1 files changed, 58 insertions, 0 deletions
diff --git a/arch/mips/lib/strncpy_user.S b/arch/mips/lib/strncpy_user.S
new file mode 100644
index 000000000000..14bed17c1648
--- /dev/null
+++ b/arch/mips/lib/strncpy_user.S
@@ -0,0 +1,58 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 1996, 1999 by Ralf Baechle
+ */
+#include <linux/errno.h>
+#include <asm/asm.h>
+#include <asm/offset.h>
+#include <asm/regdef.h>
+
+#define EX(insn,reg,addr,handler)			\
+9:	insn	reg, addr;				\
+	.section __ex_table,"a";			\
+	PTR	9b, handler;				\
+	.previous
+
+/*
+ * Returns: -EFAULT if exception before terminator, N if the entire
+ * buffer filled, else strlen.
+ */
+
+/*
+ * Ugly special case have to check: we might get passed a user space
+ * pointer which wraps into the kernel space.  We don't deal with that.  If
+ * it happens at most some bytes of the exceptions handlers will be copied.
+ */
+
+LEAF(__strncpy_from_user_asm)
+	LONG_L		v0, TI_ADDR_LIMIT($28)	# pointer ok?
+	and		v0, a1
+	bnez		v0, fault
+
+FEXPORT(__strncpy_from_user_nocheck_asm)
+	move		v0, zero
+	move		v1, a1
+	.set		noreorder
+1:	EX(lbu, t0, (v1), fault)
+	PTR_ADDIU	v1, 1
+	beqz		t0, 2f
+	 sb		t0, (a0)
+	PTR_ADDIU	v0, 1
+	bne		v0, a2, 1b
+	 PTR_ADDIU	a0, 1
+	.set		reorder
+2:	PTR_ADDU	t0, a1, v0
+	xor		t0, a1
+	bltz		t0, fault
+	jr		ra			# return n
+	END(__strncpy_from_user_asm)
+
+fault:	li		v0, -EFAULT
+	jr		ra
+
+	.section	__ex_table,"a"
+	PTR		1b, fault
+	.previous