swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: 2e6e902d185027f8e3cb8b7305238f7e35d6a436 authored by Linus Torvalds on 25 November 2018, 22:19:31 UTC
Linux 4.20-rc4
Linux 4.20-rc4
Tip revision: 2e6e902
uaccess.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.
*/
#include <linux/module.h>
#include <linux/uaccess.h>
unsigned long __generic_copy_from_user(void *to, const void __user *from,
unsigned long n)
{
unsigned long tmp, res;
asm volatile ("\n"
" tst.l %0\n"
" jeq 2f\n"
"1: "MOVES".l (%1)+,%3\n"
" move.l %3,(%2)+\n"
" subq.l #1,%0\n"
" jne 1b\n"
"2: btst #1,%5\n"
" jeq 4f\n"
"3: "MOVES".w (%1)+,%3\n"
" move.w %3,(%2)+\n"
"4: btst #0,%5\n"
" jeq 6f\n"
"5: "MOVES".b (%1)+,%3\n"
" move.b %3,(%2)+\n"
"6:\n"
" .section .fixup,\"ax\"\n"
" .even\n"
"10: lsl.l #2,%0\n"
" btst #1,%5\n"
" jeq 8f\n"
"30: addq.l #2,%0\n"
"8: btst #0,%5\n"
" jeq 6b\n"
"50: addq.l #1,%0\n"
" jra 6b\n"
" .previous\n"
"\n"
" .section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,10b\n"
" .long 3b,30b\n"
" .long 5b,50b\n"
" .previous"
: "=d" (res), "+a" (from), "+a" (to), "=&d" (tmp)
: "0" (n / 4), "d" (n & 3));
return res;
}
EXPORT_SYMBOL(__generic_copy_from_user);
unsigned long __generic_copy_to_user(void __user *to, const void *from,
unsigned long n)
{
unsigned long tmp, res;
asm volatile ("\n"
" tst.l %0\n"
" jeq 4f\n"
"1: move.l (%1)+,%3\n"
"2: "MOVES".l %3,(%2)+\n"
"3: subq.l #1,%0\n"
" jne 1b\n"
"4: btst #1,%5\n"
" jeq 6f\n"
" move.w (%1)+,%3\n"
"5: "MOVES".w %3,(%2)+\n"
"6: btst #0,%5\n"
" jeq 8f\n"
" move.b (%1)+,%3\n"
"7: "MOVES".b %3,(%2)+\n"
"8:\n"
" .section .fixup,\"ax\"\n"
" .even\n"
"20: lsl.l #2,%0\n"
"50: add.l %5,%0\n"
" jra 8b\n"
" .previous\n"
"\n"
" .section __ex_table,\"a\"\n"
" .align 4\n"
" .long 2b,20b\n"
" .long 3b,20b\n"
" .long 5b,50b\n"
" .long 6b,50b\n"
" .long 7b,50b\n"
" .long 8b,50b\n"
" .previous"
: "=d" (res), "+a" (from), "+a" (to), "=&d" (tmp)
: "0" (n / 4), "d" (n & 3));
return res;
}
EXPORT_SYMBOL(__generic_copy_to_user);
/*
* Zero Userspace
*/
unsigned long __clear_user(void __user *to, unsigned long n)
{
unsigned long res;
asm volatile ("\n"
" tst.l %0\n"
" jeq 3f\n"
"1: "MOVES".l %2,(%1)+\n"
"2: subq.l #1,%0\n"
" jne 1b\n"
"3: btst #1,%4\n"
" jeq 5f\n"
"4: "MOVES".w %2,(%1)+\n"
"5: btst #0,%4\n"
" jeq 7f\n"
"6: "MOVES".b %2,(%1)\n"
"7:\n"
" .section .fixup,\"ax\"\n"
" .even\n"
"10: lsl.l #2,%0\n"
"40: add.l %4,%0\n"
" jra 7b\n"
" .previous\n"
"\n"
" .section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,10b\n"
" .long 2b,10b\n"
" .long 4b,40b\n"
" .long 5b,40b\n"
" .long 6b,40b\n"
" .long 7b,40b\n"
" .previous"
: "=d" (res), "+a" (to)
: "d" (0), "0" (n / 4), "d" (n & 3));
return res;
}
EXPORT_SYMBOL(__clear_user);