From: Ard Biesheuvel <ardb@xxxxxxxxxx> Use PIC codegen for the compilation units containing code that may be called very early during the boot, at which point the CPU still runs from the 1:1 mapping of memory. This is necessary to prevent the compiler from emitting absolute symbol references to addresses that are not mapped yet. Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- arch/x86/kernel/Makefile | 2 ++ arch/x86/kernel/vmlinux.lds.S | 1 + arch/x86/mm/Makefile | 2 +- 3 files changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 42db41b04d8e..3819b65c64ec 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -24,7 +24,9 @@ endif # head64.c contains C code that may execute from a different virtual address # than it was linked at, so we always build it using PIE codegen CFLAGS_head64.o += $(PIE_CFLAGS) +CFLAGS_sev.o += $(PIE_CFLAGS) UBSAN_SANITIZE_head64.o := n +UBSAN_SANITIZE_sev.o := n KASAN_SANITIZE_head$(BITS).o := n KASAN_SANITIZE_dumpstack.o := n diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 77262e804250..bbdccb6362a9 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -182,6 +182,7 @@ SECTIONS DATA_DATA CONSTRUCTORS + *(.data.rel .data.rel.*) /* rarely changed data like cpu maps */ READ_MOSTLY_DATA(INTERNODE_CACHE_BYTES) diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index c80febc44cd2..f3bb8b415348 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -31,7 +31,7 @@ obj-y += pat/ # Make sure __phys_addr has no stackprotector CFLAGS_physaddr.o := -fno-stack-protector -CFLAGS_mem_encrypt_identity.o := -fno-stack-protector +CFLAGS_mem_encrypt_identity.o := $(PIE_CFLAGS) CFLAGS_fault.o := -I $(srctree)/$(src)/../include/asm/trace -- 2.43.0.429.g432eaa2c6b-goog
