Commit Graph

201 Commits

Author SHA1 Message Date
Bruce M Simpson
217f71d80c Use int instead of u_int for the 'extra' argument to the
clone_create() KPI.
This fixes a signedness bug in unit number comparisons.

Submitted by:	imp, Landon Fuller
PR:		kern/105228
MFC after:	2 weeks
2007-02-02 22:27:45 +00:00
Konstantin Belousov
1663075c64 Fix the race between devfs_fp_check and devfs_reclaim. Derefence the
vnode' v_rdev and increment the dev threadcount , as well as clear it
(in devfs_reclaim) under the dev_lock().

Reviewed by:	tegge
Approved by:	pjd (mentor)
2006-10-20 07:59:50 +00:00
Tor Egge
e0c33ad529 Wait for thread count to reach zero in destroy_devl() even when no purge
method is defined, to avoid memory being modified after free.

Temporarily increase refcount in destroy_devl() to avoid a double free
if dev_rel() is called while waiting for thread count to reach zero.
2006-10-13 20:49:24 +00:00
Poul-Henning Kamp
d595182f0b Make the printfs relating to purging threads from a device less intrusive. 2006-05-17 06:37:14 +00:00
Alfred Perlstein
7d7e053c21 Novel idea, don't print a string if it is NULL!
This protects people from loading _really_ old modules, like say from
5.x to a 6.x or 7.x system, like for instance right after an upgrade.
2006-01-12 19:15:14 +00:00
Bjoern A. Zeeb
ba0b6851b4 Minor whitespace cleanup. 2006-01-04 17:40:54 +00:00
John Baldwin
8c4b6380c7 Move the initialization of the devmtx into the mutex_init() function
called during early init before cninit().

Tested on:	i386, alpha, sparc64
Reviewed by:	phk, imp
Reported by:	Divacky Roman xdivac02 at stud dot fit dot vutbr dot cz
MFC after:	1 week
2005-10-18 18:27:44 +00:00
Poul-Henning Kamp
7bbb3a2690 Make sure the clone lists are sorted in the right order.
Explosion triggered by:	pjd
MFC:	3 days
2005-10-01 19:21:03 +00:00
Poul-Henning Kamp
e606a3c63e Rewamp DEVFS internals pretty severely [1].
Give DEVFS a proper inode called struct cdev_priv.  It is important
to keep in mind that this "inode" is shared between all DEVFS
mountpoints, therefore it is protected by the global device mutex.

Link the cdev_priv's into a list, protected by the global device
mutex.  Keep track of each cdev_priv's state with a flag bit and
of references from mountpoints with a dedicated usecount.

Reap the benefits of much improved kernel memory allocator and the
generally better defined device driver APIs to get rid of the tables
of pointers + serial numbers, their overflow tables,  the atomics
to muck about in them and all the trouble that resulted in.

This makes RAM the only limit on how many devices we can have.

The cdev_priv is actually a super struct containing the normal cdev
as the "public" part, and therefore allocation and freeing has moved
to devfs_devs.c from kern_conf.c.

The overall responsibility is (to be) split such that kern/kern_conf.c
is the stuff that deals with drivers and struct cdev and fs/devfs
handles filesystems and struct cdev_priv and their private liason
exposed only in devfs_int.h.

Move the inode number from cdev to cdev_priv and allocate inode
numbers properly with unr.  Local dirents in the mountpoints
(directories, symlinks) allocate inodes from the same pool to
guarantee against overlaps.

Various other fields are going to migrate from cdev to cdev_priv
in the future in order to hide them.  A few fields may migrate
from devfs_dirent to cdev_priv as well.

Protect the DEVFS mountpoint with an sx lock instead of lockmgr,
this lock also protects the directory tree of the mountpoint.

Give each mountpoint a unique integer index, allocated with unr.
Use it into an array of devfs_dirent pointers in each cdev_priv.
Initially the array points to a single element also inside cdev_priv,
but as more devfs instances are mounted, the array is extended with
malloc(9) as necessary when the filesystem populates its directory
tree.

