diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index 51c7bd662600..99bb2e992208 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -1,1328 +1,1321 @@
 /*-
  * SPDX-License-Identifier: BSD-4-Clause
  *
  * Copyright (c) 1994, Sean Eric Fagan
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. All advertising materials mentioning features or use of this software
  *    must display the following acknowledgement:
  *	This product includes software developed by Sean Eric Fagan.
  * 4. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/ktr.h>
 #include <sys/limits.h>
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/syscallsubr.h>
 #include <sys/sysent.h>
 #include <sys/sysproto.h>
 #include <sys/priv.h>
 #include <sys/proc.h>
 #include <sys/vnode.h>
 #include <sys/ptrace.h>
 #include <sys/rwlock.h>
 #include <sys/sx.h>
 #include <sys/malloc.h>
 #include <sys/signalvar.h>
 
 #include <machine/reg.h>
 
 #include <security/audit/audit.h>
 
 #include <vm/vm.h>
 #include <vm/pmap.h>
 #include <vm/vm_extern.h>
 #include <vm/vm_map.h>
 #include <vm/vm_kern.h>
 #include <vm/vm_object.h>
 #include <vm/vm_page.h>
 #include <vm/vm_param.h>
 
 #ifdef COMPAT_FREEBSD32
 #include <sys/procfs.h>
 #endif
 
 /*
  * Functions implemented using PROC_ACTION():
  *
  * proc_read_regs(proc, regs)
  *	Get the current user-visible register set from the process
  *	and copy it into the regs structure (<machine/reg.h>).
  *	The process is stopped at the time read_regs is called.
  *
  * proc_write_regs(proc, regs)
  *	Update the current register set from the passed in regs
  *	structure.  Take care to avoid clobbering special CPU
  *	registers or privileged bits in the PSL.
  *	Depending on the architecture this may have fix-up work to do,
  *	especially if the IAR or PCW are modified.
  *	The process is stopped at the time write_regs is called.
  *
  * proc_read_fpregs, proc_write_fpregs
  *	deal with the floating point register set, otherwise as above.
  *
  * proc_read_dbregs, proc_write_dbregs
  *	deal with the processor debug register set, otherwise as above.
  *
  * proc_sstep(proc)
  *	Arrange for the process to trap after executing a single instruction.
  */
 
 #define	PROC_ACTION(action) do {					\
 	int error;							\
 									\
 	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);			\
 	if ((td->td_proc->p_flag & P_INMEM) == 0)			\
 		error = EIO;						\
 	else								\
 		error = (action);					\
 	return (error);							\
 } while(0)
 
 int
 proc_read_regs(struct thread *td, struct reg *regs)
 {
 
 	PROC_ACTION(fill_regs(td, regs));
 }
 
 int
 proc_write_regs(struct thread *td, struct reg *regs)
 {
 
 	PROC_ACTION(set_regs(td, regs));
 }
 
 int
 proc_read_dbregs(struct thread *td, struct dbreg *dbregs)
 {
 
 	PROC_ACTION(fill_dbregs(td, dbregs));
 }
 
 int
 proc_write_dbregs(struct thread *td, struct dbreg *dbregs)
 {
 
 	PROC_ACTION(set_dbregs(td, dbregs));
 }
 
 /*
  * Ptrace doesn't support fpregs at all, and there are no security holes
  * or translations for fpregs, so we can just copy them.
  */
 int
 proc_read_fpregs(struct thread *td, struct fpreg *fpregs)
 {
 
 	PROC_ACTION(fill_fpregs(td, fpregs));
 }
 
 int
 proc_write_fpregs(struct thread *td, struct fpreg *fpregs)
 {
 
 	PROC_ACTION(set_fpregs(td, fpregs));
 }
 
 #ifdef COMPAT_FREEBSD32
 /* For 32 bit binaries, we need to expose the 32 bit regs layouts. */
 int
 proc_read_regs32(struct thread *td, struct reg32 *regs32)
 {
 
