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Subject[PATCH 3/8] asm-generic: fix unaligned access hamdling in raw_copy_{from,to}_user
Date
Use get_unaligned and put_unaligned for the small constant size cases
in the generic uaccess routines. This ensures they can be used for
architectures that do not support unaligned loads and stores, while
being a no-op for those that do.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/asm-generic/uaccess.h | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index cc3b2c8b68fab4..768502bbfb154e 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -36,19 +36,17 @@ raw_copy_from_user(void *to, const void __user * from, unsigned long n)
if (__builtin_constant_p(n)) {
switch(n) {
case 1:
- *(u8 *)to = *(u8 __force *)from;
+ *(u8 *)to = get_unaligned((u8 __force *)from);
return 0;
case 2:
- *(u16 *)to = *(u16 __force *)from;
+ *(u16 *)to = get_unaligned((u16 __force *)from);
return 0;
case 4:
- *(u32 *)to = *(u32 __force *)from;
+ *(u32 *)to = get_unaligned((u32 __force *)from);
return 0;
-#ifdef CONFIG_64BIT
case 8:
- *(u64 *)to = *(u64 __force *)from;
+ *(u64 *)to = get_unaligned((u64 __force *)from);
return 0;
-#endif
}
}

@@ -62,19 +60,17 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
if (__builtin_constant_p(n)) {
switch(n) {
case 1:
- *(u8 __force *)to = *(u8 *)from;
+ put_unaligned(*(u8 *)from, (u8 __force *)to);
return 0;
case 2:
- *(u16 __force *)to = *(u16 *)from;
+ put_unaligned(*(u16 *)from, (u16 __force *)to);
return 0;
case 4:
- *(u32 __force *)to = *(u32 *)from;
+ put_unaligned(*(u32 *)from, (u32 __force *)to);
return 0;
-#ifdef CONFIG_64BIT
case 8:
- *(u64 __force *)to = *(u64 *)from;
+ put_unaligned(*(u64 *)from, (u64 __force *)to);
return 0;
-#endif
default:
break;
}
--
2.28.0
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