From: Anton Blanchard <anton@samba.org>
Paul wrote a patch to use some of the rmap infrastructure to flush TLB
entries on ppc64. When testing it we found a problem in vmalloc where it
sets up the pte -> address mapping incorrectly. We clear the top bits of
the address but then forget to pass in the full address to
pte_alloc_kernel. The end result is the address in page->index is
truncated.
I fixed it in a similar way to how zeromap_pmd_range etc does it. I'm
guessing no one uses the rmap hooks on vmalloc pages yet, so havent seen
this problem.
---
mm/vmalloc.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff -puN mm/vmalloc.c~vmalloc-address-offset-fix mm/vmalloc.c
--- 25/mm/vmalloc.c~vmalloc-address-offset-fix 2004-01-20 20:34:28.000000000 -0800
+++ 25-akpm/mm/vmalloc.c 2004-01-20 20:34:28.000000000 -0800
@@ -114,15 +114,16 @@ static int map_area_pmd(pmd_t *pmd, unsi
unsigned long size, pgprot_t prot,
struct page ***pages)
{
- unsigned long end;
+ unsigned long base, end;
+ base = address & PGDIR_MASK;
address &= ~PGDIR_MASK;
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
do {
- pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
+ pte_t * pte = pte_alloc_kernel(&init_mm, pmd, base + address);
if (!pte)
return -ENOMEM;
if (map_area_pte(pte, address, end - address, prot, pages))
_