 	PROC_ACTION(fill_regs32(td, regs32));
 }
 
 int
 proc_write_regs32(struct thread *td, struct reg32 *regs32)
 {
 
 	PROC_ACTION(set_regs32(td, regs32));
 }
 
 int
 proc_read_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 {
 
 	PROC_ACTION(fill_dbregs32(td, dbregs32));
 }
 
 int
 proc_write_dbregs32(struct thread *td, struct dbreg32 *dbregs32)
 {
 
 	PROC_ACTION(set_dbregs32(td, dbregs32));
 }
 
 int
 proc_read_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 {
 
 	PROC_ACTION(fill_fpregs32(td, fpregs32));
 }
 
 int
 proc_write_fpregs32(struct thread *td, struct fpreg32 *fpregs32)
 {
 
 	PROC_ACTION(set_fpregs32(td, fpregs32));
 }
 #endif
 
 int
 proc_sstep(struct thread *td)
 {
 
 	PROC_ACTION(ptrace_single_step(td));
 }
 
 int
 proc_rwmem(struct proc *p, struct uio *uio)
 {
 	vm_map_t map;
 	vm_offset_t pageno;		/* page number */
 	vm_prot_t reqprot;
 	int error, fault_flags, page_offset, writing;
 
 	/*
 	 * Assert that someone has locked this vmspace.  (Should be
 	 * curthread but we can't assert that.)  This keeps the process
 	 * from exiting out from under us until this operation completes.
 	 */
 	PROC_ASSERT_HELD(p);
 	PROC_LOCK_ASSERT(p, MA_NOTOWNED);
 
 	/*
 	 * The map we want...
 	 */
 	map = &p->p_vmspace->vm_map;
 
 	/*
 	 * If we are writing, then we request vm_fault() to create a private
 	 * copy of each page.  Since these copies will not be writeable by the
 	 * process, we must explicity request that they be dirtied.
 	 */
 	writing = uio->uio_rw == UIO_WRITE;
 	reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
 	fault_flags = writing ? VM_FAULT_DIRTY : VM_FAULT_NORMAL;
 
 	/*
 	 * Only map in one page at a time.  We don't have to, but it
 	 * makes things easier.  This way is trivial - right?
 	 */
 	do {
 		vm_offset_t uva;
 		u_int len;
 		vm_page_t m;
 
 		uva = (vm_offset_t)uio->uio_offset;
 
 		/*
 		 * Get the page number of this segment.
 		 */
 		pageno = trunc_page(uva);
 		page_offset = uva - pageno;
 
 		/*
 		 * How many bytes to copy
 		 */
 		len = min(PAGE_SIZE - page_offset, uio->uio_resid);
 
 		/*
 		 * Fault and hold the page on behalf of the process.
 		 */
 		error = vm_fault(map, pageno, reqprot, fault_flags, &m);
 		if (error != KERN_SUCCESS) {
 			if (error == KERN_RESOURCE_SHORTAGE)
 				error = ENOMEM;
 			else
 				error = EFAULT;
 			break;
 		}
 
 		/*
 		 * Now do the i/o move.
 		 */
 		error = uiomove_fromphys(&m, page_offset, len, uio);
 
 		/* Make the I-cache coherent for breakpoints. */
 		if (writing && error == 0) {
 			vm_map_lock_read(map);
 			if (vm_map_check_protection(map, pageno, pageno +
 			    PAGE_SIZE, VM_PROT_EXECUTE))
 				vm_sync_icache(map, uva, len);
 			vm_map_unlock_read(map);
 		}
 
 		/*
 		 * Release the page.
 		 */
 		vm_page_unwire(m, PQ_ACTIVE);
 
 	} while (error == 0 && uio->uio_resid > 0);
 
 	return (error);
 }
 
 static ssize_t
 proc_iop(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
     size_t len, enum uio_rw rw)
 {
 	struct iovec iov;
 	struct uio uio;
 	ssize_t slen;
 
 	MPASS(len < SSIZE_MAX);
 	slen = (ssize_t)len;
 
 	iov.iov_base = (caddr_t)buf;
 	iov.iov_len = len;
 	uio.uio_iov = &iov;
 	uio.uio_iovcnt = 1;
 	uio.uio_offset = va;
 	uio.uio_resid = slen;
 	uio.uio_segflg = UIO_SYSSPACE;
 	uio.uio_rw = rw;
 	uio.uio_td = td;
 	proc_rwmem(p, &uio);
 	if (uio.uio_resid == slen)
 		return (-1);
 	return (slen - uio.uio_resid);
 }
 
 ssize_t
 proc_readmem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
     size_t len)
 {
 
 	return (proc_iop(td, p, va, buf, len, UIO_READ));
 }
 
 ssize_t
 proc_writemem(struct thread *td, struct proc *p, vm_offset_t va, void *buf,
     size_t len)
 {
 
