CVS log for src/sys/dev/cons.c

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Keyword substitution: kv
Default branch: MAIN

heartbeat(9): Move #ifdef HEARTBEAT to sys/heartbeat.h.

Less error-prone this way, and the callers are less cluttered.

cons(9): Suspend heartbeat checks while in polled-input mode.

This goes into a tight loop at high IPL, so it is to be expected that
the heartbeats will stop happening.

Should fix heartbeat panics at root device prompt on boot.

cons(9): Sort includes.

No functional change intended.

console(4), constty(4): Rip off the kernel lock, take three.

constty(4): Make MP-safe, take three.

Access to the global constty variable is coordinated as follows:

1. Setting constty to nonnull, with atomic_store_release, is allowed
   only under the new adaptive constty_lock in thread context.  This
   serializes TIOCCONS operations and ensures unlocked readers can
   safely use a constty pointer read with atomic_load_consume.

2. Changing constty from nonnull to null, with atomic_cas_ptr, is
   allowed in any context -- printf(9) uses this to disable a broken
   constty.

3. Reading constty under constty_lock is allowed with
   atomic_load_relaxed, because while constty_lock is held, it can
   only be made null by some other thread/CPU, never made nonnull.

4. Reading constty outside constty_lock is allowed with
   atomic_load_consume in a pserialize read section -- constty is
   only ever made nonnull with atomic_store_release, in (1).
   ttyclose will wait for all these pserialize read sections to
   complete before flushing the tty.

5. To continue to use a struct tty pointer in (4) after the
   pserialize read section has completed, caller must use tty_acquire
   during the pserialize read section and then tty_release when done.
   ttyclose will wait for all these references to drain before
   returning.

These access rules allow us to serialize TIOCCONS, and safely destroy
ttys, without putting any locks on the access paths like printf(9)
that use constty.  Once we set D_MPSAFE, operations on /dev/console
will contend only with other users of the same tty as constty, which
will be an improvement over contending with all other kernel lock
users in the system.

Changes second time around:
- Fix initialization of ok in cons.c cn_redirect.
- Fix reversed sense of conditional in subr_prf.c putone.

Changes third time around:
- Initialize ttyref_cv so we don't panic when trying to use it,
  leading to infinite loop when panic tries to take tty_lock to print
  the panic message while we already hold tty_lock.

Revert "constty(4): Make MP-safe."

Something is still busted and this is interfering with the releng
amd64 testbed.

Revert "console(4), constty(4): Rip off the kernel lock, take two."

Something is still busted and this is interfering with the releng
amd64 testbed.

console(4), constty(4): Rip off the kernel lock, take two.

constty(4): Make MP-safe.

Access to the global constty variable is coordinated as follows:

1. Setting constty to nonnull, with atomic_store_release, is allowed
   only under the new adaptive constty_lock in thread context.  This
   serializes TIOCCONS operations and ensures unlocked readers can
   safely use a constty pointer read with atomic_load_consume.

2. Changing constty from nonnull to null, with atomic_cas_ptr, is
   allowed in any context -- printf(9) uses this to disable a broken
   constty.

3. Reading constty under constty_lock is allowed with
   atomic_load_relaxed, because while constty_lock is held, it can
   only be made null by some other thread/CPU, never made nonnull.

4. Reading constty outside constty_lock is allowed with
   atomic_load_consume in a pserialize read section -- constty is
   only ever made nonnull with atomic_store_release, in (1).
   ttyclose will wait for all these pserialize read sections to
   complete before flushing the tty.

5. To continue to use a struct tty pointer in (4) after the
   pserialize read section has completed, caller must use tty_acquire
   during the pserialize read section and then tty_release when done.
   ttyclose will wait for all these references to drain before
   returning.

These access rules allow us to serialize TIOCCONS, and safely destroy
ttys, without putting any locks on the access paths like printf(9)
that use constty.  Once we set D_MPSAFE, operations on /dev/console
will contend only with other users of the same tty as constty, which
will be an improvement over contending with all other kernel lock
users in the system.

