remap_pte_range

From: Martin J. Bligh
Date: Tue Jun 29 2004 - 19:20:43 EST


I have no idea what remap_pte_range is trying to do here, but what it
is doing makes no sense (to me at least).

If the pfn is not valid, we CANNOT safely call PageReserved on it -
the *page returned from pfn_to_page is bullshit, and we crash deref'ing
it.

Perhaps this was what it was trying to do? Not sure.

diff -purN -X /home/mbligh/.diff.exclude virgin/mm/memory.c remap_pte_range/mm/memory.c
--- virgin/mm/memory.c 2004-06-16 10:22:15.000000000 -0700
+++ remap_pte_range/mm/memory.c 2004-06-29 17:15:35.000000000 -0700
@@ -908,7 +908,7 @@ static inline void remap_pte_range(pte_t
pfn = phys_addr >> PAGE_SHIFT;
do {
BUG_ON(!pte_none(*pte));
- if (!pfn_valid(pfn) || PageReserved(pfn_to_page(pfn)))
+ if (pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
set_pte(pte, pfn_pte(pfn, prot));
address += PAGE_SIZE;
pfn++;

-
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