Reviewed by:		markj
Differential revision:	https://reviews.freebsd.org/D35153
MFC after:		2 weeks

Reviewed by:		jhb
Differential revision:	https://reviews.freebsd.org/D35216
MFC after:		2 weeks

Reviewed by:		jhb
Differential revision:	https://reviews.freebsd.org/D35356
MFC after:		2 weeks

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96

by /etc/rc.d/jail.

license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson

pointer instead of a proc pointer and require the process pointed to
by the second argument to be locked.  We now use the thread ucred reference
for the credential checks in p_can*() as a result.  p_canfoo() should now
no longer need Giant.

which are sometimes used by the macros in <sys/mutex.h>; don't depend
on not-quite-necessary namespace pollution in <sys/mutex.h>.

Until now, the ptrace syscall was implemented as a wrapper that called
various functions in procfs depending on which ptrace operation was
requested.  Most of these functions were themselves wrappers around
procfs_{read,write}_{,db,fp}regs(), with only some extra error checks,
which weren't necessary in the ptrace case anyway.

This commit moves procfs_rwmem() from procfs_mem.c into sys_process.c
(renaming it to proc_rwmem() in the process), and implements ptrace()
directly in terms of procfs_{read,write}_{,db,fp}regs() instead of
having it fake up a struct uio and then call procfs_do{,db,fp}regs().

It also moves the prototypes for procfs_{read,write}_{,db,fp}regs()
and proc_rwmem() from proc.h to ptrace.h, and marks all procfs files
except procfs_machdep.c as "optional procfs" instead of "standard".

and so special-casing was introduced to provide extra procfs privilege
to the kmem group.  With the advent of non-setgid kmem ps, this code
is no longer required, and in fact, can is potentially harmful as it
allocates privilege to a gid that is increasingly less meaningful.
Knowledge of specific gid's in kernel is also generally bad precedent,
as the kernel security policy doesn't distinguish gid's specifically,
only uid 0.

This commit removes reference to kmem in procfs, both in terms of
access control decisions, and the applying of gid kmem to the
/proc/*/mem file, simplifying the associated code considerably.
Processes are still permitted to access the mem file based on
the debugging policy, so ps -e still works fine for normal
processes and use.

Reviewed by:	tmm
Obtained from:	TrustedBSD Project

  The p_can(...) construct was a premature (and, it turns out,
  awkward) abstraction.  The individual calls to p_canxxx() better
  reflect differences between the inter-process authorization checks,
  such as differing checks based on the type of signal.  This has
  a side effect of improving code readability.
o Replace direct credential authorization checks in ktrace() with
  invocation of p_candebug(), while maintaining the special case
  check of KTR_ROOT.  This allows ktrace() to "play more nicely"
  with new mandatory access control schemes, as well as making its
  authorization checks consistent with other "debugging class"
  checks.
o Eliminate "privused" construct for p_can*() calls which allowed the
  caller to determine if privilege was required for successful
  evaluation of the access control check.  This primitive is currently
  unused, and as such, serves only to complicate the API.

Approved by:	({procfs,linprocfs} changes) des
Obtained from:	TrustedBSD Project

(this commit is just the first stage).  Also add various GIANT_ macros to
formalize the removal of Giant, making it easy to test in a more piecemeal
fashion. These macros will allow us to test fine-grained locks to a degree
before removing Giant, and also after, and to remove Giant in a piecemeal
fashion via sysctl's on those subsystems which the authors believe can
operate without Giant.

  systems were repo-copied from sys/miscfs to sys/fs.

- Renamed the following file systems and their modules:
  fdesc -> fdescfs, portal -> portalfs, union -> unionfs.

- Renamed corresponding kernel options:
  FDESC -> FDESCFS, PORTAL -> PORTALFS, UNION -> UNIONFS.

- Install header files for the above file systems.

- Removed bogus -I${.CURDIR}/../../sys CFLAGS from userland
  Makefiles.

vm_mtx does not recurse and is required for most low level
vm operations.

faults can not be taken without holding Giant.

Memory subsystems can now call the base page allocators safely.

Almost all atomic ops were removed as they are covered under the
vm mutex.

Alpha and ia64 now need to catch up to i386's trap handlers.

FFS and NFS have been tested, other filesystems will need minor
changes (grabbing the vm lock when twiddling page properties).

Reviewed (partially) by: jake, jhb

other "system" header files.

Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.

Sort sys/*.h includes where possible in affected files.

OK'ed by:	bde (with reservations)

    int p_can(p1, p2, operation, privused)

  which allows specification of subject process, object process,
  inter-process operation, and an optional call-by-reference privused
  flag, allowing the caller to determine if privilege was required
  for the call to succeed.  This allows jail, kern.ps_showallprocs and
  regular credential-based interaction checks to occur in one block of
  code.  Possible operations are P_CAN_SEE, P_CAN_SCHED, P_CAN_KILL,
  and P_CAN_DEBUG.  p_can currently breaks out as a wrapper to a
  series of static function checks in kern_prot, which should not
  be invoked directly.

o Commented out capabilities entries are included for some checks.

o Update most inter-process authorization to make use of p_can() instead
  of manual checks, PRISON_CHECK(), P_TRESPASS(), and
  kern.ps_showallprocs.

o Modify suser{,_xxx} to use const arguments, as it no longer modifies
  process flags due to the disabling of ASU.

o Modify some checks/errors in procfs so that ENOENT is returned instead
  of ESRCH, further improving concealment of processes that should not
  be visible to other processes.  Also introduce new access checks to
  improve hiding of processes for procfs_lookup(), procfs_getattr(),
  procfs_readdir().  Correct a bug reported by bp concerning not
  handling the CREATE case in procfs_lookup().  Remove volatile flag in
  procfs that caused apparently spurious qualifier warnigns (approved by
  bde).

o Add comment noting that ktrace() has not been updated, as its access
  control checks are different from ptrace(), whereas they should
  probably be the same.  Further discussion should happen on this topic.

