Commit Graph

11 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
Atsushi Nemoto
a95e23a27b rtc: make rtc-ds1742 driver hotplug-aware
The rtc-ds1742 platform driver name doesn't match its module name,
which might prevents it from properly hotplugging.  There is only two
in-tree user of its driver, which are fixed by this patch too.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:13 -07:00
David Gibson
2e3e31c057 rtc-ds1742.c should use resource_size_t for base address
Currently the rtc driver, rtc-ds1742.c uses an unsigned long to store the
base mmio address of the NVRAM/RTC.  This breaks on systems like PowerPC
440, which is a 32-bit core with 36-bit physical addresses: IO on the
system, including the RTC, is typically above the 4GB point, and cannot fit
into an unsigned long.

This patch fixes the problem by replacing the unsigned long with a
resource_size_t.  Tested on Ebony (PPC440) (with additional patches to
instantiate the ds1742 platform device appropriately).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
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>
2007-09-19 11:24:17 -07:00
Atsushi Nemoto
ef154ec69c rtc: do not return void value
This patch fixes these sparse warnings:

drivers/rtc/rtc-ds1742.c:265:2: warning: returning void-valued expression
drivers/rtc/rtc-ds1553.c:409:2: warning: returning void-valued expression

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-21 17:49:17 -07:00
Zhang Rui
91a6902958 sysfs: add parameter "struct bin_attribute *" in .read/.write methods for sysfs binary attributes
Well, first of all, I don't want to change so many files either.

What I do:
Adding a new parameter "struct bin_attribute *" in the
.read/.write methods for the sysfs binary attributes.

In fact, only the four lines change in fs/sysfs/bin.c and
include/linux/sysfs.h do the real work.
But I have to update all the files that use binary attributes
to make them compatible with the new .read and .write methods.
I'm not sure if I missed any. :(

Why I do this:
For a sysfs attribute, we can get a pointer pointing to the
struct attribute in the .show/.store method,
while we can't do this for the binary attributes.
I don't know why this is different, but this does make it not
so handy to use the binary attributes as the regular ones.
So I think this patch is reasonable. :)

Who benefits from it:
The patch that exposes ACPI tables in sysfs
requires such an improvement.
All the table binary attributes share the same .read method.
Parameter "struct bin_attribute *" is used to get
the table signature and instance number which are used to
distinguish different ACPI table binary attributes.

Without this parameter, we need to offer different .read methods
for different ACPI table binary attributes.
This is impossible as there are various ACPI tables on different
platforms, and we don't know what they are until they are loaded.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-11 16:09:09 -07:00
Tejun Heo
7b595756ec sysfs: kill unnecessary attribute->owner
sysfs is now completely out of driver/module lifetime game.  After
deletion, a sysfs node doesn't access anything outside sysfs proper,
so there's no reason to hold onto the attribute owners.  Note that
often the wrong modules were accounted for as owners leading to
accessing removed modules.

This patch kills now unnecessary attribute->owner.  Note that with
this change, userland holding a sysfs node does not prevent the
backing module from being unloaded.

For more info regarding lifetime rule cleanup, please read the
following message.

  http://article.gmane.org/gmane.linux.kernel/510293

(tweaked by Greg to not delete the field just yet, to make it easier to
merge things properly.)

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-11 16:09:06 -07:00
Prarit Bhargava
c239122dec [PATCH] change __init to __devinit in 2 rtc drivers
Change __init to __devinit in rtc drivers' probe functions.

Resolves MODPOST warnings:

WARNING: drivers/rtc/rtc-ds1553.o - Section mismatch: reference to
.init.text:ds1553_rtc_probe from .data.rel between 'ds1553_rtc_driver' (at
offset 0x0) and 'ds1553_nvram_attr'
WARNING: drivers/rtc/rtc-ds1742.o - Section mismatch: reference to
.init.text:ds1742_rtc_probe from .data.rel between 'ds1742_rtc_driver' (at
offset 0x0) and 'ds1742_nvram_attr'

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:30 -08:00
Torsten Ertbjerg Rasmussen
f9231a0ca1 [PATCH] rtc: ds1743 support
The real time clocks ds1742 and ds1743 differs only in the size of the
nvram.  This patch changes the existing ds1742 driver to support also
ds1743.  The main change is that the nvram size is determined from the
resource attached to the device.

The patch have benefitted from suggestions from Atsushi Nemeto, who is the
author of the ds1742 driver.

Signed-off-by: Torsten Rasmussen Rasmussen <tr@newtec.dk>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:43 -08:00
Atsushi Nemoto
391b1fe67d [PATCH] RTC: rtc-ds1553, rtc-ds1742 update
Check return value of sysfs_create_bin_file().  Fix polarity of
RTC_BATT_FLAG bit in DS1742.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:25 -07:00
David Brownell
ff8371ac9a [PATCH] constify rtc_class_ops: update drivers
Update RTC framework so that drivers can constify their method tables, moving
them from ".data" to ".rodata".  Then update the drivers.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:25 -07:00
Atsushi Nemoto
5ec3e4b7ae [PATCH] RTC: add rtc-ds1742 driver
Add an RTC driver for the Dallas DS1742 RTC chip.

[akpm@osdl.org: cleanups, compile fix]
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:14 -07:00