MFC r333806:
Use NULL for SYSINIT's last arg, which is a pointer type

Sponsored by: The FreeBSD Foundation

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

Provide better debug message on kernel module name clash.

Reviewed by: kib@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Fix a typo.

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)

Style fix.

Sponsored by: Sandvine Incorporated
Requested by: jhb
Reviewed by: jhb
MFC after: 1 week
X-MFC: 215544

Scan the list in reverse order for the shutdown handlers of loaded modules.
This way, when there is a dependency between two modules, the handler of the
latter probed runs first.

This is a similar approach as the modules are unloaded in the same
linkerfile.

Sponsored by: Sandvine Incorporated
Submitted by: Nima Misaghian <nmisaghian at sandvine dot com>
MFC after: 1 week

Use ISO C99 integer types in sys/kern where possible.

There are only about 100 occurences of the BSD-specific u_int*_t
datatypes in sys/kern. The ISO C99 integer types are used here more
often.

Provide groundwork for 32-bit binary compatibility on non-x86 platforms,
for upcoming 64-bit PowerPC and MIPS support. This renames the COMPAT_IA32
option to COMPAT_FREEBSD32, removes some IA32-specific code from MI parts
of the kernel and enhances the freebsd32 compatibility code to support
big-endian platforms.

Reviewed by: kib, jhb

When the SYSINIT() to load a module invokes the MOD_LOAD event successfully,
move that module to the head of the associated linker file's list of modules.
The end result is that once all the modules are loaded, they are sorted in
the reverse of their load order. This causes the kernel linker to invoke
the MOD_QUIESCE and MOD_UNLOAD events in the reverse of the order that
MOD_LOAD was invoked. This means that the ordering of MOD_LOAD events that
is set by the SI_* paramters to DECLARE_MODULE() are now honored in the same
order they would be for SYSUNINIT() for the MOD_QUIESCE and MOD_UNLOAD
events.

MFC after: 1 month

- Invoke MOD_QUIESCE on all modules in a linker file (kld) before
unloading any modules. As a result, if any module veto's an unload
request via MOD_QUIESCE, the entire set of modules for that linker
file will remain loaded and active now rather than leaving the kld
in a weird state where some modules are loaded and some are unloaded.
- This also moves the logic for handling the "forced" unload flag out of
kern_module.c and into kern_linker.c which is a bit cleaner.
- Add a module_name() routine that returns the name of a module and use that
instead of printing pointer values in debug messages when a module fails
MOD_QUIESCE or MOD_UNLOAD.

MFC after: 1 month

In keeping with style(9)'s recommendations on macros, use a ';'
after each SYSINIT() macro invocation. This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.

MFC after: 1 month
Discussed with: imp, rink

Add an automatic kernel module version dependency to prevent loading
modules using invalid ABI versions (e.g. a 7.x module with an 8.x kernel)
for a given kernel:
- Add a 'kernel' module version whose value is __FreeBSD_version.
- Add a version dependency on 'kernel' in every module that has an
acceptable version range of __FreeBSD_version up to the end of the
branch __FreeBSD_version is part of. E.g. a module compiled on 701000
would work on kernels with versions between 701000 and 799999 inclusive.

Discussed on: arch@
MFC after: 1 week

Move several data structure definitions out of freebsd32_misc.c and into
freebsd32.h instead.

MFC after: 1 week

Remove 'MPSAFE' annotations from the comments above most system calls: all
system calls now enter without Giant held, and then in some cases, acquire
Giant explicitly.

Remove a number of other MPSAFE annotations in the credential code and
tweak one or two other adjacent comments.

Address a problem I missed in removing Giant from the kernel linker. Not
all of the module event handlers are MP safe yet, so always acquire Giant
for now when invoking module event handlers. Eventually we can add an
MPSAFE flag or some such and add appropriate locking to all module event
handlers.

o Expand an exclusive lock scope to prevent a race between two
simultaneous module_register().

Original work done by: Alex Lyashkov
Reviewed by: jhb
MFC after: 2 weeks

Add a new module_file() function that returns the linker_file_t associated
with a given module_t. I use this in some the MOD_LOAD event handler for
some test kernel modules to ask the kernel linker to look up the linker
sets in my test modules. (I use linker sets to generate the list of
possible events that I then signal to execute via a sysctl. On non-amd64,
ld(8) would resolve the entire linker set, but on amd64 I have to ask the
kernel linker to do it for me, and having the kernel linker do it works on
all archs.)

Swap the arguments for CP so we copy the correct source and
destination.

Add a 32bit syscall wrapper for modstat

Obtained from: Yahoo!

