kexec-tools build fails on my laptop with RHEL7.1 installed: gcc -g -O2 -fno-strict-aliasing -Wall -Wstrict-prototypes -I./include -I./util_lib/include -Iinclude/ -I./kexec/arch/x86_64/include -c -MD -o kexec/arch/i386/kexec-x86-common.o kexec/arch/i386/kexec-x86-common.c In file included from kexec/arch/i386/kexec-x86-common.c:36:0: kexec/arch/i386/../../kexec.h:19:2: error: #error BYTE_ORDER not defined #error BYTE_ORDER not defined ^ kexec/arch/i386/../../kexec.h:23:2: error: #error LITTLE_ENDIAN not defined #error LITTLE_ENDIAN not defined ^ kexec/arch/i386/../../kexec.h:27:2: error: #error BIG_ENDIAN not defined #error BIG_ENDIAN not defined ^ In file included from kexec/arch/i386/kexec-x86-common.c:37:0: kexec/arch/i386/../../kexec-syscall.h: In function ?kexec_load?: kexec/arch/i386/../../kexec-syscall.h:74:2: warning: implicit declaration of function ?syscall? [-Wimplicit-function-declaration] return (long) syscall(__NR_kexec_load, entry, nr_segments, segments, flags); ^ make: *** [kexec/arch/i386/kexec-x86-common.o] Error 1 The build error was introduced by below commit: commit c9c21cc107dcc9b6053e39ead1069e03717513f9 Author: Baoquan He <bhe at redhat.com> Date: Thu Aug 6 19:10:55 2015 +0800 kexec: use _DEFAULT_SOURCE instead to remove compiling warning Now compiling will print warning like below. Change code as it suggested. # warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE" ^ See manpage: http://man7.org/linux/man-pages/man7/feature_test_macros.7.html _BSD_SOURCE has been deprecated since glibc 2.20, To allow code that requires _BSD_SOURCE in glibc 2.19 and earlier and _DEFAULT_SOURCE in glibc 2.20 and later to compile without warnings, define both _BSD_SOURCE and _DEFAULT_SOURCE. Thus fix it by adding back _BSD_SOURCE along with _DEFAULT_SOURCE. Signed-off-by: Dave Young <dyoung at redhat.com> --- kexec/arch/i386/crashdump-x86.c | 1 + kexec/arch/i386/kexec-x86-common.c | 1 + 2 files changed, 2 insertions(+) --- kexec-tools.orig/kexec/arch/i386/crashdump-x86.c +++ kexec-tools/kexec/arch/i386/crashdump-x86.c @@ -20,6 +20,7 @@ */ #define _XOPEN_SOURCE 600 +#define _BSD_SOURCE #define _DEFAULT_SOURCE #include <fcntl.h> --- kexec-tools.orig/kexec/arch/i386/kexec-x86-common.c +++ kexec-tools/kexec/arch/i386/kexec-x86-common.c @@ -18,6 +18,7 @@ */ #define _XOPEN_SOURCE 600 +#define _BSD_SOURCE #define _DEFAULT_SOURCE #include <fcntl.h>