Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

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)

userret() already checks for td_locks when INVARIANTS is enabled, so
there is no need to check if Giant is acquired after it.

Reviewed by: kib
MFC after: 1 week

Copy i386 specialreg.h to x86 and merge with amd64 specialreg.h. Replace
amd64/i386/pc98 specialreg.h with stubs.

Copy i386 psl.h to x86 and replace amd64/i386/pc98 psl.h with stubs.

Move userland bits (and some common kernel bits) from amd64 and i386
segments.h to a new x86 segments.h.

Add __packed attribute to some structs (just to be sure).
Also make it clear that i386 GDT and LDT entries are used in ia64 code.

Eliminate ia32_reg.h by moving its contents to x86 and ia64 reg.h.

Reviewed by: kib

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)

Inline the syscallenter() and syscallret(). This reduces the time measured
by the syscall entry speed microbenchmarks by ~10% on amd64.

Submitted by: jhb
Approved by: re (bz)
MFC after: 2 weeks

Add support for executing the FreeBSD 1/i386 a.out binaries on amd64.

In particular:
- implement compat shims for old stat(2) variants and ogetdirentries(2);
- implement delivery of signals with ancient stack frame layout and
corresponding sigreturn(2);
- implement old getpagesize(2);
- provide a user-mode trampoline and LDT call gate for lcall $7,$0;
- port a.out image activator and connect it to the build as a module
on amd64.

The changes are hidden under COMPAT_43.

MFC after: 1 month

Prefer struct sysentvec sv_psstrings to hardcoding FREEBSD32_PS_STRINGS
in the compat32 code. Use sv_usrstack instead of FREEBSD32_USRSTACK as well.

MFC after: 1 week

Change ia64' struct syscall_args definition so that args is a pointer to
the arguments array instead of array itself. ia64 syscall arguments are
readily available in the frame, point args to it, do not do unnecessary
bcopy. Still reserve the array in syscall_args for ia32 emulation.

Suggested and reviewed by: marcel
MFC after: 1 month

Reorganize syscall entry and leave handling.

Extend struct sysvec with three new elements:
sv_fetch_syscall_args - the method to fetch syscall arguments from
usermode into struct syscall_args. The structure is machine-depended
(this might be reconsidered after all architectures are converted).
sv_set_syscall_retval - the method to set a return value for usermode
from the syscall. It is a generalization of
cpu_set_syscall_retval(9) to allow ABIs to override the way to set a
return value.
sv_syscallnames - the table of syscall names.

Use sv_set_syscall_retval in kern_sigsuspend() instead of hardcoding
the call to cpu_set_syscall_retval().

The new functions syscallenter(9) and syscallret(9) are provided that
use sv_*syscall* pointers and contain the common repeated code from
the syscall() implementations for the architecture-specific syscall
trap handlers.

Syscallenter() fetches arguments, calls syscall implementation from
ABI sysent table, and set up return frame. The end of syscall
bookkeeping is done by syscallret().

Take advantage of single place for MI syscall handling code and
implement ptrace_lwpinfo pl_flags PL_FLAG_SCE, PL_FLAG_SCX and
PL_FLAG_EXEC. The SCE and SCX flags notify the debugger that the
thread is stopped at syscall entry or return point respectively. The
EXEC flag augments SCX and notifies debugger that the process address
space was changed by one of exec(2)-family syscalls.

The i386, amd64, sparc64, sun4v, powerpc and ia64 syscall()s are
changed to use syscallenter()/syscallret(). MIPS and arm are not
converted and use the mostly unchanged syscall() implementation.

Reviewed by: jhb, marcel, marius, nwhitehorn, stas
Tested by: marcel (ia64), marius (sparc64), nwhitehorn (powerpc),
stas (mips)
MFC after: 1 month

Change the arguments of exec_setregs() so that it receives a pointer
to the image_params struct instead of several members of that struct
individually. This makes it easier to expand its arguments in the future
without touching all platforms.

Reviewed by: jhb

Add trivial implementation for the freebsd32_sysarch on ia64.
Fix comapt32 and LINT build on ia64.

Discussed with: jhb

Rework the PCPU_* (MD) interface:
- Rename PCPU_LAZY_INC into PCPU_INC
- Add the PCPU_ADD interface which just does an add on the pcpu member
given a specific value.

