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

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

dtrace: deduplicate some RISC-V functions

match_opcode() is defined in FBT, kinst, and dtrace_subr.c. The function
prologue-checking functions are defined in FBT and kinst.

Reviewed by: markj
Approved by: markj (mentor)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D40335

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 RISC-V

Reviewed by: mhorne, markj
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D39611

dtrace: implement riscv dtrace_getustackdepth()

Pretty trivial following other implementations. The existing
dtrace_getustack_common() does most of the work.

Reviewed by: markj
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D38303

dtrace: Fix RISC-V user stack unwinder

The unwind logic was copied from AArch64 which follows the peculiar
AACPS (where, unlike typical RISC architectures, its frame pointer
follows an x86/stack machine-like convention where the frame pointer
points at the bottom of the frame record, not the top). Delete the
pointless riscv_frame struct and fix this.

Reviewed by: mhorne
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D28054

dtrace: dtrace_getpcstack() tweaks for riscv

Backtraces for fbt probes are missing the caller's frame. Despite what
the inherited comment claims, we do need to insert this manually on
riscv. In fbt_invop(), set cpu_dtrace_caller to be the return address,
not addr.

We should not increment aframes within this function, since we begin the
main loop by unwinding past the current frame.

Plus some very small comment/style tweaks.

MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D37661

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

riscv: fix kernel build

A more complete fix for this function is being worked on in D28054. Fix
the uninitialized variable error so that builds can at least proceed.

Reported by: several

Stack unwinding robustness fixes for RISC-V.

- Push the kstack_contains check down into unwind_frame() so that it
is honored by DDB and DTrace.

- Check that the trapframe for an exception frame is contained in the
traced thread's kernel stack for DDB traces.

Reviewed by: markj
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27357

Use uintptr_t for pointers in stack frames.

This catches up to the changes made to struct unwind_state in r364180.

Reviewed by: mhorne
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27360

Add initial DTrace support for RISC-V.

Sponsored by: DARPA, AFRL
Sponsored by: HEIF5