Hi, For me, kernels built including this commit b059f801a937 (x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS)
results in kexec() failing to load the kernel: kexec: Undefined symbol: __stack_chk_fail kexec-bzImage64: Loading purgatory failed Can be seen: $ readelf -a arch/x86/purgatory/purgatory.ro | grep UND 0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND 51: 0000000000000000 0 NOTYPE GLOBAL DEFAULT UND __stack_chk_fail Using: gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1) Adding -ffreestanding or -fno-stack-protector to ccflags-y in arch/x86/purgatory/Makefile fixes the problem. Not sure which would be preferred.