Skip to content
Commit fc8bd77d authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

x86/kexec: Use RIP relative addressing



Normally identity_mapped is not visible to objtool, due to:

  arch/x86/kernel/Makefile:OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o := y

However, when we want to run objtool on vmlinux.o there is no hiding
it:

  vmlinux.o: warning: objtool: .text+0x4c0f1: unsupported intra-function call

Replace the (i386 inspired) pattern:

	call 1f
  1:	popq %r8
	subq $(1b - relocate_kernel), %r8

With a x86_64 RIP-relative LEA:

	leaq relocate_kernel(%rip), %r8

Suggested-by: default avatarBrian Gerst <brgerst@gmail.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarMiroslav Benes <mbenes@suse.cz>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200324160924.143334345@infradead.org
parent f0f70adb
Loading
Loading
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Please register or to comment