Commit Graph

3 Commits

Author SHA1 Message Date
David Brownell a4b1d50e61 RTCs: handle NVRAM better
Several of the RTC drivers are exporting binary "nvram" files in sysfs.  Such
NVRAM (or on many systems, EEPROM) data is often initialized during system
manufacture to hold data about identity (serial numbers, Ethernet addresses,
etc), configuration, calibration, and so forth.

This patch improves integrity and security of those files:

  - Correctly initializes the size in one of the two cases where
    that was not yet being done.

  - Improves system security/integrity by making this state not
    be world-writable by default.

Letting arbitrary userspace code mangle such state by default is at least Not
A Good Thing; and it could sometimes be worse, depending on the particular
data that might be corrupted.  (I disregard the paranoiac "don't let anyone
read it either" approach.  Anyone storing passwords in such memory doesn't
really care about security.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Torsten Ertbjerg Rasmussen <tr@newtec.dk>
Cc: Mark Zhan <rongkai.zhan@windriver.com>
Cc: Thomas Hommel <thomas.hommel@gefanuc.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-14 18:45:36 -08:00
Al Viro c98dbe59ae fix missing arguments in drivers/rtc/rtc-stk17ta8.c
struct bin_attribute * is needed in bin_attribute ->read()/->write()
now.  Incidentally, could people please run the fscking compiler
before and after applying their patch and compare the build logs?
That (and many, many other) would be caught immediately.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26 11:11:56 -07:00
Thomas Hommel 029641151b rtc: add support for STK17TA8 chip
This patch adds support for the Simtek STK17TA8 timekeeping chip.

The STK17TA8 is quite similar to the DS1553, but differs in register layout
and in various control bits in the registers.  I chose to make this a new
driver to avoid confusion in the code and to not get lost in #ifdefs.

Signed-off-by: Thomas Hommel <thomas.hommel@gefanuc.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-21 17:49:17 -07:00