From: Nathan Chancellor natechancellor@gmail.com
commit 380324734956c64cd060e1db4304f3117ac15809 upstream.
Clang warns:
In file included from ../arch/s390/purgatory/purgatory.c:10: In file included from ../include/linux/kexec.h:18: In file included from ../include/linux/crash_core.h:6: In file included from ../include/linux/elfcore.h:5: In file included from ../include/linux/user.h:1: In file included from ../arch/s390/include/asm/user.h:11: ../arch/s390/include/asm/page.h:45:6: warning: converting the result of '<<' to a boolean always evaluates to false [-Wtautological-constant-compare] if (PAGE_DEFAULT_KEY) ^ ../arch/s390/include/asm/page.h:23:44: note: expanded from macro 'PAGE_DEFAULT_KEY' #define PAGE_DEFAULT_KEY (PAGE_DEFAULT_ACC << 4) ^ 1 warning generated.
Explicitly compare this against zero to silence the warning as it is intended to be used in a boolean context.
Fixes: de3fa841e429 ("s390/mm: fix compile for PAGE_DEFAULT_KEY != 0") Link: https://github.com/ClangBuiltLinux/linux/issues/860 Link: https://lkml.kernel.org/r/20200214064207.10381-1-natechancellor@gmail.com Acked-by: Christian Borntraeger borntraeger@de.ibm.com Signed-off-by: Nathan Chancellor natechancellor@gmail.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/s390/include/asm/page.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/s390/include/asm/page.h +++ b/arch/s390/include/asm/page.h @@ -35,7 +35,7 @@ void __storage_key_init_range(unsigned l
static inline void storage_key_init_range(unsigned long start, unsigned long end) { - if (PAGE_DEFAULT_KEY) + if (PAGE_DEFAULT_KEY != 0) __storage_key_init_range(start, end); }