Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC: r234352

Implement pipe2 syscall for Linuxulator.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

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)

Second-to-last commit implementing Capsicum capabilities in the FreeBSD
kernel for FreeBSD 9.0:

Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *. With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.

Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.

In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.

Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.

Approved by: re (bz)
Submitted by: jonathan
Sponsored by: Google Inc

Move linux_clone(), linux_fork(), linux_vfork() to a MI path.

In preparation for moving linux_clone() to a MI path
introduce linux_set_upcall_kse().

In preparation for moving linux_clone () to a MI path
move the TLS code in a separate function.

Use function parameter instead of direct using register.

The kern_wait() code already removes the SIGCHLD signal for the waited
process. Removing other SIGCHLD signals is not needed and may cause
problems.

Pointed out by: jilles

MFC after: 1 Month.

Implement a variation of the linux_common_wait() which should
be used by linuxolator itself.

Move linux_wait4() to MD path as it requires native struct
rusage translation to struct l_rusage on linux32/amd64.

MFC after: 1 Month.

Add macro to test the sv_flags of any process. Change some places to test
the flags instead of explicit comparing with address of known sysentvec
structures.

MFC after: 1 month

Do not require pos parameter to be zero in MAP_ANONYMOUS mmap requests
in Linux emulation layer. Linux seems to only require that pos is
page-aligned, but otherwise ignores it. Default FreeBSD mmap parameter
checking is too strict to allow some Linux binaries to run. tsMuxeR is
one example of such a binary.

Discussed with: jhb
MFC after: 1 week

Fix some problems with effective mmap() offsets > 32 bits. This was
partially fixed on amd64 earlier. Rather than forcing linux_mmap_common()
to use a 32-bit offset, have it accept a 64-bit file offset. This offset
is then passed to the real mmap() call. Rather than inventing a structure
to hold the normal linux_mmap args that has a 64-bit offset, just pass
each of the arguments individually to linux_mmap_common() since that more
closes matches the existing style of various kern_foo() functions.

Submitted by: Christian Zander @ Nvidia
MFC after: 1 week

Return ENOSYS instead of EINVAL for invalid function codes to match the
behavior of Linux.

Reported by: Alexander Best alexbestms of math.uni-muenster.de
Approved by: re (kib)

Adapt linux emulation to use cv for vfork wait.

Submitted by: Takahiro Kurosawa <takahiro.kurosawa gmail com>
PR: kern/131506

Several cleanups related to pipe(2).

- Use `fildes[2]' instead of `*fildes' to make more clear that pipe(2)
fills an array with two descriptors.

- Remove EFAULT from the manual page. Because of the current calling
convention, pipe(2) raises a segmentation fault when an invalid
address is passed.

- Introduce kern_pipe() to make it easier for binary emulations to
implement pipe(2).

- Make Linux binary emulation use kern_pipe(), which means we don't have
to recover td_retval after calling the FreeBSD system call.

Approved by: rdivacky
Discussed on: arch

Fix Linux mmap with MAP_GROWSDOWN flag.

Reported by: Andriy Gapon (avg at icyb dot net dot ua)
Tested by: Andriy Gapon (avg at icyb dot net dot ua)
Pointyhat: me
MFC after: 3 days

Implement read_default_ldt in linux_modify_ldt(). It copies out zeroed
descriptor, like real Linux does.

Tested by: Yuriy Tsibizov <yuriy.tsibizov at gmail com>
Submitted by: rdivacky
MFC after: 1 week

i386_set_ioperm, i386_get_ldt and i386_set_ldt are now MPSAFE
(Giant/sched_lock free) so remove unuseful Giant cruft.

Approved by: jeff
Approved by: re
Sponsorized by: NGX Italy (http://www.ngx.it)

Don't add the 'pad' argument to the mmap/truncate/etc syscalls.

Submitted by: kensmith
Approved by: re (kensmith)

Commit 14/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.

Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)

Do not dereference linux_to_bsd_signal[-1] if userland has
passed zero as exit signal.

GCC 4.2 changes the kernel data segment layout not to have 0
in that memory location. This code ran by luck before and now
the luck has run out.

MFP4: 115220, 115222

- Fix style(9) and reduce diff between amd64 and i386.
- Prefix Linuxulator macros with LINUX_ to prevent future collision.

MFP4: 115094

Linux does not check file descriptor when MAP_ANONYMOUS is set.
This should fix recent LTP test regressions.

