Reduce reliance on sys/sysproto.h pollution

Add sys/errno.h, sys/malloc.h, sys/queue.h, and vm/uma.h as needed.

sys/sysproto.h currently includes sys/acl.h which currently includes
sys/param.h, sys/queue.h, and vm/uma.h which in turn bring in
sys/errno.h sys/malloc.h.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D44465

sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

sysctl: Update 'master' copy of vnet SYSCTLs on kernel environment variables change

Complete phase three of 3da1cf1e88f8.

With commit 110113bc086f, vnet sysctl variables can be loader tunable
but the feature is limited. When the kernel modules have been initialized,
any changes (e.g. via kenv) to kernel environment variable will not affect
subsequently created VNETs.

This change relexes the limitation by listening on kernel environment
variable's set / unset events, and then update the 'master' copy of vnet
SYSCTL or restore it to its initial value.

With this change, TUNABLE_XXX_FETCH can be greately eliminated for vnet
loader tunables.

Reviewed by: glebius
Fixes: 110113bc086f sysctl(9): Enable vnet sysctl variables to be loader tunable
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D41825

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

kern_environment: Partially apply style(9)

Sort include files, remove duplicates and remove trailing whitespce.

Pull Request: https://github.com/freebsd/freebsd-src/pull/589
Reviewed by: imp

kern: Support duplicate variables in early kenv

Some virtual machines pass virtio MMIO device parameters via the kernel
command line as a series of virtio_mmio.device=<parameters> options.
These get translated into FreeBSD kernel environment variables; but
unfortunately they all use the same variable name, which resulted in
all but the first such parameter being ignored when the dynamic kernel
environment is set up from the initial environment buffers.

With this commit, duplicate environment settings will instead be stored
as ${name}_1, ${name}_2... ${name}_9999. In the unlikely event that
the same variable is set over 10000 times before the dynamic kernel
environment is set up, we panic.

Variable settings after the dynamic environment is initialized continue
to override the previously-set value; the change is limited to the very
early kernel boot (prior to SI_SUB_KMEM + 1) and changes behaviour from
"ignore" to "store with a different name" only.

Reviewed by: imp
Feedback from: kevans
Sponsored by: https://patreon.com/cperciva
Differential Revision: https://reviews.freebsd.org/D36187

sysent: Get rid of bogus sys/sysent.h include.

Where appropriate hide sysent.h under proper condition.

MFC after: 2 weeks

kenv: allow listing of static kernel environments

The early environment is typically cleared, so these new options
need the PRESERVE_EARLY_KENV kernel config(8) option. These environments
are reported as missing by kenv(1) if the option is not present in the
running kernel.

Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D30835

kern: add an option for preserving the early kenv

Some downstream configurations do not store secrets in the
early (loader/static) environments and desire a way to preserve these
for diagnostic reasons. Provide an option to do so.

Reviewed by: imp, jhb (earlier version)
Differential Revision: https://reviews.freebsd.org/D30834

Move kernel env global variables, etc to sys/kenv.h

The kernel globals for kenv are confined to 2 files that need them and
a few that likely shouldn't (but as written the code does). Move them
from sys/systm.h to sys/kenv.h. This removed a XXX from systm.h and
cleans it up a little bit...

Use getenv_is_true() in init_static_kenv()

A small example of how these functions can be used to simplify checks of
this nature.

Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26271

Add getenv(9) boolean parsing functions

This adds the getenv_bool() function, to parse a boolean value from a
kernel environment variable or tunable. This works for traditional
boolean values like "0" and "1", and also "true" and "false"
(case-insensitive). These semantics do not yet apply to sysctls declared
using SYSCTL_BOOL with CTLFLAG_TUN (they still only parse 1 and 0).

Also added are two wrapper functions, getenv_is_true() and
getenv_is_false(). These are slightly simpler for callers wishing to
perform a single check of a configuration variable.

Reviewed by: jhb (slightly earlier version)
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26270

kern: clean up empty lines in .c and .h files

kenv: avoid sleepable alloc for integer tunables

Avoid performing a potentially-blocking malloc for kenv lookups that will only
perform non-destructive integer conversions on the returned buffer. Instead,
perform the strtoq() in-place with the kenv lock held.

