164 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			164 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /*
 | ||
|  |  * This file is subject to the terms and conditions of the GNU General Public | ||
|  |  * License.  See the file "COPYING" in the main directory of this archive | ||
|  |  * for more details. | ||
|  |  * | ||
|  |  * Copyright (C) 2009, Wind River Systems Inc | ||
|  |  * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com | ||
|  |  */ | ||
|  | 
 | ||
|  | #include <linux/export.h>
 | ||
|  | #include <linux/uaccess.h>
 | ||
|  | 
 | ||
|  | asm(".global	__copy_from_user\n" | ||
|  | 	"   .type __copy_from_user, @function\n" | ||
|  | 	"__copy_from_user:\n" | ||
|  | 	"   movi  r2,7\n" | ||
|  | 	"   mov   r3,r4\n" | ||
|  | 	"   bge   r2,r6,1f\n" | ||
|  | 	"   xor   r2,r4,r5\n" | ||
|  | 	"   andi  r2,r2,3\n" | ||
|  | 	"   movi  r7,3\n" | ||
|  | 	"   beq   r2,zero,4f\n" | ||
|  | 	"1: addi  r6,r6,-1\n" | ||
|  | 	"   movi  r2,-1\n" | ||
|  | 	"   beq   r6,r2,3f\n" | ||
|  | 	"   mov   r7,r2\n" | ||
|  | 	"2: ldbu  r2,0(r5)\n" | ||
|  | 	"   addi  r6,r6,-1\n" | ||
|  | 	"   addi  r5,r5,1\n" | ||
|  | 	"   stb   r2,0(r3)\n" | ||
|  | 	"   addi  r3,r3,1\n" | ||
|  | 	"   bne   r6,r7,2b\n" | ||
|  | 	"3:\n" | ||
|  | 	"   addi  r2,r6,1\n" | ||
|  | 	"   ret\n" | ||
|  | 	"13:mov   r2,r6\n" | ||
|  | 	"   ret\n" | ||
|  | 	"4: andi  r2,r4,1\n" | ||
|  | 	"   cmpeq r2,r2,zero\n" | ||
|  | 	"   beq   r2,zero,7f\n" | ||
|  | 	"5: andi  r2,r3,2\n" | ||
|  | 	"   beq   r2,zero,6f\n" | ||
|  | 	"9: ldhu  r2,0(r5)\n" | ||
|  | 	"   addi  r6,r6,-2\n" | ||
|  | 	"   addi  r5,r5,2\n" | ||
|  | 	"   sth   r2,0(r3)\n" | ||
|  | 	"   addi  r3,r3,2\n" | ||
|  | 	"6: bge   r7,r6,1b\n" | ||
|  | 	"10:ldw   r2,0(r5)\n" | ||
|  | 	"   addi  r6,r6,-4\n" | ||
|  | 	"   addi  r5,r5,4\n" | ||
|  | 	"   stw   r2,0(r3)\n" | ||
|  | 	"   addi  r3,r3,4\n" | ||
|  | 	"   br    6b\n" | ||
|  | 	"7: ldbu  r2,0(r5)\n" | ||
|  | 	"   addi  r6,r6,-1\n" | ||
|  | 	"   addi  r5,r5,1\n" | ||
|  | 	"   addi  r3,r4,1\n" | ||
|  | 	"   stb   r2,0(r4)\n" | ||
|  | 	"   br    5b\n" | ||
|  | 	".section __ex_table,\"a\"\n" | ||
|  | 	".word 2b,3b\n" | ||
|  | 	".word 9b,13b\n" | ||
|  | 	".word 10b,13b\n" | ||
|  | 	".word 7b,13b\n" | ||
|  | 	".previous\n" | ||
|  | 	); | ||
|  | EXPORT_SYMBOL(__copy_from_user); | ||
|  | 
 | ||
|  | asm( | ||
|  | 	"   .global __copy_to_user\n" | ||
|  | 	"   .type __copy_to_user, @function\n" | ||
|  | 	"__copy_to_user:\n" | ||
|  | 	"   movi  r2,7\n" | ||
|  | 	"   mov   r3,r4\n" | ||
|  | 	"   bge   r2,r6,1f\n" | ||
|  | 	"   xor   r2,r4,r5\n" | ||