 	return (proc_iop(td, p, va, buf, len, UIO_WRITE));
 }
 
 static int
 ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve)
 {
 	struct vattr vattr;
 	vm_map_t map;
 	vm_map_entry_t entry;
 	vm_object_t obj, tobj, lobj;
 	struct vmspace *vm;
 	struct vnode *vp;
 	char *freepath, *fullpath;
 	u_int pathlen;
 	int error, index;
 
 	error = 0;
 	obj = NULL;
 
 	vm = vmspace_acquire_ref(p);
 	map = &vm->vm_map;
 	vm_map_lock_read(map);
 
 	do {
 		KASSERT((map->header.eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
 		    ("Submap in map header"));
 		index = 0;
 		VM_MAP_ENTRY_FOREACH(entry, map) {
 			if (index >= pve->pve_entry &&
 			    (entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0)
 				break;
 			index++;
 		}
 		if (index < pve->pve_entry) {
 			error = EINVAL;
 			break;
 		}
 		if (entry == &map->header) {
 			error = ENOENT;
 			break;
 		}
 
 		/* We got an entry. */
 		pve->pve_entry = index + 1;
 		pve->pve_timestamp = map->timestamp;
 		pve->pve_start = entry->start;
 		pve->pve_end = entry->end - 1;
 		pve->pve_offset = entry->offset;
 		pve->pve_prot = entry->protection;
 
 		/* Backing object's path needed? */
 		if (pve->pve_pathlen == 0)
 			break;
 
 		pathlen = pve->pve_pathlen;
 		pve->pve_pathlen = 0;
 
 		obj = entry->object.vm_object;
 		if (obj != NULL)
 			VM_OBJECT_RLOCK(obj);
 	} while (0);
 
 	vm_map_unlock_read(map);
 
 	pve->pve_fsid = VNOVAL;
 	pve->pve_fileid = VNOVAL;
 
 	if (error == 0 && obj != NULL) {
 		lobj = obj;
 		for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 			if (tobj != obj)
 				VM_OBJECT_RLOCK(tobj);
 			if (lobj != obj)
 				VM_OBJECT_RUNLOCK(lobj);
 			lobj = tobj;
 			pve->pve_offset += tobj->backing_object_offset;
 		}
 		vp = vm_object_vnode(lobj);
 		if (vp != NULL)
 			vref(vp);
 		if (lobj != obj)
 			VM_OBJECT_RUNLOCK(lobj);
 		VM_OBJECT_RUNLOCK(obj);
 
 		if (vp != NULL) {
 			freepath = NULL;
 			fullpath = NULL;
 			vn_fullpath(vp, &fullpath, &freepath);
 			vn_lock(vp, LK_SHARED | LK_RETRY);
 			if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 				pve->pve_fileid = vattr.va_fileid;
 				pve->pve_fsid = vattr.va_fsid;
 			}
 			vput(vp);
 
 			if (fullpath != NULL) {
 				pve->pve_pathlen = strlen(fullpath) + 1;
 				if (pve->pve_pathlen <= pathlen) {
 					error = copyout(fullpath, pve->pve_path,
 					    pve->pve_pathlen);
 				} else
 					error = ENAMETOOLONG;
 			}
 			if (freepath != NULL)
 				free(freepath, M_TEMP);
 		}
 	}
 	vmspace_free(vm);
 	if (error == 0)
 		CTR3(KTR_PTRACE, "PT_VM_ENTRY: pid %d, entry %d, start %p",
 		    p->p_pid, pve->pve_entry, pve->pve_start);
 
 	return (error);
 }
 
 /*
  * Process debugging system call.
  */
 #ifndef _SYS_SYSPROTO_H_
 struct ptrace_args {
 	int	req;
 	pid_t	pid;
 	caddr_t	addr;
 	int	data;
 };
 #endif
 
 int
 sys_ptrace(struct thread *td, struct ptrace_args *uap)
 {
 	/*
 	 * XXX this obfuscation is to reduce stack usage, but the register
 	 * structs may be too large to put on the stack anyway.
 	 */
 	union {
 		struct ptrace_io_desc piod;
 		struct ptrace_lwpinfo pl;
 		struct ptrace_vm_entry pve;
 		struct dbreg dbreg;
 		struct fpreg fpreg;
 		struct reg reg;
 		char args[sizeof(td->td_sa.args)];
 		struct ptrace_sc_ret psr;
 		int ptevents;
 	} r;
 	void *addr;
 	int error = 0;
 