Reported by: Scot Hetzel (swhetzel at gmail dot com)
netchild

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

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

MFp4 (114193 (i386 part), 114194, 114195, 114200):
- Dont "return" in linux_clone() after we forked the new process in a case
of problems.
- Move the copyout of p2->p_pid outside the emul_lock coverage in
linux_clone().
- Cache the em->pdeath_signal in a local variable and move the copyout
out of the emul_lock coverage.
- Move the free() out of the emul_shared_lock coverage in a preparation
to switch emul_lock to non-sleepable lock (mutex).

Submitted by: rdivacky

MFP4: 113025, 113146, 113177, 113203, 113500, 113546, 113570

- PROT_READ, PROT_WRITE, or PROT_EXEC implies PROT_READ and PROT_EXEC.
Linux/ia64's i386 emulation layer does this and it complies with Linux
header files. This fixes mmap05 LTP test case on amd64.
- Do not adjust stack size when failure has occurred.
- Synchronize i386 mmap/mprotect with amd64.

Fix LOR that occurs because proctree_lock was acquired while holding
emuldata lock by moving the code upwards outside the emul_lock coverage.

Submitted by: rdivacky

- Remove setrunqueue and replace it with direct calls to sched_add().
setrunqueue() was mostly empty. The few asserts and thread state
setting were moved to the individual schedulers. sched_add() was
chosen to displace it for naming consistency reasons.
- Remove adjustrunqueue, it was 4 lines of code that was ifdef'd to be
different on all three schedulers where it was only called in one place
each.
- Remove the long ifdef'd out remrunqueue code.
- Remove the now redundant ts_state. Inspect the thread state directly.
- Don't set TSF_* flags from kern_switch.c, we were only doing this to
support a feature in one scheduler.
- Change sched_choose() to return a thread rather than a td_sched. Also,
rely on the schedulers to return the idlethread. This simplifies the
logic in choosethread(). Aside from the run queue links kern_switch.c
mostly does not care about the contents of td_sched.

Discussed with: julian

- Move the idle thread loop into the per scheduler area. ULE wants to
do something different from the other schedulers.

Suggested by: jhb

Tested on: x86/amd64 sched_{4BSD, ULE, CORE}.

MFp4 (113077, 113083, 113103, 113124, 113097):

Dont expose em->shared to the outside world before its properly
initialized. Might not affect anything but its at least a better
coding style.

Dont expose em via p->p_emuldata until its properly initialized.
This also enables us to get rid of some locking and simplify the
code because we are workin on a local copy.

In linux_fork and linux_vfork create the process in stopped state
to be sure that the new process runs with fully initialized emuldata
structure [1]. Also fix the vfork (both in linux_clone and linux_vfork)
race that could result in never woken up process [2].

Reported by: Scot Hetzel [1]
Suggested by: jhb [2]
Reviewed by: jhb (at least some important parts)
Submitted by: rdivacky
Tested by: Scot Hetzel (on amd64)

Change 2 comments (in the new code) to comply to style(9).

Suggested by: jhb

MFp4 (112893):
Make linux_vfork() actually work. This enables make to work again with 2.6.
It also fixes the LTP vfork tests.

Submitted by: rdivacky

MFp4 (112498):
Rename the locking flags to EMUL_DOLOCK and EMUL_DONTLOCK to prevent confusion.

Submitted by: rdivacky

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>

Fix a recent regression regarding valid signals.

Submitted by: rdivacky

MFP4 (106538 + 106541):
Implement CLONE_VFORK. This fixes the clone05 LTP test.

Submitted by: rdivacky

Revert my previous commit, I mismerged this to the wrong place.

Pointy hat to: netchild

MFP4 (106541): Fix the clone05 test in the LTP.

Submitted by: rdivacky

MFP4 (107144[1]): Implement CLONE_FS on i386[1] and amd64.

Submitted by: rdivacky [1]

MFP4 (107868 - 107870):
Use a macro to test for a valid signal instead of doing it my hand everywhere.

Submitted by: rdivacky

style(9)

While I'm here add a MFC reminder, I forgot it in the previous commit.

Noticed by: ssouhlal
MFC after: 1 week

Bring the i386 linux mmap code more into line with how linux (2.4.x)
behaves. This fixes a lot of test which failed before. For amd64 there
are still some problems, but without any testers which apply patches
and run some predefines tests we can't do more ATM.

Submitted by: Marcin Cieslak <saper@SYSTEM.PL> (minor fixups by myself)
Tested with: LTP

Fix video playing and network connections in realplayer (and most likely
other stuff) in the osrelease=2.6.16 case:
- implement CLONE_PARENT semantic
- fix TLS loading in clone CLONE_SETTLS
- lock proc in the currently disabled part of CLONE_THREAD

I suggest to not unload the linux module after testing this, there are
some "<defunct>" processes hanging around after exiting (they aren't
with osrelease=2.4.2) and they may panic your kernel when unloading the
linux module. They are in state Z and some of them consume CPU according
to ps. But I don't trust the CPU part, the idle threads gets too much CPU
that this may be possible (accumulating idle, X and 2 defunct processes
results in 104.7%, this looks to much to be a rounding error).

