xen: don't drop NX bit

Because NX is now enforced properly, we must put the hypercall page
into the .text segment so that it is executable.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: the arch/x86 maintainers <x86@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index f0078d9a5b78615e0d51f19ca7cbd54041c23c22..8132aa8c5d49d2797b1a3c30333cb89df6cbe9fd 100644 (file)
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -323,46 +323,54 @@ out:
                preempt_enable();
 }
 
-pteval_t xen_pte_val(pte_t pte)
+/* Assume pteval_t is equivalent to all the other *val_t types. */
+static pteval_t pte_mfn_to_pfn(pteval_t val)
 {
-       pteval_t ret = pte.pte;
+       if (val & _PAGE_PRESENT) {
+               unsigned long mfn = (val & PTE_MASK) >> PAGE_SHIFT;
+               pteval_t flags = val & ~PTE_MASK;
+               val = (mfn_to_pfn(mfn) << PAGE_SHIFT) | flags;
+       }
 
-       if (ret & _PAGE_PRESENT)
-               ret = machine_to_phys(XMADDR(ret)).paddr | _PAGE_PRESENT;
+       return val;
+}
 
-       return ret;
+static pteval_t pte_pfn_to_mfn(pteval_t val)
+{
+       if (val & _PAGE_PRESENT) {
+               unsigned long pfn = (val & PTE_MASK) >> PAGE_SHIFT;
+               pteval_t flags = val & ~PTE_MASK;
+               val = (pfn_to_mfn(pfn) << PAGE_SHIFT) | flags;
+       }
+
+       return val;
+}
+
+pteval_t xen_pte_val(pte_t pte)
+{
+       return pte_mfn_to_pfn(pte.pte);
 }
 
 pgdval_t xen_pgd_val(pgd_t pgd)
 {
-       pgdval_t ret = pgd.pgd;
-       if (ret & _PAGE_PRESENT)
-               ret = machine_to_phys(XMADDR(ret)).paddr | _PAGE_PRESENT;
-       return ret;
+       return pte_mfn_to_pfn(pgd.pgd);
 }
 
 pte_t xen_make_pte(pteval_t pte)
 {
-       if (pte & _PAGE_PRESENT)
-               pte = phys_to_machine(XPADDR(pte)).maddr;
-
-       return (pte_t){ .pte = pte };
+       pte = pte_pfn_to_mfn(pte);
+       return native_make_pte(pte);
 }
 
 pgd_t xen_make_pgd(pgdval_t pgd)
 {
-       if (pgd & _PAGE_PRESENT)
-               pgd = phys_to_machine(XPADDR(pgd)).maddr;
-
-       return (pgd_t){ pgd };
+       pgd = pte_pfn_to_mfn(pgd);
+       return native_make_pgd(pgd);
 }
 
 pmdval_t xen_pmd_val(pmd_t pmd)
 {
-       pmdval_t ret = native_pmd_val(pmd);
-       if (ret & _PAGE_PRESENT)
-               ret = machine_to_phys(XMADDR(ret)).paddr | _PAGE_PRESENT;
-       return ret;
+       return pte_mfn_to_pfn(pmd.pmd);
 }
 
 void xen_set_pud_hyper(pud_t *ptr, pud_t val)
@@ -421,9 +429,7 @@ void xen_pmd_clear(pmd_t *pmdp)
 
 pmd_t xen_make_pmd(pmdval_t pmd)
 {
-       if (pmd & _PAGE_PRESENT)
-               pmd = phys_to_machine(XPADDR(pmd)).maddr;
-
+       pmd = pte_pfn_to_mfn(pmd);
        return native_make_pmd(pmd);
 }
 

diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index ef6c9e005f90af1d40bf89898a478b6ddd960cda..7c0cf6320a0aa0ed55d56b5c627856dcb579d377 100644 (file)
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -18,7 +18,7 @@ ENTRY(startup_xen)
 
        __FINIT
 
-.pushsection .bss.page_aligned
+.pushsection .text
        .align PAGE_SIZE_asm
 ENTRY(hypercall_page)
        .skip 0x1000