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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [arch/] [x86/] [lib/] [usercopy_64.c] - Rev 3
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/* * User address space access functions. * * Copyright 1997 Andi Kleen <ak@muc.de> * Copyright 1997 Linus Torvalds * Copyright 2002 Andi Kleen <ak@suse.de> */ #include <linux/module.h> #include <asm/uaccess.h> /* * Copy a null terminated string from userspace. */ #define __do_strncpy_from_user(dst,src,count,res) \ do { \ long __d0, __d1, __d2; \ might_sleep(); \ __asm__ __volatile__( \ " testq %1,%1\n" \ " jz 2f\n" \ "0: lodsb\n" \ " stosb\n" \ " testb %%al,%%al\n" \ " jz 1f\n" \ " decq %1\n" \ " jnz 0b\n" \ "1: subq %1,%0\n" \ "2:\n" \ ".section .fixup,\"ax\"\n" \ "3: movq %5,%0\n" \ " jmp 2b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .align 8\n" \ " .quad 0b,3b\n" \ ".previous" \ : "=r"(res), "=c"(count), "=&a" (__d0), "=&S" (__d1), \ "=&D" (__d2) \ : "i"(-EFAULT), "0"(count), "1"(count), "3"(src), "4"(dst) \ : "memory"); \ } while (0) long __strncpy_from_user(char *dst, const char __user *src, long count) { long res; __do_strncpy_from_user(dst, src, count, res); return res; } EXPORT_SYMBOL(__strncpy_from_user); long strncpy_from_user(char *dst, const char __user *src, long count) { long res = -EFAULT; if (access_ok(VERIFY_READ, src, 1)) return __strncpy_from_user(dst, src, count); return res; } EXPORT_SYMBOL(strncpy_from_user); /* * Zero Userspace */ unsigned long __clear_user(void __user *addr, unsigned long size) { long __d0; might_sleep(); /* no memory constraint because it doesn't change any memory gcc knows about */ asm volatile( " testq %[size8],%[size8]\n" " jz 4f\n" "0: movq %[zero],(%[dst])\n" " addq %[eight],%[dst]\n" " decl %%ecx ; jnz 0b\n" "4: movq %[size1],%%rcx\n" " testl %%ecx,%%ecx\n" " jz 2f\n" "1: movb %b[zero],(%[dst])\n" " incq %[dst]\n" " decl %%ecx ; jnz 1b\n" "2:\n" ".section .fixup,\"ax\"\n" "3: lea 0(%[size1],%[size8],8),%[size8]\n" " jmp 2b\n" ".previous\n" ".section __ex_table,\"a\"\n" " .align 8\n" " .quad 0b,3b\n" " .quad 1b,2b\n" ".previous" : [size8] "=c"(size), [dst] "=&D" (__d0) : [size1] "r"(size & 7), "[size8]" (size / 8), "[dst]"(addr), [zero] "r" (0UL), [eight] "r" (8UL)); return size; } EXPORT_SYMBOL(__clear_user); unsigned long clear_user(void __user *to, unsigned long n) { if (access_ok(VERIFY_WRITE, to, n)) return __clear_user(to, n); return n; } EXPORT_SYMBOL(clear_user); /* * 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 __user *s, long n) { long res = 0; char c; while (1) { if (res>n) return n+1; if (__get_user(c, s)) return 0; if (!c) return res+1; res++; s++; } } EXPORT_SYMBOL(__strnlen_user); long strnlen_user(const char __user *s, long n) { if (!access_ok(VERIFY_READ, s, n)) return 0; return __strnlen_user(s, n); } EXPORT_SYMBOL(strnlen_user); long strlen_user(const char __user *s) { long res = 0; char c; for (;;) { if (get_user(c, s)) return 0; if (!c) return res+1; res++; s++; } } EXPORT_SYMBOL(strlen_user); unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len) { if (access_ok(VERIFY_WRITE, to, len) && access_ok(VERIFY_READ, from, len)) { return copy_user_generic((__force void *)to, (__force void *)from, len); } return len; } EXPORT_SYMBOL(copy_in_user);