by arch specific asm/byteorder.h. > > > > > > Signed-off-by: Pali Rohár <p...@kernel.org> > > > > --- > > > > fs/squashfs/sqfs.c | 3 +-- > > > > fs/squashfs/sqfs_dir.c | 3 +-- > > > > 2 files changed, 2 insertions(+), 4 deletions(-) > > > > > > > > diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c > > > > index 5d9c52af80ba..41cb811c1b32 100644 > > > > --- a/fs/squashfs/sqfs.c > > > > +++ b/fs/squashfs/sqfs.c > > > > @@ -11,8 +11,7 @@ > > > > #include <errno.h> > > > > #include <fs.h> > > > > #include <linux/types.h> > > > > -#include <linux/byteorder/little_endian.h> > > > > -#include <linux/byteorder/generic.h> > > > > +#include <asm/byteorder.h> > > > > #include <memalign.h> > > > > #include <stdlib.h> > > > > #include <string.h> > > > > diff --git a/fs/squashfs/sqfs_dir.c b/fs/squashfs/sqfs_dir.c > > > > index a265b98fe685..ed83c90682ff 100644 > > > > --- a/fs/squashfs/sqfs_dir.c > > > > +++ b/fs/squashfs/sqfs_dir.c > > > > @@ -7,8 +7,7 @@ > > > > > > > > #include <errno.h> > > > > #include <linux/types.h> > > > > -#include <linux/byteorder/little_endian.h> > > > > -#include <linux/byteorder/generic.h> > > > > +#include <asm/byteorder.h> > > > > #include <stdint.h> > > > > #include <stdio.h> > > > > #include <stdlib.h> > > > > > > Cheers, > > > Miquèl > > > Thanks, > Miquèl