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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/frv/kernel/uaccess.c
Initial import
Diffstat (limited to 'arch/frv/kernel/uaccess.c')
-rw-r--r--arch/frv/kernel/uaccess.c100
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/frv/kernel/uaccess.c b/arch/frv/kernel/uaccess.c
new file mode 100644
index 000000000..374f88d6c
--- /dev/null
+++ b/arch/frv/kernel/uaccess.c
@@ -0,0 +1,100 @@
+/* uaccess.c: userspace access functions
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * 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.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+
+/*****************************************************************************/
+/*
+ * copy a null terminated string from userspace
+ */
+long strncpy_from_user(char *dst, const char __user *src, long count)
+{
+ unsigned long max;
+ char *p, ch;
+ long err = -EFAULT;
+
+ BUG_ON(count < 0);
+
+ p = dst;
+
+#ifndef CONFIG_MMU
+ if ((unsigned long) src < memory_start)
+ goto error;
+#endif
+
+ if ((unsigned long) src >= get_addr_limit())
+ goto error;
+
+ max = get_addr_limit() - (unsigned long) src;
+ if ((unsigned long) count > max) {
+ memset(dst + max, 0, count - max);
+ count = max;
+ }
+
+ err = 0;
+ for (; count > 0; count--, p++, src++) {
+ __get_user_asm(err, ch, src, "ub", "=r");
+ if (err < 0)
+ goto error;
+ if (!ch)
+ break;
+ *p = ch;
+ }
+
+ err = p - dst; /* return length excluding NUL */
+
+ error:
+ if (count > 0)
+ memset(p, 0, count); /* clear remainder of buffer [security] */
+
+ return err;
+
+} /* end strncpy_from_user() */
+
+EXPORT_SYMBOL(strncpy_from_user);
+
+/*****************************************************************************/
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 on exception, a value greater than N if too long
+ */
+long strnlen_user(const char __user *src, long count)
+{
+ const char __user *p;
+ long err = 0;
+ char ch;
+
+ BUG_ON(count < 0);
+
+#ifndef CONFIG_MMU
+ if ((unsigned long) src < memory_start)
+ return 0;
+#endif
+
+ if ((unsigned long) src >= get_addr_limit())
+ return 0;
+
+ for (p = src; count > 0; count--, p++) {
+ __get_user_asm(err, ch, p, "ub", "=r");
+ if (err < 0)
+ return 0;
+ if (!ch)
+ break;
+ }
+
+ return p - src + 1; /* return length including NUL */
+
+} /* end strnlen_user() */
+
+EXPORT_SYMBOL(strnlen_user);