Changes second time around:
- Fix initialization of ok in cons.c cn_redirect.
- Fix reversed sense of conditional in subr_prf.c putone.

Revert "constty(4): Make MP-safe."

Something appears to be wrong with this.

Revert "console(4), constty(4): Rip off the kernel lock."

Needs more testing.

console(4), constty(4): Rip off the kernel lock.

constty(4): Make MP-safe.

Access to the global constty variable is coordinated as follows:

1. Setting constty to nonnull, with atomic_store_release, is allowed
   only under the new adaptive constty_lock in thread context.  This
   serializes TIOCCONS operations and ensures unlocked readers can
   safely use a constty pointer read with atomic_load_consume.

2. Changing constty from nonnull to null, with atomic_cas_ptr, is
   allowed in any context -- printf(9) uses this to disable a broken
   constty.

3. Reading constty under constty_lock is allowed with
   atomic_load_relaxed, because while constty_lock is held, it can
   only be made null by some other thread/CPU, never made nonnull.

4. Reading constty outside constty_lock is allowed with
   atomic_load_consume in a pserialize read section -- constty is
   only ever made nonnull with atomic_store_release, in (1).
   ttyclose will wait for all these pserialize read sections to
   complete before flushing the tty.

5. To continue to use a struct tty pointer in (4) after the
   pserialize read section has completed, caller must use tty_acquire
   during the pserialize read section and then tty_release when done.
   ttyclose will wait for all these references to drain before
   returning.

These access rules allow us to serialize TIOCCONS, and safely destroy
ttys, without putting any locks on the access paths like printf(9)
that use constty.  Once we set D_MPSAFE, operations on /dev/console
will contend only with other users of the same tty as constty, which
will be an improvement over contending with all other kernel lock
users in the system.

cons(9): Check the unit number on close too.

Races between multiple opens, some of which fail, might lead to
closing a bad unit number -- not clear there's a good way to prevent
this.

cons(9): Serialize open and close.

Kernel lock wasn't enough for this -- cdevvp, vn_lock, or VOP_OPEN
could block, allowing another thread to re-enter open.

cons(9): New function cn_set_tab.

Increment of progress toward eliminating bare access to cn_tab so we
can make more things MP-safe without the kernel lock (and maybe some
day better formalize console detection and switching).

cons(4): Don't barge ahead if cdevvp has failed -- return error now.

cons(4): Ignore error from vn_lock(vp, LK_EXCUSIVE|LK_RETRY).

This never fails, as is asserted in vn_lock whenever LK_RETRY is set
and LK_NOWAIT is not.

Merge changes from current as of 20200406

Pull up following revision(s) (requested by riastradh in ticket #528):

	sys/dev/cons.c: revision 1.76
	sys/dev/cons.c: revision 1.77

Fix reference count leak in cons(4).

Don't forget to vrele after you're done, folks!
XXX pullup-9
XXX pullup-8
XXX pullup-7
XXX pullup-6... 5... 4 might not have had this bug!

Restore historical $Hdr$ tag after git cvsexportcommit nixed it.

Pull up following revision(s) (requested by riastradh in ticket #1469):

	sys/dev/cons.c: revision 1.76
	sys/dev/cons.c: revision 1.77

Fix reference count leak in cons(4).
Don't forget to vrele after you're done, folks!
Restore historical $Hdr$ tag after git cvsexportcommit nixed it.

Pull up following revision(s) (requested by riastradh in ticket #1717):

	sys/dev/cons.c: revision 1.76
	sys/dev/cons.c: revision 1.77

Fix reference count leak in cons(4).
Don't forget to vrele after you're done, folks!
Restore historical $Hdr$ tag after git cvsexportcommit nixed it.

Pull up following revision(s) (requested by riastradh in ticket #1717):

	sys/dev/cons.c: revision 1.76
	sys/dev/cons.c: revision 1.77

Fix reference count leak in cons(4).
Don't forget to vrele after you're done, folks!
Restore historical $Hdr$ tag after git cvsexportcommit nixed it.

Pull up following revision(s) (requested by riastradh in ticket #1717):

	sys/dev/cons.c: revision 1.76
	sys/dev/cons.c: revision 1.77

Fix reference count leak in cons(4).
Don't forget to vrele after you're done, folks!
Restore historical $Hdr$ tag after git cvsexportcommit nixed it.

Restore historical $Hdr$ tag after git cvsexportcommit nixed it.

Fix reference count leak in cons(4).

Don't forget to vrele after you're done, folks!

XXX pullup-9
XXX pullup-8
XXX pullup-7
XXX pullup-6... 5... 4 might not have had this bug!

update from HEAD

Sync with HEAD

for some reason the previous commit causes ARCS firmware on sgimips64 to
spew an endless stream of white ( or rather, blue ) spaces. So revert to
the old code for sgimips only until I can figure out why.
Now sgimips64 n32 kernels boot again.

Sync with HEAD

Pull up following revision(s) (requested by nakayama in ticket #1267):
	sys/dev/cons.c: revision 1.74 via patch
Fix strange kernel output sequence "\n\r" observed in serial
consoles.  Output '\r' before '\n' in conversion.

Pull up following revision(s) (requested by nakayama in ticket #1952):
	sys/dev/cons.c: revision 1.74
Fix strange kernel output sequence "\n\r" observed in serial
consoles.  Output '\r' before '\n' in conversion.

Pull up following revision(s) (requested by nakayama in ticket #574):
	sys/dev/cons.c: revision 1.74
Fix strange kernel output sequence "\n\r" observed in serial
consoles.  Output '\r' before '\n' in conversion.

Fix strange kernel output sequence "\n\r" observed in serial
consoles.  Output '\r' before '\n' in conversion.

Fall back to nullcons if configured.

Rebase to HEAD as of a few days ago.

Rebase.

Add d_discard to all struct cdevsw instances I could find.

All have been set to "nodiscard"; some should get a real implementation.

sync with head.

for a reference, the tree before this commit was tagged
as yamt-pagecache-tag8.

this commit was splitted into small chunks to avoid
a limitation of cvs.  ("Protocol error: too many arguments")

sync with head

Change (mostly mechanically) every cdevsw/bdevsw I can find to use
designated initializers.

I have not built every extant kernel so I have probably broken at
least one build; however I've also found and fixed some wrong
cdevsw/bdevsw entries so even if so I think we come out ahead.

raise spl to IPL_HIGH when calling cngetc.  Make sure to call
do_critpollhooks() when outputing and getting input.

sync with head

sync to latest -current.

Replace the remaining KAUTH_GENERIC_ISSUSER authorization calls with
something meaningful. All relevant documentation has been updated or
written.

Most of these changes were brought up in the following messages:

    http://mail-index.netbsd.org/tech-kern/2012/01/18/msg012490.html
    http://mail-index.netbsd.org/tech-kern/2012/01/19/msg012502.html
    http://mail-index.netbsd.org/tech-kern/2012/02/17/msg012728.html

Thanks to christos, manu, njoly, and jmmv for input.

Huge thanks to pgoyette for spinning these changes through some build
cycles and ATF.

Sync with HEAD.

sync with head

Sync with HEAD

Remove clause 3 (UCB advertising clause) from the University of Utah
copyright.  Confirmed by Mike Hibler, mike at cs.utah.edu - thanks!
Also, merge UCB and Utah copyright texts back into one, as they
originally were.

Extra verification by snj@.

Add critpollhooks.

Sync with HEAD.

sync with head.

sync with head

Clean up vnode lock operations pass 2:

VOP_UNLOCK(vp, flags) -> VOP_UNLOCK(vp): Remove the unneeded flags argument.

Welcome to 5.99.32.

Discussed on tech-kern.

sync with head

Remove some unecessary includes sys/user.h header.

sync with HEAD

Sync with HEAD.

sync with head.

specfs changes for PR kern/37717 (raidclose() is no longer called on
shutdown). There are still problems with device access and a PR will be
filed.

- Kill checkalias(). Allow multiple vnodes to reference a single device.

- Don't play dangerous tricks with block vnodes to ensure that only one
  vnode can describe a block device. Instead, prohibit concurrent opens of
  block devices. As a bonus remove the unreliable code that prevents
  multiple file system mounts on the same device. It's no longer needed.

- Track opens by vnode and by device. Issue cdev_close() when the last open
  goes away, instead of abusing vnode::v_usecount to tell if the device is
  open.

sync with head.

Sync with head.

Merge some of the less invasive changes from the vmlocking branch:

- kthread, callout, devsw API changes
- select()/poll() improvements
- miscellaneous MT safety improvements

- Make the devsw interface MP safe, and add some comments.
- Allow individual block/character drivers to be marked MP safe.
- Provide wrappers around the device methods that look up the
  device, returning ENXIO if it's not found, and acquire the
  kernel lock if needed.

Sync with HEAD.

Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

sync with head.

Merge newlock2 to head.

sync with head.

sync with head.

__unused removal on arguments; approved by core.

sync with head

Add #ifdef'd out locking around constty.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

sync with head

sync with head

- Use the LWP cached credentials where sane.
- Minor cosmetic changes.

sync with head.

Sync with head.

Merge 2006-05-24 NetBSD-current into the "peter-altq" branch.

sync with head.

integrate kauth.

- Move kauth_cred_t declaration to <sys/types.h>
- Cleanup struct ucred; forward declarations that are unused.
- Don't include <sys/kauth.h> in any header, but include it in the c files
  that need it.

Approved by core.

generic_authorize() -> kauth_authorize_generic().

Adapt to kernel authorization KPI.

merge ktrace-lwp.

Sync with HEAD. Here we go again...

PR-30566: Poll must not return <sys/errno.h> values.
Start with those places I can easily test.

sync with -current

White space police.

sync with head.  xen and whitespace.  xen part is not finished.

Sync with HEAD.

Hi Perry!

nuke trailing whitespace

Fix the sync with head I botched.

Sync with HEAD.

Sync with HEAD

"panicking" needs a k.

Revert previous change as it breaks the build on a number of ports.

Introduce null console. This pseudo device acts as a normal console with the
exception that it discards any output, and is useful for booting the kernel
on headless boxes.

Make 'minor(dev) == 1' a device that isn't affected by TIOCCONS.
For /dev/constty so that you can grab kernel messages when logged in
on the 'console'.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

Apply the aborted ktrace-lwp changes to a specific branch.  This is just for
others to review, I'm concerned that patch fuziness may have resulted in some
errant code being generated but I'll look at that later by comparing the diff
from the base to the branch with the file I attempt to apply to it.  This will,
at the very least, put the changes in a better context for others to review
them and attempt to tinker with removing passing of 'struct lwp' through
the kernel.

Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records.  The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

Add cn_halt and cn_flush entries to consdevs.  (needed for dma-only console
devices).

Catch up to -current

merge kqueue branch into -current

kqueue provides a stateful and efficient event notification framework
currently supported events include socket, file, directory, fifo,
pipe, tty and device changes, and monitoring of processes and signals

kqueue is supported by all writable filesystems in NetBSD tree
(with exception of Coda) and all device drivers supporting poll(2)

based on work done by Jonathan Lemon for FreeBSD
initial NetBSD port done by Luke Mewburn and Jason Thorpe

Catch up to -current.

sync kqueue with -current; this includes merge of gehenna-devsw branch,
merge of i386 MP branch, and part of autoconf rototil work

remove trailing \n in panic().  approved perry.

Catch up to -current.

Merge the gehenna-devsw branch into the trunk.

This merge changes the device switch tables from static array to
dynamically generated by config(8).

- All device switches is defined as a constant structure in device drivers.

- The new grammer ``device-major'' is introduced to ``files''.

	device-major <prefix> char <num> [block <num>] [<rules>]

- All device major numbers must be listed up in port dependent majors.<arch>
  by using this grammer.

- Added the new naming convention.
  The name of the device switch must be <prefix>_[bc]devsw for auto-generation
  of device switch tables.

- The backward compatibility of loading block/character device
  switch by LKM framework is broken. This is necessary to convert
  from block/character device major to device name in runtime and vice versa.

- The restriction to assign device major by LKM is completely removed.
  We don't need to reserve LKM entries for dynamic loading of device switch.

- In compile time, device major numbers list is packed into the kernel and
  the LKM framework will refer it to assign device major number dynamically.

sync kqueue branch with HEAD

catch up with -current.

Catch up to -current.

As in PR kern/10999 from  Matthew Orgass, make the panic message more
helpful in the case where no console device has registered.

Add the character device switch.
Replace the direct-access to devsw table with calling devsw API.

Sync kqueue branch with -current.

Catch up to -current.

add RCSIDs

Revert the t_dev -> t_devvp change in struct tty. The way that tty
structs are currently used (especially by console ttys) aren't
ready for it, and this will require quite a few changes.

* add a VCLONED vnode flag that indicates a vnode representing a cloned
  device.
* rename REVOKEALL to REVOKEALIAS, and add a REVOKECLONE flag, to pass
  to VOP_REVOKE
* the revoke system call will revoke all aliases, as before, but not the
  clones
* vdevgone is called when detaching a device, so make it use REVOKECLONE
  to get rid of all clones as well
* clean up all uses of VOP_OPEN wrt. locking.
* add a few VOPS to spec_vnops that need to do something when it's a
  clone vnode (access and getattr)
* add a copy of the vnode vattr structure of the original 'master' vnode
  to the specinfo of a cloned vnode. could possibly redirect getattr to
  the 'master' vnode, but this has issues with revoke
* add a vdev_reassignvp function that disassociates a vnode from its
  original device, and reassociates it with the specified dev_t. to be
  used by cloning devices only, in case a new minor is allocated.
* change all direct references in drivers to v_devcookie and v_rdev
  to vdev_privdata(vp) and vdev_rdev(vp). for diagnostic purposes
  when debugging race conditions that still exist wrt. locking and
  revoking vnodes.
* make the locking state of a vnode consistent when passed to
  d_open and d_close (unlocked). locked would be better, but has
  some deadlock issues

Use vget, not vref, when acquiring an already existing console device vnode.

Various changes to make cloning devices possible:

	* Add an extra argument (struct vnode **) to VOP_OPEN. If it is
	  not NULL, specfs will create a cloned (aliased) vnode during
	  the call, and return it there. The caller should release and
	  unlock the original vnode if a new vnode was returned. The
	  new vnode is returned locked.

	* Add a flag field to the cdevsw and bdevsw structures.
	  DF_CLONING indicates that it wants a new vnode for each
	  open (XXX is there a better way? devprop?)

	* If a device is cloning, always call the close entry
	  point for a VOP_CLOSE.


Also, rewrite cons.c to do the right thing with vnodes. Use VOPs
rather then direct device entry calls. Suggested by mycroft@

Light to moderate testing done an i386 system (arch doesn't matter
though, these are MI changes).

Commit my "devvp" changes to the thorpej-devvp branch.  This
replaces the use of dev_t in most places with a struct vnode *.

This will form the basic infrastructure for real cloning device
support (besides being architecurally cleaner -- it'll be good
to get away from using numbers to represent objects).

implement cnkqfilter()

Catch up to -current.

