| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141 | #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))#elsestatic 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
 |