Commit 1d351f189434 for kernel
commit 1d351f1894342c378b96bb9ed89f8debb1e24e9f
Author: Andrew Morton <akpm@linux-foundation.org>
Date: Mon Nov 28 13:21:40 2022 -0800
revert "kbuild: fix -Wimplicit-function-declaration in license_is_gpl_compatible"
It causes build failures with unusual CC/HOSTCC combinations.
Quoting
https://lkml.kernel.org/r/A222B1E6-69B8-4085-AD1B-27BDB72CA971@goldelico.com:
HOSTCC scripts/mod/modpost.o - due to target missing
In file included from include/linux/string.h:5,
from scripts/mod/../../include/linux/license.h:5,
from scripts/mod/modpost.c:24:
include/linux/compiler.h:246:10: fatal error: asm/rwonce.h: No such file or directory
246 | #include <asm/rwonce.h>
| ^~~~~~~~~~~~~~
compilation terminated.
...
The problem is that HOSTCC is not necessarily the same compiler or even
architecture as CC and pulling in <linux/compiler.h> or <asm/rwonce.h>
files indirectly isn't a good idea then.
My toolchain is providing HOSTCC = gcc (MacPorts) and CC = arm-linux-gnueabihf
(built from gcc source) and all running on Darwin.
If I change the include to <string.h> I can then "HOSTCC scripts/mod/modpost.c"
but then it fails for "CC kernel/module/main.c" not finding <string.h>:
CC kernel/module/main.o - due to target missing
In file included from kernel/module/main.c:43:0:
./include/linux/license.h:5:20: fatal error: string.h: No such file or directory
#include <string.h>
^
compilation terminated.
Reported-by: "H. Nikolaus Schaller" <hns@goldelico.com>
Cc: Sam James <sam@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/include/linux/license.h b/include/linux/license.h
index ad937f57f2cb..7cce390f120b 100644
--- a/include/linux/license.h
+++ b/include/linux/license.h
@@ -2,8 +2,6 @@
#ifndef __LICENSE_H
#define __LICENSE_H
-#include <linux/string.h>
-
static inline int license_is_gpl_compatible(const char *license)
{
return (strcmp(license, "GPL") == 0