 	AUDIT_ARG_PID(uap->pid);
 	AUDIT_ARG_CMD(uap->req);
 	AUDIT_ARG_VALUE(uap->data);
 	addr = &r;
 	switch (uap->req) {
 	case PT_GET_EVENT_MASK:
 	case PT_LWPINFO:
 	case PT_GET_SC_ARGS:
 	case PT_GET_SC_RET:
 		break;
 	case PT_GETREGS:
 		bzero(&r.reg, sizeof(r.reg));
 		break;
 	case PT_GETFPREGS:
 		bzero(&r.fpreg, sizeof(r.fpreg));
 		break;
 	case PT_GETDBREGS:
 		bzero(&r.dbreg, sizeof(r.dbreg));
 		break;
 	case PT_SETREGS:
 		error = copyin(uap->addr, &r.reg, sizeof(r.reg));
 		break;
 	case PT_SETFPREGS:
 		error = copyin(uap->addr, &r.fpreg, sizeof(r.fpreg));
 		break;
 	case PT_SETDBREGS:
 		error = copyin(uap->addr, &r.dbreg, sizeof(r.dbreg));
 		break;
 	case PT_SET_EVENT_MASK:
 		if (uap->data != sizeof(r.ptevents))
 			error = EINVAL;
 		else
 			error = copyin(uap->addr, &r.ptevents, uap->data);
 		break;
 	case PT_IO:
 		error = copyin(uap->addr, &r.piod, sizeof(r.piod));
 		break;
 	case PT_VM_ENTRY:
 		error = copyin(uap->addr, &r.pve, sizeof(r.pve));
 		break;
 	default:
 		addr = uap->addr;
 		break;
 	}
 	if (error)
 		return (error);
 
 	error = kern_ptrace(td, uap->req, uap->pid, addr, uap->data);
 	if (error)
 		return (error);
 
 	switch (uap->req) {
 	case PT_VM_ENTRY:
 		error = copyout(&r.pve, uap->addr, sizeof(r.pve));
 		break;
 	case PT_IO:
 		error = copyout(&r.piod, uap->addr, sizeof(r.piod));
 		break;
 	case PT_GETREGS:
 		error = copyout(&r.reg, uap->addr, sizeof(r.reg));
 		break;
 	case PT_GETFPREGS:
 		error = copyout(&r.fpreg, uap->addr, sizeof(r.fpreg));
 		break;
 	case PT_GETDBREGS:
 		error = copyout(&r.dbreg, uap->addr, sizeof(r.dbreg));
 		break;
 	case PT_GET_EVENT_MASK:
 		/* NB: The size in uap->data is validated in kern_ptrace(). */
 		error = copyout(&r.ptevents, uap->addr, uap->data);
 		break;
 	case PT_LWPINFO:
 		/* NB: The size in uap->data is validated in kern_ptrace(). */
 		error = copyout(&r.pl, uap->addr, uap->data);
 		break;
 	case PT_GET_SC_ARGS:
 		error = copyout(r.args, uap->addr, MIN(uap->data,
 		    sizeof(r.args)));
 		break;
 	case PT_GET_SC_RET:
 		error = copyout(&r.psr, uap->addr, MIN(uap->data,
 		    sizeof(r.psr)));
 		break;
 	}
 
 	return (error);
 }
 
 #ifdef COMPAT_FREEBSD32
 /*
  *   PROC_READ(regs, td2, addr);
  * becomes either:
  *   proc_read_regs(td2, addr);
  * or
  *   proc_read_regs32(td2, addr);
  * .. except this is done at runtime.  There is an additional
  * complication in that PROC_WRITE disallows 32 bit consumers
  * from writing to 64 bit address space targets.
  */
 #define	PROC_READ(w, t, a)	wrap32 ? \
 	proc_read_ ## w ## 32(t, a) : \
 	proc_read_ ## w (t, a)
 #define	PROC_WRITE(w, t, a)	wrap32 ? \
 	(safe ? proc_write_ ## w ## 32(t, a) : EINVAL ) : \
 	proc_write_ ## w (t, a)
 #else
 #define	PROC_READ(w, t, a)	proc_read_ ## w (t, a)
 #define	PROC_WRITE(w, t, a)	proc_write_ ## w (t, a)
 #endif
 
