MFC r330822 (by emaste@):

imgact_linux.c: use standard indentation.

MFC r330798 (by emaste@):

Linuxulator: apply style(9) to return.

MFC r329794, r329801 (by emaste@):

Correct proper nouns in the Linuxulator

- Capitalize Linux
- Spell FreeBSD out in full
- Address some style(9) on changed lines

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

MFC r329370, r330239: Rationalize license text on Linuxolator files

Many licenses on Linuxolator files contained small variations from the
standard FreeBSD license text. To avoid license proliferation switch to
the standard 2-clause FreeBSD license for those files where I have
permission from each of the listed copyright holders.

Approved by: dchagin, kan, marcel, rdivacky, sos
Sponsored by: The FreeBSD Foundation

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Implement lockless resource limits.

Use the same scheme implemented to manage credentials.

Code needing to look at process's credentials (as opposed to thred's) is
provided with *_proc variants of relevant functions.

Places which possibly had to take the proc lock anyway still use the proc
pointer to access limits.

Add a mmap flag (MAP_32BIT) on 64-bit platforms to request that a mapping use
an address in the first 2GB of the process's address space. This flag should
have the same semantics as the same flag on Linux.

To facilitate this, add a new parameter to vm_map_find() that specifies an
optional maximum virtual address. While here, fix several callers of
vm_map_find() to use a VMFS_* constant for the findspace argument instead of
TRUE and FALSE.

Reviewed by: alc
Approved by: re (kib)

Fix misuse of the kernel map in miscellaneous image activators.
Vnode-backed mappings cannot be put into the kernel map, since it is a
system map.

Use exec_map for transient mappings, and remove the mappings with
kmem_free_wakeup() to notify the waiters on available map space.

Do not map the whole executable into KVA at all to copy it out into
usermode. Directly use vn_rdwr() for the case of not page aligned
binary.

There is one place left where the potentially unbounded amount of data
is mapped into exec_map, namely, in the COFF image activator
enumeration of the needed shared libraries.

Reviewed by: alc
MFC after: 2 weeks

Convert files to UTF-8

Add accounting for most of the memory-related resources.

Sponsored by: The FreeBSD Foundation
Reviewed by: kib (earlier version)

Setting VV_TEXT here is redundant. It is already set by do_execve().

Reviewed by: kib

VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.

KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.

Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>

vn_lock() is currently only used with the 'curthread' passed as argument.
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.

Manpage and FreeBSD_version will be updated through further commits.

As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.

Tested by: Diego Sardina <siarodx at gmail dot com>,
Andrea Di Pasquale <whyx dot it at gmail dot com>

Fix for the panic("vm_thread_new: kstack allocation failed") and
silent NULL pointer dereference in the i386 and sparc64 pmap_pinit()
when the kmem_alloc_nofault() failed to allocate address space. Both
functions now return error instead of panicing or dereferencing NULL.

As consequence, vmspace_exec() and vmspace_unshare() returns the errno
int. struct vmspace arg was added to vm_forkproc() to avoid dealing
with failed allocation when most of the fork1() job is already done.

The kernel stack for the thread is now set up in the thread_alloc(),
that itself may return NULL. Also, allocation of the first process
thread is performed in the fork1() to properly deal with stack
allocation failure. proc_linkup() is separated into proc_linkup()
called from fork1(), and proc_linkup0(), that is used to set up the
kernel process (was known as swapper).

In collaboration with: Peter Holm
Reviewed by: jhb

Partial MFp4 of 114977:
Whitespace commit: Fix grammar, spelling and punctuation.

Submitted by: "Scot Hetzel" <swhetzel@gmail.com>

- Change the vm_mmap() function to accept an objtype_t parameter specifying
the type of object represented by the handle argument.
- Allow vm_mmap() to map device memory via cdev objects in addition to
vnodes and anonymous memory. Note that mmaping a cdev directly does not
currently perform any MAC checks like mapping a vnode does.
- Unbreak the DRM getbufs ioctl by having it call vm_mmap() directly on the
cdev the ioctl is acting on rather than trying to find a suitable vnode
to map from.

Reviewed by: alc, arch@

o Split out kernel part of execve(2) syscall into two parts: one that
copies arguments into the kernel space and one that operates
completely in the kernel space;

o use kernel-only version of execve(2) to kill another stackgap in
linuxlator/i386.

Obtained from: DragonFlyBSD (partially)
MFC after: 2 weeks

Add casts so all these quantities are a constant type.