While here, factor the logic around kenv_lock acquire and release into
kenv_acquire() and kenv_release(), and use these functions for some light
cleanup. Collapse getenv_string_buffer() into kern_getenv(), as the former
no longer has any other callers and the only additional task performed by
the latter is a WITNESS check that hasn't been useful since r362231.

PR: 248250
Reported by: gbe
Reviewed by: mjg
Tested by: gbe
Differential Revision: https://reviews.freebsd.org/D26010

Use zfree() instead of explicit_bzero() and free().

In addition to reducing lines of code, this also ensures that the full
allocation is always zeroed avoiding possible bugs with incorrect
lengths passed to explicit_bzero().

Suggested by: cem
Reviewed by: cem, delphij
Approved by: csprng (cem)
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D25435

Make KENV_MVALLEN tunable

When doing secure boot, loader wants to export loader.ve.hashed
the value of which typically exceeds KENV_MVALLEN.

Replace use of KENV_MVALLEN with tunable kenv_mvallen.

Add getenv_string_buffer() for the case where a stack buffer cannot be
created and use uma_zone_t kenv_zone for suitably sized buffers.

Reviewed by: stevek, kevans
Obtained from: Abhishek Kulkarni <abkulkarni@juniper.net>
MFC after: 1 week
Sponsored by: Juniper Networks
Differential Revision: https://reviews.freebsd.org//D25259

Follow up r352244: kenv: tighten up assertions

As I like to forget: static kenv var formatting is actually such that an
empty environment would be double null bytes. We should make sure that a
non-zero buffer has at least enough for this, though most of the current
usage is with a 4k buffer.

kenv: assert that an empty static buffer passed in is "empty"

Garbage in the passed-in buffer can cause problems if any attempts to read
the kenv are inadvertently made between init_static_kenv and the first
kern_setenv -- assuming there is one.

This is cheap and easy, so do it. This also helps rule out some class of
bugs as one tries to debug; tunables fetch from the static environment up
until SI_SUB_KMEM + 1, and many of these buffers are global ~4k buffers that
rely on BSS clearing while others just grab a page of free memory and use it
(e.g. xen).

Fix zapping of static hints and env in init_static_kenv(). Environments
are terminated by 2 NULs, but only 1 NUL was zapped. Zapping only 1
NUL just splits the first string into an empty string and a corrupted
string. All other strings in static hints and env remained live early
in the boot when they were supposed to be disabled.

Support calling init_static_kenv() very early in the boot, so as to
use the env very early in the boot. Then the pointer to the loader
env may change after the first call due to enabling paging or otherwise
remapping the pointer. Another call is needed to register the change.
Don't use the previous pointer in this (or any) later call.

Reviewed by: kib

Add dynamic_kenv assertion to init_static_kenv

Both to formally document the requirement that this not be called after the
dynamic kenv is setup, and to perhaps help static analyzers figure out
what's going on. While calling init_static_kenv this late isn't fatal, there
are some caveats that the caller should be aware of:

- Late calls are effectively a no-op, as far as default FreeBSD is
concerned, as everything will switch to searching the dynamic kenv once it's
available.

- Each of the kern_getenv calls will leak memory, as it's assumed that
these are searching static environment and allocations will not be made.

As such, this usage is not sensible and should be detected.

Add FALLTHROUGH comments to appease Coverity.

CID: 1017862-1017864, 1017866-1017868
MFC after: 2 weeks

kern_environment: Give the static environment a chance to disable MD env

This variable has been given the name "loader_env.disabled" as it's the
primary way most people will have an MD environment. This restores the
previously-default behavior of ignoring the loader(8) environment, which may
be useful for vendor distributions or other scenarios where inheriting the
loader environment may be considered a security issue or potentially
breaking of a more locked-down environment.

As the change to config(5) indicates, disabling the loader environment
should not be a choice made lightly since it may provide ACPI hints and
other useful things that the system can rely on to boot.

An UPDATING entry has been added to mention an upgrade path for those that
may have relied on the previous behavior.

Discussed with: bde
Relnotes: yes (maybe)

kern_environment: bool'itize dynamic_kenv; fix small style(9) nit

kern_environment: Fix SYSINIT ordering

The dynamic environment was being initialized at SI_SUB_KMEM, SI_ORDER_ANY.
I added the hint-merging at SI_SUB_KMEM, SI_ORDER_ANY as well in r335998 -
this can only work by coincidence.