Retire the cdev alias lists, the cdev_priv now know about all the
relevant devfs_dirents (and their vnodes) and devfs_revoke() will
pick them up from there.  We still spelunk into other mountpoints
and fondle their data without 100% good locking.  It may make better
sense to vector the revoke event into the tty code and there do a
destroy_dev/make_dev on the tty's devices, but that's for further
study.

Lots of shuffling of stuff and churn of bits for no good reason[2].

XXX: There is still nothing preventing the dev_clone EVENTHANDLER
from being invoked at the same time in two devfs mountpoints.  It
is not obvious what the best course of action is here.

XXX: comment out an if statement that lost its body, until I can
find out what should go there so it doesn't do damage in the meantime.

XXX: Leave in a few extra malloc types and KASSERTS to help track
down any remaining issues.

Much testing provided by:		Kris
Much confusion caused by (races in):	md(4)

[1] You are not supposed to understand anything past this point.

[2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
Poul-Henning Kamp
74f46f19aa Retire unused dev_named() function. 2005-09-15 08:01:57 +00:00
Poul-Henning Kamp
1d45c50ec3 Properly un-giant-trick the cdevsw in fini_cdevsw()
Tripped over by:	Huang wen hui <huang@gddsn.org.cn>
2005-08-20 12:13:51 +00:00
Poul-Henning Kamp
516ad423b1 Handle device drivers with D_NEEDGIANT in a way which does not
penalize the 'good' drivers:  Allocate a shadow cdevsw and populate
it with wrapper functions which grab Giant
2005-08-17 08:19:52 +00:00
Poul-Henning Kamp
b3740d656f Remove stale comment. 2005-08-16 19:47:42 +00:00
Poul-Henning Kamp
9c0af1310c Create a new internal .h file to communicate very private stuff
from kern_conf.c to devfs.

For now just two prototypes, more to come.
2005-08-16 19:08:01 +00:00
Robert Watson
d26dd2d99e When devfs cloning takes place, provide access to the credential of the
process that caused the clone event to take place for the device driver
creating the device.  This allows cloned device drivers to adapt the
device node based on security aspects of the process, such as the uid,
gid, and MAC label.

- Add a cred reference to struct cdev, so that when a device node is
  instantiated as a vnode, the cloning credential can be exposed to
  MAC.

- Add make_dev_cred(), a version of make_dev() that additionally
  accepts the credential to stick in the struct cdev.  Implement it and
  make_dev() in terms of a back-end make_dev_credv().

- Add a new event handler, dev_clone_cred, which can be registered to
  receive the credential instead of dev_clone, if desired.

- Modify the MAC entry point mac_create_devfs_device() to accept an
  optional credential pointer (may be NULL), so that MAC policies can
  inspect and act on the label or other elements of the credential
  when initializing the skeleton device protections.

- Modify tty_pty.c to register clone_dev_cred and invoke make_dev_cred(),
  so that the pty clone credential is exposed to the MAC Framework.

While currently primarily focussed on MAC policies, this change is also
a prerequisite for changes to allow ptys to be instantiated with the UID
of the process looking up the pty.  This requires further changes to the
pty driver -- in particular, to immediately recycle pty nodes on last
close so that the credential-related state can be recreated on next
lookup.

Submitted by:	Andrew Reisse <andrew.reisse@sparta.com>
Obtained from:	TrustedBSD Project
Sponsored by:	SPAWAR, SPARTA
MFC after:	1 week
MFC note:	Merge to 6.x, but not 5.x for ABI reasons
2005-07-14 10:22:09 +00:00
Poul-Henning Kamp
9477d73e32 cdev (still) needs per instance uid/gid/mode
Add unlocked version of dev_ref()

Clean up various stuff in sys/conf.h
2005-03-31 10:29:57 +00:00
Poul-Henning Kamp
eb151cb989 Rename dev_ref() to dev_refl() 2005-03-31 06:51:54 +00:00
Poul-Henning Kamp
b3d82c03fc Remove the global cdev hash and use the cdevsw list instead.
Don't remove the now unused element from cdev yet, wait until
we have a better reason to bump the version.

