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631d8b674f
When compiling a MMU kernel with CPU_HAS_ADDRESS_SPACES=n (e.g. "MMU=y
allnoconfig": "echo CONFIG_MMU=y > allno.config && make KCONFIG_ALLCONFIG=1
allnoconfig"), we use plain "move" instead of "moves", and I got:
CC arch/m68k/lib/uaccess.o
{standard input}: Assembler messages:
{standard input}:47: Error: operands mismatch -- statement `move.b %a0,(%a1)' ignored
This happens because plain "move" doesn't support byte transfers between
memory and address registers, while "moves" does.
Fix the asm constraints for __generic_copy_from_user(),
__generic_copy_to_user(), and __clear_user() to only use data registers
when accessing userspace.
Also, relax the asm constraints for 16-bit userspace accesses in
__put_user() and __get_user(), as both "move" and "moves" do support
such transfers between memory and address registers.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
149 lines
2.9 KiB
C
149 lines
2.9 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*/
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#include <linux/module.h>
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#include <asm/uaccess.h>
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unsigned long __generic_copy_from_user(void *to, const void __user *from,
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unsigned long n)
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{
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unsigned long tmp, res;
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asm volatile ("\n"
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" tst.l %0\n"
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" jeq 2f\n"
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"1: "MOVES".l (%1)+,%3\n"
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" move.l %3,(%2)+\n"
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" subq.l #1,%0\n"
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" jne 1b\n"
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"2: btst #1,%5\n"
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" jeq 4f\n"
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"3: "MOVES".w (%1)+,%3\n"
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" move.w %3,(%2)+\n"
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"4: btst #0,%5\n"
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" jeq 6f\n"
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"5: "MOVES".b (%1)+,%3\n"
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" move.b %3,(%2)+\n"
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"6:\n"
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" .section .fixup,\"ax\"\n"
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" .even\n"
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"10: move.l %0,%3\n"
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"7: clr.l (%2)+\n"
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" subq.l #1,%3\n"
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" jne 7b\n"
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" lsl.l #2,%0\n"
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" btst #1,%5\n"
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" jeq 8f\n"
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"30: clr.w (%2)+\n"
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" addq.l #2,%0\n"
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"8: btst #0,%5\n"
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" jeq 6b\n"
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"50: clr.b (%2)+\n"
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" addq.l #1,%0\n"
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" jra 6b\n"
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" .previous\n"
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"\n"
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" .section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 1b,10b\n"
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" .long 3b,30b\n"
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" .long 5b,50b\n"
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" .previous"
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: "=d" (res), "+a" (from), "+a" (to), "=&d" (tmp)
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: "0" (n / 4), "d" (n & 3));
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return res;
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}
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EXPORT_SYMBOL(__generic_copy_from_user);
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unsigned long __generic_copy_to_user(void __user *to, const void *from,
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unsigned long n)
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{
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unsigned long tmp, res;
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asm volatile ("\n"
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" tst.l %0\n"
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" jeq 4f\n"
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"1: move.l (%1)+,%3\n"
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"2: "MOVES".l %3,(%2)+\n"
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"3: subq.l #1,%0\n"
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" jne 1b\n"
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"4: btst #1,%5\n"
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" jeq 6f\n"
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" move.w (%1)+,%3\n"
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"5: "MOVES".w %3,(%2)+\n"
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"6: btst #0,%5\n"
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" jeq 8f\n"
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" move.b (%1)+,%3\n"
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"7: "MOVES".b %3,(%2)+\n"
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"8:\n"
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" .section .fixup,\"ax\"\n"
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" .even\n"
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"20: lsl.l #2,%0\n"
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"50: add.l %5,%0\n"
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" jra 8b\n"
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" .previous\n"
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"\n"
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" .section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 2b,20b\n"
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" .long 3b,20b\n"
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" .long 5b,50b\n"
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" .long 6b,50b\n"
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" .long 7b,50b\n"
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" .long 8b,50b\n"
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" .previous"
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: "=d" (res), "+a" (from), "+a" (to), "=&d" (tmp)
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: "0" (n / 4), "d" (n & 3));
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return res;
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}
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EXPORT_SYMBOL(__generic_copy_to_user);
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/*
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* Zero Userspace
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*/
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unsigned long __clear_user(void __user *to, unsigned long n)
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{
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unsigned long res;
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asm volatile ("\n"
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" tst.l %0\n"
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" jeq 3f\n"
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"1: "MOVES".l %2,(%1)+\n"
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"2: subq.l #1,%0\n"
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" jne 1b\n"
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"3: btst #1,%4\n"
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" jeq 5f\n"
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"4: "MOVES".w %2,(%1)+\n"
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"5: btst #0,%4\n"
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" jeq 7f\n"
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"6: "MOVES".b %2,(%1)\n"
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"7:\n"
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" .section .fixup,\"ax\"\n"
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" .even\n"
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"10: lsl.l #2,%0\n"
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"40: add.l %4,%0\n"
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" jra 7b\n"
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" .previous\n"
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"\n"
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" .section __ex_table,\"a\"\n"
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" .align 4\n"
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" .long 1b,10b\n"
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" .long 2b,10b\n"
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" .long 4b,40b\n"
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" .long 5b,40b\n"
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" .long 6b,40b\n"
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" .long 7b,40b\n"
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" .previous"
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: "=d" (res), "+a" (to)
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: "d" (0), "0" (n / 4), "d" (n & 3));
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return res;
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}
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EXPORT_SYMBOL(__clear_user);
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