Merge branch 'perf/urgent' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 29 insertions, 7 deletions

diff --git a/mm/util.c b/mm/util.c
index 34e57fae959d..c1250501364f 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -150,18 +150,14 @@ EXPORT_SYMBOL(kmemdup_nul);
  * @src: source address in user space
  * @len: number of bytes to copy
  *
- * Returns an ERR_PTR() on failure.
+ * Returns an ERR_PTR() on failure.  Result is physically
+ * contiguous, to be freed by kfree().
  */
 void *memdup_user(const void __user *src, size_t len)
 {
 	void *p;
 
-	/*
-	 * Always use GFP_KERNEL, since copy_from_user() can sleep and
-	 * cause pagefault, which makes it pointless to use GFP_NOFS
-	 * or GFP_ATOMIC.
-	 */
-	p = kmalloc_track_caller(len, GFP_KERNEL);
+	p = kmalloc_track_caller(len, GFP_USER);
 	if (!p)
 		return ERR_PTR(-ENOMEM);
 
@@ -174,6 +170,32 @@ void *memdup_user(const void __user *src, size_t len)
 }
 EXPORT_SYMBOL(memdup_user);
 
+/**
+ * vmemdup_user - duplicate memory region from user space
+ *
+ * @src: source address in user space
+ * @len: number of bytes to copy
+ *
+ * Returns an ERR_PTR() on failure.  Result may be not
+ * physically contiguous.  Use kvfree() to free.
+ */
+void *vmemdup_user(const void __user *src, size_t len)
+{
+	void *p;
+
+	p = kvmalloc(len, GFP_USER);
+	if (!p)
+		return ERR_PTR(-ENOMEM);
+
+	if (copy_from_user(p, src, len)) {
+		kvfree(p);
+		return ERR_PTR(-EFAULT);
+	}
+
+	return p;
+}
+EXPORT_SYMBOL(vmemdup_user);
+
 /*
  * strndup_user - duplicate an existing string from user space
  * @s: The string to duplicate