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linux/arch/x86_64/lib/usercopy.c
Jan Beulich 5f1d189f8a [PATCH] x86_64: Display meaningful part of filename during BUG()
When building in a separate objtree, file names produced by BUG() & Co. can
get fairly long; printing only the first 50 characters may thus result in
(almost) no useful information. The following change makes it so that rather
the last 50 characters of the filename get printed.

Signed-Off-By: Jan Beulich <jbeulich@novell.com>

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 19:05:03 -08:00

158 lines
3.3 KiB
C

/*
* User address space access functions.
*
* Copyright 1997 Andi Kleen <ak@muc.de>
* Copyright 1997 Linus Torvalds
* Copyright 2002 Andi Kleen <ak@suse.de>
*/
#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;
}
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
*/
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;
}
unsigned long clear_user(void __user *to, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
return __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 __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++;
}
}
long strnlen_user(const char __user *s, long n)
{
if (!access_ok(VERIFY_READ, s, n))
return 0;
return __strnlen_user(s, n);
}
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++;
}
}
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;
}