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m68k/uaccess: Fix asm constraints for userspace access 

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>
wifi-calibration
Geert Uytterhoeven 2013-06-09 20:12:42 +02:00
parent 957d6bf665
commit 631d8b674f
2 changed files with 7 additions and 7 deletions
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8
arch/m68k/include/asm/uaccess_mm.h
View File

@ -90,7 +90,7 @@ asm volatile ("\n" \
__put_user_asm(__pu_err, __pu_val, ptr, b, d, -EFAULT); \
break; \
case 2: \
__put_user_asm(__pu_err, __pu_val, ptr, w, d, -EFAULT); \
__put_user_asm(__pu_err, __pu_val, ptr, w, r, -EFAULT); \
break; \
case 4: \
__put_user_asm(__pu_err, __pu_val, ptr, l, r, -EFAULT); \
@ -158,7 +158,7 @@ asm volatile ("\n" \
__get_user_asm(__gu_err, x, ptr, u8, b, d, -EFAULT); \
break; \
case 2: \
__get_user_asm(__gu_err, x, ptr, u16, w, d, -EFAULT); \
__get_user_asm(__gu_err, x, ptr, u16, w, r, -EFAULT); \
break; \
case 4: \
__get_user_asm(__gu_err, x, ptr, u32, l, r, -EFAULT); \
@ -245,7 +245,7 @@ __constant_copy_from_user(void *to, const void __user *from, unsigned long n)
__get_user_asm(res, *(u8 *)to, (u8 __user *)from, u8, b, d, 1);
break;
case 2:
__get_user_asm(res, *(u16 *)to, (u16 __user *)from, u16, w, d, 2);
__get_user_asm(res, *(u16 *)to, (u16 __user *)from, u16, w, r, 2);
break;
case 3:
__constant_copy_from_user_asm(res, to, from, tmp, 3, w, b,);
@ -326,7 +326,7 @@ __constant_copy_to_user(void __user *to, const void *from, unsigned long n)
__put_user_asm(res, *(u8 *)from, (u8 __user *)to, b, d, 1);
break;
case 2:
__put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, d, 2);
__put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, r, 2);
break;
case 3:
__constant_copy_to_user_asm(res, to, from, tmp, 3, w, b,);

6
arch/m68k/lib/uaccess.c
View File

@ -52,7 +52,7 @@ unsigned long __generic_copy_from_user(void *to, const void __user *from,
" .long 3b,30b\n"
" .long 5b,50b\n"
" .previous"
: "=d" (res), "+a" (from), "+a" (to), "=&r" (tmp)
: "=d" (res), "+a" (from), "+a" (to), "=&d" (tmp)
: "0" (n / 4), "d" (n & 3));
return res;
@ -96,7 +96,7 @@ unsigned long __generic_copy_to_user(void __user *to, const void *from,
" .long 7b,50b\n"
" .long 8b,50b\n"
" .previous"
: "=d" (res), "+a" (from), "+a" (to), "=&r" (tmp)
: "=d" (res), "+a" (from), "+a" (to), "=&d" (tmp)
: "0" (n / 4), "d" (n & 3));
return res;
@ -141,7 +141,7 @@ unsigned long __clear_user(void __user *to, unsigned long n)
" .long 7b,40b\n"
" .previous"
: "=d" (res), "+a" (to)
: "r" (0), "0" (n / 4), "d" (n & 3));
: "d" (0), "0" (n / 4), "d" (n & 3));
return res;
}