Merge commit 'paulus-perf/master' into next

1 files changed, 19 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 50f2ad36ed09..1808876edcc9 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -731,6 +731,11 @@ BEGIN_FTR_SECTION
         bne-    do_ste_alloc            /* If so handle it */
 END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
 
+        clrrdi  r11,r1,THREAD_SHIFT
+        lwz     r0,TI_PREEMPT(r11)      /* If we're in an "NMI" */
+        andis.  r0,r0,NMI_MASK@h        /* (i.e. an irq when soft-disabled) */
+        bne     77f                     /* then don't call hash_page now */
+
         /*
          * On iSeries, we soft-disable interrupts here, then
          * hard-enable interrupts so that the hash_page code can spin on
@@ -835,6 +840,20 @@ handle_page_fault:
         bl      .low_hash_fault
         b       .ret_from_except
 
+/*
+ * We come here as a result of a DSI at a point where we don't want
+ * to call hash_page, such as when we are accessing memory (possibly
+ * user memory) inside a PMU interrupt that occurred while interrupts
+ * were soft-disabled.  We want to invoke the exception handler for
+ * the access, or panic if there isn't a handler.
+ */
+77:     bl      .save_nvgprs
+        mr      r4,r3
+        addi    r3,r1,STACK_FRAME_OVERHEAD
+        li      r5,SIGSEGV
+        bl      .bad_page_fault
+        b       .ret_from_except
+
         /* here we have a segment miss */
 do_ste_alloc:
         bl      .ste_allocate           /* try to insert stab entry */