Locking for the per-process resource limits structure.
- struct plimit includes a mutex to protect a reference count. The plimit
structure is treated similarly to struct ucred in that is is always copy
on write, so having a reference to a structure is sufficient to read from
it without needing a further lock.
- The proc lock protects the p_limit pointer and must be held while reading
limits from a process to keep the limit structure from changing out from
under you while reading from it.
- Various global limits that are ints are not protected by a lock since
int writes are atomic on all the archs we support and thus a lock
wouldn't buy us anything.
- All accesses to individual resource limits from a process are abstracted
behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return
either an rlimit, or the current or max individual limit of the specified
resource from a process.
- dosetrlimit() was renamed to kern_setrlimit() to match existing style of
other similar syscall helper functions.
- The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit()
(it didn't used the stackgap when it should have) but uses lim_rlimit()
and kern_setrlimit() instead.
- The svr4 compat no longer uses the stackgap for resource limits calls,
but uses lim_rlimit() and kern_setrlimit() instead.
- The ibcs2 compat no longer uses the stackgap for resource limits. It
also no longer uses the stackgap for accessing sysctl's for the
ibcs2_sysconf() syscall but uses kernel_sysctl() instead. As a result,
ibcs2_sysconf() no longer needs Giant.
- The p_rlimit macro no longer exists.

Submitted by: mtm (mostly, I only did a few cleanups and catchups)
Tested on: i386
Compiled on: alpha, amd64

Restored non-egregious casts so that this file compiles on i386's with
64-bit longs again.

Use __FBSDID().

Clean up whitespace and remove register keyword.

More caddr_t removal, in conjunction with copy{in,out}(9) this time.
Also clean up some egregious casts and incorrect use of sizeof.

Style(9). Make some function declarations consistent with the rest,
and remove some nearby extraneous {}'s.

Use the fields in the sysentvec and in the vm map header in place of the
constants VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS, USRSTACK and PS_STRINGS.
This is mainly so that they can be variable even for the native abi, based
on different machine types. Get stack protections from the sysentvec too.
This makes it trivial to map the stack non-executable for certain abis, on
machines that support it.

- Hold the vnode lock throughout execve.
- Set VV_TEXT in the top level execve code.
- Fixup the image activators to deal with the newly locked vnode.

- Replace v_flag with v_iflag and v_vflag
- v_vflag is protected by the vnode lock and is used when synchronization
with VOP calls is needed.
- v_iflag is protected by interlock and is used for dealing with vnode
management issues. These flags include X/O LOCK, FREE, DOOMED, etc.
- All accesses to v_iflag and v_vflag have either been locked or marked with
mp_fixme's.
- Many ASSERT_VOP_LOCKED calls have been added where the locking was not
clear.
- Many functions in vfs_subr.c were restructured to provide for stronger
locking.

Idea stolen from: BSD/OS

Infrastructure tweaks to allow having both an Elf32 and an Elf64 executable
handler in the kernel at the same time. Also, allow for the
exec_new_vmspace() code to build a different sized vmspace depending on
the executable environment. This is a big help for execing i386 binaries
on ia64. The ELF exec code grows the ability to map partial pages when
there is a page size difference, eg: emulating 4K pages on 8K or 16K
hardware pages.

Flesh out the i386 emulation support for ia64. At this point, the only
binary that I know of that fails is cvsup, because the cvsup runtime
tries to execute code in pages not marked executable.

Obtained from: dfr (mostly, many tweaks from me).

Fix typo in the BSD copyright: s/withough/without/

Spotted and suggested by: des
MFC after: 3 weeks

Remove __P.

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

Reviewed by: peter
MFC after: 2 weeks

Undo part of the tangle of having sys/lock.h and sys/mutex.h included in
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)

Proc locking.

Fix #! script exec under linux emulation. If a script is exec'd from a
program running under linux emulation, the script binary is checked for
in /compat/linux first. Without this patch the wrong script binary
(i.e. the FreeBSD binary) will be run instead of the linux binary.
For example, #!/bin/sh, thus breaking out of linux compatibility mode.

This solves a number of problems people have had installing linux
software on FreeBSD boxes.

Implement pluggable ioctl handlers.

Other modules can register and unregister ioctl handlers to extend the
ioctls known by the Linuxulator. A recent application is the vmware
port. The Linuxulator itself uses the new interface to register its
handlers as well. Handlers for the following types of ioctls have been
defined:
cdrom
console (=keyboard and VT handling)
socket
sound
termio

All ioctl related defines and declarations have been moved to a new
file (linux_ioctl.h), except for the pluggable ioctl handler interface
definition.

