lkml.org 
[lkml]   [2013]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 06/76] asm-generic: uaccess: Allow arches to over-ride __{get,put}_user_fn()
Date
As of now these default to calling the arch provided __copy_{to,from}_user()
routines which being general purpose (w.r.t buffer alignment and lengths)
would lead to alignment checks in generated code (for arches which don't
support unaligned load/stores).

Given that in this case we already know that data involved is "unit"
sized and aligned, using the vanilla copy backend is a bit wasteful.

This change thus allows arches to over-ride the aforementioned routines.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
include/asm-generic/uaccess.h | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index 5f6ee61..c184aa8 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -169,12 +169,18 @@ static inline __must_check long __copy_to_user(void __user *to,
-EFAULT; \
})

+#ifndef __put_user_fn
+
static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
{
size = __copy_to_user(ptr, x, size);
return size ? -EFAULT : size;
}

+#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
+
+#endif
+
extern int __put_user_bad(void) __attribute__((noreturn));

#define __get_user(x, ptr) \
@@ -225,12 +231,17 @@ extern int __put_user_bad(void) __attribute__((noreturn));
-EFAULT; \
})

+#ifndef __get_user_fn
static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
{
size = __copy_from_user(x, ptr, size);
return size ? -EFAULT : size;
}

+#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
+
+#endif
+
extern int __get_user_bad(void) __attribute__((noreturn));

#ifndef __copy_from_user_inatomic
--
1.7.4.1


\
 
 \ /
  Last update: 2013-01-18 14:42    [W:0.514 / U:0.336 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site