Re: BUG: Current 2.5-BK tree dies on boot!

[Anton Blanchard]

> This is without preempt. I tried both with and without SMP, with and without
> large TLB pages, with and without pte highmem, all die in the same place.

I needed this to boot the latest BK on my ppc64 box. The question is
why we are suddenly ending up with prev == NULL, hch mentioned his
patch was only a cleanup in this area.

Anton

===== mm/mprotect.c 1.16 vs edited =====
--- 1.16/mm/mprotect.c	Wed Sep 18 04:05:14 2002
+++ edited/mm/mprotect.c	Wed Sep 18 22:44:40 2002
@@ -281,7 +281,7 @@
 		}
 	}
 
-	if (next && prev->vm_end == next->vm_start &&
+	if (prev && next && prev->vm_end == next->vm_start &&
 			can_vma_merge(next, prev->vm_flags) &&
 			!prev->vm_file && !(prev->vm_flags & VM_SHARED)) {
 		spin_lock(&prev->vm_mm->page_table_lock);