While there, cleanup linux.h some more.

linux.h and linux_ioctl.[ch] have been made to conform to style(9) as
much as possible.

Inspired and reviewed by: Vladimir N. Silyaev

useracc() the prequel:

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.

$Id$ -> $FreeBSD$

Fix a couple of warnings and some bitrot in comments.

Minor cleanup; no more references to LKM's.

*gulp*. Jordan specifically OK'ed this..

This is the bulk of the support for doing kld modules. Two linker_sets
were replaced by SYSINIT()'s. VFS's and exec handlers are self registered.
kld is now a superset of lkm. I have converted most of them, they will
follow as a seperate commit as samples.
This all still works as a static a.out kernel using LKM's.

Use [u]intptr_t instead of [u_]long for casts between pointers and
integers. Don't forget to cast to (void *) as well.

Fixed print format errors.

De-staticize enough to make all the LKMs work again. Add comments where
deemed relevant.

Staticize.

Don't include <sys/lock.h> in headers when only `struct simplelock' is
required. Fixed everything that depended on the pollution.

Removed unused #includes.

Fixed data+bss limit (use the current rlimit instead of MAXDSIZ).

Fully implement vfork. Vfork is now much much faster than even our
fork. (On my machine, fork is about 240usecs, vfork is 78usecs.)

Implement rfork(!RFPROC !RFMEM), which allows a thread to divorce its memory
from the other threads of a group.

Implement rfork(!RFPROC RFCFDG), which closes all file descriptors, eliminating
possible existing shares with other threads/processes.

Implement rfork(!RFPROC RFFDG), which divorces the file descriptors for a
thread from the rest of the group.

Fix the case where a thread does an exec. It is almost nonsense for a thread
to modify the other threads address space by an exec, so we
now automatically divorce the address space before modifying it.

Removed potentially harmful garbage <vm/lock.h> and fixed bogus
use of it. It was actually harmless because the use was null due
to fortuitous include orders and identical (wrong) idempotency
macros.

Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

*Ahem* - opt_rlimit.h does not exist in the LKM case. This was another
2.2 build-breaker.. :(

Make DFLDSIZ and MAXDSIZ fully-supported options.

"Don't forget to do a ``make depend''" :-)

Fixed some more easy cases of const poisoning in the kernel. Cosmetic.

First pass at cleaning up macros relating to pages, clusters and all that.

Removed unnecessary #includes from <sys/imgact.h> so that it is
self-sufficient and added explicit #includes where required.

Fixed unsigned longs that should have been vm_offset_t.

vm_offset_t is currently unsigned long but should probably be plain
unsigned for i386's to match the choice of minimal types to represent
for fixed-width types in Lite2. Anyway, it shouldn't be assumed
to be unsigned long.

I only fixed the type mismatches that were detected when I changed
vm_offset_t to unsigned. Only pointer type mismatches were detected.

Remove references to MAP_FILE.. That is now "default" and is only
a "#define MAP_FILE 0" that is still there for net-2 source compatability.

Fix the vm_map_remove and vm_map_protect calls.. Somewhere along the
line, these had got (start, length) arguments instead of (start, end)
args. This could be the cause of Robert Sanders lockups with ZMAGIC
binaries.

First attempt at FreeBSD & Linux ELF support.

Compile and link a new kernel, that will give native ELF support, and
provide the hooks for other ELF interpreters as well.

To make native ELF binaries use John Polstras elf-kit-1.0.1..
For the time being also use his ld-elf.so.1 and put it in
/usr/libexec.

The Linux emulator has been enhanced to also run ELF binaries, it
is however in its very first incarnation.
Just get some Linux ELF libs (Slackware-3.0) and put them in the
prober place (/compat/linux/...).
I've ben able to run all the Slackware-3.0 binaries I've tried
so far.
(No it won't run quake yet :)

Mega-commit for Linux emulator update.. This has been stress tested under
netscape-2.0 for Linux running all the Java stuff. The scrollbars are now
working, at least on my machine. (whew! :-)

I'm uncomfortable with the size of this commit, but it's too
inter-dependant to easily seperate out.

The main changes:

COMPAT_LINUX is *GONE*. Most of the code has been moved out of the i386
machine dependent section into the linux emulator itself. The int 0x80
syscall code was almost identical to the lcall 7,0 code and a minor tweak
allows them to both be used with the same C code. All kernels can now
just modload the lkm and it'll DTRT without having to rebuild the kernel
first. Like IBCS2, you can statically compile it in with "options LINUX".

