From: Masahiro Yamada yamada.masahiro@socionext.com
commit 2a6cc8a6c0cb44baf7df2f64e5090aaf726002c3 upstream.
Patch series "linux/const.h: cleanups of macros such as UL(), _BITUL(), BIT() etc", v3.
ARM, ARM64, UniCore32 define UL() as a shorthand of _AC(..., UL). More architectures may introduce it in the future.
UL() is arch-agnostic, and useful. So let's move it to include/linux/const.h
Currently, <asm/memory.h> must be included to use UL(). It pulls in more bloats just for defining some bit macros.
I posted V2 one year ago.
The previous posts are: https://patchwork.kernel.org/patch/9498273/ https://patchwork.kernel.org/patch/9498275/ https://patchwork.kernel.org/patch/9498269/ https://patchwork.kernel.org/patch/9498271/
At that time, what blocked this series was a comment from David Howells: You need to be very careful doing this. Some userspace stuff depends on the guard macro names on the kernel header files.
(https://patchwork.kernel.org/patch/9498275/)
Looking at the code closer, I noticed this is not a problem.
See the following line. https://github.com/torvalds/linux/blob/v4.16-rc2/scripts/headers_install.sh#...
scripts/headers_install.sh rips off _UAPI prefix from guard macro names.
I ran "make headers_install" and confirmed the result is what I expect.
So, we can prefix the include guard of include/uapi/linux/const.h, and add a new include/linux/const.h.
This patch (of 4):
I am going to add include/linux/const.h for the kernel space.
Add _UAPI to the include guard of include/uapi/linux/const.h to prepare for that.
Please notice the guard name of the exported one will be kept as-is. So, this commit has no impact to the userspace even if some userspace stuff depends on the guard macro names.
scripts/headers_install.sh processes exported headers by SED, and rips off "_UAPI" from guard macro names.
#ifndef _UAPI_LINUX_CONST_H #define _UAPI_LINUX_CONST_H
will be turned into
#ifndef _LINUX_CONST_H #define _LINUX_CONST_H
Link: http://lkml.kernel.org/r/1519301715-31798-2-git-send-email-yamada.masahiro@s... Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com Cc: David Howells dhowells@redhat.com Cc: Will Deacon will.deacon@arm.com Cc: Guan Xuetao gxt@mprc.pku.edu.cn Cc: Geert Uytterhoeven geert@linux-m68k.org Cc: Catalin Marinas catalin.marinas@arm.com Cc: Russell King rmk+kernel@armlinux.org.uk Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org [nd: resolve trivial conflict due to b732e14e6218b being backported before this] Signed-off-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/uapi/linux/const.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/include/uapi/linux/const.h +++ b/include/uapi/linux/const.h @@ -1,8 +1,8 @@ /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ /* const.h: Macros for dealing with constants. */
-#ifndef _LINUX_CONST_H -#define _LINUX_CONST_H +#ifndef _UAPI_LINUX_CONST_H +#define _UAPI_LINUX_CONST_H
/* Some constant macros are used in both assembler and * C code. Therefore we cannot annotate them always with @@ -30,4 +30,4 @@
#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
-#endif /* !(_LINUX_CONST_H) */ +#endif /* _UAPI_LINUX_CONST_H */