Noticed by: Intron <mag@intron.ac>
Submitted by: rdivacky (in collaboration with Intron)
Tested by: Intron, netchild
Reviewed by: jhb (previous version)

Emulate what vfork does instead of using it in linux_vfork. This way
we can do the stuff we need to do with linux processes at fork and
don't panic the kernel at exit of the child.

Submitted by: rdivacky
Tested with: tst-vfork* (glibc regression tests)
Tested by: netchild

Move some stuff into headers where they belong.

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Noticed by: jhb, ssouhlal

Style fixes to comments.

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Noticed by: jhb, ssouhlal

Add the linux 2.6.x stuff (not used by default!):
- TLS - complete
- pid/tid mangling - complete
- thread area - complete
- futexes - complete with issues
- clone() extension - complete with some possible minor issues
- mq*/timer*/clock* stuff - complete but untested and the mq* stuff is
disabled when not build as part of the kernel with native FreeBSD mq*
support (module support for this will come later)

Tested with:
- linux-firefox - works, tested
- linux-opera - works, tested
- linux-realplay - doesnt work, issue with futexes
- linux-skype - doesnt work, issue with futexes
- linux-rt2-demo - works, tested
- linux-acroread - doesnt work, unknown reason (coredump) and sometimes
issue with futexes
- various unix utilities in linux-base-gentoo3 and linux-base-fc4:
everything tried worked

On amd64 not everything is supported like on i386, the catchup is planned for
later when the remaining bugs in the new functions are fixed.

To test this new stuff, you have to run
sysctl compat.linux.osrelease=2.6.16
to switch back use
sysctl compat.linux.osrelease=2.4.2

Don't switch while running a linux program, strange things may or may not
happen.

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Some suggestions/help by: jhb, kib, manu@NetBSD.org, netchild

- Always call exec_free_args() in kern_execve() instead of doing it in all
the callers if the exec either succeeds or fails early.
- Move the code to call exit1() if the exec fails after the vmspace is
gone to the bottom of kern_execve() to cut down on some code duplication.

Propagate error code of kern_execve() to the caller properly.

PR: 81670
Submitted by: Andrew Bliznak <andriko.b@gmail.com>
Pointy hat to: sobomax

In linux emulation layer try to detect attempt to use linux_clone() to
create kernel threads and call rfork(2) with RFTHREAD flag set in this case,
which puts parent and child into the same threading group. As a result
all threads that belong to the same program end up in the same threading
group.

This is similar to what linuxthreads port does, though in this case we don't
have a luxury of having access to the source code and there is no definite
way to differentiate linux_clone() called for threading purposes from other
uses, so that we have to resort to heuristics.

Allow SIGTHR to be delivered between all processes in the same threading
group previously it has been blocked for s[ug]id processes.

This also should improve locking of the same file descriptor from different
threads in programs running under linux compat layer.

PR: kern/72922
Reported by: Andriy Gapon <avg@icyb.net.ua>
Idea suggested by: rwatson

Use the LCONVPATHEXIST() macro rather than it's exact expansion to be
consistent.

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

o Move copyin()/copyout() out of i386_{get,set}_ldt() and
i386_{get,set}_ioperm() and make those APIs visible in the kernel namespace;

o use i386_{get,set}_ldt() and i386_{get,set}_ioperm() instead of sysarch()
in the linuxlator, which allows to kill another two stackgaps.

MFC after: 2 weeks

Add a few stub syscalls to get TransGaming's winex a bit closer to
working.

Give setrunqueue() and sched_add() more of a clue as to
where they are coming from and what is expected from them.

MFC after: 2 days

Correct the arguments to kern_sigaltstack() as they were reversed.

PR: kern/68079
Submitted by: Georg-W. Koltermann gwk at rahn-koltermann dot de

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

Use __FBSDID().

Synchronize the two linux_clone() implementations which includes a few
minor cleanups in both.

- Move p->p_sigmask to td->td_sigmask. Signal masks will be per thread with
a follow on commit to kern_sig.c
- signotify() now operates on a thread since unmasked pending signals are
stored in the thread.
- PS_NEEDSIGCHK moves to TDF_NEEDSIGCHK.

Print the return value from mmap() in the DEBUG case.

