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Diffstat (limited to 'arch/x86/boot/compressed/Makefile')
| -rw-r--r-- | arch/x86/boot/compressed/Makefile | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index cfdd8c3f8af2..536ccfcc01c6 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -85,9 +85,26 @@ vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \ $(objtree)/drivers/firmware/efi/libstub/lib.a vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o +# The compressed kernel is built with -fPIC/-fPIE so that a boot loader +# can place it anywhere in memory and it will still run. However, since +# it is executed as-is without any ELF relocation processing performed +# (and has already had all relocation sections stripped from the binary), +# none of the code can use data relocations (e.g. static assignments of +# pointer values), since they will be meaningless at runtime. This check +# will refuse to link the vmlinux if any of these relocations are found. +quiet_cmd_check_data_rel = DATAREL $@ +define cmd_check_data_rel + for obj in $(filter %.o,$^); do \ + readelf -S $$obj | grep -qF .rel.local && { \ + echo "error: $$obj has data relocations!" >&2; \ + exit 1; \ + } || true; \ + done +endef + $(obj)/vmlinux: $(vmlinux-objs-y) FORCE + $(call if_changed,check_data_rel) $(call if_changed,ld) - @: OBJCOPYFLAGS_vmlinux.bin := -R .comment -S $(obj)/vmlinux.bin: vmlinux FORCE |