There is now no longer any upper limit on how many device drivers
a FreeBSD kernel can have.
2005-03-29 11:15:54 +00:00
Poul-Henning Kamp
ff7284eeb4 Remove the global cdev hash and use the cdevsw list instead.
Don't remove the now unused element from cdev yet, wait until
we have a better reason to bump the version.
2005-03-29 09:56:21 +00:00
Poul-Henning Kamp
fd5f6f4cf2 Privatize major(). 2005-03-29 08:13:17 +00:00
Poul-Henning Kamp
bde1a9c98b Kill MAJOR_AUTO 2005-03-17 13:37:28 +00:00
Poul-Henning Kamp
800b42bde0 Prepare for the final onslaught on devices:
Move uid/gid/mode from cdev to cdevsw.

Add kind field to use for devd(8) later.

Bump both D_VERSION and __FreeBSD_version
2005-03-17 12:07:00 +00:00
Poul-Henning Kamp
4ba679d6d0 Remove findcdev(). 2005-03-15 12:58:08 +00:00
Poul-Henning Kamp
0a2e49f1f8 Rename cdev->si_udev to cdev->si_drv0 to reflect the new nature of
the field.
2005-03-15 11:33:28 +00:00
Poul-Henning Kamp
b43ab0e378 Try to fix the mess I made of devname, with the minimal subset of the
larger minor/major patch which was posted for testing.
2005-03-10 18:21:34 +00:00
Poul-Henning Kamp
3238ec33e1 Fix signedness of minor2unit(). 2005-03-08 10:40:03 +00:00
Poul-Henning Kamp
8045ce213d Also handle d_maj hints from cloning drivers correctly. 2005-02-27 22:57:32 +00:00
Poul-Henning Kamp
84f580a093 Whine about any drivers which hardcode the device major number. 2005-02-27 22:41:07 +00:00
Poul-Henning Kamp
89685e2269 Use dynamic major number allocation for /dev/console, there is no
longer any benefit from hard wiring it.

Remove special hack used to wire major to zero despite zero having a
different magic meaning as well.
2005-02-27 21:52:42 +00:00
Poul-Henning Kamp
aa2f6ddc3f Reap more benefits from DEVFS:
List devfs_dirents rather than vnodes off their shared struct cdev, this
saves a pointer field in the vnode at the expense of a field in the
devfs_dirent.  There are often 100 times more vnodes so this is bargain.
In addition it makes it harder for people to try to do stypid things like
"finding the vnode from cdev".

Since DEVFS handles all VCHR nodes now, we can do the vnode related
cleanup in devfs_reclaim() instead of in dev_rel() and vgonel().
Similarly, we can do the struct cdev related cleanup in dev_rel()
instead of devfs_reclaim().

	rename idestroy_dev() to destroy_devl() for consistency.

	Add LIST_ENTRY de_alias to struct devfs_dirent.
	Remove v_specnext from struct vnode.
	Change si_hlist to si_alist in struct cdev.
	String new devfs vnodes' devfs_dirent on si_alist when
	we create them and take them off in devfs_reclaim().

	Fix devfs_revoke() accordingly.  Also don't clear fields
	devfs_reclaim() will clear when called from vgone();

	Let devfs_reclaim() call dev_rel() instead of vgonel().

	Move the usecount tracking from dev_rel() to devfs_reclaim(),
	and let dev_rel() take a struct cdev argument instead of vnode.

	Destroy SI_CHEAPCLONE devices in dev_rel() (instead of
	devfs_reclaim()) when they are no longer used.   (This
	should maybe happen in devfs_close() instead.)
2005-02-22 15:51:07 +00:00
Poul-Henning Kamp
1a1457d427 Make dev_ref() require the dev_lock() to be held and use it from
devfs instead of directly frobbing the si_refcount.
2005-02-22 14:41:04 +00:00
Poul-Henning Kamp
d9aaa28f63 Use MAXMINOR 2005-01-29 16:50:04 +00:00
Poul-Henning Kamp
37085a3931 Typo. 2005-01-29 15:10:30 +00:00
Poul-Henning Kamp
3a85fd262c Add MAXMINOR #define, we should have had this long time ago.
Add minor2unit() in addition to dev2unit() and unit2minor().

