MFC r328890 (by emaste@):

Linuxolator whitespace cleanup

A version of each of the MD files by necessity exists for each CPU
architecture supported by the Linuxolator. Clean these up so that new
architectures do not inherit whitespace issues.

Clean up shared Linuxolator files while here.

MFC r314782:

Add UNIMPLEMENTED() placeholder macro for
the syscalls that are not implemented in Linux kernel itself.
Cleanup DUMMY() macros.

Approved by: trasz

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

As <machine/vmparam.h> is included from <vm/vm_param.h>, there is no
need to include it explicitly when <vm/vm_param.h> is already included.

Suggested by: alc
Reviewed by: alc
Differential Revision: https://reviews.freebsd.org/D5379

Fix linux_common module build with KTR option.

Differential Revision: https://reviews.freebsd.org/D1096
Reviewed by: trasz

Implement epoll family system calls. This is a tiny wrapper
around kqueue() to implement epoll subset of functionality.
The kqueue user data are 32bit on i386 which is not enough for
epoll user data, so we keep user data in the proc emuldata.

Initial patch developed by rdivacky@ in 2007, then extended
by Yuri Victorovich @ r255672 and finished by me
in collaboration with mjg@ and jillies@.

Differential Revision: https://reviews.freebsd.org/D1092

Where possible we will use M_LINUX malloc(9) type.
Move M_FUTEX defines to the linux_common.ko.

Differential Revision: https://reviews.freebsd.org/D1077
Reviewed by: emaste

Introduce a new module linux_common.ko which is intended for the
following primary purposes:

1. Remove the dependency of linsysfs and linprocfs modules from linux.ko,
which will be architecture specific on amd64.

2. Incorporate into linux_common.ko general code for platforms on which
we'll support two Linuxulator modules (for both instruction set - 32 & 64 bit).

3. Move malloc(9) declaration to linux_common.ko, to enable getting memory
usage statistics properly.

Currently linux_common.ko incorporates a code from linux_mib.c and linux_util.c
and linprocfs, linsysfs and linux kernel modules depend on linux_common.ko.

Temporarily remove dtrace garbage from linux_mib.c and linux_util.c

Differential Revision: https://reviews.freebsd.org/D1072
In collaboration with: Vassilis Laganakos.

Reviewed by: trasz

- >500 static DTrace probes for the linuxulator
- DTrace scripts to check for errors, performance, ...
they serve mostly as examples of what you can do with the static probe;s
with moderate load the scripts may be overwhelmed, excessive lock-tracing
may influence program behavior (see the last design decission)

Design decissions:
- use "linuxulator" as the provider for the native bitsize; add the
bitsize for the non-native emulation (e.g. "linuxuator32" on amd64)
- Add probes only for locks which are acquired in one function and released
in another function. Locks which are aquired and released in the same
function should be easy to pair in the code, inter-function
locking is more easy to verify in DTrace.
- Probes for locks should be fired after locking and before releasing to
prevent races (to provide data/function stability in DTrace, see the
man-page of "dtrace -v ..." and the corresponding DTrace docs).

Remove direct access to si_name.

Code should just use the devtoname() function to obtain the name of a
character device. Also add const keywords to pieces of code that need it
to build properly.

MFC after: 2 weeks

Remove stale comment.

Submitted by: arundel
MFC after: 3 days

Add preliminary KTR(9) support to the linux emulation layer.

Approved by: kib (mentor)
MFC after: 1 month

Implement the linux syscalls
openat, mkdirat, mknodat, fchownat, futimesat, fstatat, unlinkat,
renameat, linkat, symlinkat, readlinkat, fchmodat, faccessat.

Submitted by: rdivacky
Sponsored by: Google Summer of Code 2007
Tested by: pho

Implement the openat() linux syscall
Submitted by: Roman Divacky (rdivacky@)
MFC after: 2 weeks

Axe the stackgap macros as the Linux ABIs no longer use the stackgap.

Enhance the Linux emulation layer to make MegaRAID SAS managements tool happy.
Add back in a scheme to emulate old type major/minor numbers via hooks into
stat, linprocfs to return major/minors that Linux app's expect. Currently
only /dev/null is always registered. Drivers can register via the Linux
type shim similar to the ioctl shim but by using
linux_device_register_handler/linux_device_unregister_handler functions.
The structure is:

struct linux_device_handler {
char *bsd_driver_name;
char *linux_driver_name;
char *bsd_device_name;
char *linux_device_name;
int linux_major;
int linux_minor;
int linux_char_device;
};

Linprocfs uses this to display the major number of the driver. The
soon to be available linsysfs will use it to fill in the driver name.
Linux_stat uses it to translate the major/minor into Linux type values.