Re-do both to operate at SI_SUB_KMEM + 1, SI_ORDER_FIRST and SI_ORDER_SECOND
respectively to be safe. It's sufficiently obfuscated away as to when in
SU_SUB_KMEM malloc will be available, and the dynamic environment cannot be
relied upon there anyways since it's initialized at SI_ORDER_ANY.

Reported by: bde
Discussed with: bde
X-MFC-With: r335998

kern_environment: use any provided environments, evict hintmode/envmode

At the moment, hintmode and envmode are used to indicate whether static
hints or static env have been provided in the kernel config(5) and the
static versions are mutually exclusive with loader(8)-provided environment.
hintmode *can* be reconfigured later to pull from the dynamic environment,
thus taking advantage of the loader(8) or post-kmem environment setting.

This changeset fixes both problems at once to move us from a semi-confusing
state to a consistent state: if an environment file, hints file, or
loader(8) environment are provided, we use them in a well-known order of
precedence:

- loader(8) environment
- static environment
- static hints file

Once the dynamic environment is setup this becomes a moot point. The
loader(8) and static environments are merged (respecting the above order of
precedence), and the static hints are merged in on an as-needed basis after
the dynamic environment has been setup.

Hints lookup are changed to respect all of the above. Before the dynamic
environment is setup, lookups use the above-mentioned order and fallback to
the next environment if a matching hint is not found. Once the dynamic
environment is setup, that is used on its own since it captures all of the
above information plus any dynamic kenv settings that came up later in boot.

The following tangentially related changes were made to res_find:

- A hintp cookie is now passed in so that related searches continue using
the chain of environments (or dynamic environment) without relying on
global state
- All three environments will be searched if they actually have valid hints
to use, rather than just choosing the first environment that actually had
a hint and rolling with that only

The hintmode sysctl has been ripped out. static_{env,hints}.disabled are
still honored and will disable their respective environments from being used
for hint lookups and from being merged into the dynamic environment, as
expected.

MFC after: 1 month (maybe)
Differential Revision: https://reviews.freebsd.org/D15953

Revert r335995 due to accidental changes snuck in

kern_environment: use any provided environments, evict hintmode/envmode

At the moment, hintmode and envmode are used to indicate whether static
hints or static env have been provided in the kernel config(5) and the
static versions are mutually exclusive with loader(8)-provided environment.
hintmode *can* be reconfigured later to pull from the dynamic environment,
thus taking advantage of the loader(8) or post-kmem environment setting.

This changeset fixes both problems at once to move us from a semi-confusing
state to a consistent state: if an environment file, hints file, or
loader(8) environment are provided, we use them in a well-known order of
precedence:

- loader(8) environment
- static environment
- static hints file

Once the dynamic environment is setup this becomes a moot point. The
loader(8) and static environments are merged (respecting the above order of
precedence), and the static hints are merged in on an as-needed basis after
the dynamic environment has been setup.

Hints lookup are changed to respect all of the above. Before the dynamic
environment is setup, lookups use the above-mentioned order and fallback to
the next environment if a matching hint is not found. Once the dynamic
environment is setup, that is used on its own since it captures all of the
above information plus any dynamic kenv settings that came up later in boot.

The following tangentially related changes were made to res_find:

- A hintp cookie is now passed in so that related searches continue using
the chain of environments (or dynamic environment) without relying on
global state
- All three environments will be searched if they actually have valid hints
to use, rather than just choosing the first environment that actually had
a hint and rolling with that only

The hintmode sysctl has been ripped out. static_{env,hints}.disabled are
still honored and will disable their respective environments from being used
for hint lookups and from being merged into the dynamic environment, as
expected.

MFC after: 1 month (maybe)
Differential Revision: https://reviews.freebsd.org/D15953

Permit the kernel environment to set an array of numeric values for a single
sysctl(9) node.

Reviewed by: kib@, imp@, jhb@
Differential Revision: https://reviews.freebsd.org/D15802
MFC after: 1 week
Sponsored by: Mellanox Technologies

Use explicit_bzero() when cleaning values out of the kernel environment.

Sometimes the values contain geli passphrases being communicated from
loader(8) to the kernel, and some day the compiler may decide to start
eliding calls to memset() for a pointer which is not dereferenced again
before being passed to free().

sys/kern: adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

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.

