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-rw-r--r--arch/x86/mm/pageattr.c37
1 files changed, 26 insertions, 11 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 84ba748..8253bc9 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -482,6 +482,13 @@ static int split_large_page(pte_t *kpte, unsigned long address)
pbase = (pte_t *)page_address(base);
paravirt_alloc_pte(&init_mm, page_to_pfn(base));
ref_prot = pte_pgprot(pte_clrhuge(*kpte));
+ /*
+ * If we ever want to utilize the PAT bit, we need to
+ * update this function to make sure it's converted from
+ * bit 12 to bit 7 when we cross from the 2MB level to
+ * the 4K level:
+ */
+ WARN_ON_ONCE(pgprot_val(ref_prot) & _PAGE_PAT_LARGE);
#ifdef CONFIG_X86_64
if (level == PG_LEVEL_1G) {
@@ -508,18 +515,13 @@ static int split_large_page(pte_t *kpte, unsigned long address)
#endif
/*
- * Install the new, split up pagetable. Important details here:
- *
- * On Intel the NX bit of all levels must be cleared to make a
- * page executable. See section 4.13.2 of Intel 64 and IA-32
- * Architectures Software Developer's Manual).
+ * Install the new, split up pagetable.
*
- * Mark the entry present. The current mapping might be
- * set to not present, which we preserved above.
+ * We use the standard kernel pagetable protections for the new
+ * pagetable protections, the actual ptes set above control the
+ * primary protection behavior:
*/
- ref_prot = pte_pgprot(pte_mkexec(pte_clrhuge(*kpte)));
- pgprot_val(ref_prot) |= _PAGE_PRESENT;
- __set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
+ __set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE)));
base = NULL;
out_unlock:
@@ -575,7 +577,6 @@ static int __change_page_attr(struct cpa_data *cpa, int primary)
address = cpa->vaddr[cpa->curpage];
else
address = *cpa->vaddr;
-
repeat:
kpte = lookup_address(address, &level);
if (!kpte)
@@ -812,6 +813,13 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
vm_unmap_aliases();
+ /*
+ * If we're called with lazy mmu updates enabled, the
+ * in-memory pte state may be stale. Flush pending updates to
+ * bring them up to date.
+ */
+ arch_flush_lazy_mmu_mode();
+
cpa.vaddr = addr;
cpa.numpages = numpages;
cpa.mask_set = mask_set;
@@ -854,6 +862,13 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
} else
cpa_flush_all(cache);
+ /*
+ * If we've been called with lazy mmu updates enabled, then
+ * make sure that everything gets flushed out before we
+ * return.
+ */
+ arch_flush_lazy_mmu_mode();
+
out:
return ret;
}
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