patch-2.4.19 linux-2.4.19/include/asm-ppc64/uaccess.h

• Lines: 286
• Date: Fri Aug 2 17:39:45 2002
• Orig file: linux-2.4.18/include/asm-ppc64/uaccess.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/include/asm-ppc64/uaccess.h linux-2.4.19/include/asm-ppc64/uaccess.h
@@ -0,0 +1,285 @@
+#ifndef _PPC64_UACCESS_H
+#define _PPC64_UACCESS_H
+
+/* 
+ * 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.
+ */
+
+#ifndef __ASSEMBLY__
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <asm/processor.h>
+
+#define VERIFY_READ	0
+#define VERIFY_WRITE	1
+
+/*
+ * The fs value determines whether argument validity checking should be
+ * performed or not.  If get_fs() == USER_DS, checking is performed, with
+ * get_fs() == KERNEL_DS, checking is bypassed.
+ *
+ * For historical reasons, these macros are grossly misnamed.
+ */
+
+#define KERNEL_DS	((mm_segment_t) { 0 })
+#define USER_DS		((mm_segment_t) { 1 })
+
+#define get_ds()	(KERNEL_DS)
+#define get_fs()	(current->thread.fs)
+#define set_fs(val)	(current->thread.fs = (val))
+
+#define segment_eq(a,b)	((a).seg == (b).seg)
+
+#define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
+#define __user_ok(addr,size) (((size) <= TASK_SIZE)&&((addr) <= TASK_SIZE-(size)))
+#define __access_ok(addr,size) (__kernel_ok || __user_ok((addr),(size)))
+#define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size))
+
+extern inline int verify_area(int type, const void * addr, unsigned long size)
+{
+	return access_ok(type,addr,size) ? 0 : -EFAULT;
+}
+
+
+/*
+ * The exception table consists of pairs of addresses: the first is the
+ * address of an instruction that is allowed to fault, and the second is
+ * the address at which the program should continue.  No registers are
+ * modified, so it is entirely up to the continuation code to figure out
+ * what to do.
+ *
+ * All the routines below use bits of fixup code that are out of line
+ * with the main instruction path.  This means when everything is well,
+ * we don't even have to jump over them.  Further, they do not intrude
+ * on our cache or tlb entries.
+ */
+
+struct exception_table_entry
+{
+	unsigned long insn, fixup;
+};
+
+/* Returns 0 if exception not found and fixup otherwise.  */
+extern unsigned long search_exception_table(unsigned long);
+extern void sort_exception_table(void);
+
+/*
+ * These are the main single-value transfer routines.  They automatically
+ * use the right size if we just have the right pointer type.
+ *
+ * This gets kind of ugly. We want to return _two_ values in "get_user()"
+ * and yet we don't want to do any pointers, because that is too much
+ * of a performance impact. Thus we have a few rather ugly macros here,
+ * and hide all the uglyness from the user.
+ *
+ * The "__xxx" versions of the user access functions are versions that
+ * do not verify the address space, that must have been done previously
+ * with a separate "access_ok()" call (this is used when we do multiple
+ * accesses to the same area of user memory).
+ *
+ * As we use the same address space for kernel and user data on the
+ * PowerPC, we can just do these as direct assignments.  (Of course, the
+ * exception handling means that it's no longer "just"...)
+ */
+#define get_user(x,ptr) \
+  __get_user_check((x),(ptr),sizeof(*(ptr)))
+#define put_user(x,ptr) \
+  __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
+
+#define __get_user(x,ptr) \
+  __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
+#define __put_user(x,ptr) \
+  __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
+
+extern long __put_user_bad(void);
+
+#define __put_user_nocheck(x,ptr,size)			\
+({							\
+	long __pu_err;					\
+	__put_user_size((x),(ptr),(size),__pu_err);	\
+	__pu_err;					\
+})
+
+#define __put_user_check(x,ptr,size)				\
+({								\
+	long __pu_err = -EFAULT;				\
+	__typeof__(*(ptr)) *__pu_addr = (ptr);			\
+	if (access_ok(VERIFY_WRITE,__pu_addr,size))		\
+		__put_user_size((x),__pu_addr,(size),__pu_err);	\
+	__pu_err;						\
+})
+
+#define __put_user_size(x,ptr,size,retval)			\
+do {								\
+	retval = 0;						\
+	switch (size) {						\
+	  case 1: __put_user_asm(x,ptr,retval,"stb"); break;	\
+	  case 2: __put_user_asm(x,ptr,retval,"sth"); break;	\
+	  case 4: __put_user_asm(x,ptr,retval,"stw"); break;	\
+	  case 8: __put_user_asm(x,ptr,retval,"std"); break; 	\
+	  default: __put_user_bad();				\
+	}							\
+} while (0)
+
+struct __large_struct { unsigned long buf[100]; };
+#define __m(x) (*(struct __large_struct *)(x))
+
+/*
+ * We don't tell gcc that we are accessing memory, but this is OK
+ * because we do not write to any memory gcc knows about, so there
+ * are no aliasing issues.
