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Document a few kernel functions and the sysctl tunables that

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affect their behaviour.
This commit is contained in:
jkoshy 2003-12-11 13:29:05 +00:00
parent eaf40818a9
commit 616805ba21
5 changed files with 357 additions and 1 deletions
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4
share/man/man9/Makefile
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@ -29,6 +29,7 @@ MAN= BUF_LOCK.9 BUF_LOCKFREE.9 BUF_LOCKINIT.9 BUF_REFCNT.9 \
bus_set_resource.9 \
byteorder.9 \
cd.9 cdevsw_add.9 cdevsw_remove.9 condvar.9 copy.9 \
cr_seeothergids.9 cr_seeotheruids.9 \
critical_enter.9 crypto.9 \
devclass.9 devclass_add_driver.9 devclass_find.9 \
devclass_get_device.9 devclass_get_devices.9 \
@ -59,7 +60,7 @@ MAN= BUF_LOCK.9 BUF_LOCKFREE.9 BUF_LOCKINIT.9 BUF_REFCNT.9 \
mi_switch.9 microseq.9 microtime.9 microuptime.9 \
module.9 mtx_pool.9 mutex.9 \
namei.9 \
panic.9 pbuf.9 pci.9 pfil.9 pfind.9 pgfind.9 \
p_candebug.9 panic.9 pbuf.9 pci.9 pfil.9 pfind.9 pgfind.9 \
physio.9 printf.9 pseudofs.9 psignal.9 \
pmap.9 pmap_activate.9 pmap_addr_hint.9 pmap_change_wiring.9 \
pmap_clear_modify.9 pmap_copy.9 pmap_enter.9 pmap_extract.9 \
@ -68,6 +69,7 @@ MAN= BUF_LOCK.9 BUF_LOCKFREE.9 BUF_LOCKINIT.9 BUF_REFCNT.9 \
pmap_mincore.9 pmap_object_init_pt.9 pmap_page_exists_quick.9 \
pmap_page_protect.9 pmap_pinit.9 pmap_qenter.9 \
pmap_release.9 pmap_remove.9 pmap_resident_count.9 pmap_zero_page.9 \
prison_check.9 \
random.9 resettodr.9 resource_int_value.9 \
rtalloc.9 rtentry.9 runqueue.9 random_harvest.9 rijndael.9 \
rman.9 \

81
share/man/man9/cr_seeothergids.9 Normal file
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@ -0,0 +1,81 @@
.\"
.\" Copyright (c) 2003 Joseph Koshy <jkoshy@freebsd.org>
.\"
.\" All rights reserved.
.\"
.\" This program is free software.
.\"
.\" 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 DEVELOPERS ``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 DEVELOPERS 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 November 11, 2003
.Os
.Dt cr_seeothergids 9
.Sh NAME
.Nm cr_seeothergids
.Nd determine visibility of objects given their group memberships
.Sh SYNOPSIS
.Ft int
.Fn cr_seeothergids "struct ucred *u1" "struct ucred *u2"
.Sh DESCRIPTION
This function determines the visibility of objects in the
kernel based on the group ids in the credentials
.Fa u1
and
.Fa u2
associated with them.
.Pp
The visibility of objects is influenced by the
.Xr sysctl 8
tunable
.Va security.bsd.see_other_gids .
If this tunable is non-zero, then all objects in the kernel
are visible to each othe irrespective of their group membership.
If this tunable is zero, then the object with credentials
.Fa u2
is visible to the object with credentials
.Fa u1
if either
.Fa u1
is the super-user credential, or if at least one of
.Fa u1 Ns 's
group ids is present in
.Fa u2 Ns 's
group set.
.Sh SYSCTL TUNABLES
.Bl -tag -width indent
.It Va security.bsd.see_other_gids
must be non-zero if objects with unprivileged credentials are to be
able to see each other.
.El
.Sh RETURN VALUES
Ths function returns zero if the object with credential
.Fa u1
can
.Dq see
the object with credential
.Fa u2 ,
or
.Er ESRCH
otherwise.
.Sh SEE ALSO
.Xr cr_seeotheruids 9 ,
.Xr p_candebug 9

