xen: make sure iret faults are trapped

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index f0f8934fc30324fc29af50dc436db6f14b198a93..568c6ccd7ae2d227fbef975636745736539db37d 100644 (file)
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -409,7 +409,7 @@ restore_nocheck_notrace:
 irq_return:
        INTERRUPT_RETURN
 .section .fixup,"ax"
-iret_exc:
+ENTRY(iret_exc)
        pushl $0                        # no error code
        pushl $do_iret_error
        jmp error_code

diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index fe161ed4b01e49de531b6e5b26462aad7d0c222d..99223cc323be9ac8de724f5534b27f814958c307 100644 (file)
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -184,8 +184,12 @@ iret_restore_end:
           region is OK. */
        je xen_hypervisor_callback
 
-       iret
+1:     iret
 xen_iret_end_crit:
+.section __ex_table,"a"
+       .align 4
+       .long 1b,iret_exc
+.previous
 
 hyper_iret:
        /* put this out of line since its very rarely used */