diff options
Diffstat (limited to 'kernel/arch/mn10300/lib/usercopy.c')
| -rw-r--r-- | kernel/arch/mn10300/lib/usercopy.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/kernel/arch/mn10300/lib/usercopy.c b/kernel/arch/mn10300/lib/usercopy.c new file mode 100644 index 000000000..7826e6c36 --- /dev/null +++ b/kernel/arch/mn10300/lib/usercopy.c @@ -0,0 +1,166 @@ +/* MN10300 Userspace accessor functions + * + * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd. + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#include <asm/uaccess.h> + +unsigned long +__generic_copy_to_user(void *to, const void *from, unsigned long n) +{ + if (access_ok(VERIFY_WRITE, to, n)) + __copy_user(to, from, n); + return n; +} + +unsigned long +__generic_copy_from_user(void *to, const void *from, unsigned long n) +{ + if (access_ok(VERIFY_READ, from, n)) + __copy_user_zeroing(to, from, n); + return n; +} + +/* + * Copy a null terminated string from userspace. + */ +#define __do_strncpy_from_user(dst, src, count, res) \ +do { \ + int w; \ + asm volatile( \ + " mov %1,%0\n" \ + " cmp 0,%1\n" \ + " beq 2f\n" \ + "0:\n" \ + " movbu (%5),%2\n" \ + "1:\n" \ + " movbu %2,(%6)\n" \ + " inc %5\n" \ + " inc %6\n" \ + " cmp 0,%2\n" \ + " beq 2f\n" \ + " add -1,%1\n" \ + " bne 0b\n" \ + "2:\n" \ + " sub %1,%0\n" \ + "3:\n" \ + " .section .fixup,\"ax\"\n" \ + "4:\n" \ + " mov %3,%0\n" \ + " jmp 3b\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .balign 4\n" \ + " .long 0b,4b\n" \ + " .long 1b,4b\n" \ + " .previous" \ + :"=&r"(res), "=r"(count), "=&r"(w) \ + :"i"(-EFAULT), "1"(count), "a"(src), "a"(dst) \ + : "memory", "cc"); \ +} while (0) + +long +__strncpy_from_user(char *dst, const char *src, long count) +{ + long res; + __do_strncpy_from_user(dst, src, count, res); + return res; +} + +long +strncpy_from_user(char *dst, const char *src, long count) +{ + long res = -EFAULT; + if (access_ok(VERIFY_READ, src, 1)) + __do_strncpy_from_user(dst, src, count, res); + return res; +} + + +/* + * Clear a userspace memory + */ +#define __do_clear_user(addr, size) \ +do { \ + int w; \ + asm volatile( \ + " cmp 0,%0\n" \ + " beq 1f\n" \ + " clr %1\n" \ + "0: movbu %1,(%3,%2)\n" \ + " inc %3\n" \ + " cmp %0,%3\n" \ + " bne 0b\n" \ + "1:\n" \ + " sub %3,%0\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: jmp 2b\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .balign 4\n" \ + " .long 0b,3b\n" \ + ".previous\n" \ + : "+r"(size), "=&r"(w) \ + : "a"(addr), "d"(0) \ + : "memory", "cc"); \ +} while (0) + +unsigned long +__clear_user(void *to, unsigned long n) +{ + __do_clear_user(to, n); + return n; +} + +unsigned long +clear_user(void *to, unsigned long n) +{ + if (access_ok(VERIFY_WRITE, to, 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 + */ +long strnlen_user(const char *s, long n) +{ + unsigned long res, w; + + if (!__addr_ok(s)) + return 0; + + if (n < 0 || n + (u_long) s > current_thread_info()->addr_limit.seg) + n = current_thread_info()->addr_limit.seg - (u_long)s; + + asm volatile( + "0: cmp %4,%0\n" + " beq 2f\n" + "1: movbu (%0,%3),%1\n" + " inc %0\n" + " cmp 0,%1\n" + " beq 3f\n" + " bra 0b\n" + "2: clr %0\n" + "3:\n" + ".section .fixup,\"ax\"\n" + "4: jmp 2b\n" + ".previous\n" + ".section __ex_table,\"a\"\n" + " .balign 4\n" + " .long 1b,4b\n" + ".previous\n" + :"=d"(res), "=&r"(w) + :"0"(0), "a"(s), "r"(n) + : "memory", "cc"); + return res; +} |