- 根目录:
- arch
- m32r
- lib
- usercopy.c
/*
* User address space access functions.
* The non inlined parts of asm-m32r/uaccess.h are here.
*
* Copyright 1997 Andi Kleen <ak@muc.de>
* Copyright 1997 Linus Torvalds
* Copyright 2001, 2002, 2004 Hirokazu Takata
*/
#include <linux/prefetch.h>
#include <linux/string.h>
#include <linux/thread_info.h>
#include <asm/uaccess.h>
unsigned long
__generic_copy_to_user(void __user *to, const void *from, unsigned long n)
{
prefetch(from);
if (access_ok(VERIFY_WRITE, to, n))
__copy_user(to,from,n);
return n;
}
unsigned long
__generic_copy_from_user(void *to, const void __user *from, unsigned long n)
{
prefetchw(to);
if (access_ok(VERIFY_READ, from, n))
__copy_user_zeroing(to,from,n);
else
memset(to, 0, n);
return n;
}
/*
* Copy a null terminated string from userspace.
*/
#ifdef CONFIG_ISA_DUAL_ISSUE
#define __do_strncpy_from_user(dst,src,count,res) \
do { \
int __d0, __d1, __d2; \
__asm__ __volatile__( \
" beqz %1, 2f\n" \
" .fillinsn\n" \
"0: ldb r14, @%3 || addi %3, #1\n" \
" stb r14, @%4 || addi %4, #1\n" \
" beqz r14, 1f\n" \
" addi %1, #-1\n" \
" bnez %1, 0b\n" \
" .fillinsn\n" \
"1: sub %0, %1\n" \
" .fillinsn\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"3: seth r14, #high(2b)\n" \
" or3 r14, r14, #low(2b)\n" \
" jmp r14 || ldi %0, #%5\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,3b\n" \
".previous" \
: "=&r"(res), "=&r"(count), "=&r" (__d0), "=&r" (__d1), \
"=&r" (__d2) \
: "i"(-EFAULT), "0"(count), "1"(count), "3"(src), \
"4"(dst) \
: "r14", "cbit", "memory"); \
} while (0)
#else /* not CONFIG_ISA_DUAL_ISSUE */
#define __do_strncpy_from_user(dst,src,count,res) \
do { \
int __d0, __d1, __d2; \
__asm__ __volatile__( \
" beqz %1, 2f\n" \
" .fillinsn\n" \
"0: ldb r14, @%3\n" \
" stb r14, @%4\n" \
" addi %3, #1\n" \
" addi %4, #1\n" \
" beqz r14, 1f\n" \
" addi %1, #-1\n" \
" bnez %1, 0b\n" \
" .fillinsn\n" \
"1: sub %0, %1\n" \
" .fillinsn\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"3: ldi %0, #%5\n" \
" seth r14, #high(2b)\n" \
" or3 r14, r14, #low(2b)\n" \
" jmp r14\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,3b\n" \
".previous" \
: "=&r"(res), "=&r"(count), "=&r" (__d0), "=&r" (__d1), \
"=&r" (__d2) \
: "i"(-EFAULT), "0"(count), "1"(count), "3"(src), \
"4"(dst) \
: "r14", "cbit", "memory"); \
} while (0)
#endif /* CONFIG_ISA_DUAL_ISSUE */
long
__strncpy_from_user(char *dst, const char __user *src, long count)
{
long res;
__do_strncpy_from_user(dst, src, count, res);
return res;
}
long
strncpy_from_user(char *dst, const char __user *src, long count)
{
long res = -EFAULT;
if (access_ok(VERIFY_READ, src, 1))
__do_strncpy_from_user(dst, src, count, res);
return res;
}
/*
* Zero Userspace
*/
#ifdef CONFIG_ISA_DUAL_ISSUE
#define __do_clear_user(addr,size) \
do { \
int __dst, __c; \
__asm__ __volatile__( \
" beqz %1, 9f\n" \
" and3 r14, %0, #3\n" \
" bnez r14, 2f\n" \
" and3 r14, %1, #3\n" \
" bnez r14, 2f\n" \
" and3 %1, %1, #3\n" \
" beqz %2, 2f\n" \
" addi %0, #-4\n" \
" .fillinsn\n" \
"0: ; word clear \n" \
" st %6, @+%0 || addi %2, #-1\n" \
" bnez %2, 0b\n" \
" beqz %1, 9f\n" \
" .fillinsn\n" \
"2: ; byte clear \n" \
" stb %6, @%0 || addi %1, #-1\n" \
" addi %0, #1\n" \
" bnez %1, 2b\n" \
" .fillinsn\n" \
"9:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"4: slli %2, #2\n" \
" seth r14, #high(9b)\n" \
" or3 r14, r14, #low(9b)\n" \
" jmp r14 || add %1, %2\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,4b\n" \
" .long 2b,9b\n" \
".previous\n" \
: "=&r"(__dst), "=&r"(size), "=&r"(__c) \
: "0"(addr), "1"(size), "2"(size / 4), "r"(0) \
: "r14", "cbit", "memory"); \
} while (0)
#else /* not CONFIG_ISA_DUAL_ISSUE */
#define __do_clear_user(addr,size) \
do { \
int __dst, __c; \
__asm__ __volatile__( \
" beqz %1, 9f\n" \
" and3 r14, %0, #3\n" \
" bnez r14, 2f\n" \
" and3 r14, %1, #3\n" \
" bnez r14, 2f\n" \
" and3 %1, %1, #3\n" \
" beqz %2, 2f\n" \
" addi %0, #-4\n" \
" .fillinsn\n" \