|  | 	"   andi  r2,r2,3\n" | ||
|  | 	"   movi  r7,3\n" | ||
|  | 	"   beq   r2,zero,4f\n" | ||
|  | 	/* Bail if we try to copy zero bytes  */ | ||
|  | 	"1: addi  r6,r6,-1\n" | ||
|  | 	"   movi  r2,-1\n" | ||
|  | 	"   beq   r6,r2,3f\n" | ||
|  | 	/* Copy byte by byte for small copies and if src^dst != 0 */ | ||
|  | 	"   mov   r7,r2\n" | ||
|  | 	"2: ldbu  r2,0(r5)\n" | ||
|  | 	"   addi  r5,r5,1\n" | ||
|  | 	"9: stb   r2,0(r3)\n" | ||
|  | 	"   addi  r6,r6,-1\n" | ||
|  | 	"   addi  r3,r3,1\n" | ||
|  | 	"   bne   r6,r7,2b\n" | ||
|  | 	"3: addi  r2,r6,1\n" | ||
|  | 	"   ret\n" | ||
|  | 	"13:mov   r2,r6\n" | ||
|  | 	"   ret\n" | ||
|  | 	/*  If 'to' is an odd address byte copy */ | ||
|  | 	"4: andi  r2,r4,1\n" | ||
|  | 	"   cmpeq r2,r2,zero\n" | ||
|  | 	"   beq   r2,zero,7f\n" | ||
|  | 	/* If 'to' is not divideable by four copy halfwords */ | ||
|  | 	"5: andi  r2,r3,2\n" | ||
|  | 	"   beq   r2,zero,6f\n" | ||
|  | 	"   ldhu  r2,0(r5)\n" | ||
|  | 	"   addi  r5,r5,2\n" | ||
|  | 	"10:sth   r2,0(r3)\n" | ||
|  | 	"   addi  r6,r6,-2\n" | ||
|  | 	"   addi  r3,r3,2\n" | ||
|  | 	/* Copy words */ | ||
|  | 	"6: bge   r7,r6,1b\n" | ||
|  | 	"   ldw   r2,0(r5)\n" | ||
|  | 	"   addi  r5,r5,4\n" | ||
|  | 	"11:stw   r2,0(r3)\n" | ||
|  | 	"   addi  r6,r6,-4\n" | ||
|  | 	"   addi  r3,r3,4\n" | ||
|  | 	"   br    6b\n" | ||
|  | 	/* Copy remaining bytes */ | ||
|  | 	"7: ldbu  r2,0(r5)\n" | ||
|  | 	"   addi  r5,r5,1\n" | ||
|  | 	"   addi  r3,r4,1\n" | ||
|  | 	"12: stb  r2,0(r4)\n" | ||
|  | 	"   addi  r6,r6,-1\n" | ||
|  | 	"   br    5b\n" | ||
|  | 	".section __ex_table,\"a\"\n" | ||
|  | 	".word 9b,3b\n" | ||
|  | 	".word 10b,13b\n" | ||
|  | 	".word 11b,13b\n" | ||
|  | 	".word 12b,13b\n" | ||
|  | 	".previous\n"); | ||
|  | EXPORT_SYMBOL(__copy_to_user); | ||
|  | 
 | ||
|  | long strncpy_from_user(char *__to, const char __user *__from, long __len) | ||
|  | { | ||
|  | 	int l = strnlen_user(__from, __len); | ||
|  | 	int is_zt = 1; | ||
|  | 
 | ||
|  | 	if (l > __len) { | ||
|  | 		is_zt = 0; | ||
|  | 		l = __len; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	if (l == 0 || copy_from_user(__to, __from, l)) | ||
|  | 		return -EFAULT; | ||
|  | 
 | ||
|  | 	if (is_zt) | ||
|  | 		l--; | ||
|  | 	return l; | ||
|  | } | ||
|  | 
 | ||
|  | long strnlen_user(const char __user *s, long n) | ||
|  | { | ||
|  | 	long i; | ||
|  | 
 | ||
|  | 	for (i = 0; i < n; i++) { | ||
|  | 		char c; | ||
|  | 
 | ||
|  | 		if (get_user(c, s + i) == -EFAULT) | ||
|  | 			return 0; | ||
|  | 		if (c == 0) | ||
|  | 			return i + 1; | ||
|  | 	} | ||
|  | 	return n + 1; | ||
|  | } |