commit 
8535c239ac674f7ead0f2652932d35c52c4123b2 upstream.
make sure that ->orig_r2 is negative for everything except
the syscalls.
Fixes: 82ed08dd1b0e ("nios2: Exception handling")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 
        stw     r13, PT_R13(sp)
        stw     r14, PT_R14(sp)
        stw     r15, PT_R15(sp)
-       stw     r2, PT_ORIG_R2(sp)
+       movi    r24, -1
+       stw     r24, PT_ORIG_R2(sp)
        stw     r7, PT_ORIG_R7(sp)
 
        stw     ra, PT_RA(sp)
 
        ldw     r5, PT_R5(sp)
 
 local_restart:
+       stw     r2, PT_ORIG_R2(sp)
        /* Check that the requested system call is within limits */
        movui   r1, __NR_syscalls
        bgeu    r2, r1, ret_invsyscall
        /* skip if no interrupt is pending */
        beq     r12, r0, ret_from_interrupt
 
-       movi    r24, -1
-       stw     r24, PT_ORIG_R2(sp)
-
        /*
         * Process an external hardware interrupt.
         */