x86/build: Build compressed x86 kernels as PIE when !CONFIG_RELOCATABLE as well

Since the bootloader may load the compressed x86 kernel at any address,
it should always be built as PIE, not just when CONFIG_RELOCATABLE=y.

Otherwise, linker in binutils 2.27 will optimize GOT load into the
absolute address when building the compressed x86 kernel as a non-PIE
executable.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
[ Small wording changes. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
H.J. Lu 2016-11-18 13:07:19 -08:00 committed by Ingo Molnar
parent 8c5c86fb6a
commit a980ce352f

View File

@ -40,8 +40,8 @@ GCOV_PROFILE := n
UBSAN_SANITIZE :=n
LDFLAGS := -m elf_$(UTS_MACHINE)
ifeq ($(CONFIG_RELOCATABLE),y)
# If kernel is relocatable, build compressed kernel as PIE.
# Compressed kernel should be built as PIE since it may be loaded at any
# address by the bootloader.
ifeq ($(CONFIG_X86_32),y)
LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker)
else
@ -51,7 +51,6 @@ else
LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \
&& echo "-z noreloc-overflow -pie --no-dynamic-linker")
endif
endif
LDFLAGS_vmlinux := -T
hostprogs-y := mkpiggy