From b9dce7f1ba01be340975c17bd37a46ec6054bd2b Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 20 Oct 2016 11:12:57 +0100 Subject: [PATCH] arm64: kernel: force ET_DYN ELF type for CONFIG_RELOCATABLE=y GNU ld used to set the ELF file type to ET_DYN for PIE executables, which is the same file type used for shared libraries. However, this was changed recently, and now PIE executables are emitted as ET_EXEC instead. The distinction is only relevant for ELF loaders, and so there is little reason to care about the difference when building the kernel, which is why the change has gone unnoticed until now. However, debuggers do use the ELF binary, and expect ET_EXEC type files to appear in memory at the exact offset described in the ELF metadata. This means source level debugging is no longer possible when KASLR is in effect or when executing the stub. So add the -shared LD option when building with CONFIG_RELOCATABLE=y. This forces the ELF file type to be set to ET_DYN (which is what you get when building with binutils 2.24 and earlier anyway), and has no other ill effects. Signed-off-by: Ard Biesheuvel Signed-off-by: Will Deacon --- arch/arm64/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index ab51aed6b6c1..3635b8662724 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -15,7 +15,7 @@ CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET) GZFLAGS :=-9 ifneq ($(CONFIG_RELOCATABLE),) -LDFLAGS_vmlinux += -pie -Bsymbolic +LDFLAGS_vmlinux += -pie -shared -Bsymbolic endif ifeq ($(CONFIG_ARM64_ERRATUM_843419),y) -- 2.20.1