If it wasn't such a hazzle we should redefine minor numbers in
the kernel without the gap for the major number, but it's not worth
the bother (yet).
2005-01-29 15:07:13 +00:00
Poul-Henning Kamp
027b1f716c Fix a list corruption issue in cloning device management using the
western strategy ("allocate first, ask questions later") so we can
extend the devmtx coverage to the clone list.
2005-01-24 12:44:56 +00:00
Poul-Henning Kamp
1a1b280063 Get rid of the magic "stash" of cdev structures, we no longer call
make_dev() before malloc works.
2004-10-25 13:12:06 +00:00
Poul-Henning Kamp
ba2851254f Fix a LOR relating to freeing cdevs. 2004-10-01 06:33:39 +00:00
Brian Feldman
1abf2c3678 Account for alias devices when tearing them down in destroy_dev() so we
don't panic on a NULL cdev->si_devsw.
2004-09-29 16:38:38 +00:00
Poul-Henning Kamp
a5993c332a Used cached cdevsw pointer. 2004-09-27 06:34:30 +00:00
Poul-Henning Kamp
743cd76a73 Add cdevsw->d_purge() support.
This device method shall wake up any threads sleeping in the device driver
and make the depart the drivers code for good.
2004-09-27 06:18:25 +00:00
Poul-Henning Kamp
b2deb1d205 Remove the cdevsw() function which is now unused. 2004-09-24 08:30:57 +00:00
Poul-Henning Kamp
8ff33adb8c Hold threadref while we throb cdevsw in devtoname() 2004-09-24 06:29:23 +00:00
Poul-Henning Kamp
2c15afd888 Introduce dev_re[lf]thread() functions.
dev_refthread() will return the cdevsw pointer or NULL.  If the
return value is non-NULL a threadcount is held which much be released
with dev_relthread().  If the returned cdevsw is NULL no threadcount
is held on the device.
2004-09-24 05:54:32 +00:00
Poul-Henning Kamp
a0e78d2eb0 Do not refcount the cdevsw, but rather maintain a cdev->si_threadcount
of the number of threads which are inside whatever is behind the
cdevsw for this particular cdev.

Make the device mutex visible through dev_lock() and dev_unlock().
We may want finer granularity later.

Replace spechash_mtx use with dev_lock()/dev_unlock().
2004-09-23 07:17:41 +00:00
Poul-Henning Kamp
67673e6677 Create struct snapdata which contains the snapshot fields from cdev
and the previously malloc'ed snapshot lock.

Malloc struct snapdata instead of just the lock.

Replace snapshot fields in cdev with pointer to snapdata (saves 16 bytes).

While here, give the private readblock() function a vnode argument
in preparation for moving UFS to access GEOM directly.
2004-09-13 07:29:45 +00:00
Pawel Jakub Dawidek
2e4db7cfd7 Add a missing '\n'. 2004-08-30 01:10:20 +00:00
John-Mark Gurney
ad3b9257c2 Add locking to the kqueue subsystem. This also makes the kqueue subsystem
a more complete subsystem, and removes the knowlege of how things are
implemented from the drivers.  Include locking around filter ops, so a
module like aio will know when not to be unloaded if there are outstanding
knotes using it's filter ops.

Currently, it uses the MTX_DUPOK even though it is not always safe to
aquire duplicate locks.  Witness currently doesn't support the ability
to discover if a dup lock is ok (in some cases).

Reviewed by:	green, rwatson (both earlier versions)
2004-08-15 06:24:42 +00:00
Poul-Henning Kamp
9ef295b7e0 Better descriptions of the cdev malloc class and mutex. 2004-07-11 19:26:43 +00:00
Lukas Ertl
9a98ae94ba Fix a few spelling mistakes in comments and clean them up a bit. 2004-06-22 20:22:24 +00:00
Poul-Henning Kamp
f3732fd15b Second half of the dev_t cleanup.
The big lines are:
	NODEV -> NULL
	NOUDEV -> NODEV
	udev_t -> dev_t
	udev2dev() -> findcdev()

Various minor adjustments including handling of userland access to kernel
space struct cdev etc.
2004-06-17 17:16:53 +00:00