 void
 proc_set_traced(struct proc *p, bool stop)
 {
 
 	sx_assert(&proctree_lock, SX_XLOCKED);
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	p->p_flag |= P_TRACED;
 	if (stop)
 		p->p_flag2 |= P2_PTRACE_FSTP;
 	p->p_ptevents = PTRACE_DEFAULT;
 }
 
 int
 kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 {
 	struct iovec iov;
 	struct uio uio;
 	struct proc *curp, *p, *pp;
 	struct thread *td2 = NULL, *td3;
 	struct ptrace_io_desc *piod = NULL;
 	struct ptrace_lwpinfo *pl;
 	struct ptrace_sc_ret *psr;
 	int error, num, tmp;
 	int proctree_locked = 0;
 	lwpid_t tid = 0, *buf;
 #ifdef COMPAT_FREEBSD32
 	int wrap32 = 0, safe = 0;
 #endif
 
 	curp = td->td_proc;
 
 	/* Lock proctree before locking the process. */
 	switch (req) {
 	case PT_TRACE_ME:
 	case PT_ATTACH:
 	case PT_STEP:
 	case PT_CONTINUE:
 	case PT_TO_SCE:
 	case PT_TO_SCX:
 	case PT_SYSCALL:
 	case PT_FOLLOW_FORK:
 	case PT_LWP_EVENTS:
 	case PT_GET_EVENT_MASK:
 	case PT_SET_EVENT_MASK:
 	case PT_DETACH:
 	case PT_GET_SC_ARGS:
 		sx_xlock(&proctree_lock);
 		proctree_locked = 1;
 		break;
 	default:
 		break;
 	}
 
 	if (req == PT_TRACE_ME) {
 		p = td->td_proc;
 		PROC_LOCK(p);
 	} else {
 		if (pid <= PID_MAX) {
 			if ((p = pfind(pid)) == NULL) {
 				if (proctree_locked)
 					sx_xunlock(&proctree_lock);
 				return (ESRCH);
 			}
 		} else {
 			td2 = tdfind(pid, -1);
 			if (td2 == NULL) {
 				if (proctree_locked)
 					sx_xunlock(&proctree_lock);
 				return (ESRCH);
 			}
 			p = td2->td_proc;
 			tid = pid;
 			pid = p->p_pid;
 		}
 	}
 	AUDIT_ARG_PROCESS(p);
 
 	if ((p->p_flag & P_WEXIT) != 0) {
 		error = ESRCH;
 		goto fail;
 	}
 	if ((error = p_cansee(td, p)) != 0)
 		goto fail;
 
 	if ((error = p_candebug(td, p)) != 0)
 		goto fail;
 
 	/*
 	 * System processes can't be debugged.
 	 */
 	if ((p->p_flag & P_SYSTEM) != 0) {
 		error = EINVAL;
 		goto fail;
 	}
 
 	if (tid == 0) {
 		if ((p->p_flag & P_STOPPED_TRACE) != 0) {
 			KASSERT(p->p_xthread != NULL, ("NULL p_xthread"));
 			td2 = p->p_xthread;
 		} else {
 			td2 = FIRST_THREAD_IN_PROC(p);
 		}
 		tid = td2->td_tid;
 	}
 
 #ifdef COMPAT_FREEBSD32
 	/*
 	 * Test if we're a 32 bit client and what the target is.
 	 * Set the wrap controls accordingly.
 	 */
 	if (SV_CURPROC_FLAG(SV_ILP32)) {
 		if (SV_PROC_FLAG(td2->td_proc, SV_ILP32))
 			safe = 1;
 		wrap32 = 1;
 	}
 #endif
 	/*
 	 * Permissions check
 	 */
 	switch (req) {
 	case PT_TRACE_ME:
 		/*
 		 * Always legal, when there is a parent process which
 		 * could trace us.  Otherwise, reject.
 		 */
 		if ((p->p_flag & P_TRACED) != 0) {
 			error = EBUSY;
 			goto fail;
 		}
 		if (p->p_pptr == initproc) {
 			error = EPERM;
 			goto fail;
 		}
 		break;
 
 	case PT_ATTACH:
 		/* Self */
 		if (p == td->td_proc) {
 			error = EINVAL;
 			goto fail;
 		}
 
 		/* Already traced */
 		if (p->p_flag & P_TRACED) {
 			error = EBUSY;
 			goto fail;
 		}
 