Note major numbers are dynamically assigned via passing in a -1 for
the major number so we don't need to keep track of them.

This is somewhat needed due to us switching to our devfs. MegaCli
will not run until I add in the linsysfs and mfi Linux compat changes.

Sponsored by: IronPort Systems

Suppress logging about unimplemented syscalls to one time per process. This
prevents hard flood of the system console.

Reviewed by: bde

Remove linux_emul_find() and the CHECKALT*() macros as they are no longer
used.

Start each of the license/copyright comments with /*-

Rename thread args to be called "td" rather than "p" to be
consistent with other bits of this file. There should be no
functional change.

Submitted by: Andrea Campi (many moons ago)
MFC after: 2 month

Use sv_psstrings from the current process's sysentvec structure instead
of PS_STRINGS. This is a no-op at present, but it will be needed when
running 32-bit Linux binaries on amd64 to ensure PS_STRINGS is in
addressable memory.

Add function linux_msg() for regulating output from the linux emulation
code, make the emulator use it.

Rename unsupported_msg() to unimplemented_syscall(). Rename some arguments
for clarity

Fixup grammar.

Requested by: bde

When complaining about obsolete/unimplemented syscalls output the process
name to make things more clear for the user.

PR: 46661
MFC After: 3 days

Add a new function linux_emul_convpath(), which is a version of
linux_emul_find() that does not use stack gap storage but instead
always returns the resulting path in a malloc'd kernel buffer.
Implement linux_emul_find() in terms of this function. Also add
LCONVPATH* macros that wrap linux_emul_convpath in the same way
that the CHECKALT* macros wrap linux_emul_find().

Remove __P.

Garbage collect options AVM_A1_PCI, AVM_A1_PCMCIA, DEBUG_LINUX, DEV_APM,
GUS_DMA, GUS_DMA2, GUS_IRQ, OLTR_NO_BULLSEYE_MAC, OLTR_NO_HAWKEYE_MAC,
OLTR_NO_TMS_MAC and PCIC_RESUME_RESET.

Eliminate the prefix parameter to linux_emul_find(), which was always
linux_emul_path anyway. Linux_emul_find() has interesting bugs in its
prefix handling (which luckily are not currently exploitable); this
commit is preliminary to an attempt at cleaning it up.

Approved by: marcel

Whitespace fix.

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

The MI/MD split wasn't perfect and the MI files need hacks for the
AlphaLinux compat bits. This will be better cleaned up soon.

Agreed to what ever was necessary by: marcel

Remove the only use of SCARG and perform dead code elimination.

Add bounds checking to stackgap_alloc. Previously it was possible
to construct a path that was long enough (ie longer than
SPARE_USRSPACE bytes) and trash the stack.

Note that SPARE_USRSPACE is much smaller than MAXPATHLEN so that
the Linuxulator will now return ENAMETOOLONG even if the path
is smaller than MAXPATHLEN.

PR: 12749

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

$Id$ -> $FreeBSD$

We don't end up checking for a return value of EFAULT from the copyinstr()
in the pathname translation procedure. This proves fatal, and can be
easily fixed. This or a similar change needs to be committed to svr4_util.h
and ibcs2_util.h. I will update ibcs2_util.h, if noone else thinks of a
better way to do this, in the same manner. I will leave svr4 to the
respective maintainer.

This closes the problem of the only crash I've been able to produce as
a user recently, except for (currently not-in-the-source tree) fd
table sharing fixes. Thanks goes to pho for his stress-testers.

Removed the cast to a pointer in the definition of PS_STRINGS and
adjusted related casts to match (only in the kernel in this commit).
The pointer was only wanted in one place in kern_exec.c. Applications
should use the kern.ps_strings sysctl instead of PS_STRINGS, so they
shouldn't notice this change.

remove option LINUX as it did nothing, add DEBUG_LINUX to debug the
linux emulation...

(actually moved LINUX to opt_dontuse.h)

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.

Fix a (mostly harmless) bogon when allocating space above the stack
in the stack gap..

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.