Create wrappers for uint64_t and int64_t for the tunables. While not
strictly necessary, it is more convenient.

Allow a dynamic env to override a compiled-in static env by passing in the
override indication in the env data.

Submitted by: bde

Make the 'env' directive described in config(5) work on all architectures,
providing compiled-in static environment data that is used instead of any
data passed in from a boot loader.

Previously 'env' worked only on i386 and arm xscale systems, because it
required the MD startup code to examine the global envmode variable and
decide whether to use static_env or an environment obtained from the boot
loader, and set the global kern_envp accordingly. Most startup code wasn't
doing so. Making things even more complex, some mips startup code uses an
alternate scheme that involves calling init_static_kenv() to pass an empty
buffer and its size, then uses a series of kern_setenv() calls to populate
that buffer.

Now all MD startup code calls init_static_kenv(), and that routine provides
a single point where envmode is checked and the decision is made whether to
use the compiled-in static_kenv or the values provided by the MD code.

The routine also continues to serve its original purpose for mips; if a
non-zero buffer size is passed the routine installs the empty buffer ready
to accept kern_setenv() values. Now if the size is zero, the provided buffer
full of existing env data is installed. A NULL pointer can be passed if the
boot loader provides no env data; this allows the static env to be installed
if envmode is set to do so.

Most of the work here is a near-mechanical change to call the init function
instead of directly setting kern_envp. A notable exception is in xen/pv.c;
that code was originally installing a buffer full of preformatted env data
along with its non-zero size (like mips code does), which would have allowed
kern_setenv() calls to wipe out the preformatted data. Now it passes a zero
for the size so that the buffer of data it installs is treated as
non-writeable.

Test if 'env' is NULL before doing memset() and strlen(),
the caller may pass NULL to freeenv().

Avoid leaking data from the kernel environment: When we convert the
initial static environment to a dynamic one, zero the static environment
buffer, and zero individual values when kern_unsetenv and freeenv are
called.

Tested by: kmoore (VM memory dump + grep)
Tested by: cperciva (kernel panic dump + grep)

Follow up to r225617. In order to maximize the re-usability of kernel code
in userland rename in-kernel getenv()/setenv() to kern_setenv()/kern_getenv().
This fixes a namespace collision with libc symbols.

Submitted by: kmacy
Tested by: make universe

Make getenv_*() functions and respectively TUNABLE_*_FETCH() macros not
allocate memory and so not require sleepable environment. getenv() has
already used on-stack temporary storage, so just use it more rationally.
getenv_string() receives buffer as argument, so don't need another one.

r249408 and r249436 cause a NULL pointer dereference on the CUBIEBOARD
since it doesn't set the kernel envrionment at all. Work around this
by making sure kern_envp is non-NULL before dereferencing it.

Fix changes made in r249408.

In some cases, kern_envp is set by the architecture code and env_pos does
not contain the length of the static kernel environment. In these cases
r249408 causes the kernel to discard the environment.

Fix this by updating the check for empty static env to *kern_envp != '\0'

Reported by: np@

Fix kenv behavior when there is no static environment

In case where there are no static kernel environment entries, the
function init_dynamic_kenv() adds an incorrect entry at position 0 of
the dynamic kernel environment. This in turn causes kenv(1) to print
and empty list even though there are dynamic entries added later.

Fix this by checking env_pos in init_dynamic_kenv() and adding dynamic
entries only if there are static entries.

Reserve room for the terminating NUL when setting or getting kernel
environment variables. KENV_MNAMELEN and KENV_MVALLEN doesn't include
space for the terminating NUL.

In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by: rwatson
Approved by: re (bz)

In init_dynamic_kenv(), ignore environment strings exceeding the
KENV_MNAMELEN + 1 + KENV_MVALLEN + 1 length limit to avoid buffer
overflow in getenv(). Currenly loader(8) doesn't limit the length of
environment strings.

PR: kern/132104
MFC after: 1 month

To avoid duplicated warning, move WITNESS_WARN() added in r221597 to the
branch which doesn't call malloc(9).

Suggested by: kib

Add WITNESS_WARN() to getenv() to explicitly note that the function may
sleep. This helps to expose bugs when the requested environment variable
doesn't exist.