Don't bother calling the module event handlers from module_shutdown()
in the shutdown_final state if the RB_NOSYNC flag is set.

The specific motivation in this case is that a system panic in an
interrupt context results in a call to module_shutdown(), which
calls g_modevent(), which calls g_malloc(..., M_WAITOK), which
results in a second panic. While g_modevent() could be fixed to
not call malloc() for MOD_SHUTDOWN events (which it doesn't handle
in any case), it is probably also a good idea to entirely skip the
execution of the module shutdown handlers after a panic.

This may be a MFC candidate for RELENG_5.

Do a pass over all modules in the kernel and make them return EOPNOTSUPP
for unknown events.

A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".

A module with no modevent function gets modevent_nop() as default.

Until now the function has just returned zero for any event, but
that is downright wrong for MOD_UNLOAD and not very useful for any
future events we add where it may be crucial to be able to tell
if the event was unhandled or successful.

Change the function to return as follows:

MOD_LOAD -> 0
MOD_UNLOAD -> EBUSY
anything else -> EOPNOTSUPP

Give kldunload a -f(orce) argument.

Add a MOD_QUIESCE event for modules. This should return error (EBUSY)
of the module is in use.

MOD_UNLOAD should now only fail if it is impossible (as opposed to
inconvenient) to unload the module. Valid reasons are memory references
into the module which cannot be tracked down and eliminated.

When kldunloading, we abandon if MOD_UNLOAD fails, and if -force is
not given, MOD_QUIESCE failing will also prevent the unload.

For backwards compatibility, we treat EOPNOTSUPP from MOD_QUIESCE as
success.

Document that modules should return EOPNOTSUPP for unknown events.

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.

Move the MOD_SHUTDOWN event from shutdown_post_sync to shutdown_final,
so that entities that want to use the post_sync hook to write stuff
to devices and other tidy-up can do so before the device tree is
shot down. eg: da doing a SYNC_CACHE etc. This should get crashdumps
working on mpt devices again, and stops the ia64 boxes locking up
on regular shutdown when da tries to issue the scsi commands to mpt.

Obtained from: njl, gibbs

SCARGS removal take II.

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

Remove SCARGS.

Reviewed by: md5

- The previous commit message should have read that Giant was removed
from modnext(), modfnext(), modstat(), and modfind(). Please excuse
the fumble.

- Remove Giant acquisition from modevent(), modfnext(), modstat() and
modfind(). Giant is no longer needed by these functions for safe
execution.

Reviewed by: jhb

- Lock down the ``module'' structure by adding an SX lock that is used by
all the global bits of ``module'' data. This commit adds a few generic
macros, MOD_SLOCK, MOD_XLOCK, etc., that are meant to be used as ways
of accessing the SX lock. It is also the first step in helping to lock
down the kernel linker and module systems.

Reviewed by: jhb, jake, smp@

Fix a warning. Do not assume pointer == long.

- Whitespace fixup left over from previous commit.
- Remove bogus cast.

Submitted by: bde

- Fix style further by adding parentheses around return values so that
they look like:
return (val); instead of: return val;

- Style.9 formatting fix; this commit is mostly white space related with
the next commit actually doing the:
return val; -> return (val);
changes. This commit was done in preparation for getting ``struct
modules'' locked down.

Reviewed by: bde
Approved by: dfr

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

Giant Pushdown. Saved the worst P4 tree breakage for last.

reboot() getpriority() setpriority() rtprio() osetrlimit() ogetrlimit()
setrlimit() getrlimit() getrusage() getpid() getppid() getpgrp()
getpgid() getsid() getgid() getegid() getgroups() setsid() setpgid()
setuid() seteuid() setgid() setegid() setgroups() setreuid() setregid()
setresuid() setresgid() getresuid() getresgid () __setugid() getlogin()
setlogin() modnext() modfnext() modstat() modfind() kldload() kldunload()
kldfind() kldnext() kldstat() kldfirstmod() kldsym() getdtablesize()
dup2() dup() fcntl() close() ofstat() fstat() nfsstat() fpathconf()
flock()

Mechanical change to use <sys/queue.h> macro API instead of
fondling implementation details.

Created with: sed(1)
Reviewed by: md5(1)

Staticize some malloc M_ instances.

Back out the previous change to the queue(3) interface.
It was not discussed and should probably not happen.

Requested by: msmith and others

Change the way that the queue(3) structures are declared; don't assume that
the type argument to *_HEAD and *_ENTRY is a struct.

Suggested by: phk
Reviewed by: phk
Approved by: mdodd

First round implementation of a fine grain enhanced module to module
version dependency system. This isn't quite finished, but it is at a
useful stage to do a functional checkpoint.

