Re: [RFC][CFT][PATCHSET v1] uaccess unification

Max Filippov
2017-04-04T20:27:05Z

On Wed, Mar 29, 2017 at 06:57:06AM +0100, Al Viro wrote:
> I hope that infrastructure part is stable enough to put it into never-rebased
> state. Some of per-architecture branches might be even done right; however,
> most of them got no testing whatsoever, so any help with testing (as well
> as "Al, for fuck sake, dump that garbage of yours, here's the correct patch"
> from maintainers) would be very welcome. So would the review, of course.

For the xtensa part:
Tested-by: Max Filippov <jcmvbkbc@gmail.com>

I believe that the xtensa part needs the following correction:

---8<---
>From 4505d69c3514fb12405409a7943e45831d037960 Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Tue, 4 Apr 2017 13:20:34 -0700
Subject: [PATCH] xtensa: fix prefetch in the raw_copy_to_user

'from' is the input buffer, it should be prefetched with prefetch, not
prefetchw.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/include/asm/uaccess.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h
index 8e93ed8..2e7bac0 100644
--- a/arch/xtensa/include/asm/uaccess.h
+++ b/arch/xtensa/include/asm/uaccess.h
@@ -245,7 +245,7 @@ raw_copy_from_user(void *to, const void __user *from, unsigned long n)
static inline unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
- prefetchw(from);
+ prefetch(from);
return __xtensa_copy_user((__force void *)to, from, n);
}
#define INLINE_COPY_FROM_USER
---8<---

--
Thanks.
-- Max