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Merge change r198561 from projects/mips to head:

r198561 | thompsa | 2009-10-28 15:25:22 -0600 (Wed, 28 Oct 2009) | 4 lines
Allow a scratch buffer to be set in order to be able to use setenv() while
booting, before dynamic kenv is running. A few platforms implement their own
scratch+sprintf handling to save data from the boot environment.

Allow a scratch buffer to be set in order to be able to use setenv() while
booting, before dynamic kenv is running. A few platforms implement their own
scratch+sprintf handling to save data from the boot environment.

Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with: pjd

Correctly sanity-check timer IDs. [SA-09:06]

Limit the size of malloced buffer when dumping environment
variables. [EN-09:01]

Approved by: so (cperciva)
Approved by: re (kensmith)
Security: FreeBSD-SA-09:06.ktimer
Errata: FreeBSD-EN-09:01.kenv

- Import the HEAD csup code which is the basis for the cvsmode work.

Implement the following macros for completeness:

SYSCTL_QUAD()
SYSCTL_ADD_QUAD()
TUNABLE_QUAD()
TUNABLE_QUAD_FETCH()

Now we can use 64bit tunables on 32bit systems.

Merge first in a series of TrustedBSD MAC Framework KPI changes
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:

mac_<object>_<method/action>
mac_<object>_check_<method/action>

The previous naming scheme was inconsistent and mostly
reversed from the new scheme. Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier. Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods. Also simplify, slightly,
some entry point names.

All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.

Sponsored by: SPARTA (original patches against Mac OS X)
Obtained from: TrustedBSD Project, Apple Computer

I don't know what I was smoking when I wrote these three years ago; the
return value is an error code, hence always an int.

While I'm here, add getenv_uint() for completeness.

Further system call comment cleanup:

- Remove also "MP SAFE" after prior "MPSAFE" pass. (suggested by bde)
- Remove extra blank lines in some cases.
- Add extra blank lines in some cases.
- Remove no-op comments consisting solely of the function name, the word
"syscall", or the system call name.
- Add punctuation.
- Re-wrap some comments.

Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges. These may
require some future tweaking.

Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>

Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.

This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.

Obtained from: TrustedBSD Project
Sponsored by: SPARTA

Use a sleep mutex instead of an sx lock for the kernel environment. This
allows greater flexibility for drivers that want to query the environment.

Reviewed by: jhb, mux

Fix memory leak introduced in previous revision.

Discussed with: phk

Ignore kenv strings which overflow the room we have, rather than pretend
we have room for them.

Reorder statements to avoid accessing unknown memory.
In theory, invoking kenv with very long string can panic
kernel.

Add bounds checking to the setenv part of the kernel environment.

This has no security implications since only root is allowed to use
kenv(1) (and corrupt the kernel memory after adding too much variables
previous to this commit).

This is based upon the PR [1] mentioned below, but extended to check both
bounds (in case of an overflow of the counting variable) and to comply
to the style of the function. An overflow of the counting variable
shouldn't happen after adding the check for the upper bound, but better
safe than sorry (in case some other function in the kernel overwrites
random memory).

An interested soul may want to add a printf to notify root in case the
bounds are hit.

Also allocate KENV_SIZE+1 entries (the array is NULL-terminated), since
the comment for KENV_SIZE says it's the maximum number of environment
strings. [2]

PR: 83687 [1]
Submitted by: Harry Coin <harrycoin@qconline.com> [1]
Submitted by: Ariff Abdullah <skywizard@MyBSD.org.my> [2]

My addled brains didn't realize that since vtp points into value, we
can't freeenv(value) before we're done inspecting vtp[0].

Tested by: Anish Mistry <mistry.7@osu.edu>

Teach getenv_quad() to recognize k/m/g/t suffixes in both lower- and
upper-case. This means (almost) all tunables now support those suffixes.

Make a bunch of malloc types static.

Found by: src/tools/tools/kernxref

Retire TUNABLE_QUAD_*.

Add TUNABLE_LONG and TUNABLE_ULONG, and use the latter for the
hw.pci.host_mem_start tunable. Add comments to TUNABLE_INT and
TUNABLE_QUAD recommending against their use.

MFC after: 3 weeks

If the buffer supplied to kenv(KENV_DUMP, ...) isn't big enough,
return the number of bytes needed instead of 0. The manpage claims
that we do this anyway.

Use __FBSDID().

Back out M_* changes, per decision of the TRB.

Approved by: trb

Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.

remove syscallarg().