"0: st %6, @+%0 ; word clear \n" \
" addi %2, #-1\n" \
" bnez %2, 0b\n" \
" beqz %1, 9f\n" \
" .fillinsn\n" \
"2: stb %6, @%0 ; byte clear \n" \
" addi %1, #-1\n" \
" addi %0, #1\n" \
" bnez %1, 2b\n" \
" .fillinsn\n" \
"9:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"4: slli %2, #2\n" \
" add %1, %2\n" \
" seth r14, #high(9b)\n" \
" or3 r14, r14, #low(9b)\n" \
" jmp r14\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,4b\n" \
" .long 2b,9b\n" \
".previous\n" \
: "=&r"(__dst), "=&r"(size), "=&r"(__c) \
: "0"(addr), "1"(size), "2"(size / 4), "r"(0) \
: "r14", "cbit", "memory"); \
} while (0)
#endif /* not CONFIG_ISA_DUAL_ISSUE */
unsigned long
clear_user(void __user *to, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
__do_clear_user(to, n);
return n;
}
unsigned long
__clear_user(void __user *to, unsigned long n)
{
__do_clear_user(to, n);
return n;
}
/*
* Return the size of a string (including the ending 0)
*
* Return 0 on exception, a value greater than N if too long
*/
#ifdef CONFIG_ISA_DUAL_ISSUE
long strnlen_user(const char __user *s, long n)
{
unsigned long mask = -__addr_ok(s);
unsigned long res;
__asm__ __volatile__(
" and %0, %5 || mv r1, %1\n"
" beqz %0, strnlen_exit\n"
" and3 r0, %1, #3\n"
" bnez r0, strnlen_byte_loop\n"
" cmpui %0, #4\n"
" bc strnlen_byte_loop\n"
"strnlen_word_loop:\n"
"0: ld r0, @%1+\n"
" pcmpbz r0\n"
" bc strnlen_last_bytes_fixup\n"
" addi %0, #-4\n"
" beqz %0, strnlen_exit\n"
" bgtz %0, strnlen_word_loop\n"
"strnlen_last_bytes:\n"
" mv %0, %4\n"
"strnlen_last_bytes_fixup:\n"
" addi %1, #-4\n"
"strnlen_byte_loop:\n"
"1: ldb r0, @%1 || addi %0, #-1\n"
" beqz r0, strnlen_exit\n"
" addi %1, #1\n"
" bnez %0, strnlen_byte_loop\n"
"strnlen_exit:\n"
" sub %1, r1\n"
" add3 %0, %1, #1\n"
" .fillinsn\n"
"9:\n"
".section .fixup,\"ax\"\n"
" .balign 4\n"
"4: addi %1, #-4\n"
" .fillinsn\n"
"5: seth r1, #high(9b)\n"
" or3 r1, r1, #low(9b)\n"
" jmp r1 || ldi %0, #0\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .balign 4\n"
" .long 0b,4b\n"
" .long 1b,5b\n"
".previous"
: "=&r" (res), "=r" (s)
: "0" (n), "1" (s), "r" (n & 3), "r" (mask), "r"(0x01010101)
: "r0", "r1", "cbit");
/* NOTE: strnlen_user() algorithm:
* {
* char *p;
* for (p = s; n-- && *p != '\0'; ++p)
* ;
* return p - s + 1;
* }
*/
/* NOTE: If a null char. exists, return 0.
* if ((x - 0x01010101) & ~x & 0x80808080)\n"
* return 0;\n"
*/
return res & mask;
}
#else /* not CONFIG_ISA_DUAL_ISSUE */
long strnlen_user(const char __user *s, long n)
{
unsigned long mask = -__addr_ok(s);
unsigned long res;
__asm__ __volatile__(
" and %0, %5\n"
" mv r1, %1\n"
" beqz %0, strnlen_exit\n"
" and3 r0, %1, #3\n"
" bnez r0, strnlen_byte_loop\n"
" cmpui %0, #4\n"
" bc strnlen_byte_loop\n"
" sll3 r3, %6, #7\n"
"strnlen_word_loop:\n"
"0: ld r0, @%1+\n"
" not r2, r0\n"
" sub r0, %6\n"
" and r2, r3\n"
" and r2, r0\n"
" bnez r2, strnlen_last_bytes_fixup\n"
" addi %0, #-4\n"
" beqz %0, strnlen_exit\n"
" bgtz %0, strnlen_word_loop\n"
"strnlen_last_bytes:\n"
" mv %0, %4\n"
"strnlen_last_bytes_fixup:\n"
" addi %1, #-4\n"
"strnlen_byte_loop:\n"
"1: ldb r0, @%1\n"
" addi %0, #-1\n"
" beqz r0, strnlen_exit\n"
" addi %1, #1\n"
" bnez %0, strnlen_byte_loop\n"
"strnlen_exit:\n"
" sub %1, r1\n"
" add3 %0, %1, #1\n"
" .fillinsn\n"
"9:\n"
".section .fixup,\"ax\"\n"
" .balign 4\n"
"4: addi %1, #-4\n"
" .fillinsn\n"
"5: ldi %0, #0\n"
" seth r1, #high(9b)\n"
" or3 r1, r1, #low(9b)\n"
" jmp r1\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .balign 4\n"
" .long 0b,4b\n"
" .long 1b,5b\n"
".previous"
: "=&r" (res), "=r" (s)
: "0" (n), "1" (s), "r" (n & 3), "r" (mask), "r"(0x01010101)
: "r0", "r1", "r2", "r3", "cbit");
/* NOTE: strnlen_user() algorithm:
* {
* char *p;
* for (p = s; n-- && *p != '\0'; ++p)
* ;
* return p - s + 1;
* }
*/
/* NOTE: If a null char. exists, return 0.
* if ((x - 0x01010101) & ~x & 0x80808080)\n"
* return 0;\n"
*/
return res & mask;
}
#endif /* CONFIG_ISA_DUAL_ISSUE */