x86: Always flush pages in change_page_attr
Fix a bug introduced with the CLFLUSH changes: we must always flush pages
changed in cpa(), not just when they are reverted.
Reenable CLFLUSH usage with that now (it was temporarily disabled
for .22)
Add some BUG_ONs
Contains fixes from Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c
index 9148f4a..36377b6 100644
--- a/arch/x86_64/mm/pageattr.c
+++ b/arch/x86_64/mm/pageattr.c
@@ -74,14 +74,12 @@
struct page *pg;
/* When clflush is available always use it because it is
- much cheaper than WBINVD. Disable clflush for now because
- the high level code is not ready yet */
- if (1 || !cpu_has_clflush)
+ much cheaper than WBINVD. */
+ if (!cpu_has_clflush)
asm volatile("wbinvd" ::: "memory");
else list_for_each_entry(pg, l, lru) {
void *adr = page_address(pg);
- if (cpu_has_clflush)
- cache_flush_page(adr);
+ cache_flush_page(adr);
}
__flush_tlb_all();
}
@@ -95,7 +93,8 @@
static inline void save_page(struct page *fpage)
{
- list_add(&fpage->lru, &deferred_pages);
+ if (!test_and_set_bit(PG_arch_1, &fpage->flags))
+ list_add(&fpage->lru, &deferred_pages);
}
/*
@@ -129,9 +128,12 @@
pte_t *kpte;
struct page *kpte_page;
pgprot_t ref_prot2;
+
kpte = lookup_address(address);
if (!kpte) return 0;
kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK);
+ BUG_ON(PageLRU(kpte_page));
+ BUG_ON(PageCompound(kpte_page));
if (pgprot_val(prot) != pgprot_val(ref_prot)) {
if (!pte_huge(*kpte)) {
set_pte(kpte, pfn_pte(pfn, prot));
@@ -159,10 +161,9 @@
/* on x86-64 the direct mapping set at boot is not using 4k pages */
BUG_ON(PageReserved(kpte_page));
- if (page_private(kpte_page) == 0) {
- save_page(kpte_page);
+ save_page(kpte_page);
+ if (page_private(kpte_page) == 0)
revert_page(address, ref_prot);
- }
return 0;
}
@@ -234,6 +235,10 @@
flush_map(&l);
list_for_each_entry_safe(pg, next, &l, lru) {
+ list_del(&pg->lru);
+ clear_bit(PG_arch_1, &pg->flags);
+ if (page_private(pg) != 0)
+ continue;
ClearPagePrivate(pg);
__free_page(pg);
}