Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

mmap map_at_zero test: handle W^X

Use kern.elfXX.allow_wx to decide whether to map W+X or W-only memory.

Future work could expand this test to add an "allow_wx" axis to the
test matrix, but I would argue that a separate test should be written,
since that's orthogonal to map_at_zero.

MFC after: 1 week
Sponsored by: Dell EMC Isilon

Fix write only mappings on arm64

When trapping on a wrote access to a buffer the kernel has mapped as write
only we should only pass the VM_PROT_WRITE flag. Previously the call to
vm_fault_trap as the VM_PROT_READ flag was unexpected.

Reported by: manu
Sponsored by: Innovate UK

Revert r313565 -- :mmap__bad_arguments passes again after r313655

PR: 216976
Sponsored by: Dell EMC Isilon

Expect :mmap__bad_arguments to fail

Some recent changes to vm related to mmap(2) have broken the prot checks that
would result with an EINVAL with this case

I suspect r313352 is the root-cause the issue

PR: 216976
Sponsored by: Dell EMC Isilon

Fix -Wsign-compare warnings

The loop index (i) doesn't need to be size_t as its comparison is signed

MFC after: 1 week
Sponsored by: Dell EMC Isilon

Fix leaks and test for getpagesize() returning == -1

- close file descriptors after use.
- Always munmap memory regions after mmap'ing them.
- Make sure getpagesize() returns a value greater than 0 and use a
cached value instead of always calling getpagesize(3).

CID: 1331374-1331377, 1331653-1331662
Differential Revision: https://reviews.freebsd.org/D6011
MFC after: 2 weeks
Reported by: Coverity
Reviewed by: cem
Sponsored by: EMC / Isilon Storage Division

Add more mmap tests related to character devices.
- Add cdev-related tests for bad args.
- Add two simple tests cases for mapping /dev/zero that test for
MAP_ANON-like behavior.

Reviewed by: alc, kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D3323

Add various tests to ensure that invalid arguments passed to mmap()
trigger failures.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D3269

Convert the map_at_zero test case to ATF. In particular, this will
facilitate adding more mmap() tests.

MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D3268

Move tests/sys/kern/mmap_test to tests/sys/vm/mmap_test

As jhb noted, the actual mmap(2) implementation is under sys/vm, not
sys/kern/, so the correct logical place is tests/sys/vm/, not
tests/sys/kern/

X-MFC with: r282076
MFC after: 6 days