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-rw-r--r--arch/x86_64/mm/pageattr.c23
1 files changed, 14 insertions, 9 deletions
diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c
index efe5af14c7d..531ad21447b 100644
--- a/arch/x86_64/mm/pageattr.c
+++ b/arch/x86_64/mm/pageattr.c
@@ -45,6 +45,13 @@ static struct page *split_large_page(unsigned long address, pgprot_t prot,
pte_t *pbase;
if (!base)
return NULL;
+ /*
+ * page_private is used to track the number of entries in
+ * the page table page have non standard attributes.
+ */
+ SetPagePrivate(base);
+ page_private(base) = 0;
+
address = __pa(address);
addr = address & LARGE_PAGE_MASK;
pbase = (pte_t *)page_address(base);
@@ -124,8 +131,8 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
set_pte(kpte, pfn_pte(pfn, prot));
} else {
/*
- * split_large_page will take the reference for this change_page_attr
- * on the split page.
+ * split_large_page will take the reference for this
+ * change_page_attr on the split page.
*/
struct page *split;
@@ -137,23 +144,20 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
set_pte(kpte,mk_pte(split, ref_prot2));
kpte_page = split;
}
- get_page(kpte_page);
+ page_private(kpte_page)++;
} else if ((kpte_flags & _PAGE_PSE) == 0) {
set_pte(kpte, pfn_pte(pfn, ref_prot));
- __put_page(kpte_page);
+ BUG_ON(page_private(kpte_page) == 0);
+ page_private(kpte_page)--;
} else
BUG();
/* on x86-64 the direct mapping set at boot is not using 4k pages */
BUG_ON(PageReserved(kpte_page));
- switch (page_count(kpte_page)) {
- case 1:
+ if (page_private(kpte_page) == 0) {
save_page(kpte_page);
revert_page(address, ref_prot);
- break;
- case 0:
- BUG(); /* memleak and failed 2M page regeneration */
}
return 0;
}
@@ -216,6 +220,7 @@ void global_flush_tlb(void)
while (dpage) {
struct page *tmp = dpage;
dpage = (struct page *)dpage->lru.next;
+ ClearPagePrivate(tmp);
__free_page(tmp);
}
}