A pile of new syscalls implemented, including getdents(), llseek(),
readv(), writev(), msync(), personality(). The Linux-ELF libraries want
to use some of these.

linux_select() now obeys Linux semantics, ie: returns the time remaining
of the timeout value rather than leaving it the original value.

Quite a few bugs removed, including incorrect arguments being used in
syscalls.. eg: mixups between passing the sigset as an int, vs passing
it as a pointer and doing a copyin(), missing return values, unhandled
cases, SIOC* ioctls, etc.

The build for the code has changed. i386/conf/files now knows how
to build linux_genassym and generate linux_assym.h on the fly.

Supporting changes elsewhere in the kernel:

The user-mode signal trampoline has moved from the U area to immediately
below the top of the stack (below PS_STRINGS). This allows the different
binary emulations to have their own signal trampoline code (which gets rid
of the hardwired syscall 103 (sigreturn on BSD, syslog on Linux)) and so
that the emulator can provide the exact "struct sigcontext *" argument to
the program's signal handlers.

The sigstack's "ss_flags" now uses SS_DISABLE and SS_ONSTACK flags, which
have the same values as the re-used SA_DISABLE and SA_ONSTACK which are
intended for sigaction only. This enables the support of a SA_RESETHAND
flag to sigaction to implement the gross SYSV and Linux SA_ONESHOT signal
semantics where the signal handler is reset when it's triggered.

makesyscalls.sh no longer appends the struct sysentvec on the end of the
generated init_sysent.c code. It's a lot saner to have it in a seperate
file rather than trying to update the structure inside the awk script. :-)

At exec time, the dozen bytes or so of signal trampoline code are copied
to the top of the user's stack, rather than obtaining the trampoline code
the old way by getting a clone of the parent's user area. This allows
Linux and native binaries to freely exec each other without getting
trampolines mixed up.

This is an extract of changes from what I am currently running...
- Optimise the linux a.out loading and uselib system calls so they
take advantage of some of John's recent interface improvements.
Basically, this means they make far less map changes than before.
- Attempt to plug some potentially nasty kernel_map memory leaks..
- Improve support for QMAGIC libs (I only use QMAGIC (ie: a.out libraries from
the slackware 3.0 dist) but this depends on other changes to enhance
the /compat/linux support)
- uselib goes out through a single exit as part of the resource tracking
that I did when closing the resource leaks on errors. This could be
cleaner than what I did, but making a 30-deep nested if/else was not my
idea of fun, neither did I want to repeat the same code 30 times over for
each failure possibility. I guess this function needs to be split into
smaller functions to solve this.

I've been running the Linux Netscape-2.0 (with Java) to test this, and apart
from the long-standing problem with the missing scrollbars, it appears to
still work as before with ZMAGIC libs (and the leaks).. However, I've
been using it with mods for the signal trampoline code for native linux stack
frames on signals and exterminated the blasted sigreturn printf() problem,
so I can't be certain that there is not a dependency on something else.

Fixed vm_map_find for new vm updates.

Restored a vm #include.

Attempt to make the Linux LKM compile again after the recent VM include
de-nesting changes...
(I figured this might be usefulif it actually built, since I've told
everybody to rebuild it or die.. :-)

Completed function declarations and added prototypes.

Removed some unnecessary #includes.

Fixed warnings about nested externs.

All:
Changed vnodep -> vp for consistency with the rest of the kernel, and
changed iparams -> imgp for brevity.

kern_exec.c:
Explicitly initialized some additional parts of the image_params struct
to avoid bzeroing it. Rewrote the set-id code to reduce the number of
logical tests. The rewrite exposed a mostly benign bug in the algorithm:
traced set-id images would get ktracing disabled even if the set-id didn't
happen for other reasons.

Moved setting of VTEXT flag into the appropriate image activators. This
fixes a bug where linux binaries would get the flag set inappropriately.

First incarnation of our Linux emulator or rather compatibility code.
This first shot only incorporaties so much functionality that DOOM
can run (the X version), signal handling is VERY weak, so is many
other things. But it meets my milestone number one (you guessed it
- running DOOM).

Uses /compat/linux as prefix for loading shared libs, so it won't
conflict with our own libs.

Kernel must be compiled with "options COMPAT_LINUX" for this to work.