Note that for most architectures PCPU_INC and PCPU_ADD are not safe.
This is a point that needs some discussions/work in the next days.

Reviewed by: alc, bde
Approved by: jeff (mentor)

Include freebsd32_signal.h now that signal-related definitions are
moved there.

Found by: ia64 tinderbox.

Add audit hooks for ppc, ia64 system call paths.

Reviewed by: marcel (ia64)
Obtained from: TrustedBSD Project
MFC after: 3 days

Retire SYF_ARGMASK and remove both SYF_MPSAFE and SYF_ARGMASK. sy_narg is
now back to just being an argument count.

Now that all system calls are MPSAFE, retire the SYF_MPSAFE flag used to
mark system calls as being MPSAFE:
- Stop conditionally acquiring Giant around system call invocations.
- Remove all of the 'M' prefixes from the master system call files.
- Remove support for the 'M' prefix from the script that generates the
syscall-related files from the master system call files.
- Don't explicitly set SYF_MPSAFE when registering nfssvc.

Unify the checking for lock misbehavior in the various syscall()
implementations and adjust some of the checks while I'm here:
- Add a new check to make sure we don't return from a syscall in a critical
section.
- Add a new explicit check before userret() to make sure we don't return
with any locks held. The advantage here is that we can include the
syscall number and name in syscall() whereas that info is not available
in userret().
- Drop the mtx_assert()'s of sched_lock and Giant. They are replaced by
the more general checks just added.

MFC after: 2 weeks

Add KTR_SYSC tracing to the syscall() implementations that didn't have it
yet.

MFC after: 1 week

Add missing ptrace(2) system-call stops to various syscall()
implementations.

MFC after: 1 week

Simplify system time accounting for profiling.

Rename struct thread's td_sticks to td_pticks, we will need the
other name for more appropriately named use shortly. Reduce it
from uint64_t to u_int.

Clear td_pticks whenever we enter the kernel instead of recording
its value as reference for userret(). Use the absolute value of
td->pticks in userret() and eliminate third argument.

1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most
changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.

2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.

3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.

4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.

5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.

6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.

Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64

Implement 32 bit getcontext/setcontext/swapcontext on amd64. I've added
stubs for ia64 to keep it compiling. These are used by 32 bit apps such
as gdb.

Move the ia32_sigcode structure from ia32_sigtramp.c to ia32_signal.c.
It's a bit excessive to have it in a file of its own.

Remove redundant $FreeBSD$

Jumbo-commit to enhance 32 bit application support on 64 bit kernels.
This is good enough to be able to run a RELENG_4 gdb binary against
a RELENG_4 application, along with various other tools (eg: 4.x gcore).
We use this at work.

ia32_reg.[ch]: handle the 32 bit register file format, used by ptrace,
procfs and core dumps.
procfs_*regs.c: vary the format of proc/XXX/*regs depending on the client
and target application.
procfs_map.c: Don't print a 64 bit value to 32 bit consumers, or their
sscanf fails. They expect an unsigned long.
imgact_elf.c: produce a valid 32 bit coredump for 32 bit apps.
sys_process.c: handle 32 bit consumers debugging 32 bit targets. Note
that 64 bit consumers can still debug 32 bit targets.

IA64 has got stubs for ia32_reg.c.

Known limitations: a 5.x/6.x gdb uses get/setcontext(), which isn't
implemented in the 32/64 wrapper yet. We also make a tiny patch to
gdb pacify it over conflicting formats of ld-elf.so.1.

Approved by: re

Use PCPU_LAZY_INC() for cnt.v_{intr,trap,syscalls} rather than atomic
operations in some places and simple non-per CPU math in others.

/* -> /*- for copyright notices, minor format tweaks as necessary

...And fix WITNESS builds: declare syscallnames.

Fix INVARIANTS build: Include <machine/cpu.h>.

Move the IA-32 trap handling from trap() to ia32_trap(). Move the
ia32_syscall() function along with it to ia32_trap.c. When COMPAT_IA32
is not defined, we'll raise SIGEMT instead.

Add missing #include "opt_compat.h" so that the compatability function
freebsd4_freebsd32_sigreturn() is defined when expected. This should
unbreak the tinderbox. Sorry.