81
share/man/man9/cr_seeotheruids.9 Normal file
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@ -0,0 +1,81 @@
.\"
.\" Copyright (c) 2003 Joseph Koshy <jkoshy@freebsd.org>
.\"
.\" All rights reserved.
.\"
.\" This program is free software.
.\"
.\" 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 DEVELOPERS ``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 DEVELOPERS 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 November 11, 2003
.Os
.Dt cr_seeotheruids 9
.Sh NAME
.Nm cr_seeotheruids
.Nd determine visibility of objects given their user credentials
.Sh SYNOPSIS
.Ft int
.Fn cr_seeotheruids "struct ucred *u1" "struct ucred *u2"
.Sh DESCRIPTION
This function determines the visibility of objects in the
kernel based on the real user ids in the credentials
.Fa u1
and
.Fa u2
associated with them.
.Pp
The visibility of objects is influenced by the
.Xr sysctl 8
tunable
.Va security.bsd.see_other_uids .
If this tunable is non-zero, then all objects in the kernel
are visible to each other irrespective of their user ids.
If this tunable is zero, then the object with credentials
.Fa u2
is visible to the object with credentials
.Fa u1
if either
.Fa u1
is the super-user credential, or if
.Fa u1
and
.Fa u2
have the same real user id.
.Sh SYSCTL TUNABLES
.Bl -tag -width indent
.It Va security.bsd.see_other_uids
must be non-zero if objects with unprivileged credentials are to be
able to see each other.
.El
.Sh RETURN VALUES
Ths function returns zero if the object with credential
.Fa u1
can
.Dq see
the object with credential
.Fa u2 ,
or
.Er ESRCH
otherwise.
.Sh SEE ALSO
.Xr cr_seeothergids 9 ,
.Xr p_candebug 9

132
share/man/man9/p_candebug.9 Normal file
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.\"
.\" Copyright (c) 2003 Joseph Koshy <jkoshy@freebsd.org>
.\"
.\" All rights reserved.
.\"
.\" This program is free software.
.\"
.\" 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 DEVELOPERS ``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 DEVELOPERS 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 November 11, 2003
.Os
.Dt p_candebug 9
.Sh NAME
.Nm p_candebug
.Nd determine debuggability of a process
.Sh SYNOPSIS
.In sys/proc.h
.Ft int
.Fn p_candebug "struct thread *td" "struct proc *p"
.Sh DESCRIPTION
This function can be used to determine if a given process
.Fa p
is debuggable by the thread
.Fa td .
.Sh SYSCTL TUNABLES
The following
.Xr sysctl 8
tunables directly influence the behaviour of
.Fn p_candebug :
.Bl -tag -width indent
.It Va kern.securelevel
debugging of the init process is not allowed if this tunable is
.Li 1
or greater.
.It Va security.bsd.unprivileged_proc_debug
must be set to a non-zero value to allow unprivileged processes
access to the kernel's debug facilities.
.El
.Sh RETURN VALUES
.Fn p_candebug
returns
.Li 0
if the process denoted by
.Ar p
is debuggable by thread
.Ar td ,
or a non-zero error return value otherwise.
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EACCESS
The MAC subsystem denied debuggability.
.It Bq Er EAGAIN
Process
.Fa p
is in the process of being
.Fn exec Ns 'ed.
.It Bq Er EPERM
Thread
.Fa td
lacks super-user credentials and process
.Fa p
is executing a set-user-id or set-group-id executable.
.It Bq Er EPERM
Thread
.Fa td
lacks super-user credentials and process
.Fa p Ns 's
group set is not a subset of
.Fa td Ns 's
effective group set.
.It Bq Er EPERM
Thread
.Fa td
lacks super-user credentials and process
.Fa p Ns 's
user ids do not match thread
.Fa td Ns 's
effective user id.
.It Bq Er EPERM
Process
.Fa p
denotes the initial process
.Fn initproc
and the sysctl tunable
.Va kern.securelevel
is greater than zero.
.It Bq Er ESRCH
Process
.Fa p
is not visible to thread
.Fa td
as determined by
.Xr cr_seeotheruids 9
or
.Xr cr_seeothergids 9 .
.It Bq Er ESRCH
Thread
.Fa td
has been jailed and process
.Fa p
does not belong to the same jail as
.Fa td .
.It Bq Er ESRCH
The MAC subsystem denied debuggability.
.El
.Sh SEE ALSO
.Xr intro 2 ,
.Xr jail 2 ,
.Xr sysctl 8 ,
.Xr cr_seeotheruids 9 ,
.Xr cr_seeothergids 9 ,
.Xr mac 9 ,
.Xr prison_check 9

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share/man/man9/prison_check.9 Normal file
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.\"
.\" Copyright (c) 2003 Joseph Koshy <jkoshy@freebsd.org>
.\"
.\" All rights reserved.
.\"
.\" This program is free software.
.\"
.\" 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 DEVELOPERS ``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 DEVELOPERS 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 December 11, 2003
.Os
.Dt prison_check 9
.Sh NAME
.Nm prison_check
.Nd determine if two credentials belong to the same jail
.Sh SYNOPSIS
.In sys/jail.h
.Ft int
.Fn prison_check "struct ucred *cred1" "struct ucred *cred2"
.Sh DESCRIPTION
This function can be used to determine if the two credentials
.Fa cred1
and
.Fa cred2
belong to the same jail.
.Sh RETURN VALUES
.Fn prison_check
returns
.Er ESRCH
if
.Fa cred1
has been jailed, and
.Fa cred1
and
.Fa cred2
do not belong to the same jail.
In all other cases,
.Fn prison_check
returns zero.
.Sh SEE ALSO
.Xr jail 2