From 5fc8965206e2192a9adad101ef6eb0c89acb3cdb Mon Sep 17 00:00:00 2001
From: Zachary Amsden <zach@vmware.com>
Date: Sat, 3 Sep 2005 15:56:50 -0700
Subject: [PATCH] --- yaml --- r: 6989 b: refs/heads/master c:
 d7271b14b2e9e5905aba0fbf5c4dc4f8980c0cb2 h: refs/heads/master i:   6987:
 bf7f07509dff80f1b5843d9092cbedaa9d2e91c3 v: v3

---
 [refs]                           |  2 +-
 trunk/arch/i386/kernel/smpboot.c |  4 ++--
 trunk/arch/i386/mm/pgtable.c     | 10 +++++-----
 trunk/include/asm-i386/pgtable.h | 15 +++++++++++++++
 4 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/[refs] b/[refs]
index 32cc719abb42..18b0e63d0f92 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 748f2edb52712aa3d926470a888608dc500d17e8
+refs/heads/master: d7271b14b2e9e5905aba0fbf5c4dc4f8980c0cb2
diff --git a/trunk/arch/i386/kernel/smpboot.c b/trunk/arch/i386/kernel/smpboot.c
index 8ac8e9fd5614..8e950cdff1a0 100644
--- a/trunk/arch/i386/kernel/smpboot.c
+++ b/trunk/arch/i386/kernel/smpboot.c
@@ -1017,8 +1017,8 @@ int __devinit smp_prepare_cpu(int cpu)
 	tsc_sync_disabled = 1;
 
 	/* init low mem mapping */
-	memcpy(swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
-			sizeof(swapper_pg_dir[0]) * KERNEL_PGD_PTRS);
+	clone_pgd_range(swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
+			KERNEL_PGD_PTRS);
 	flush_tlb_all();
 	schedule_work(&task);
 	wait_for_completion(&done);
diff --git a/trunk/arch/i386/mm/pgtable.c b/trunk/arch/i386/mm/pgtable.c
index bd2f7afc7a2a..dcdce2c6c532 100644
--- a/trunk/arch/i386/mm/pgtable.c
+++ b/trunk/arch/i386/mm/pgtable.c
@@ -207,19 +207,19 @@ void pgd_ctor(void *pgd, kmem_cache_t *cache, unsigned long unused)
 {
 	unsigned long flags;
 
-	if (PTRS_PER_PMD == 1)
+	if (PTRS_PER_PMD == 1) {
+		memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
 		spin_lock_irqsave(&pgd_lock, flags);
+	}
 
-	memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD,
+	clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
 			swapper_pg_dir + USER_PTRS_PER_PGD,
-			(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
-
+			KERNEL_PGD_PTRS);
 	if (PTRS_PER_PMD > 1)
 		return;
 
 	pgd_list_add(pgd);
 	spin_unlock_irqrestore(&pgd_lock, flags);
-	memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
 }
 
 /* never called when PTRS_PER_PMD > 1 */
diff --git a/trunk/include/asm-i386/pgtable.h b/trunk/include/asm-i386/pgtable.h
index d74185aee15b..47bc1ffa3d4c 100644
--- a/trunk/include/asm-i386/pgtable.h
+++ b/trunk/include/asm-i386/pgtable.h
@@ -277,6 +277,21 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
 	clear_bit(_PAGE_BIT_RW, &ptep->pte_low);
 }
 
+/*
+ * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
+ *
+ *  dst - pointer to pgd range anwhere on a pgd page
+ *  src - ""
+ *  count - the number of pgds to copy.
+ *
+ * dst and src can be on the same page, but the range must not overlap,
+ * and must not cross a page boundary.
+ */
+static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
+{
+       memcpy(dst, src, count * sizeof(pgd_t));
+}
+
 /*
  * Macro to mark a page protection value as "uncacheable".  On processors which do not support
  * it, this is a no-op.