linux.git/drivers/base/core.c, branch v2.6.33

Driver-core: Fix bogus 0 error return in device_add()

2009-12-23T19:23:44+00:00

If device_add() is called with a device which does not have dev->p set
up, then device_private_init() is called. If that succeeds, then the
error variable is set to 0. Now if the dev_name(dev) check further
down fails, then device_add() correctly terminates, but returns 0.
That of course lets the driver progress. If later another driver uses
this half set up device as parent then device_add() of the child
device explodes and renders sysfs completely unusable.

Set the error to -EINVAL if dev_name() check fails.

Signed-off-by: Thomas Gleixner 
Cc: Kay Sievers 
Cc: "Hans J. Koch" 
Signed-off-by: Greg Kroah-Hartman

Driver core: bin_attribute parameters can often be const*

2009-12-23T19:23:43+00:00

Many struct bin_attribute descriptors are purely read-only
structures, and there's no need to change them. Therefore
make the promise not to, which will let those descriptors
be put in a ro section.

Signed-off-by: Phil Carmody 
Signed-off-by: Greg Kroah-Hartman

Driver core: device_attribute parameters can often be const*

2009-12-23T19:23:43+00:00

Most device_attributes are const, and are begging to be
put in a ro section. However, the create and remove
file interfaces were failing to propagate the const promise
which the only functions they call offer.

Signed-off-by: Phil Carmody 
Signed-off-by: Greg Kroah-Hartman

Driver core: fix race in dev_driver_string

2009-12-11T19:24:55+00:00

This patch (as1310) works around a race in dev_driver_string().  If
the device is unbound while the function is running, dev->driver might
become NULL after we test it and before we dereference it.

Signed-off-by: Alan Stern 
Cc: stable 
Cc: Oliver Neukum 
Signed-off-by: Greg Kroah-Hartman

Driver core: Don't remove kobjects in device_shutdown.

2009-12-11T19:24:52+00:00

device_shutdown is defined to just shutdown the hardware and to not
clean up any kernel data structures.  Therefore don't put the kobjects
for /sys/dev and /sys/dev/block and /sys/dev/char.

This ensures we don't remove /sys/dev/block and /sys/dev/char while
we still have symlinks from there to the actual devices.

Acked-by: Kay Sievers 
Signed-off-by: Eric W. Biederman 
Signed-off-by: Greg Kroah-Hartman

Driver Core: devtmpfs: cleanup node on device creation error

2009-12-11T19:24:52+00:00

Signed-off-by: Kay Sievers 
Signed-off-by: Greg Kroah-Hartman

Driver-Core: extend devnode callbacks to provide permissions

2009-09-19T19:50:38+00:00

This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers 
Signed-off-by: Greg Kroah-Hartman

Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev

2009-09-15T16:50:49+00:00

Devtmpfs lets the kernel create a tmpfs instance called devtmpfs
very early at kernel initialization, before any driver-core device
is registered. Every device with a major/minor will provide a
device node in devtmpfs.

Devtmpfs can be changed and altered by userspace at any time,
and in any way needed - just like today's udev-mounted tmpfs.
Unmodified udev versions will run just fine on top of it, and will
recognize an already existing kernel-created device node and use it.
The default node permissions are root:root 0600. Proper permissions
and user/group ownership, meaningful symlinks, all other policy still
needs to be applied by userspace.

If a node is created by devtmps, devtmpfs will remove the device node
when the device goes away. If the device node was created by
userspace, or the devtmpfs created node was replaced by userspace, it
will no longer be removed by devtmpfs.

If it is requested to auto-mount it, it makes init=/bin/sh work
without any further userspace support. /dev will be fully populated
and dynamic, and always reflect the current device state of the kernel.
With the commonly used dynamic device numbers, it solves the problem
where static devices nodes may point to the wrong devices.

It is intended to make the initial bootup logic simpler and more robust,
by de-coupling the creation of the inital environment, to reliably run
userspace processes, from a complex userspace bootstrap logic to provide
a working /dev.

Signed-off-by: Kay Sievers 
Signed-off-by: Jan Blunck 
Tested-By: Harald Hoyer 
Tested-By: Scott James Remnant 
Signed-off-by: Greg Kroah-Hartman

driver model: constify attribute groups

2009-09-15T16:50:47+00:00

Let attribute group vectors be declared "const".  We'd
like to let most attribute metadata live in read-only
sections... this is a start.

Signed-off-by: David Brownell 
Signed-off-by: Greg Kroah-Hartman

Driver core: move dev_get/set_drvdata to drivers/base/dd.c

2009-09-15T16:50:47+00:00

No one should directly access the driver_data field, so remove the field
and make it private.  We dynamically create the private field now if it
is needed, to handle drivers that call get/set before they are
registered with the driver core.

Also update the copyright notices on these files while we are there.

Cc: Kay Sievers 
Signed-off-by: Greg Kroah-Hartman