Highlights:
- version and dependency metadata is gathered via linker sets, so things
are handled the same for static kernels and code built to live in a kld.
- The dependencies are at module level (versus at file level).
- Dependencies determine kld symbol search order - this means that you
cannot link against symbols in another file unless you depend on it. This
is so that you cannot accidently unload the target out from underneath
the ones referencing it.
- It is flexible enough that we can put tags in #include files and macros
so that we can get decent hooks for enforcing recompiles on incompatable
ABI changes. eg: if we change struct proc, we could force a recompile
for all kld's that reference the proc struct.
- Tangled dependency references at boot time are sorted. Files are
relocated once all their dependencies are already relocated.

Caveats:
- Loader support is incomplete, but has been worked on seperately.
- Actual enforcement of the version number tags is not active yet - just
the module dependencies are live. The actual structure of versioning
hasn't been agreed on yet. (eg: major.minor, or whatever)
- There is some backwards compatability for old modules without metadata
but I'm not sure how good it is.

This is based on work originally done by Boris Popov (bp@freebsd.org),
but I'm not sure he'd recognize much of it now. Don't blame him. :-)
Also, ideas have been borrowed from Mike Smith.

A hack basically.. We have a bunch of code that used to call
devsw_module_handler() indirectly and not use the chain arguments. To
eliminate this indirection via that function (which does nothing now)
without duplicating a modevent handler into all the routines that don't
presently have one, supply a NOP (do nothing, return OK) routine which
is functionally equivalent to what's there now. This is a hack and is
still wrong, because there doesn't appear to be anything to reclaim
resources on an unload of a module with one of these in it. I'm not
sure whether to make the NOP handler refuse a MOD_UNLOAD event or what.

$Id$ -> $FreeBSD$

Implement a new generic mechanism for attaching handler functions to
events, in order to pave the way for removing a number of the ad-hoc
implementations currently in use.

Retire the at_shutdown family of functions and replace them with
new event handler lists.

Rework kern_shutdown.c to take greater advantage of the use of event
handlers.

Reviewed by: green

Oops, set module->file..

PR: 1179
Submitted-by: lha@stacken.kth.se

First stages of a module dependency cleanup. This part fixes a
particularly annoying hack, namely having the linker bash the moduledata
to set the container pointer, preventing it being const. In the process,
a stack of warnings were fixed and will probably allow a revisit of the
const C_SYSINIT() changes. This explicitly registers modules in files or
preload areas with the module system first, and let them initialize via
SYSINIT/DECLARE_MODULE later in their SI_ORDER_xxx order. The kludge of
finding the containing file is no longer needed since the registration
of modules onto the modules list is done in the context of initializing
the linker file.

More -Wall / -Wcast-qual cleanup. Also, EXEC_SET can't use
C_DECLARE_MODULE due to the linker_file_sysinit() function
making modifications to the data.

Fix warnings in preparation for adding -Wall -Wcast-qual to the
kernel compile

Remove a diagnostic message left in by mistake.

Implement a mechanism for a module to report a small amount of module
specific data back to the user via kldstat(2). Use that mechanism in
the syscall handler to report the syscall number used.

put a \n on an error message printf

*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.

Keep track of the containing file for modules. This is a bit of a hack,
but I can't think of another (relatively) easy way of getting the info
since the boot-time initialization is not done immediately after "loading".
XXX module_register() gained an extra arg. This might break the alpha
compile, if so, just add a zero to get the old behavior.

Send a MOD_UNLOAD event before deleting the module. if the MOD_LOAD event
failed.

Changed to the C9x draft spelling of the (unsigned) integral type
suitable for holding object pointers (ptrint_t -> uintptr_t).
Added corresponding signed type (intptr_t). Changed/added
corresponding non-C9x types for function pointers to match. Don't
use nonstandard types to implement these types, and don't comment
on them in <machine/types.h>.

Fixed printf format errors.

Remove a bunch of variables which were unused both in GENERIC and LINT.

Found by: -Wunused

Move the "retval" (3rd) parameter from all syscall functions and put
it in struct proc instead.

This fixes a boatload of compiler warning, and removes a lot of cruft
from the sources.

I have not removed the /*ARGSUSED*/, they will require some looking at.

libkvm, ps and other userland struct proc frobbing programs will need
recompiled.

Removed unused #includes.

make a couple functions static...

also change module_register_static to module_register_init as this
function initalizes the module for both dynamic and static modules...

Removed unused #includes.

This is the kernel linker. To use it, you will first need to apply
the patches in freefall:/home/dfr/ld.diffs to your ld sources and set
BINFORMAT to aoutkld when linking the kernel.

Library changes and userland utilities will appear in a later commit.