Including <sys/stdint.h> is (almost?) universally only to be able to use
%j in printfs, so put a newsted include in <sys/systm.h> where the printf
prototype lives and save everybody else the trouble.

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.

Fixed syntax errors and printf format errors.

- Add support for IPC_64 extensions into shmctl(2), semctl(2) and msgctl(2);
- add wrappers for mmap2(2) and ftruncate64(2) system calls;
- don't spam console with printf's when VFAT_READDIR_BOTH ioctl(2) is invoked;
- add support for SOUND_MIXER_READ_STEREODEVS ioctl(2);
- make msgctl(IPC_STAT) and IPC_SET actually working by converting from
BSD msqid_ds to Linux and vice versa;
- properly return EINVAL if semget(2) is called with nsems being negative.

Reviewed by: marcel
Approved by: marcel
Tested with: LSB runtime test

Some kernel threads try to do significant work, and the default KSTACK_PAGES
doesn't give them enough stack to do much before blowing away the pcb.
This adds MI and MD code to allow the allocation of an alternate kstack
who's size can be speficied when calling kthread_create. Passing the
value 0 prevents the alternate kstack from being created. Note that the
ia64 MD code is missing for now, and PowerPC was only partially written
due to the pmap.c being incomplete there.
Though this patch does not modify anything to make use of the alternate
kstack, acpi and usb are good candidates.

Reviewed by: jake, peter, jhb

Completely redo thread states.

Reviewed by: davidxu@freebsd.org

Use the new kern_* functions to avoid the need to store arguments
in the stack gap. This converts most VFS and signal related system
calls, as well as select().

Discussed on: -arch
Approved by: marcel

Part 1 of KSE-III

The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)

Reviewed by: Almost everyone who counts
(at various times, peter, jhb, matt, alfred, mini, bernd,
and a cast of thousands)

NOTE: this is still Beta code, and contains lots of debugging stuff.
expect slight instability in signals..

Change the suser() API to take advantage of td_ucred as well as do a
general cleanup of the API. The entire API now consists of two functions
similar to the pre-KSE API. The suser() function takes a thread pointer
as its only argument. The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0. The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.

Discussed on: smp@

Fix format warning.

Submitted by: LINT, -Werror

Simple p_ucred -> td_ucred changes to start using the per-thread ucred
reference.

Pre-KSE/M3 commit.
this is a low-functionality change that changes the kernel to access the main
thread of a process via the linked list of threads rather than
assuming that it is embedded in the process. It IS still embeded there
but remove all teh code that assumes that in preparation for the next commit
which will actually move it out.

Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,

Oops, these already included sys/lock.h, they just did so after
sys/mutex.h which is too late.

Add missing includes of sys/lock.h.

o Modify access control checks in linux_iopl() to use securelevel_gt()
rather than direct variable checks. (Yet another API to perform
direct hardware I/O.)

Obtained from: TrustedBSD Project

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

Round of cleanups and enhancements. These include (in random order):

o Introduce private types for use in linux syscalls for two reasons:
1. establish type independence for ease in porting and,
2. provide a visual queue as to which syscalls have proper
prototypes to further cleanup the i386/alpha split.
Linuxulator types are prefixed by 'l_'. void and char have not
been "virtualized".

o Provide dummy functions for all syscalls and remove dummy functions
or implementations of truely obsolete syscalls.

o Sanitize the shm*, sem* and msg* syscalls.

o Make a first attempt to implement the linux_sysctl syscall. At this
time it only returns one MIB (KERN_VERSION), but most importantly,
it tells us when we need to add additional sysctls :-)

o Bump the kenel version up to 2.4.2 (this is not the same as the
KERN_VERSION MIB, BTW).

o Implement new syscalls, of which most are specific to i386. Our
syscall table is now up to date with Linux 2.4.2. Some highlights:
- Implement the 32-bit uid_t and gid_t bases syscalls.
- Implement a couple of 64-bit file size/offset bases syscalls.

o Fix or improve numerous syscalls and prototypes.

o Reduce style(9) violations while I'm here. Especially indentation
inconsistencies within the same file are addressed. Re-indenting
did not obfuscate actual changes to the extend that it could not
be combined.

NOTE: I spend some time testing these changes and found that if there
were regressions, they were not caused by these changes AFAICT.
It was observed that installing a RH 7.1 runtime environment
did make matters worse. Hangs and/or reboots have been observed
with and without these changes, so when it failed to make life
better in cases it doesn't look like it made it worse.

Add a new MI pointer to the process' trapframe p_frame instead of using
various differently named pointers buried under p_md.