 		/* Can't trace an ancestor if you're being traced. */
 		if (curp->p_flag & P_TRACED) {
 			for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) {
 				if (pp == p) {
 					error = EINVAL;
 					goto fail;
 				}
 			}
 		}
 
 		/* OK */
 		break;
 
 	case PT_CLEARSTEP:
 		/* Allow thread to clear single step for itself */
 		if (td->td_tid == tid)
 			break;
 
 		/* FALLTHROUGH */
 	default:
 		/* not being traced... */
 		if ((p->p_flag & P_TRACED) == 0) {
 			error = EPERM;
 			goto fail;
 		}
 
 		/* not being traced by YOU */
 		if (p->p_pptr != td->td_proc) {
 			error = EBUSY;
 			goto fail;
 		}
 
 		/* not currently stopped */
 		if ((p->p_flag & P_STOPPED_TRACE) == 0 ||
 		    p->p_suspcount != p->p_numthreads  ||
 		    (p->p_flag & P_WAITED) == 0) {
 			error = EBUSY;
 			goto fail;
 		}
 
 		/* OK */
 		break;
 	}
 
 	/* Keep this process around until we finish this request. */
 	_PHOLD(p);
 
-#ifdef FIX_SSTEP
-	/*
-	 * Single step fixup ala procfs
-	 */
-	FIX_SSTEP(td2);
-#endif
-
 	/*
 	 * Actually do the requests
 	 */
 
 	td->td_retval[0] = 0;
 
 	switch (req) {
 	case PT_TRACE_ME:
 		/* set my trace flag and "owner" so it can read/write me */
 		proc_set_traced(p, false);
 		if (p->p_flag & P_PPWAIT)
 			p->p_flag |= P_PPTRACE;
 		CTR1(KTR_PTRACE, "PT_TRACE_ME: pid %d", p->p_pid);
 		break;
 
 	case PT_ATTACH:
 		/* security check done above */
 		/*
 		 * It would be nice if the tracing relationship was separate
 		 * from the parent relationship but that would require
 		 * another set of links in the proc struct or for "wait"
 		 * to scan the entire proc table.  To make life easier,
 		 * we just re-parent the process we're trying to trace.
 		 * The old parent is remembered so we can put things back
 		 * on a "detach".
 		 */
 		proc_set_traced(p, true);
 		proc_reparent(p, td->td_proc, false);
 		CTR2(KTR_PTRACE, "PT_ATTACH: pid %d, oppid %d", p->p_pid,
 		    p->p_oppid);
 
 		sx_xunlock(&proctree_lock);
 		proctree_locked = 0;
 		MPASS(p->p_xthread == NULL);
 		MPASS((p->p_flag & P_STOPPED_TRACE) == 0);
 
 		/*
 		 * If already stopped due to a stop signal, clear the
 		 * existing stop before triggering a traced SIGSTOP.
 		 */
 		if ((p->p_flag & P_STOPPED_SIG) != 0) {
 			PROC_SLOCK(p);
 			p->p_flag &= ~(P_STOPPED_SIG | P_WAITED);
 			thread_unsuspend(p);
 			PROC_SUNLOCK(p);
 		}
 
 		kern_psignal(p, SIGSTOP);
 		break;
 
 	case PT_CLEARSTEP:
 		CTR2(KTR_PTRACE, "PT_CLEARSTEP: tid %d (pid %d)", td2->td_tid,
 		    p->p_pid);
 		error = ptrace_clear_single_step(td2);
 		break;
 
 	case PT_SETSTEP:
 		CTR2(KTR_PTRACE, "PT_SETSTEP: tid %d (pid %d)", td2->td_tid,
 		    p->p_pid);
 		error = ptrace_single_step(td2);
 		break;
 
 	case PT_SUSPEND:
 		CTR2(KTR_PTRACE, "PT_SUSPEND: tid %d (pid %d)", td2->td_tid,
 		    p->p_pid);
 		td2->td_dbgflags |= TDB_SUSPEND;
 		thread_lock(td2);
 		td2->td_flags |= TDF_NEEDSUSPCHK;
 		thread_unlock(td2);
 		break;
 
 	case PT_RESUME:
 		CTR2(KTR_PTRACE, "PT_RESUME: tid %d (pid %d)", td2->td_tid,
 		    p->p_pid);
 		td2->td_dbgflags &= ~TDB_SUSPEND;
 		break;
 
