Commit graph

6 commits

Author SHA1 Message Date
David S. Miller
2922585b93 lib: Sparc's strncpy_from_user is generic enough, move under lib/
To use this, an architecture simply needs to:

1) Provide a user_addr_max() implementation via asm/uaccess.h

2) Add "select GENERIC_STRNCPY_FROM_USER" to their arch Kcnfig

3) Remove the existing strncpy_from_user() implementation and symbol
   exports their architecture had.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: David Howells <dhowells@redhat.com>
2012-05-24 13:12:28 -07:00
David S. Miller
446969084d kernel: Move REPEAT_BYTE definition into linux/kernel.h
And make sure that everything using it explicitly includes
that header file.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-24 13:10:05 -07:00
David S. Miller
35c9646062 sparc: Increase portability of strncpy_from_user() implementation.
Hide details of maximum user address calculation in a new
asm/uaccess.h interface named user_addr_max().

Provide little-endian implementation in find_zero(), which should work
but can probably be improved.

Abstrace alignment check behind IS_UNALIGNED() macro.

Kill double-semicolon, noticed by David Howells.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-24 13:04:24 -07:00
David S. Miller
4efcac3a24 sparc: Optimize strncpy_from_user() zero byte search.
Compute a mask that will only have 0x80 in the bytes which
had a zero in them.  The formula is:

	~(((x & 0x7f7f7f7f) + 0x7f7f7f7f) | x | 0x7f7f7f7f)

In the inner word iteration, we have to compute the "x | 0x7f7f7f7f"
part, so we can reuse that in the above calculation.

Once we have this mask, we perform divide and conquer to find the
highest 0x80 location.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-23 19:20:20 -07:00
David S. Miller
ff06dffbc8 sparc: Add full proper error handling to strncpy_from_user().
Linus removed the end-of-address-space hackery from
fs/namei.c:do_getname() so we really have to validate these edge
conditions and cannot cheat any more (as x86 used to as well).

Move to a common C implementation like x86 did.  And if both
src and dst are sufficiently aligned we'll do word at a time
copies and checks as well.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-22 23:32:27 -07:00
David S. Miller
fb34035e7b sparc: Use __builtin_object_size() to validate the buffer size for copy_from_user()
This mirrors x86 commit 9f0cf4adb6
(x86: Use __builtin_object_size() to validate the buffer size for copy_from_user())

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-10 23:05:23 -08:00