diff options
Diffstat (limited to 'arch/x86/entry/entry_32.S')
| -rw-r--r-- | arch/x86/entry/entry_32.S | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index a1f28a54f23a..16c2c022540d 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -244,6 +244,18 @@ ENTRY(__switch_to_asm) movl %ebx, PER_CPU_VAR(stack_canary)+stack_canary_offset #endif +#ifdef CONFIG_RETPOLINE + /* + * When switching from a shallower to a deeper call stack + * the RSB may either underflow or use entries populated + * with userspace addresses. On CPUs where those concerns + * exist, overwrite the RSB with entries which capture + * speculative execution to prevent attack. + */ + /* Clobbers %ebx */ + FILL_RETURN_BUFFER RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW +#endif + /* restore callee-saved registers */ popl %esi popl %edi @@ -554,6 +566,11 @@ restore_all: .Lrestore_nocheck: RESTORE_REGS 4 # skip orig_eax/error_code .Lirq_return: + /* + * ARCH_HAS_MEMBARRIER_SYNC_CORE rely on IRET core serialization + * when returning from IPI handler and when returning from + * scheduler to user-space. + */ INTERRUPT_RETURN .section .fixup, "ax" @@ -883,6 +900,9 @@ BUILD_INTERRUPT3(xen_hvm_callback_vector, HYPERVISOR_CALLBACK_VECTOR, BUILD_INTERRUPT3(hyperv_callback_vector, HYPERVISOR_CALLBACK_VECTOR, hyperv_vector_handler) +BUILD_INTERRUPT3(hyperv_reenlightenment_vector, HYPERV_REENLIGHTENMENT_VECTOR, + hyperv_reenlightenment_intr) + #endif /* CONFIG_HYPERV */ ENTRY(page_fault) |
