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 r316426:

Use the kern_clock_nanosleep() to implement Linux clock_nanosleep() with
the proper handling of the TIMER_ABSTIME flag.

MFC r317324:

Map Linux CLOCK_BOOTTIME to native CLOCK_UPTIME.

MFC r316394:

The value in the tv_nsec field should be in the range 0 to 999999999.

MFC r316393:

As noted by bde@ negative tv_sec values are not checked for overflow,
so overflow can still occur. Fix that. Also remove the extra check for
tv_sec size as under COMPAT_LINUX32 it is always true.

MFC r315498:

Check for negative nanoseconds.
Linux do that in timespec_valid().

MFC r314295:

Implement timerfd family syscalls.

MFC r314293:

Return EOVERFLOW error in case then the size of tv_sec field of struct timespec
in COMPAT_LINUX32 Linuxulator's not equal to the size of native tv_sec.

MFC r315510

nanosleep: plug a kernel memory disclosure

nanosleep() updates rmtp on EINVAL. In that case, kern_nanosleep()
has not updated rmt, so sys_nanosleep() updates the user-space rmtp
by copying garbage from its stack frame. This is not only a kernel
memory disclosure, it's also not POSIX-compliant. Fix it to update
rmtp only on EINTR.

Security: possibly
Sponsored by: Dell EMC

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

Linux nanosleep() and clock_nanosleep() system calls always
writes the remaining time into the structure pointed to by rmtp
unless rmtp is NULL. The value of *rmtp can then be used to call
nanosleep() again and complete the specified pause if the previous
call was interrupted.

Note. clock_nanosleep() with an absolute time value does not write
the remaining time.

While here fix whitespaces and typo in SDT_PROBE.

Delete the duplicate of linux_to_native_clockid() function.

Differential Revision: https://reviews.freebsd.org/D1521
Reviewed by: trasz

Do not use struct l_timespec without conversion. While here move
args->timeout handling before acquiring the futex key at FUTEX_WAIT path.

Differential Revision: https://reviews.freebsd.org/D1520
Reviewed by: trasz

Add some clock mappings used in glibc 2.20.

Differential Revision: https://reviews.freebsd.org/D1465
Reviewd by: trasz

- For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
version of the releasing functions for mutex, rwlock and sxlock.
Failing to do so skips the lockstat_probe_func invokation for
unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
kernel compiled without lock debugging options, potentially every
consumer must be compiled including opt_kdtrace.h.
Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested. As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while. Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by: EMC / Isilon storage division
Discussed with: rstone
[0] Reported by: rstone
[1] Discussed with: philip

Reduce duplication between i386/linux/linux.h and amd64/linux32/linux.h
by moving bits that are MI out into headers in compat/linux.

Reviewed by: Chagin Dmitry dmitry | gmail
MFC after: 2 weeks

- >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).

The NetBSD Foundation has granted permission to remove clause 3 and 4 from
their software.

Obtained from: NetBSD

MFP4: 109655

- Move linux_nanosleep() from src/sys/amd64/linux32/linux32_machdep.c to
src/sys/compat/linux/linux_time.c.
- Validate timespec ranges before use as Linux kernel does.
- Fix l_timespec structure.
- Clean up style(9) nits.

Add some new files needed for linux 2.6.x compatibility.

Please don't style(9) the NetBSD code, we want to stay in sync. Not imported
on a vendor branch since we need local changes.

Sponsored by: Google SoC 2006
Submitted by: rdivacky
With help from: manu@NetBSD.org
Obtained from: NetBSD (linux_{futex,time}.*)