xen/x86: don't corrupt %eip when returning from a signal handler

[karo-tx-linux.git] / arch / x86 / kernel / entry_32.S

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index bcda8163bb0058d761211ab9b02820e114c32bf9..4893d580305f4d6fa7ece1139a5ff5a66ee76373 100644 (file)
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1025,7 +1025,7 @@ ENTRY(xen_sysenter_target)
 
 ENTRY(xen_hypervisor_callback)
        CFI_STARTPROC
-       pushl_cfi $0
+       pushl_cfi $-1 /* orig_ax = -1 => not a system call */
        SAVE_ALL
        TRACE_IRQS_OFF
 
@@ -1067,14 +1067,16 @@ ENTRY(xen_failsafe_callback)
 2:     mov 8(%esp),%es
 3:     mov 12(%esp),%fs
 4:     mov 16(%esp),%gs
+       /* EAX == 0 => Category 1 (Bad segment)
+          EAX != 0 => Category 2 (Bad IRET) */
        testl %eax,%eax
        popl_cfi %eax
        lea 16(%esp),%esp
        CFI_ADJUST_CFA_OFFSET -16
        jz 5f
        addl $16,%esp
-       jmp iret_exc            # EAX != 0 => Category 2 (Bad IRET)
-5:     pushl_cfi $0            # EAX == 0 => Category 1 (Bad segment)
+       jmp iret_exc
+5:     pushl_cfi $-1 /* orig_ax = -1 => not a system call */
        SAVE_ALL
        jmp ret_from_exception
        CFI_ENDPROC