sys: Remove $FreeBSD$: two-line .h pattern

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

arm64: Remove struct arm64_frame

It was used in one place and was added specifically to support dtrace
stack unwinding code. Write an equivalent expression using struct
unwind_state instead. No functional change intended.

Reviewed by: andrew
MFC after: 1 week
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D40538

dtrace: rename rp to frame in dtrace_getreg()

Reviewed by: mhorne, markj
Approved by: markj (mentor)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D40231

dtrace: add register bindings for arm64

Reviewed by: mhorne, markj
Approved by: markj (mentor)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D39956

dtrace: remove unused defines

Reviewed by: markj, emaste
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D37659

Create sys/reg.h for the common code previously in machine/reg.h

Move the common kernel function signatures from machine/reg.h to a new
sys/reg.h. This is in preperation for adding PT_GETREGSET to ptrace(2).

Reviewed by: imp, markj
Sponsored by: DARPA, AFRL (original work)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19830

arm64: Improve DDB backtrace support

The existing implementation relies on each trap handler saving a normal
stack frame record, which is a waste of time and space when we're
already saving a trapframe to the stack. It's also wrong as it currently
saves LR not ELR.

Instead of patching it up, rewrite it based on the RISC-V implementation
with inspiration from the amd64 implementation for how to handle
vectored traps to provide an improved implementation. This includes
compressing the information down to one line like other architectures
rather than the highly-verbose old form that repeats itself by printing
LR and FP in one frame only to print them as PC and SP in the next. It
also includes printing out actually useful information about the traps
that occurred, though FAR is not saved in the trapframe so we cannot
print it (in general it can be clobbered between when the trap happened
and now), only ESR.

The AAPCS also allows the stack frame record to be located anywhere in
the frame, not just the top, so the caller's SP is not at a fixed offset
from the callee's FP like on almost all other architectures in
existence. This means there is no way to derive the caller's SP in the
unwinder, and so we have to drop that bit of (unused) state everywhere.

Reviewed by: jhb, markj
Differential Revision: https://reviews.freebsd.org/D28026

Check that the frame pointer is within the current stack.

This same check is used on other architectures. Previously this would
permit a stack frame to unwind into any arbitrary kernel address
(including unmapped addresses).

Reviewed by: andrew, markj
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27362

Use uintptr_t instead of uint64_t for pointers in stack frames.

Reviewed by: andrew
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27361

DTrace aarch64: Avoid calling unwind_frame() in the probe context.

unwind_frame() may be instrumented by FBT, leading to recursion into
dtrace_probe(). Manually inline unwind_frame() as we do with stack
unwinding code for other architectures.

Submitted by: Domagoj Stolfa
Reviewed by: manu
MFC after: 1 week
Sponsored by: DARPA / AFRL
Differential Revision: https://reviews.freebsd.org/D15359

Set oldfp so the check for fp == oldfp works as expected.

Obtained from: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation

Implement dtrace_getupcstack in ARM64

Allow using DTRACE for performance analysis of userspace
applications - the function call stack can be captured.
This is almost an exact copy of AMD64 solution.

Obtained from: Semihalf
Sponsored by: Cavium
Reviewed by: emaste, gnn, jhibbits
Differential Revision: https://reviews.freebsd.org/D5779

As <machine/vmparam.h> is included from <vm/vm_param.h>, there is no
need to include it explicitly when <vm/vm_param.h> is already included.

Suggested by: alc
Reviewed by: alc
Differential Revision: https://reviews.freebsd.org/D5379

First cut of DTrace for AArch64.

Reviewed by: andrew, emaste
Sponsored by: ARM Limited
Differential Revision: https://reviews.freebsd.org/D2738