Assimilate ia64 back into the fold with the common freebsd32/ia32 code.
The split-up code is derived from the ia64 code originally.

Note that I have only compile-tested this, not actually run-tested it.
The ia64 side of the force is missing some significant chunks of signal
delivery code.

Regen.

Sync with global syscalls.master. ptrace(), dup(), pipe(), ktrace(),
ia32_sigaltstack(), sysarch(), issetugid(), utrace(), and ia32_sigaction()
are MP safe.

Add sysentvec->sv_fixlimits() hook so that we can catch cases on 64 bit
systems where the data/stack/etc limits are too big for a 32 bit process.

Move the 5 or so identical instances of ELF_RTLD_ADDR() into imgact_elf.c.

Supply an ia32_fixlimits function. Export the clip/default values to
sysctl under the compat.ia32 heirarchy.

Have mmap(0, ...) respect the current p->p_limits[RLIMIT_DATA].rlim_max
value rather than the sysctl tweakable variable. This allows mmap to
place mappings at sensible locations when limits have been reduced.

Have the imgact_elf.c ld-elf.so.1 placement algorithm use the same
method as mmap(0, ...) now does.

Note that we cannot remove all references to the sysctl tweakable
maxdsiz etc variables because /etc/login.conf specifies a datasize
of 'unlimited'. And that causes exec etc to fail since it can no
longer find space to mmap things.

Regen.

Swap sigaction/sigreturn since they are in the wrong order.

Noticed indirectly by: peter

Fixup the ELF branding information to point to the new home of rtld.

Revamp of the syscall path, exception and context handling. The
prime objectives are:
o Implement a syscall path based on the epc inststruction (see
sys/ia64/ia64/syscall.s).
o Revisit the places were we need to save and restore registers
and define those contexts in terms of the register sets (see
sys/ia64/include/_regset.h).

Secundairy objectives:
o Remove the requirement to use contigmalloc for kernel stacks.
o Better handling of the high FP registers for SMP systems.
o Switch to the new cpu_switch() and cpu_throw() semantics.
o Add a good unwinder to reconstruct contexts for the rare
cases we need to (see sys/contrib/ia64/libuwx)

Many files are affected by this change. Functionally it boils
down to:
o The EPC syscall doesn't preserve registers it does not need
to preserve and places the arguments differently on the stack.
This affects libc and truss.
o The address of the kernel page directory (kptdir) had to
be unstaticized for use by the nested TLB fault handler.
The name has been changed to ia64_kptdir to avoid conflicts.
The renaming affects libkvm.
o The trapframe only contains the special registers and the
scratch registers. For syscalls using the EPC syscall path
no scratch registers are saved. This affects all places where
the trapframe is accessed. Most notably the unaligned access
handler, the signal delivery code and the debugger.
o Context switching only partly saves the special registers
and the preserved registers. This affects cpu_switch() and
triggered the move to the new semantics, which additionally
affects cpu_throw().
o The high FP registers are either in the PCB or on some
CPU. context switching for them is done lazily. This affects
trap().
o The mcontext has room for all registers, but not all of them
have to be defined in all cases. This mostly affects signal
delivery code now. The *context syscalls are as of yet still
unimplemented.

Many details went into the removal of the requirement to use
contigmalloc for kernel stacks. The details are mostly CPU
specific and limited to exception_save() and exception_restore().
The few places where we create, destroy or switch stacks were
mostly simplified by not having to construct physical addresses
and additionally saving the virtual addresses for later use.

Besides more efficient context saving and restoring, which of
course yields a noticable speedup, this also fixes the dreaded
SMP bootup problem as a side-effect. The details of which are
still not fully understood.

This change includes all the necessary backward compatibility
code to have it handle older userland binaries that use the
break instruction for syscalls. Support for break-based syscalls
has been pessimized in favor of a clean implementation. Due to
the overall better performance of the kernel, this will still
be notived as an improvement if it's noticed at all.

Approved by: re@ (jhb)

Regen.

Oops, the thr_* and jail_attach() syscall entries should be NOPROTO rather
than STD.

Regen.

Fix the thr_create() entry by adding a trailing \. Also, sync up the
MP safe flag for thr_* with the main table.

