From acce1041cd757a6c02987a29b2990932368af6bf Mon Sep 17 00:00:00 2001
From: Laura Abbott <lauraa@codeaurora.org>
Date: Mon, 11 Nov 2013 17:25:33 -0800
Subject: [PATCH] mm: make is_vmalloc_addr work properly.

There was a typo in the config guard for CONFIG_ENABLE_VMALLOC_SAVING
which meant that the code was never actually being compiled. As a
result, it was never noticed that the code had major flaws. Fix
the code to actually work as intended.

Change-Id: Ief3c00d16cf54e3b945ffb1bfde6b1fea2fa142e
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
---
 mm/vmalloc.c | 73 ++++++++++++++++++++++++++++++----------------------
 1 file changed, 42 insertions(+), 31 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index eb5ed0e703bf..4d95f4d93c58 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -204,36 +204,6 @@ static int vmap_page_range(unsigned long start, unsigned long end,
 	return ret;
 }
 
-#ifdef ENABLE_VMALLOC_SAVING
-int is_vmalloc_addr(const void *x)
-{
-	struct rb_node *n;
-	struct vmap_area *va;
-	int ret = 0;
-
-	spin_lock(&vmap_area_lock);
-
-	for (n = rb_first(vmap_area_root); n; rb_next(n)) {
-		va = rb_entry(n, struct vmap_area, rb_node);
-		if (x >= va->va_start && x < va->va_end) {
-			ret = 1;
-			break;
-		}
-	}
-
-	spin_unlock(&vmap_area_lock);
-	return ret;
-}
-#else
-int is_vmalloc_addr(const void *x)
-{
-	unsigned long addr = (unsigned long)x;
-
-	return addr >= VMALLOC_START && addr < VMALLOC_END;
-}
-#endif
-EXPORT_SYMBOL(is_vmalloc_addr);
-
 int is_vmalloc_or_module_addr(const void *x)
 {
 	/*
@@ -299,9 +269,9 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
 #define VM_LAZY_FREEING	0x02
 #define VM_VM_AREA	0x04
 
-static DEFINE_SPINLOCK(vmap_area_lock);
 /* Export for kexec only */
 LIST_HEAD(vmap_area_list);
+static DEFINE_SPINLOCK(vmap_area_lock);
 static struct rb_root vmap_area_root = RB_ROOT;
 
 /* The vmap cache globals are protected by vmap_area_lock */
@@ -312,6 +282,47 @@ static unsigned long cached_align;
 
 static unsigned long vmap_area_pcpu_hole;
 
+#ifdef CONFIG_ENABLE_VMALLOC_SAVING
+int is_vmalloc_addr(const void *x)
+{
+	struct vmap_area *va;
+	int ret = 0;
+
+	spin_lock(&vmap_area_lock);
+	list_for_each_entry(va, &vmap_area_list, list) {
+		if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING))
+			continue;
+
+		if (!(va->flags & VM_VM_AREA))
+			continue;
+
+		if (va->vm == NULL)
+			continue;
+
+		if (va->vm->flags & VM_LOWMEM)
+			continue;
+
+		if ((unsigned long)x >= va->va_start &&
+		    (unsigned long)x < va->va_end) {
+			ret = 1;
+			break;
+		}
+	}
+	spin_unlock(&vmap_area_lock);
+	return ret;
+}
+#else
+int is_vmalloc_addr(const void *x)
+{
+	unsigned long addr = (unsigned long)x;
+
+	return addr >= VMALLOC_START && addr < VMALLOC_END;
+}
+#endif
+EXPORT_SYMBOL(is_vmalloc_addr);
+
+
+
 static struct vmap_area *__find_vmap_area(unsigned long addr)
 {
 	struct rb_node *n = vmap_area_root.rb_node;