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-rw-r--r--arch/x86/include/asm/io.h1
-rw-r--r--arch/x86/mm/ioremap.c5
-rw-r--r--arch/x86/xen/mmu.c26
3 files changed, 24 insertions, 8 deletions
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index 30a3e9776123..66aee6c4123b 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -348,6 +348,7 @@ extern void __iomem *early_memremap(resource_size_t phys_addr,
unsigned long size);
extern void early_iounmap(void __iomem *addr, unsigned long size);
extern void fixup_early_ioremap(void);
+extern bool is_early_ioremap_ptep(pte_t *ptep);
#define IO_SPACE_LIMIT 0xffff
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 3ba6e0608c55..0369843511dc 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -362,6 +362,11 @@ static inline pte_t * __init early_ioremap_pte(unsigned long addr)
return &bm_pte[pte_index(addr)];
}
+bool __init is_early_ioremap_ptep(pte_t *ptep)
+{
+ return ptep >= &bm_pte[0] && ptep < &bm_pte[PAGE_SIZE/sizeof(pte_t)];
+}
+
static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;
void __init early_ioremap_init(void)
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 4fe04ac0bae0..7d55e9ee3a76 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -56,6 +56,7 @@
#include <asm/e820.h>
#include <asm/linkage.h>
#include <asm/page.h>
+#include <asm/init.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
@@ -360,7 +361,8 @@ void make_lowmem_page_readonly(void *vaddr)
unsigned int level;
pte = lookup_address(address, &level);
- BUG_ON(pte == NULL);
+ if (pte == NULL)
+ return; /* vaddr missing */
ptev = pte_wrprotect(*pte);
@@ -375,7 +377,8 @@ void make_lowmem_page_readwrite(void *vaddr)
unsigned int level;
pte = lookup_address(address, &level);
- BUG_ON(pte == NULL);
+ if (pte == NULL)
+ return; /* vaddr missing */
ptev = pte_mkwrite(*pte);
@@ -1509,13 +1512,25 @@ static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
#endif
}
-#ifdef CONFIG_X86_32
static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
{
+ unsigned long pfn = pte_pfn(pte);
+
+#ifdef CONFIG_X86_32
/* If there's an existing pte, then don't allow _PAGE_RW to be set */
if (pte_val_ma(*ptep) & _PAGE_PRESENT)
pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
pte_val_ma(pte));
+#endif
+
+ /*
+ * If the new pfn is within the range of the newly allocated
+ * kernel pagetable, and it isn't being mapped into an
+ * early_ioremap fixmap slot, make sure it is RO.
+ */
+ if (!is_early_ioremap_ptep(ptep) &&
+ pfn >= e820_table_start && pfn < e820_table_end)
+ pte = pte_wrprotect(pte);
return pte;
}
@@ -1528,7 +1543,6 @@ static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
xen_set_pte(ptep, pte);
}
-#endif
static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
{
@@ -1973,11 +1987,7 @@ static const struct pv_mmu_ops xen_mmu_ops __initdata = {
.alloc_pmd_clone = paravirt_nop,
.release_pmd = xen_release_pmd_init,
-#ifdef CONFIG_X86_64
- .set_pte = xen_set_pte,
-#else
.set_pte = xen_set_pte_init,
-#endif
.set_pte_at = xen_set_pte_at,
.set_pmd = xen_set_pmd_hyper,