patch-2.1.79 linux/arch/i386/lib/usercopy.c

• Lines: 137
• Date: Sat Jan 10 21:28:41 1998
• Orig file: v2.1.78/linux/arch/i386/lib/usercopy.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.78/linux/arch/i386/lib/usercopy.c linux/arch/i386/lib/usercopy.c
@@ -0,0 +1,136 @@
+/* 
+ * User address space access functions.
+ * The non inlined parts of asm-i386/uaccess.h are here.
+ *
+ * Copyright 1997 Andi Kleen <ak@muc.de>
+ * Copyright 1997 Linus Torvalds
+ */
+#include <asm/uaccess.h>
+
+inline unsigned long
+__generic_copy_to_user(void *to, const void *from, unsigned long n)
+{
+	if (access_ok(VERIFY_WRITE, to, n))
+		__copy_user(to,from,n);
+	return n;
+}
+
+inline unsigned long
+__generic_copy_from_user(void *to, const void *from, unsigned long n)
+{
+	if (access_ok(VERIFY_READ, from, n))
+		__copy_user(to,from,n);
+	return n;
+}
+
+
+/*
+ * Copy a null terminated string from userspace.
+ */
+
+#define __do_strncpy_from_user(dst,src,count,res)			   \
+	__asm__ __volatile__(						   \
+		"	testl %1,%1\n"					   \
+		"	jz 2f\n"					   \
+		"0:	lodsb\n"					   \
+		"	stosb\n"					   \
+		"	testb %%al,%%al\n"				   \
+		"	jz 1f\n"					   \
+		"	decl %1\n"					   \
+		"	jnz 0b\n"					   \
+		"1:	subl %1,%0\n"					   \
+		"2:\n"							   \
+		".section .fixup,\"ax\"\n"				   \
+		"3:	movl %2,%0\n"					   \
+		"	jmp 2b\n"					   \
+		".previous\n"						   \
+		".section __ex_table,\"a\"\n"				   \
+		"	.align 4\n"					   \
+		"	.long 0b,3b\n"					   \
+		".previous"						   \
+		: "=d"(res), "=c"(count)				   \
+		: "i"(-EFAULT), "0"(count), "1"(count), "S"(src), "D"(dst) \
+		: "si", "di", "ax", "memory")
+
+long
+__strncpy_from_user(char *dst, const char *src, long count)
+{
+	long res;
+	__do_strncpy_from_user(dst, src, count, res);
+	return res;
+}
+
+long
+strncpy_from_user(char *dst, const char *src, long count)
+{
+	long res = -EFAULT;
+	if (access_ok(VERIFY_READ, src, 1))
+		__do_strncpy_from_user(dst, src, count, res);
+	return res;
+}
+
+
+/*
+ * Zero Userspace
+ */
+
+#define __do_clear_user(addr,size)						\
+	__asm__ __volatile__(						\
+		"0:	rep; stosl\n"					\
+		"	movl %1,%0\n"					\
+		"1:	rep; stosb\n"					\
+		"2:\n"							\
+		".section .fixup,\"ax\"\n"				\
+		"3:	lea 0(%1,%0,4),%0\n"				\
+		"	jmp 2b\n"					\
+		".previous\n"						\
+		".section __ex_table,\"a\"\n"				\
+		"	.align 4\n"					\
+		"	.long 0b,3b\n"					\
+		"	.long 1b,2b\n"					\
+		".previous"						\
+		: "=c"(size)						\
+		: "r"(size & 3), "0"(size / 4), "D"(addr), "a"(0)	\
+		: "di")
+
+unsigned long
+clear_user(void *to, unsigned long n)
+{
+	if (access_ok(VERIFY_WRITE, to, n))
+		__do_clear_user(to, n);
+	return n;
+}
+
+unsigned long
+__clear_user(void *to, unsigned long n)
+{
+	__do_clear_user(to, n);
+	return n;
+}
+
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 for error
+ */
+
+long strlen_user(const char *s)
+{
+	unsigned long res;
+
+	__asm__ __volatile__(
+		"0:	repne; scasb\n"
+		"	notl %0\n"
+		"1:\n"
+		".section .fixup,\"ax\"\n"
+		"2:	xorl %0,%0\n"
+		"	jmp 1b\n"
+		".previous\n"
+		".section __ex_table,\"a\"\n"
+		"	.align 4\n"
+		"	.long 0b,2b\n"
+		".previous"
+		:"=c" (res), "=D" (s)
+		:"1" (s), "a" (0), "0" (-__addr_ok(s)));
+	return res & -__addr_ok(s);
+}