patch-2.4.20 linux-2.4.20/include/asm-x86_64/uaccess.h
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- Lines: 255
- Date:
Thu Nov 28 15:53:15 2002
- Orig file:
linux-2.4.19/include/asm-x86_64/uaccess.h
- Orig date:
Wed Dec 31 16:00:00 1969
diff -urN linux-2.4.19/include/asm-x86_64/uaccess.h linux-2.4.20/include/asm-x86_64/uaccess.h
@@ -0,0 +1,254 @@
+#ifndef __X86_64_UACCESS_H
+#define __X86_64_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/prefetch.h>
+#include <asm/page.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 MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
+
+#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFFFFFFFFF)
+#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
+
+#define get_ds() (KERNEL_DS)
+#define get_fs() (current->addr_limit)
+#define set_fs(x) (current->addr_limit = (x))
+
+#define segment_eq(a,b) ((a).seg == (b).seg)
+
+#define __addr_ok(addr) (!((unsigned long)(addr) & (current->addr_limit.seg)))
+
+/*
+ * Uhhuh, this needs 65-bit arithmetic. We have a carry..
+ */
+#define __range_not_ok(addr,size) ({ \
+ unsigned long flag,sum; \
+ asm("# range_ok\n\r" \
+ "addq %3,%1 ; sbbq %0,%0 ; cmpq %1,%4 ; sbbq $0,%0" \
+ :"=&r" (flag), "=r" (sum) \
+ :"1" (addr),"g" ((long)(size)),"g" (current->addr_limit.seg)); \
+ flag; })
+
+#define access_ok(type,addr,size) (__range_not_ok(addr,size) == 0)
+
+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);
+
+
+/*
+ * 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).
+ */
+
+extern void __get_user_1(void);
+extern void __get_user_2(void);
+extern void __get_user_4(void);
+extern void __get_user_8(void);
+
+#define __get_user_x(size,ret,x,ptr) \
+ __asm__ __volatile__("call __get_user_" #size \
+ :"=a" (ret),"=d" (x) \
+ :"0" (ptr) \
+ :"rbx")
+
+/* Careful: we have to cast the result to the type of the pointer for sign reasons */
+#define get_user(x,ptr) \
+({ long __ret_gu,__val_gu; \
+ switch(sizeof (*(ptr))) { \
+ case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \
+ case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \
+ case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \
+ case 8: __get_user_x(8,__ret_gu,__val_gu,ptr); break; \
+ default: __get_user_bad(); break; \
+ } \
+ (x) = (__typeof__(*(ptr)))__val_gu; \
+ __ret_gu; \
+})
+
+extern void __put_user_1(void);
+extern void __put_user_2(void);
+extern void __put_user_4(void);
+extern void __put_user_8(void);
+
+extern void __put_user_bad(void);
+
+#define __put_user_x(size,ret,x,ptr) \
+ __asm__ __volatile__("call __put_user_" #size \
+ :"=a" (ret) \
+ :"0" (ptr),"d" (x) \
+ :"rbx")
+
+#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)))
+
+#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,"b","b","iq"); break; \
+ case 2: __put_user_asm(x,ptr,retval,"w","w","ir"); break; \
+ case 4: __put_user_asm(x,ptr,retval,"l","k","ir"); break; \
+ case 8: __put_user_asm(x,ptr,retval,"q","","ir"); break; \
+ default: __put_user_bad(); \
+ } \
+} while (0)
+
+/* FIXME: this hack is definitely wrong -AK */
+struct __large_struct { unsigned long buf[100]; };
+#define __m(x) (*(struct __large_struct *)(x))
+
+/*
+ * Tell gcc we read from memory instead of writing: this is because
+ * we do not write to any memory gcc knows about, so there are no
+ * aliasing issues.
+ */
+#define __put_user_asm(x, addr, err, itype, rtype, ltype) \
+ __asm__ __volatile__( \
+ "1: mov"itype" %"rtype"1,%2\n" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: movq %3,%0\n" \
+ " jmp 2b\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .align 8\n" \
+ " .quad 1b,3b\n" \
+ ".previous" \
+ : "=r"(err) \
+ : ltype (x), "m"(__m(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; \
+})
+
+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,"b","b","=q"); break; \
+ case 2: __get_user_asm(x,ptr,retval,"w","w","=r"); break; \
+ case 4: __get_user_asm(x,ptr,retval,"l","k","=r"); break; \
+ case 8: __get_user_asm(x,ptr,retval,"q","","=r"); break; \
+ default: (x) = __get_user_bad(); \
+ } \
+} while (0)
+
+#define __get_user_asm(x, addr, err, itype, rtype, ltype) \
+ __asm__ __volatile__( \
+ "1: mov"itype" %2,%"rtype"1\n" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: mov %3,%0\n" \
+ " xor"itype" %"rtype"1,%"rtype"1\n" \
+ " jmp 2b\n" \
+ ".previous\n" \
+ ".section __ex_table,\"a\"\n" \
+ " .align 8\n" \
+ " .quad 1b,3b\n" \
+ ".previous" \
+ : "=r"(err), ltype (x) \
+ : "m"(__m(addr)), "i"(-EFAULT), "0"(err))
+
+/*
+ * Copy To/From Userspace
+ *
+ * This relies on an optimized common worker function.
+ *
+ * Could do special inline versions for small constant copies, but avoid this
+ * for now. It's not clear it is worth it.
+ */
+
+extern unsigned long copy_user_generic(void *to, const void *from, unsigned len);
+
+extern unsigned long copy_to_user(void *to, const void *from, unsigned len);
+extern unsigned long copy_from_user(void *to, const void *from, unsigned len);
+#define __copy_to_user copy_user_generic
+#define __copy_from_user copy_user_generic
+
+long strncpy_from_user(char *dst, const char *src, long count);
+long __strncpy_from_user(char *dst, const char *src, long count);
+#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
+long strnlen_user(const char *str, long n);
+unsigned long clear_user(void *mem, unsigned long len);
+unsigned long __clear_user(void *mem, unsigned long len);
+
+#endif /* __X86_64_UACCESS_H */
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