[src/trunk]: src/sys/arch/sparc64/sparc64 If we trap due to a bad kernel stac...

[eeh <eeh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1e83df2d3b71
branches:  trunk
changeset: 485244:1e83df2d3b71
user:      eeh <eeh%NetBSD.org@localhost>
date:      Sat Apr 22 22:06:06 2000 +0000

description:
If we trap due to a bad kernel stack, try to switch to the interrupt strack
before breaking into the debugger.

diffstat:

 sys/arch/sparc64/sparc64/locore.s |  22 +++++++++++++++++++++-
 1 files changed, 21 insertions(+), 1 deletions(-)

diffs (36 lines):

diff -r ac0fbbe14f10 -r 1e83df2d3b71 sys/arch/sparc64/sparc64/locore.s
--- a/sys/arch/sparc64/sparc64/locore.s Sat Apr 22 21:40:40 2000 +0000
+++ b/sys/arch/sparc64/sparc64/locore.s Sat Apr 22 22:06:06 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: locore.s,v 1.55 2000/04/18 02:12:25 eeh Exp $  */
+/*     $NetBSD: locore.s,v 1.56 2000/04/22 22:06:06 eeh Exp $  */
 /*
  * Copyright (c) 1996-1999 Eduardo Horvath
  * Copyright (c) 1996 Paul Kranenburg
@@ -2709,6 +2709,26 @@
        CHKPT(%g2,%g1,0x17)
 !      sir
 #endif
+       !!
+       !! Here we managed to fault trying to access a kernel window
+       !! This is a bug.  Switch to the interrupt stack if we aren't
+       !! there already and then trap into the debugger or panic.
+       !!
+       sethi   %hi(_C_LABEL(eintstack)-BIAS), %g6
+       btst    1, %sp
+       bnz,pt  %icc, 0f
+        mov    %sp, %g1
+       add     %sp, -BIAS, %g1
+0:
+       or      %g6, %lo(_C_LABEL(eintstack)-BIAS), %g6
+       set     (_C_LABEL(eintstack)-_C_LABEL(intstack)), %g7   ! XXXXXXXXXX This assumes kernel addresses are unique from user addresses
+       sub     %g6, %g1, %g2                           ! Determine if we need to switch to intr stack or not
+       dec     %g7                                     ! Make it into a mask
+       andncc  %g2, %g7, %g0                           ! XXXXXXXXXX This assumes kernel addresses are unique from user addresses */ \
+       movz    %xcc, %g1, %g6                          ! Stay on interrupt stack?
+       add     %g6, -CCFSZ, %g6                        ! Allocate a stack frame
+       mov     %sp, %l6                                ! XXXXX Save old stack pointer
+       mov     %g6, %sp
        ta      1; nop                                  ! Enter debugger
        NOTREACHED
 1: