b1e1f725e7
and devd(8) can't handle names with such characters properly. PR: bin/144736, kern/161912 Discussed with: imp, kib, pjd
406 lines
9.9 KiB
Groff
406 lines
9.9 KiB
Groff
.\" Copyright (c) 1999 Chris Costello
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd Dec 22, 2012
|
|
.Dt MAKE_DEV 9
|
|
.Os
|
|
.Sh NAME
|
|
.Nm make_dev ,
|
|
.Nm make_dev_cred ,
|
|
.Nm make_dev_credf ,
|
|
.Nm make_dev_p ,
|
|
.Nm make_dev_alias ,
|
|
.Nm make_dev_alias_p ,
|
|
.Nm destroy_dev ,
|
|
.Nm destroy_dev_sched ,
|
|
.Nm destroy_dev_sched_cb ,
|
|
.Nm destroy_dev_drain ,
|
|
.Nm dev_depends
|
|
.Nd manage
|
|
.Vt cdev Ns 's
|
|
and DEVFS registration for devices
|
|
.Sh SYNOPSIS
|
|
.In sys/param.h
|
|
.In sys/conf.h
|
|
.Ft struct cdev *
|
|
.Fn make_dev "struct cdevsw *cdevsw" "int unit" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
|
|
.Ft struct cdev *
|
|
.Fn make_dev_cred "struct cdevsw *cdevsw" "int unit" "struct ucred *cr" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
|
|
.Ft struct cdev *
|
|
.Fn make_dev_credf "int flags" "struct cdevsw *cdevsw" "int unit" "struct ucred *cr" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
|
|
.Ft int
|
|
.Fn make_dev_p "int flags" "struct cdev **cdev" "struct cdevsw *devsw" "struct ucred *cr" "uid_t uid" "gid_t gid" "int mode" "const char *fmt" ...
|
|
.Ft struct cdev *
|
|
.Fn make_dev_alias "struct cdev *pdev" "const char *fmt" ...
|
|
.Ft int
|
|
.Fn make_dev_alias_p "int flags" "struct cdev **cdev" "struct cdev *pdev" "const char *fmt" ...
|
|
.Ft void
|
|
.Fn destroy_dev "struct cdev *dev"
|
|
.Ft void
|
|
.Fn destroy_dev_sched "struct cdev *dev"
|
|
.Ft void
|
|
.Fn destroy_dev_sched_cb "struct cdev *dev" "void (*cb)(void *)" "void *arg"
|
|
.Ft void
|
|
.Fn destroy_dev_drain "struct cdevsw *csw"
|
|
.Ft void
|
|
.Fn dev_depends "struct cdev *pdev" "struct cdev *cdev"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn make_dev_credf
|
|
function creates a
|
|
.Fa cdev
|
|
structure for a new device.
|
|
It also notifies
|
|
.Xr devfs 5
|
|
of the presence of the new device, that causes corresponding nodes
|
|
to be created.
|
|
Besides this, a
|
|
.Xr devctl 4
|
|
notification is sent.
|
|
The device will be owned by
|
|
.Va uid ,
|
|
with the group ownership as
|
|
.Va gid .
|
|
The name is the expansion of
|
|
.Va fmt
|
|
and following arguments as
|
|
.Xr printf 9
|
|
would print it.
|
|
The name determines its path under
|
|
.Pa /dev
|
|
or other
|
|
.Xr devfs 5
|
|
mount point and may contain slash
|
|
.Ql /
|
|
characters to denote subdirectories.
|
|
The permissions of the file specified in
|
|
.Va perms
|
|
are defined in
|
|
.In sys/stat.h :
|
|
.Pp
|
|
.Bd -literal -offset indent -compact
|
|
#define S_IRWXU 0000700 /* RWX mask for owner */
|
|
#define S_IRUSR 0000400 /* R for owner */
|
|
#define S_IWUSR 0000200 /* W for owner */
|
|
#define S_IXUSR 0000100 /* X for owner */
|
|
|
|
#define S_IRWXG 0000070 /* RWX mask for group */
|
|
#define S_IRGRP 0000040 /* R for group */
|
|
#define S_IWGRP 0000020 /* W for group */
|
|
#define S_IXGRP 0000010 /* X for group */
|
|
|
|
#define S_IRWXO 0000007 /* RWX mask for other */
|
|
#define S_IROTH 0000004 /* R for other */
|
|
#define S_IWOTH 0000002 /* W for other */
|
|
#define S_IXOTH 0000001 /* X for other */
|
|
|
|
#define S_ISUID 0004000 /* set user id on execution */
|
|
#define S_ISGID 0002000 /* set group id on execution */
|
|
#define S_ISVTX 0001000 /* sticky bit */
|
|
#ifndef _POSIX_SOURCE
|
|
#define S_ISTXT 0001000
|
|
#endif
|
|
.Ed
|
|
.Pp
|
|
The
|
|
.Va cr
|
|
argument specifies credentials that will be stored in the
|
|
.Fa si_cred
|
|
member of the initialized
|
|
.Fa struct cdev .
|
|
The
|
|
.Va flags
|
|
argument alters the operation of
|
|
.Fn make_dev_credf
|
|
or
|
|
.Fn make_dev_p .
|
|
The following values are currently accepted:
|
|
.Pp
|
|
.Bl -tag -width "MAKEDEV_CHECKNAME" -compact -offset indent
|
|
.It MAKEDEV_REF
|
|
reference the created device
|
|
.It MAKEDEV_NOWAIT
|
|
do not sleep, the call may fail
|
|
.It MAKEDEV_WAITOK
|
|
allow the function to sleep to satisfy malloc
|
|
.It MAKEDEV_ETERNAL
|
|
created device will be never destroyed
|
|
.It MAKEDEV_CHECKNAME
|
|
return an error if the device name is invalid or already exists
|
|
.El
|
|
.Pp
|
|
Only
|
|
.Dv MAKEDEV_NOWAIT ,
|
|
.Dv MAKEDEV_WAITOK
|
|
and
|
|
.Dv MAKEDEV_CHECKNAME
|
|
values are accepted for the
|
|
.Fn make_dev_alias_p
|
|
function.
|
|
.Pp
|
|
The
|
|
.Dv MAKEDEV_WAITOK
|
|
flag is assumed if none of
|
|
.Dv MAKEDEV_WAITOK ,
|
|
.Dv MAKEDEV_NOWAIT
|
|
is specified.
|
|
.Pp
|
|
The
|
|
.Xr dev_clone 9
|
|
event handler shall specify
|
|
.Dv MAKEDEV_REF
|
|
flag when creating a device in response to lookup, to avoid race where
|
|
the device created is destroyed immediately after
|
|
.Xr devfs_lookup 9
|
|
drops his reference to cdev.
|
|
.Pp
|
|
The
|
|
.Dv MAKEDEV_ETERNAL
|
|
flag allows the kernel to not acquire some locks when translating system
|
|
calls into the cdevsw methods calls.
|
|
It is responsibility of the driver author to make sure that
|
|
.Fn destroy_dev
|
|
is never called on the returned cdev.
|
|
For the convenience, use the
|
|
.Dv MAKEDEV_ETERNAL_KLD
|
|
flag for the code that can be compiled into kernel or loaded
|
|
(and unloaded) as loadable module.
|
|
.Pp
|
|
A panic will occur if the MAKEDEV_CHECKNAME flag is not specified
|
|
and the device name is invalid or already exists.
|
|
.Pp
|
|
The
|
|
.Fn make_dev_cred
|
|
function is equivalent to the call
|
|
.Bd -literal -offset indent
|
|
make_dev_credf(0, cdevsw, unit, cr, uid, gid, perms, fmt, ...);
|
|
.Ed
|
|
.Pp
|
|
The
|
|
.Fn make_dev
|
|
function call is the same as
|
|
.Bd -literal -offset indent
|
|
make_dev_credf(0, cdevsw, unit, NULL, uid, gid, perms, fmt, ...);
|
|
.Ed
|
|
.Pp
|
|
The
|
|
.Fn make_dev_p
|
|
function is similar to
|
|
.Fn make_dev_credf
|
|
but it may return an error number and takes a pointer to the resulting
|
|
.Ft *cdev
|
|
as an argument.
|
|
.Pp
|
|
The
|
|
.Fn make_dev_alias
|
|
function takes the returned
|
|
.Ft cdev
|
|
from
|
|
.Fn make_dev
|
|
and makes another (aliased) name for this device.
|
|
It is an error to call
|
|
.Fn make_dev_alias
|
|
prior to calling
|
|
.Fn make_dev .
|
|
.Pp
|
|
.Fn make_dev_alias_p
|
|
function is similar to
|
|
.Fn make_dev_alias
|
|
but it takes a pointer to the resulting
|
|
.Ft *cdev
|
|
as an argument and may return an error.
|
|
.Pp
|
|
The
|
|
.Fa cdev
|
|
returned by
|
|
.Fn make_dev
|
|
and
|
|
.Fn make_dev_alias
|
|
has two fields,
|
|
.Fa si_drv1
|
|
and
|
|
.Fa si_drv2 ,
|
|
that are available to store state.
|
|
Both fields are of type
|
|
.Ft void * .
|
|
These are designed to replace the
|
|
.Fa unit
|
|
argument to
|
|
.Fn make_dev ,
|
|
which can be obtained with
|
|
.Fn dev2unit .
|
|
.Pp
|
|
The
|
|
.Fn destroy_dev
|
|
function takes the returned
|
|
.Fa cdev
|
|
from
|
|
.Fn make_dev
|
|
and destroys the registration for that device.
|
|
The notification is sent to
|
|
.Xr devctl 4
|
|
about the destruction event.
|
|
Do not call
|
|
.Fn destroy_dev
|
|
on devices that were created with
|
|
.Fn make_dev_alias .
|
|
.Pp
|
|
The
|
|
.Fn dev_depends
|
|
function establishes a parent-child relationship between two devices.
|
|
The net effect is that a
|
|
.Fn destroy_dev
|
|
of the parent device will also result in the destruction of the
|
|
child device(s),
|
|
if any exist.
|
|
A device may simultaneously be a parent and a child,
|
|
so it is possible to build a complete hierarchy.
|
|
.Pp
|
|
The
|
|
.Fn destroy_dev_sched_cb
|
|
function schedules execution of the
|
|
.Fn destroy_dev
|
|
for the specified
|
|
.Fa cdev
|
|
in the safe context.
|
|
After
|
|
.Fn destroy_dev
|
|
is finished, and if the supplied
|
|
.Fa cb
|
|
is not
|
|
.Dv NULL ,
|
|
the callback
|
|
.Fa cb
|
|
is called, with argument
|
|
.Fa arg .
|
|
The
|
|
.Fn destroy_dev_sched
|
|
function is the same as
|
|
.Bd -literal -offset indent
|
|
destroy_dev_sched_cb(cdev, NULL, NULL);
|
|
.Ed
|
|
.Pp
|
|
The
|
|
.Fn d_close
|
|
driver method cannot call
|
|
.Fn destroy_dev
|
|
directly.
|
|
Doing so causes deadlock when
|
|
.Fn destroy_dev
|
|
waits for all threads to leave the driver methods.
|
|
Also, because
|
|
.Fn destroy_dev
|
|
sleeps, no non-sleepable locks may be held over the call.
|
|
The
|
|
.Fn destroy_dev_sched
|
|
family of functions overcome these issues.
|
|
.Pp
|
|
The device driver may call the
|
|
.Fn destroy_dev_drain
|
|
function to wait until all devices that have supplied
|
|
.Fa csw
|
|
as cdevsw, are destroyed.
|
|
This is useful when driver knows that
|
|
.Fn destroy_dev_sched
|
|
is called for all instantiated devices, but need to postpone module
|
|
unload until
|
|
.Fn destroy_dev
|
|
is actually finished for all of them.
|
|
.Sh RETURN VALUES
|
|
If successful,
|
|
.Fn make_dev_p
|
|
will return 0, otherwise it will return an error.
|
|
If successful,
|
|
.Fn make_dev_credf
|
|
will return a valid
|
|
.Fa cdev
|
|
pointer, otherwise it will return
|
|
.Dv NULL .
|
|
.Sh ERRORS
|
|
The
|
|
.Fn make_dev_p
|
|
and
|
|
.Fn make_dev_alias_p
|
|
call will fail and the device will be not registered if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er ENOMEM
|
|
The
|
|
.Dv MAKEDEV_NOWAIT
|
|
flag was specified and a memory allocation request could not be satisfied.
|
|
.It Bq Er ENAMETOOLONG
|
|
The
|
|
.Dv MAKEDEV_CHECKNAME
|
|
flag was specified and the provided device name is longer than
|
|
.Dv SPECNAMELEN .
|
|
.It Bq Er EINVAL
|
|
The
|
|
.Dv MAKEDEV_CHECKNAME
|
|
flag was specified and the provided device name is empty, contains a
|
|
.Qq \&.
|
|
or
|
|
.Qq ..
|
|
path component or ends with
|
|
.Ql / .
|
|
.It Bq Er EINVAL
|
|
The
|
|
.Dv MAKEDEV_CHECKNAME
|
|
flag was specified and the provided device name contains invalid characters.
|
|
.It Bq Er EEXIST
|
|
The
|
|
.Dv MAKEDEV_CHECKNAME
|
|
flag was specified and the provided device name already exists.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr devctl 4 ,
|
|
.Xr devfs 5 ,
|
|
.Xr destroy_dev_drain 9 ,
|
|
.Xr dev_clone 9
|
|
.Sh HISTORY
|
|
The
|
|
.Fn make_dev
|
|
and
|
|
.Fn destroy_dev
|
|
functions first appeared in
|
|
.Fx 4.0 .
|
|
The function
|
|
.Fn make_dev_alias
|
|
first appeared in
|
|
.Fx 4.1 .
|
|
The function
|
|
.Fn dev_depends
|
|
first appeared in
|
|
.Fx 5.0 .
|
|
The functions
|
|
.Fn make_dev_credf ,
|
|
.Fn destroy_dev_sched ,
|
|
.Fn destroy_dev_sched_cb
|
|
first appeared in
|
|
.Fx 7.0 .
|
|
The function
|
|
.Fn make_dev_p
|
|
first appeared in
|
|
.Fx 8.2 .
|