xen64: set up userspace syscall patch

[linux-2.6-omap-h63xx.git] / arch / x86 / xen / enlighten.c

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 87d36044054d7f90976bb6c53ef0d45adc75dacf..f64b8729cd0719891f4c8c3e6c4f01e77c385943 100644 (file)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -56,6 +56,18 @@ EXPORT_SYMBOL_GPL(hypercall_page);
 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
 
+/*
+ * Identity map, in addition to plain kernel map.  This needs to be
+ * large enough to allocate page table pages to allocate the rest.
+ * Each page can map 2MB.
+ */
+static pte_t level1_ident_pgt[PTRS_PER_PTE * 4] __page_aligned_bss;
+
+#ifdef CONFIG_X86_64
+/* l3 pud for userspace vsyscall mapping */
+static pud_t level3_user_vsyscall[PTRS_PER_PUD] __page_aligned_bss;
+#endif /* CONFIG_X86_64 */
+
 /*
  * Note about cr3 (pagetable base) values:
  *
@@ -831,12 +843,20 @@ static int xen_pgd_alloc(struct mm_struct *mm)
 #ifdef CONFIG_X86_64
        {
                struct page *page = virt_to_page(pgd);
+               pgd_t *user_pgd;
 
                BUG_ON(page->private != 0);
 
-               page->private = __get_free_page(GFP_KERNEL | __GFP_ZERO);
-               if (page->private == 0)
-                       ret = -ENOMEM;
+               ret = -ENOMEM;
+
+               user_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+               page->private = (unsigned long)user_pgd;
+
+               if (user_pgd != NULL) {
+                       user_pgd[pgd_index(VSYSCALL_START)] =
+                               __pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
+                       ret = 0;
+               }
 
                BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd))));
        }
@@ -977,6 +997,9 @@ static __init void xen_post_allocator_init(void)
        pv_mmu_ops.release_pud = xen_release_pud;
 #endif
 
+#ifdef CONFIG_X86_64
+       SetPagePinned(virt_to_page(level3_user_vsyscall));
+#endif
        xen_mark_init_mm_pinned();
 }
 
@@ -1088,6 +1111,15 @@ static void xen_set_fixmap(unsigned idx, unsigned long phys, pgprot_t prot)
        }
 
        __native_set_fixmap(idx, pte);
+
+#ifdef CONFIG_X86_64
+       /* Replicate changes to map the vsyscall page into the user
+          pagetable vsyscall mapping. */
+       if (idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) {
+               unsigned long vaddr = __fix_to_virt(idx);
+               set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
+       }
+#endif
 }
 
 static const struct pv_info xen_info __initdata = {
@@ -1427,13 +1459,6 @@ static void set_page_prot(void *addr, pgprot_t prot)
                BUG();
 }
 
-/*
- * Identity map, in addition to plain kernel map.  This needs to be
- * large enough to allocate page table pages to allocate the rest.
- * Each page can map 2MB.
- */
-static pte_t level1_ident_pgt[PTRS_PER_PTE * 4] __page_aligned_bss;
-
 static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
 {
        unsigned pmdidx, pteidx;
@@ -1533,6 +1558,7 @@ static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pf
        set_page_prot(init_level4_pgt, PAGE_KERNEL_RO);
        set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO);
        set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO);
+       set_page_prot(level3_user_vsyscall, PAGE_KERNEL_RO);
        set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
        set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO);