Prepare install_extint() for the vector being relative-negative (ie

lower in the address space).  Previously it could only be higher
than... uhm locore.o
Discussed with drahn and tom

diff --git a/sys/arch/macppc/macppc/machdep.c b/sys/arch/macppc/macppc/machdep.c
index 0b6548f..18ed83f 100644 (file)
--- a/sys/arch/macppc/macppc/machdep.c
+++ b/sys/arch/macppc/macppc/machdep.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: machdep.c,v 1.180 2017/04/30 16:45:45 mpi Exp $       */
+/*     $OpenBSD: machdep.c,v 1.181 2017/06/13 01:42:12 deraadt Exp $   */
 /*     $NetBSD: machdep.c,v 1.4 1996/10/16 19:33:11 ws Exp $   */
 
 /*
@@ -331,16 +331,17 @@ install_extint(void (*handler)(void))
        void extint(void);
        void extsize(void);
        extern u_long extint_call;
-       u_long offset = (u_long)handler - (u_long)&extint_call;
+       long offset = (u_long)handler - (u_long)&extint_call;
        int omsr, msr;
 
-#ifdef DIAGNOSTIC
-       if (offset > 0x1ffffff)
+#ifdef DIAGNOSTIC
+       if (offset > 0x1ffffff || offset < -0x1ffffff)
                panic("install_extint: too far away");
 #endif
        omsr = ppc_mfmsr();
        msr = omsr & ~PSL_EE;
        ppc_mtmsr(msr);
+       offset &= 0x3ffffff;
        extint_call = (extint_call & 0xfc000003) | offset;
        bcopy(&extint, (void *)EXC_EXI, (size_t)&extsize);
        syncicache((void *)&extint_call, sizeof extint_call);