+ */
+#define __put_user_asm(x, addr, err, op)			\
+	__asm__ __volatile__(					\
+		"1:	"op" %1,0(%2)\n"			\
+		"2:\n"						\
+		".section .fixup,\"ax\"\n"			\
+		"3:	li %0,%3\n"				\
+		"	b 2b\n"					\
+		".previous\n"					\
+		".section __ex_table,\"a\"\n"			\
+		"	.align 3\n"				\
+		"	.llong 1b,3b\n"				\
+		".previous"					\
+		: "=r"(err)					\
+		: "r"(x), "b"(addr), "i"(-EFAULT), "0"(err))
+
+
+#define __get_user_nocheck(x,ptr,size)				\
+({								\
+	long __gu_err, __gu_val;				\
+	__get_user_size(__gu_val,(ptr),(size),__gu_err);	\
+	(x) = (__typeof__(*(ptr)))__gu_val;			\
+	__gu_err;						\
+})
+
+#define __get_user_check(x,ptr,size)					\
+({									\
+	long __gu_err = -EFAULT, __gu_val = 0;				\
+	const __typeof__(*(ptr)) *__gu_addr = (ptr);			\
+	if (access_ok(VERIFY_READ,__gu_addr,size))			\
+		__get_user_size(__gu_val,__gu_addr,(size),__gu_err);	\
+	(x) = (__typeof__(*(ptr)))__gu_val;				\
+	__gu_err;							\
+})
+
+extern long __get_user_bad(void);
+
+#define __get_user_size(x,ptr,size,retval)			\
+do {								\
+	retval = 0;						\
+	switch (size) {						\
+	  case 1: __get_user_asm(x,ptr,retval,"lbz"); break;	\
+	  case 2: __get_user_asm(x,ptr,retval,"lhz"); break;	\
+	  case 4: __get_user_asm(x,ptr,retval,"lwz"); break;	\
+	  case 8: __get_user_asm(x,ptr,retval,"ld");  break;    \
+	  default: (x) = __get_user_bad();			\
+	}							\
+} while (0)
+
+#define __get_user_asm(x, addr, err, op)		\
+	__asm__ __volatile__(				\
+		"1:	"op" %1,0(%2)\n"		\
+		"2:\n"					\
+		".section .fixup,\"ax\"\n"		\
+		"3:	li %0,%3\n"			\
+		"	li %1,0\n"			\
+		"	b 2b\n"				\
+		".previous\n"				\
+		".section __ex_table,\"a\"\n"		\
+		"	.align 3\n"			\
+		"	.llong 1b,3b\n"			\
+		".previous"				\
+		: "=r"(err), "=r"(x)			\
+		: "b"(addr), "i"(-EFAULT), "0"(err))
+
+/* more complex routines */
+
+extern unsigned long __copy_tofrom_user(void *to, const void *from, unsigned long size);
+
+extern inline unsigned long
+copy_from_user(void *to, const void *from, unsigned long n)
+{
+	unsigned long over;
+
+	if (access_ok(VERIFY_READ, from, n))
+		return __copy_tofrom_user(to, from, n);
+	if ((unsigned long)from < TASK_SIZE) {
+		over = (unsigned long)from + n - TASK_SIZE;
+		return __copy_tofrom_user(to, from, n - over) + over;
+	}
+	return n;
+}
+
+extern inline unsigned long
+copy_to_user(void *to, const void *from, unsigned long n)
+{
+	unsigned long over;
+
+	if (access_ok(VERIFY_WRITE, to, n))
+		return __copy_tofrom_user(to, from, n);
+	if ((unsigned long)to < TASK_SIZE) {
+		over = (unsigned long)to + n - TASK_SIZE;
+		return __copy_tofrom_user(to, from, n - over) + over;
+	}
+	return n;
+}
+
+#define __copy_from_user(to, from, size) \
+	__copy_tofrom_user((to), (from), (size))
+#define __copy_to_user(to, from, size) \
+	__copy_tofrom_user((to), (from), (size))
+
+extern unsigned long __clear_user(void *addr, unsigned long size);
+
+extern inline unsigned long
+clear_user(void *addr, unsigned long size)
+{
+	if (access_ok(VERIFY_WRITE, addr, size))
+		return __clear_user(addr, size);
+	return size? -EFAULT: 0;
+}
+
+extern int __strncpy_from_user(char *dst, const char *src, long count);
+
+extern inline long
+strncpy_from_user(char *dst, const char *src, long count)
+{
+	if (access_ok(VERIFY_READ, src, 1))
+		return __strncpy_from_user(dst, src, count);
+	return -EFAULT;
+}
+
+/*
+ * Return the size of a string (including the ending 0)
+ *
+ * Return 0 for error
+ */
+
+extern int __strnlen_user(const char *str, long len, unsigned long top);
+
+/*
+ * Returns the length of the string at str (including the null byte),
+ * or 0 if we hit a page we can't access,
+ * or something > len if we didn't find a null byte.
+ *
+ * The `top' parameter to __strnlen_user is to make sure that
+ * we can never overflow from the user area into kernel space.
+ */
+extern __inline__ int strnlen_user(const char *str, long len)
+{
+	unsigned long top = __kernel_ok? ~0UL: TASK_SIZE - 1;
+
+	if ((unsigned long)str > top)
+		return 0;
+	return __strnlen_user(str, len, top);
+}
+
+#define strlen_user(str)	strnlen_user((str), 0x7ffffffe)
+
+#endif  /* __ASSEMBLY__ */
+
+#endif	/* _PPC64_UACCESS_H */