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- #ifndef _ASM_M32R_UACCESS_H
- #define _ASM_M32R_UACCESS_H
- /*
- * linux/include/asm-m32r/uaccess.h
- *
- * M32R version.
- * Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org>
- */
- /*
- * User space memory access functions
- */
- #include <linux/errno.h>
- #include <linux/thread_info.h>
- #include <asm/page.h>
- #include <asm/setup.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) })
- #ifdef CONFIG_MMU
- #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
- #define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
- #define get_ds() (KERNEL_DS)
- #define get_fs() (current_thread_info()->addr_limit)
- #define set_fs(x) (current_thread_info()->addr_limit = (x))
- #else /* not CONFIG_MMU */
- #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
- #define USER_DS MAKE_MM_SEG(0xFFFFFFFF)
- #define get_ds() (KERNEL_DS)
- static inline mm_segment_t get_fs(void)
- {
- return USER_DS;
- }
- static inline void set_fs(mm_segment_t s)
- {
- }
- #endif /* not CONFIG_MMU */
- #define segment_eq(a,b) ((a).seg == (b).seg)
- #define __addr_ok(addr) \
- ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
- /*
- * Test whether a block of memory is a valid user space address.
- * Returns 0 if the range is valid, nonzero otherwise.
- *
- * This is equivalent to the following test:
- * (u33)addr + (u33)size >= (u33)current->addr_limit.seg
- *
- * This needs 33-bit arithmetic. We have a carry...
- */
- #define __range_ok(addr,size) ({ \
- unsigned long flag, roksum; \
- __chk_user_ptr(addr); \
- asm ( \
- " cmpu %1, %1 ; clear cbit\n" \
- " addx %1, %3 ; set cbit if overflow\n" \
- " subx %0, %0\n" \
- " cmpu %4, %1\n" \
- " subx %0, %5\n" \
- : "=&r" (flag), "=r" (roksum) \
- : "1" (addr), "r" ((int)(size)), \
- "r" (current_thread_info()->addr_limit.seg), "r" (0) \
- : "cbit" ); \
- flag; })
- /**
- * access_ok: - Checks if a user space pointer is valid
- * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
- * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
- * to write to a block, it is always safe to read from it.
- * @addr: User space pointer to start of block to check
- * @size: Size of block to check
- *
- * Context: User context only. This function may sleep.
- *
- * Checks if a pointer to a block of memory in user space is valid.
- *
- * Returns true (nonzero) if the memory block may be valid, false (zero)
- * if it is definitely invalid.
- *
- * Note that, depending on architecture, this function probably just
- * checks that the pointer is in the user space range - after calling
- * this function, memory access functions may still return -EFAULT.
- */
- #ifdef CONFIG_MMU
- #define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
- #else
- static inline int access_ok(int type, const void *addr, unsigned long size)
- {
- unsigned long val = (unsigned long)addr;
- return ((val >= memory_start) && ((val + size) < memory_end));
- }
- #endif /* CONFIG_MMU */
- /*
- * 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;
- };
- extern int fixup_exception(struct pt_regs *regs);
- /*
- * 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
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