Suggested by: peter

SCARGS removal take II.

Backout removal SCARGS, the code freeze is only "selectively" over.

Remove SCARGS.

Reviewed by: md5

Add MAC checks for various kenv() operations: dump, get, set, unset,
permitting MAC policies to limit access to the kernel environment.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Use strlcpy() instead of strncpy() to copy NUL terminated strings
for safety and consistency.

Cosmetic tweaks. Try and keep the style more consistent, catch some stray
whitespace and update a comment.

Fixed some longstanding bugs in _getenv_static():
- malformed environment strings (ones without an '=') were not rejected.
There shouldn't be any of these, but when the static environment is
empty it always begins with one of these; this one should be considered
as the terminator after the end of the environment, but it isn't.
- the comparison of the name being looked up with the name in the
environment was fuzzy -- only the characters up to the length of the
latter were compared, so _getenv_static("foobar") matched "foo=..."
in the environment and everything matched "" in the empty environment.

MFC after: 3 days

Avoid calling malloc() or free() while holding the
kenv lock.

Reviewed by: jake

Rework the kernel environment subsystem. We now convert the static
environment needed at boot time to a dynamic subsystem when VM is
up. The dynamic kernel environment is protected by an sx lock.

This adds some new functions to manipulate the kernel environment :
freeenv(), setenv(), unsetenv() and testenv(). freeenv() has to be
called after every getenv() when you have finished using the string.
testenv() only tests if an environment variable is present, and
doesn't require a freeenv() call. setenv() and unsetenv() are self
explanatory.

The kenv(2) syscall exports these new functionalities to userland,
mainly for kenv(1).

Reviewed by: peter

Fix an inverted test csae. Success of getenv() is determined by a return
value of !NUL rather than NUL.

Submitted by: luigi
Pointy hat to: jhb

- Change getenv_quad() to return an int instead of a quad_t since it
returns an success/failure code rather than the actual value.
- Add getenv_string() which copies a string from the environment to another
string and returns true on success.

Make MAXTSIZ, DFLDSIZ, MAXDSIZ, DFLSSIZ, MAXSSIZ, SGROWSIZ loader
tunable.

Reviewed by: peter
MFC after: 2 weeks

Add a pointer to kenv(1).

Revert last commit. The same functionality can be obtained through the
'kenv' command, which I obviously was unaware of.

Add a sysctl MIB 'kern.env', that dumps the contents of the kernel
environment from the loader, as well as the kernel's compiled in static
hints.

Fix some warnings in kern_environment.c. Make the getenv*() family
take a const 'name', since they dont modify anything.
159: warning: passing arg 1 of `getenv_int' discards qualifiers...
167: warning: passing arg 1 of `getenv' discards qualifiers from pointer..

"Fix" the previous initial attempt at fixing TUNABLE_INT(). This time
around, use a common function for looking up and extracting the tunables
from the kernel environment. This saves duplicating the same function
over and over again. This way typically has an overhead of 8 bytes + the
path string, versus about 26 bytes + the path string.

Previous commit changing SYSCTL_HANDLER_ARGS violated KNF.

Pointed out by: bde

Style police catches up with rev 1.26 of src/sys/sys/sysctl.h:

Sanitize SYSCTL_HANDLER_ARGS so that simplistic tools can grog our
sources:

-sysctl_vm_zone SYSCTL_HANDLER_ARGS
+sysctl_vm_zone (SYSCTL_HANDLER_ARGS)

Change the prototype of the strto* routines to make the second
parameter a char ** instead of a const char **. This make these
kernel routines consistent with the corresponding libc userland
routines.

Which is actually 'correct' is debatable, but consistency and
following the spec was deemed more important in this case.

Reviewed by (in concept): phk, bde

add in actual getenv_quad function

Trim unused options (or #ifdef for undoc options).

Submitted by: phk

$Id$ -> $FreeBSD$

Fix warnings related to -Wall -Wcast-qual

Fix getenv() comparison against '=' ... was *cp = '=' instead of
*cp == '='.

Add getenv_int(), specifically for retrieving integer values from kernel
environment variables. This makes it easy to pass tuning parameters
in from the bootloader.

Don't try to initialise the environment out of a sysinit, it's handled
in MD code instead.

Fix damaged comment.

Kernel environment access, preloaded module lookup.