From 36ecbd682292842230ecb63974d9cd4cffc150ab Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy@goop.org>
Date: Tue, 8 Jul 2008 15:07:15 -0700
Subject: [PATCH] --- yaml --- r: 104447 b: refs/heads/master c:
 bf18bf94dc72db998d0fbebc846c07c858a59c90 h: refs/heads/master i:   104445:
 01dc27237cb157efac8648c3bf316119f4de6789   104443:
 afa42a676d4b5fa765ec7bf11e3e4764f1ac41bc   104439:
 45b2c9401fe869e5cd610f122412e4708f20efed   104431:
 25bce7acab4611e83df3133bea7150beda62da73   104415:
 2793a4144d670044b84eab1450e64bab59ae52cb   104383:
 9eb4f0f659d1ef0c4ef01ee5cd8ac3317c37241d   104319:
 3e9215796e22dd0d5f4c0f1d7d6851918d580c94   104191:
 48eb18563cd8036976572066f7d8429414f03158   103935:
 32b16df755fa7326ce519fc20410da55661c796d   103423:
 088dc7586fbfbea8d144e0fec084998e251b670f   102399:
 63fdcdaf4356b95cb44246c04a5df2626bacf212 v: v3

---
 [refs]                         |  2 +-
 trunk/arch/x86/xen/enlighten.c | 46 ++++++++++++++++++++++++++--------
 2 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/[refs] b/[refs]
index bd7f124a50e0..bacd93a046fe 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6fcac6d305e8238939e169f4c52e8ec8a552a31f
+refs/heads/master: bf18bf94dc72db998d0fbebc846c07c858a59c90
diff --git a/trunk/arch/x86/xen/enlighten.c b/trunk/arch/x86/xen/enlighten.c
index 87d36044054d..f64b8729cd07 100644
--- a/trunk/arch/x86/xen/enlighten.c
+++ b/trunk/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);