Reviewed by: jake (in principle)

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)

rfork() masks RFSTOPPED out of the flags it passes to fork1(), so we have
to call fork1() directly if we don't want out process queued right away.
This has the serendipitous side effect of saving us a call to pfind().

This makes threaded Linux apps (such as Opera) work again.

Create clone'd linux processes as stopped processes at first and don't
actually make them runnable until after the emulator layer has had a chance
to perform fixups.

Linux does not filesystem-sync file-backed writable mmap pages on
a regular basis. Adjust our linux emulation to conform. This will
cause more dirty pages to be left for the pagedaemon to deal with,
but our new low-memory handling code can deal with it. The linux
way appears to be a trend, and we may very well make MAP_NOSYNC the
default for FreeBSD as well (once we have reasonable sequential
write-behind heuristics for random faults).
(will be MFC'd prior to 4.3 freeze)

Suggested by: Andrew Gallatin

Allow debugging output to be controlled on a per-syscall granularity.
Also clean up debugging output in a slightly more uniform fashion.

The default behavior remains the same (all debugging output is turned on)

- Proc locking.
- Use NULL instead of 0.

Don't use p->p_sigstk.ss_flags to keep state of whether the
process is on the alternate stack or not. For compatibility
with sigstack(2) state is being updated if such is needed.

We now determine whether the process is on the alternate
stack by looking at its stack pointer. This allows a process
to siglongjmp from a signal handler on the alternate stack
to the place of the sigsetjmp on the normal stack. When
maintaining state, this would have invalidated the state
information and causing a subsequent signal to be delivered
on the normal stack instead of the alternate stack.

PR: 22286

Revert auto-generation. The Alpha port is broken.
Syncing with it is wrong.

Make MINSIGSTKSZ machine dependent, and have the sigaltstack
syscall compare against a variable sv_minsigstksz in struct
sysentvec as to properly take the size of the machine- and
ABI dependent struct sigframe into account.

The SVR4 and iBCS2 modules continue to have a minsigstksz of
8192 to preserve behavior. The real values (if different) are
not known at this time. Other ABI modules use the real
values.

The native MINSIGSTKSZ is now defined as follows:

Arch MINSIGSTKSZ
---- -----------
alpha 4096
i386 2048
ia64 12288

Reviewed by: mjacob
Suggested by: bde

Sync with Alpha:
Do not use sysent.c, proto.h and syscall.h in source tree;
use auto-generated versions.

fix the sigaltstack hack by lowering the stack size to the original value
if the request was for less than MINSIGSTKSZ (in which case we "round up").
discussed with: marcel

Some linux apps, such as IBM's JDK 1.3, will attempt to mmap thread
stacks near the top of their address space. If their TOS is greater
than vm_maxsaddr, vm_map_growstack() will confuse the thread stack
with the process stack and deliver a SEGV if they attempt to grow the
thread stack past their current stacksize rlimit. To avoid this,
adjust vm_maxsaddr upwards to reflect the current stacksize rlimit
rather than the maximum possible stacksize. It would be better to
adjust the mmap'ed region, but some apps (again, IBM's JDK 1.3) do not
check mmap's return value..

This commit (in conjunction with setting MINSIGSTKSZ to 2048 &
rebuilding your kernel and modules) will get IBM's JDK 1.3 working
with FreeBSD at least well enough to run many of the example applets.

Reviewed by: marcel
Tested by: sto@stat.duke.edu, many others on freebsd-java@

This is the first of 3 commits that will get IBM's JDK 1.3 working
with FreeBSD (not including the MINSIGSTKSZ issue, which belongs to
Marcel). Due to time constraints, I'm going to space them out over a
few days.

This fixes two problems with linux_sigaltstack()

o ss == 0 is perfectly valid use, so do not fail in this case.

o Fix flag handling:
- Our SS_DISABLE is 4, linux's is 2, so we need conversion routines.
These conversion routines will be needed by linux_rt_sendsig()
and linux_rt_sigreturn (forthcoming), so they are not static.
- Linux's flag 0 historically meant SS_ONSTACK according to a comment
in their linux/kernel/signal.c file.

Among other things, this fixes a warning from Sun's JDK 1.3:
"Java HotSpot(TM) Client VM warning: cannot uninstall alt signal stack"

Reviewed by: marcel
Tested by: sto@stat.duke.edu, many others on freebsd-java@

When sigaltstack is called with a stack size that's not smaller
than LINUX_MINSIGSTKSZ but smaller than MINSIGSTKSZ, cheat and
pass MINSIGSTKSZ to the kernel. This is a workaround.

Submitted through: nate

Fix typo in license.

Collect the MD syscalls from /sys/compat/linux here. Since this
is a new file, fix most of the style bugs at the same time.