Remove LIBELF_PIC.

Sponsored by:	The FreeBSD Foundation
Load tunable from loader.conf(5) instead of device.hints(5).
It seems all Broadcom controllers have a bug that can generate UDP
datagrams with checksum value 0 when TX UDP checksum offloading is
enabled.  Generating UDP checksum value 0 is RFC 768 violation.
Even though the probability of generating such UDP datagrams is
low, I don't want to see FreeBSD boxes to inject such datagrams
into network so disable UDP checksum offloading by default.  Users
still override this behavior by setting a sysctl variable or loader
tunable, dev.bge.%d.forced_udpcsum.

I have no idea why this issue was not reported so far given that
bge(4) is one of the most commonly used controller on high-end
server class systems. Thanks to andre@ who passed the PR to me.

PR:	kern/104826
Document newly introduced tunable dev.bge.%d.forced_udpcsum.
While I'm here also mention tunable dev.bge.%d.forced_collapse.
Add support for whiteouts on tmpfs.

Right now unionfs only allows filesystems to be mounted on top of
another if it supports whiteouts. Even though I have sent a patch to
daichi@ to let unionfs work without it, we'd better also add support for
whiteouts to tmpfs.

This patch implements .vop_whiteout and makes necessary changes to
lookup() and readdir() to take them into account. We must also make sure
that when adding or removing a file, we honour the componentname's
DOWHITEOUT and ISWHITEOUT, to prevent duplicate filenames.

MFC after:	1 month
Add the FreeBSD definition for the fasttrap ioctls.

Sponsored by:	The FreeBSD Foundation
Add a function compatibility function dtrace_instr_size_isa() that on
FreeBSD does the same as dtrace_dis_isize().

Sponsored by:	The FreeBSD Foundation
Kernel DTrace support for:
o uregs  (sson@)
o ustack (sson@)
o /dev/dtrace/helper device (needed for USDT probes)

The work done by me was:
Sponsored by:	The FreeBSD Foundation
sh: Add a test for breaking from a loop outside the current function.

It is unwise to rely on this but I'd like to know if this would break.
Add more compatibility structure members needed by the upcoming fasttrap
DTrace device.

Sponsored by:	The FreeBSD Foundation
Destroy the helper device when unloading.

Sponsored by:	The FreeBSD Foundation
Fix keyword expansion properties.
Fix style issues.

Sponsored by:	The FreeBSD Foundation
Bump KDTRACE_THREAD_ZERO and use M_ZERO as a malloc flag instead of
calling bzero.

Sponsored by:	The FreeBSD Foundation
Remove an elif and add an or-clause.

Sponsored by:	The FreeBSD Foundation
Add an extra comment to the SDT probes definition. This allows us to get
use '-' in probe names, matching the probe names in Solaris.[1]

Add userland SDT probes definitions to sys/sdt.h.

Sponsored by:	The FreeBSD Foundation
Discussed with:	rwaston [1]
Call the systrace_probe_func() when the error value.

Sponsored by:	The FreeBSD Foundation
Port this to FreeBSD. We miss some suword functions, so we use copyout.

Sponsored by:	The FreeBSD Foundation
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M    sys/fasttrap_impl.h
UTFize my name.
sh(1): Add a brief summary of arithmetic expressions.