1 files changed, 106 insertions, 0 deletions
diff --git a/arch/powerpc/lib/checksum_wrappers.c b/arch/powerpc/lib/checksum_wrappers.c
new file mode 100644
index 000000000..8d83c39be
--- /dev/null
+++ b/arch/powerpc/lib/checksum_wrappers.c
@@ -0,0 +1,106 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2010
+ *
+ * Author: Anton Blanchard <anton@au.ibm.com>
+ */
+#include <linux/export.h>
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <asm/checksum.h>
+#include <linux/uaccess.h>
+
+__wsum csum_and_copy_from_user(const void __user *src, void *dst,
+			       int len, __wsum sum, int *err_ptr)
+{
+	unsigned int csum;
+
+	might_sleep();
+	allow_read_from_user(src, len);
+
+	*err_ptr = 0;
+
+	if (!len) {
+		csum = 0;
+		goto out;
+	}
+
+	if (unlikely((len < 0) || !access_ok(VERIFY_READ, src, len))) {
+		*err_ptr = -EFAULT;
+		csum = (__force unsigned int)sum;
+		goto out;
+	}
+
+	csum = csum_partial_copy_generic((void __force *)src, dst,
+					 len, sum, err_ptr, NULL);
+
+	if (unlikely(*err_ptr)) {
+		int missing = __copy_from_user(dst, src, len);
+
+		if (missing) {
+			memset(dst + len - missing, 0, missing);
+			*err_ptr = -EFAULT;
+		} else {
+			*err_ptr = 0;
+		}
+
+		csum = csum_partial(dst, len, sum);
+	}
+
+out:
+	prevent_read_from_user(src, len);
+	return (__force __wsum)csum;
+}
+EXPORT_SYMBOL(csum_and_copy_from_user);
+
+__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
+			     __wsum sum, int *err_ptr)
+{
+	unsigned int csum;
+
+	might_sleep();
+	allow_write_to_user(dst, len);
+
+	*err_ptr = 0;
+
+	if (!len) {
+		csum = 0;
+		goto out;
+	}
+
+	if (unlikely((len < 0) || !access_ok(VERIFY_WRITE, dst, len))) {
+		*err_ptr = -EFAULT;
+		csum = -1; /* invalid checksum */
+		goto out;
+	}
+
+	csum = csum_partial_copy_generic(src, (void __force *)dst,
+					 len, sum, NULL, err_ptr);
+
+	if (unlikely(*err_ptr)) {
+		csum = csum_partial(src, len, sum);
+
+		if (copy_to_user(dst, src, len)) {
+			*err_ptr = -EFAULT;
+			csum = -1; /* invalid checksum */
+		}
+	}
+
+out:
+	prevent_write_to_user(dst, len);
+	return (__force __wsum)csum;
+}
+EXPORT_SYMBOL(csum_and_copy_to_user);