- Replace inline implementations of sigprocmask() with calls to
kern_sigprocmask() in the various binary compatibility emulators.
- Replace calls to sigsuspend(), sigaltstack(), sigaction(), and
sigprocmask() that used the stackgap with calls to the corresponding
kern_sig*() functions instead without using the stackgap.

o In struct prison, add an allprison linked list of prisons (protected
by allprison_mtx), a unique prison/jail identifier field, two path
fields (pr_path for reporting and pr_root vnode instance) to store
the chroot() point of each jail.
o Add jail_attach(2) to allow a process to bind to an existing jail.
o Add change_root() to perform the chroot operation on a specified
vnode.
o Generalize change_dir() to accept a vnode, and move namei() calls
to callers of change_dir().
o Add a new sysctl (security.jail.list) which is a group of
struct xprison instances that represent a snapshot of active jails.

Reviewed by: rwatson, tjr

- Add thr and umtx system calls.

- Add a placeholder for sigwait

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

Approved by: trb

Remove #include <sys/dkstat.h>

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

Synchronize to kern/syscalls.master:1.139.

Obtained from: TrustedBSD Project

Regen: swapoff

Change swapoff from MNOPROTO to UNIMPL. The former doesn't work.

This is David Schultz's swapoff code which I am finally able to commit.
This should be considered highly experimental for the moment.

Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU>
MFC after: 3 weeks

SCARGS removal take II.

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

Remove SCARGS.

Reviewed by: md5

Regenerate after adding syscalls.

Add *context() syscalls to ia64 32-bit compatability table as requested
in kern/syscalls.master.

Sync to src/sys/kern/syscalls.master

Stake a claim on 418 (__xstat), 419 (__xfstat), 420 (__xlstat)

Grab 416/417 real estate before I get burned while testing again.
This is for the not-quite-ready signal/fpu abi stuff. It may not see
the light of day, but I'm certainly not going to be able to validate it
when getting shot in the foot due to syscall number conflicts.

Add a placeholder for the execve_mac() system call, similar to SELinux's
execve_secure() system call, which permits a process to pass in a label
for a label change during exec. This permits SELinux to change the
label for the resulting exec without a race following a manual label
change on the process. Because this interface uses our general purpose
MAC label abstraction, we call it execve_mac(), and wrap our port of
SELinux's execve_secure() around it with appropriate sid mappings.

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

re-regen. Sigh.

Sigh. Fix fat-fingering of diff. I knew this was going to happen.

regenerate. sendfile stuff and other recently picked up stubs.

Try and deal with the #ifdef COMPAT_FREEBSD4 sendfile stuff. This would
have been a lot easier if do_sendfile() was usable externally.

Try and patch up some tab-to-space spammage.

Add placeholder stubs for nsendfile, mac_syscall, ksem_close, ksem_post,
ksem_wait, ksem_trywait, ksem_init, ksem_open, ksem_unlink, ksem_getvalue,
ksem_destroy, __mac_get_pid, __mac_get_link, __mac_set_link,
extattr_set_link, extattr_get_link, extattr_delete_link.

Let kse_wakeup() take a KSE mailbox pointer argument.

Reviewed by: julian

Make the following name changes to KSE related functions, etc., to better
represent their purpose and minimize namespace conflicts:

kse_fn_t -> kse_func_t
struct thread_mailbox -> struct kse_thr_mailbox
thread_interrupt() -> kse_thr_interrupt()
kse_yield() -> kse_release()
kse_new() -> kse_create()

Add missing declaration of kse_thr_interrupt() to <sys/kse.h>.
Regenerate the various generated syscall files. Minor style fixes.

Reviewed by: julian

Added fields for VM_MIN_ADDRESS, PS_STRINGS and stack protections to
sysentvec. Initialized all fields of all sysentvecs, which will allow
them to be used instead of constants in more places. Provided stack
fixup routines for emulations that previously used the default.

Regenerate

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).

Use suword32/64 and fuword32/64 like elsewhere instead of inventing
suhword/fuhword.

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

Spotted and suggested by: des
MFC after: 3 weeks

Initial support for executing IA-32 binaries. This will not compile
without a few patches for the rest of the kernel to allow the image
activator to override exec_copyout_strings and setregs.

None of the syscall argument translation has been done. Possibly, this
translation layer can be shared with any platform that wants to support
running ILP32 binaries on an LP64 host (e.g. sparc32 binaries?)