Use back the 'u'&037 form - since it's CTRL-u, it's more readable that way
Use \007 instead of symbolic constant, since that's what is more often used.
Pointed out by Robert Elz.

cngetsn(): cosmetic only - use '\025' instead 'u'&037, and '\b' instead '\007'

fix comment

Update thorpej_scsipi to -current as of a month ago
A i386 GENERIC kernel compiles without the siop, ahc and bha drivers
(will be updated later). i386 IDE/ATAPI and ncr work, as well as
sparc/esp_sbus. alpha should work as well (untested yet).
siop, ahc and bha will be updated once I've updated the branch to current
-current, as well as machine-dependant code.

Sync w/ netbsd-1-5-base.

check for when cnopen() will call itself recursively, and panic instead of losing badly.

move static function getstr() to cons.c, make it publically available
as cngetsn().  there will be other consumer.

Remove register declarations.

- Implement cnbell() -- ring the console bell.  The cn_bell entrypoint
  is optional.
- Add cn_bell to statically allocated consdevs as appropriate.

Pull up revision 1.33 (requested by he):
  Catch a console configuration error.  Instead of jumping through
  cdevsw indexed on major(NODEV), call panic, fixing PR#8690.

Catch a console configuration error. Instead of jumping through cdevsw indexed
on major(NODEV), call panic...

Implement poll(2).

tty stop functions really should return void, not int, and certainly not both.

fixes for -Wall -Wmissing-prototypes:
add "return (0);" to cnstop()'s emtpy body.

cnputc returns void

fix definition of nullcnpollc, and add a prototype for it.

Remove duplicate definition of `constty'.

Split cninit from cons so ports that can't use it don't have to include it.

Add a dummy cnstop().

don't let args default, return values, add protos

Remove extra arg to d_open and vn_open().

added extra argument to vn_open

Add a nullcnpollc(), for people who don't want to deal.

be more careful with types, also pull in headers where necessary.

Implement cnpollc().

New RCS ID's, take two.  they're more aesthecially pleasant, and use 'NetBSD'

new standard, minimally intrusive ID format

Reverse sense of vfinddev().

undo that last

don't cdevvp() if a vnode for the dev already exists.  Note that that's
conceptually icky; you end up ref'ing a 'real' vnode, and hence perhaps
tying down a file system; should be able to reference a 'fake' one,
but i doesn't appear save to cdevvp() if vnode for same dev is already
around...  also, mark vfinddev()s XXX (for later).

and fix the other case.  ugly fix, but it works

get sense of two comparisons right.  from Chris Hopps <chopps@lamp>

new location of cons.h

make behaviour with constty consistent, deal properly with the case
where there's no console, and set things up so that this can be made
'shared' eventually.  look at diffs for exact changes.

if CN_REMOTE, don't redirect output.  this file needs some help,
but now at least i'm thinking about it again.

Don't compile com console stuff, for now.

Rename cninit() to consinit(), and junk the old, empty consinit().

cn_init --> cn_attach

decommit that last one; it's not nearly that easy to fix right...
see also: vnode aliases!

fix from Christoph Robitschko to keep 'kill -HUP' of syslogd
from spamming the console.  arguably less-than-elegant, but it works
and i don't want to see a slew of bug reports come 0.9...

pccons.c now dynamically allocates it's "struct tty"
cons.c's "struct tty *cn_tty" wasn't used by any of the kernel, and goes away.

ANSIfications - removed all implicit function return types and argument
definitions.  Ensured that all files include "systm.h" to gain access to
general prototypes.  Casts where necessary.

1. It is now possible to build a kernel that does not have a pc0 device driver.
2. "press any key to reboot" reads the key from the console.
3. wddump() still needs a non-blocking getc() routine (or flush)

add include of select.h if necessary for protos, or delete if extraneous

make kernel select interface be one-stop shopping & clean it all up.

add pg_wait, which must be set if you want pg() to actually wait for keybd
input.  this one is way useful...

after 0.2.2 "stable" patches applied

initial import of 386bsd-0.1 sources

Initial revision