- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

MFC 287442,287537,288944:
Fix corruption of coredumps due to procstat notes changing size during
coredump generation. The changes in r287442 required some reworking
since the 'fo_fill_kinfo' file op does not exist in stable/10.

287442:
Detect badly behaved coredump note helpers

Coredump notes depend on being able to invoke dump routines twice; once
in a dry-run mode to get the size of the note, and another to actually
emit the note to the corefile.

When a note helper emits a different length section the second time
around than the length it requested the first time, the kernel produces
a corrupt coredump.

NT_PROCSTAT_FILES output length, when packing kinfo structs, is tied to
the length of filenames corresponding to vnodes in the process' fd table
via vn_fullpath. As vnodes may move around during dump, this is racy.

So:

- Detect badly behaved notes in putnote() and pad underfilled notes.

- Add a fail point, debug.fail_point.fill_kinfo_vnode__random_path to
exercise the NT_PROCSTAT_FILES corruption. It simply picks random
lengths to expand or truncate paths to in fo_fill_kinfo_vnode().

- Add a sysctl, kern.coredump_pack_fileinfo, to allow users to
disable kinfo packing for PROCSTAT_FILES notes. This should avoid
both FILES note corruption and truncation, even if filenames change,
at the cost of about 1 kiB in padding bloat per open fd. Document
the new sysctl in core.5.

- Fix note_procstat_files to self-limit in the 2nd pass. Since
sometimes this will result in a short write, pad up to our advertised
size. This addresses note corruption, at the risk of sometimes
truncating the last several fd info entries.

- Fix NT_PROCSTAT_FILES consumers libutil and libprocstat to grok the
zero padding.

287537:
Follow-up to r287442: Move sysctl to compiled-once file

Avoid duplicate sysctl nodes.

288944:
Fix core corruption caused by race in note_procstat_vmmap

This fix is spiritually similar to r287442 and was discovered thanks to
the KASSERT added in that revision.

NT_PROCSTAT_VMMAP output length, when packing kinfo structs, is tied to
the length of filenames corresponding to vnodes in the process' vm map
via vn_fullpath. As vnodes may move during coredump, this is racy.

We do not remove the race, only prevent it from causing coredump
corruption.

- Add a sysctl, kern.coredump_pack_vmmapinfo, to allow users to disable
kinfo packing for PROCSTAT_VMMAP notes. This avoids VMMAP corruption
and truncation, even if names change, at the cost of up to PATH_MAX
bytes per mapped object. The new sysctl is documented in core.5.

- Fix note_procstat_vmmap to self-limit in the second pass. This
addresses corruption, at the cost of sometimes producing a truncated
result.

- Fix PROCSTAT_VMMAP consumers libutil (and libprocstat, via copy-paste)
to grok the new zero padding.

Approved by: re (gjb)

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

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

Include param.h instead of types.h when using user.h. Otherwise there is
a dependence on ucred.h including audit.h including param.h, which we
would like to eliminate.

MFC after: 3 weeks

Initialize the cntp pointer to 0 prior to doing any work so that callers
don't try to iterate through garbage or NULL memory. Additionally, return
NULL instead of 0 on error.

Reviewed by: peter
Approved by: peter

Attempt a quick bandaid for arm build breakage. I went to the trouble of
maintaining alignment, but I'm not sure how to tell gcc this.

Merge user/peter/kinfo branch as of r185547 into head.

This changes struct kinfo_filedesc and kinfo_vmentry such that they are
same on both 32 and 64 bit platforms like i386/amd64 and won't require
sysctl wrapping.

Two new OIDs are assigned. The old ones are available under
COMPAT_FREEBSD7 - but it isn't that simple. The superceded interface
was never actually released on 7.x.

The other main change is to pack the data passed to userland via the
sysctl. kf_structsize and kve_structsize are reduced for the copyout.
If you have a process with 100,000+ sockets open, the unpacked records
require a 132MB+ copyout. With packing, it is "only" ~35MB. (Still
seriously unpleasant, but not quite as devastating). A similar problem
exists for the vmentry structure - have lots and lots of shared libraries
and small mmaps and its copyout gets expensive too.

My immediate problem is valgrind. It traditionally achieves this
functionality by parsing procfs output, in a packed format. Secondly, when
tracing 32 bit binaries on amd64 under valgrind, it uses a cross compiled
32 bit binary which ran directly into the differing data structures in 32
vs 64 bit mode. (valgrind uses this to track file descriptor operations
and this therefore affected every single 32 bit binary)

I've added two utility functions to libutil to unpack the structures into
a fixed record length and to make it a little more convenient to use.

Add experimental front ends to the kinfo_vmentry and kinfo_filedesc
sysctls.