Reviewed by:	bde, green, phk, freebsd-security, others
Approved by:	bde
Obtained from:	TrustedBSD Project

maps onto the upages.  We used to use this extensively, particularly
for ps and gdb.  Both of these have been "fixed".  ps gets the p_stats
via eproc along with all the other stats, and gdb uses the regs, fpregs
etc files.

Once apon a time the UPAGES were mapped here, but that changed back
in January '96.  This essentially kills my revisions 1.16 and 1.17.
The 2-page "hole" above the stack can be reclaimed now.

Obtained from:	http://bogon.freebsd.dk/include

        p_trespass(struct proc *p1, struct proc *p2)
which returns zero or an errno depending on the legality of p1 trespassing
on p2.

Replace kern_sig.c:CANSIGNAL() with call to p_trespass() and one
extra signal related check.

Replace procfs.h:CHECKIO() macros with calls to p_trespass().

Only show command lines to process which can trespass on the target
process.

should be "VM_FAULT_NORMAL".

file object.  Also explain some possible directions to re-implement it --
I'm not sure it should be, given the minimal application use.  (Other
than having the debugger automatically access the symbols for a process,
the main use I'd found was with some minor accounting ability, but _that_
depends on it being in the filesystem space; an ioctl access method would
be useless in that case.)

This is a code-less change; only a comment has been added.

Merge the contents (less some trivial bordering the silly comments)
of <vm/vm_prot.h> and <vm/vm_inherit.h> into <vm/vm.h>.  This puts
the #defines for the vm_inherit_t and vm_prot_t types next to their
typedefs.

This paves the road for the commit to follow shortly: change
useracc() to use VM_PROT_{READ|WRITE} rather than B_{READ|WRITE}
as argument.

1:
  s/suser/suser_xxx/

2:
  Add new function: suser(struct proc *), prototyped in <sys/proc.h>.

3:
  s/suser_xxx(\([a-zA-Z0-9_]*\)->p_ucred, \&\1->p_acflag)/suser(\1)/

The remaining suser_xxx() calls will be scrutinized and dealt with
later.

There may be some unneeded #include <sys/cred.h>, but they are left
as an exercise for Bruce.

More changes to the suser() API will come along with the "jail" code.

the caller can select either inactive or active queue to put the page on.

respectively.  Most of the longs should probably have been
u_longs, but this changes is just to prevent warnings about
casts between pointers and integers of different sizes, not
to fix poorly chosen types.

FreeBSD/alpha.  The most significant item is to change the command
argument to ioctl functions from int to u_long.  This change brings us
inline with various other BSD versions.  Driver writers may like to
use (__FreeBSD_version == 300003) to detect this change.

The prototype FreeBSD/alpha machdep will follow in a couple of days
time.

the current registers should be accessible.
Reviewed by:	David Greenman <dg@root.com>

1)	Start using TSM.
	Struct procs continue to point to upages structure, after being freed.
	Struct vmspace continues to point to pte object and kva space for kstack.
	u_map is now superfluous.
2)	vm_map's don't need to be reference counted.  They always exist either
	in the kernel or in a vmspace.  The vmspaces are managed by reference
	counts.
3)	Remove the "wired" vm_map nonsense.
4)	No need to keep a cache of kernel stack kva's.
5)	Get rid of strange looking ++var, and change to var++.
6)	Change more data structures to use our "zone" allocator.  Added
	struct proc, struct vmspace and struct vnode.  This saves a significant
	amount of kva space and physical memory.  Additionally, this enables
	TSM for the zone managed memory.
7)	Keep ioopt disabled for now.
8)	Remove the now bogus "single use" map concept.
9)	Use generation counts or id's for data structures residing in TSM, where
	it allows us to avoid unneeded restart overhead during traversals, where
	blocking might occur.
10)	Account better for memory deficits, so the pageout daemon will be able
	to make enough memory available (experimental.)
11)	Fix some vnode locking problems. (From Tor, I think.)
12)	Add a check in ufs_lookup, to avoid lots of unneeded calls to bcmp.
	(experimental.)
13)	Significantly shrink, cleanup, and make slightly faster the vm_fault.c
	code.  Use generation counts, get rid of unneded collpase operations,
	and clean up the cluster code.
14)	Make vm_zone more suitable for TSM.

This commit is partially as a result of discussions and contributions from
other people, including DG, Tor Egge, PHK, and probably others that I
have forgotten to attribute (so let me know, if I forgot.)

This is not the infamous, final cleanup of the vnode stuff, but a necessary
step.  Vnode mgmt should be correct, but things might still change, and
there is still some missing stuff (like ioopt, and physical backing of
non-merged cache files, debugging of layering concepts.)