Change the assembly code to use only relative references of symbols for the kernel to be PIE compatible. Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> --- arch/x86/entry/entry_64.S | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index f2bb91e87877..2c8200d35797 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1329,7 +1329,8 @@ SYM_CODE_START_LOCAL(error_entry) movl %ecx, %eax /* zero extend */ cmpq %rax, RIP+8(%rsp) je .Lbstep_iret - cmpq $.Lgs_change, RIP+8(%rsp) + leaq .Lgs_change(%rip), %rcx + cmpq %rcx, RIP+8(%rsp) jne .Lerror_entry_done_lfence /* @@ -1529,10 +1530,10 @@ SYM_CODE_START(nmi) * resume the outer NMI. */ - movq $repeat_nmi, %rdx + leaq repeat_nmi(%rip), %rdx cmpq 8(%rsp), %rdx ja 1f - movq $end_repeat_nmi, %rdx + leaq end_repeat_nmi(%rip), %rdx cmpq 8(%rsp), %rdx ja nested_nmi_out 1: @@ -1586,7 +1587,8 @@ nested_nmi: pushq %rdx pushfq pushq $__KERNEL_CS - pushq $repeat_nmi + leaq repeat_nmi(%rip), %rdx + pushq %rdx /* Put stack back */ addq $(6*8), %rsp @@ -1625,7 +1627,11 @@ first_nmi: addq $8, (%rsp) /* Fix up RSP */ pushfq /* RFLAGS */ pushq $__KERNEL_CS /* CS */ - pushq $1f /* RIP */ + pushq $0 /* Space for RIP */ + pushq %rdx /* Save RDX */ + leaq 1f(%rip), %rdx /* Put the address of 1f label into RDX */ + movq %rdx, 8(%rsp) /* Store it in RIP field */ + popq %rdx /* Restore RDX */ iretq /* continues at repeat_nmi below */ UNWIND_HINT_IRET_REGS 1: -- 2.25.1.481.gfbce0eb801-goog
