This is a note to let you know that I've just added the patch titled
m68k/uaccess: Fix asm constraints for userspace access
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
m68k-uaccess-fix-asm-constraints-for-userspace-access.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 631d8b674f5f8235e9cb7e628b0fe9e5200e3158 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Date: Sun, 9 Jun 2013 20:12:42 +0200
Subject: m68k/uaccess: Fix asm constraints for userspace access
From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
commit 631d8b674f5f8235e9cb7e628b0fe9e5200e3158 upstream.
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@xxxxxxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/m68k/include/asm/uaccess_mm.h | 8 ++++----
arch/m68k/lib/uaccess.c | 6 +++---
2 files changed, 7 insertions(+), 7 deletions(-)
--- a/arch/m68k/include/asm/uaccess_mm.h
+++ b/arch/m68k/include/asm/uaccess_mm.h
@@ -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, cons
__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,
__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,);
--- a/arch/m68k/lib/uaccess.c
+++ b/arch/m68k/lib/uaccess.c
@@ -52,7 +52,7 @@ unsigned long __generic_copy_from_user(v
" .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(voi
" .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 *
" .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;
}
Patches currently in stable-queue which might be from geert@xxxxxxxxxxxxxx are
queue-3.10/m68k-uaccess-fix-asm-constraints-for-userspace-access.patch
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