1 files changed, 25 insertions, 9 deletions

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 87ef8f5ee5bc..200afa5bcfb7 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1452,20 +1452,36 @@ do_ste_alloc:
 _GLOBAL(do_stab_bolted)
         stw     r9,PACA_EXSLB+EX_CCR(r13)       /* save CR in exc. frame */
         std     r11,PACA_EXSLB+EX_SRR0(r13)     /* save SRR0 in exc. frame */
+        mfspr   r11,SPRN_DAR                    /* ea */
 
+        /*
+         * check for bad kernel/user address
+         * (ea & ~REGION_MASK) >= PGTABLE_RANGE
+         */
+        rldicr. r9,r11,4,(63 - 46 - 4)
+        li      r9,0    /* VSID = 0 for bad address */
+        bne-    0f
+
+        /*
+         * Calculate VSID:
+         * This is the kernel vsid, we take the top for context from
+         * the range. context = (MAX_USER_CONTEXT) + ((ea >> 60) - 0xc) + 1
+         * Here we know that (ea >> 60) == 0xc
+         */
+        lis     r9,(MAX_USER_CONTEXT + 1)@ha
+        addi    r9,r9,(MAX_USER_CONTEXT + 1)@l
+
+        srdi    r10,r11,SID_SHIFT
+        rldimi  r10,r9,ESID_BITS,0 /* proto vsid */
+        ASM_VSID_SCRAMBLE(r10, r9, 256M)
+        rldic   r9,r10,12,16    /* r9 = vsid << 12 */
+
+0:
         /* Hash to the primary group */
         ld      r10,PACASTABVIRT(r13)
-        mfspr   r11,SPRN_DAR
-        srdi    r11,r11,28
+        srdi    r11,r11,SID_SHIFT
         rldimi  r10,r11,7,52    /* r10 = first ste of the group */
 
-        /* Calculate VSID */
-        /* This is a kernel address, so protovsid = ESID | 1 << 37 */
-        li      r9,0x1
-        rldimi  r11,r9,(CONTEXT_BITS + USER_ESID_BITS),0
-        ASM_VSID_SCRAMBLE(r11, r9, 256M)
-        rldic   r9,r11,12,16    /* r9 = vsid << 12 */
-
         /* Search the primary group for a free entry */
 1:      ld      r11,0(r10)      /* Test valid bit of the current ste    */
         andi.   r11,r11,0x80