[POWERPC] Save trap number in bad_stack

Save the trap number in the case of getting a bad stack in an exception
handler. It is sometimes useful to know what exception it was that caused
this to happen. Without this, no trap number is reported.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 8 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index aff5398a5f63..1111fcec7673 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -278,8 +278,12 @@ exception_marker:
         beq-    1f;                                                        \
         ld      r1,PACAKSAVE(r13);      /* kernel stack to use          */ \
 1:      cmpdi   cr1,r1,0;               /* check if r1 is in userspace  */ \
-        bge-    cr1,bad_stack;          /* abort if it is               */ \
-        std     r9,_CCR(r1);            /* save CR in stackframe        */ \
+        bge-    cr1,2f;                 /* abort if it is               */ \
+        b       3f;                                                        \
+2:      li      r1,(n);                 /* will be reloaded later       */ \
+        sth     r1,PACA_TRAP_SAVE(r13);                                    \
+        b       bad_stack;                                                 \
+3:      std     r9,_CCR(r1);            /* save CR in stackframe        */ \
         std     r11,_NIP(r1);           /* save SRR0 in stackframe      */ \
         std     r12,_MSR(r1);           /* save SRR1 in stackframe      */ \
         std     r10,0(r1);              /* make stack chain pointer     */ \
@@ -940,6 +944,8 @@ bad_stack:
         SAVE_2GPRS(7,r1)
         SAVE_10GPRS(12,r1)
         SAVE_10GPRS(22,r1)
+        lhz     r12,PACA_TRAP_SAVE(r13)
+        std     r12,_TRAP(r1)
         addi    r11,r1,INT_FRAME_SIZE
         std     r11,0(r1)
         li      r12,0