patch-2.3.48 linux/arch/mips/lib/strnlen_user.S

• Lines: 55
• Date: Thu Feb 24 22:52:30 2000
• Orig file: v2.3.47/linux/arch/mips/lib/strnlen_user.S
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.47/linux/arch/mips/lib/strnlen_user.S linux/arch/mips/lib/strnlen_user.S
@@ -0,0 +1,54 @@
+/* $Id: strnlen_user.S,v 1.2 1999/12/04 03:59:00 ralf Exp $
+ *
+ * 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, 1998, 1999 by Ralf Baechle
+ * Copyright (c) 1999 Silicon Graphics, Inc.
+ */
+#include <asm/asm.h>
+#include <asm/offset.h>
+#include <asm/regdef.h>
+#include <asm/sgidefs.h>
+
+#define EX(insn,reg,addr,handler)			\
+9:	insn	reg, addr;				\
+	.section __ex_table,"a";			\
+	PTR	9b, handler;				\
+	.previous
+
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 for error, len of string but at max a1 otherwise
+ *
+ * Note: for performance reasons we deliberately accept that a user may
+ *       make strlen_user and strnlen_user access the first few KSEG0
+ *       bytes.  There's nothing secret there ...
+ */
+LEAF(__strnlen_user_asm)
+	lw	v0, THREAD_CURDS($28)	# pointer ok?
+	and	v0, a0
+	bltz	v0, fault
+
+EXPORT(__strnlen_user_nocheck_asm)
+	.type	__strnlen_user_nocheck_asm,@function
+	move	v0, a0
+	addu	a1, a0			# stop pointer
+	.set	noreorder
+1:	beq	v0, a1, 1f		# limit reached?
+	 addiu	v0, 1
+	.set	reorder
+	EX(lb, t0, -1(v0), fault)
+	bnez	t0, 1b
+1:	subu	v0, a0
+	jr	ra
+	END(__strnlen_user_asm)
+
+	.section	__ex_table,"a"
+	PTR		1b, fault
+	.previous
+
+fault:	move	v0, zero
+	jr	ra