 	case PT_FOLLOW_FORK:
 		CTR3(KTR_PTRACE, "PT_FOLLOW_FORK: pid %d %s -> %s", p->p_pid,
 		    p->p_ptevents & PTRACE_FORK ? "enabled" : "disabled",
 		    data ? "enabled" : "disabled");
 		if (data)
 			p->p_ptevents |= PTRACE_FORK;
 		else
 			p->p_ptevents &= ~PTRACE_FORK;
 		break;
 
 	case PT_LWP_EVENTS:
 		CTR3(KTR_PTRACE, "PT_LWP_EVENTS: pid %d %s -> %s", p->p_pid,
 		    p->p_ptevents & PTRACE_LWP ? "enabled" : "disabled",
 		    data ? "enabled" : "disabled");
 		if (data)
 			p->p_ptevents |= PTRACE_LWP;
 		else
 			p->p_ptevents &= ~PTRACE_LWP;
 		break;
 
 	case PT_GET_EVENT_MASK:
 		if (data != sizeof(p->p_ptevents)) {
 			error = EINVAL;
 			break;
 		}
 		CTR2(KTR_PTRACE, "PT_GET_EVENT_MASK: pid %d mask %#x", p->p_pid,
 		    p->p_ptevents);
 		*(int *)addr = p->p_ptevents;
 		break;
 
 	case PT_SET_EVENT_MASK:
 		if (data != sizeof(p->p_ptevents)) {
 			error = EINVAL;
 			break;
 		}
 		tmp = *(int *)addr;
 		if ((tmp & ~(PTRACE_EXEC | PTRACE_SCE | PTRACE_SCX |
 		    PTRACE_FORK | PTRACE_LWP | PTRACE_VFORK)) != 0) {
 			error = EINVAL;
 			break;
 		}
 		CTR3(KTR_PTRACE, "PT_SET_EVENT_MASK: pid %d mask %#x -> %#x",
 		    p->p_pid, p->p_ptevents, tmp);
 		p->p_ptevents = tmp;
 		break;
 
 	case PT_GET_SC_ARGS:
 		CTR1(KTR_PTRACE, "PT_GET_SC_ARGS: pid %d", p->p_pid);
 		if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0
 #ifdef COMPAT_FREEBSD32
 		    || (wrap32 && !safe)
 #endif
 		    ) {
 			error = EINVAL;
 			break;
 		}
 		bzero(addr, sizeof(td2->td_sa.args));
 		bcopy(td2->td_sa.args, addr, td2->td_sa.callp->sy_narg *
 		    sizeof(register_t));
 		break;
 
 	case PT_GET_SC_RET:
 		if ((td2->td_dbgflags & (TDB_SCX)) == 0
 #ifdef COMPAT_FREEBSD32
 		    || (wrap32 && !safe)
 #endif
 		    ) {
 			error = EINVAL;
 			break;
 		}
 		psr = addr;
 		bzero(psr, sizeof(*psr));
 		psr->sr_error = td2->td_errno;
 		if (psr->sr_error == 0) {
 			psr->sr_retval[0] = td2->td_retval[0];
 			psr->sr_retval[1] = td2->td_retval[1];
 		}
 		CTR4(KTR_PTRACE,
 		    "PT_GET_SC_RET: pid %d error %d retval %#lx,%#lx",
 		    p->p_pid, psr->sr_error, psr->sr_retval[0],
 		    psr->sr_retval[1]);
 		break;
 
 	case PT_STEP:
 	case PT_CONTINUE:
 	case PT_TO_SCE:
 	case PT_TO_SCX:
 	case PT_SYSCALL:
 	case PT_DETACH:
 		/* Zero means do not send any signal */
 		if (data < 0 || data > _SIG_MAXSIG) {
 			error = EINVAL;
 			break;
 		}
 
 		switch (req) {
 		case PT_STEP:
 			CTR3(KTR_PTRACE, "PT_STEP: tid %d (pid %d), sig = %d",
 			    td2->td_tid, p->p_pid, data);
 			error = ptrace_single_step(td2);
 			if (error)
 				goto out;
 			break;
 		case PT_CONTINUE:
 		case PT_TO_SCE:
 		case PT_TO_SCX:
 		case PT_SYSCALL:
 			if (addr != (void *)1) {
 				error = ptrace_set_pc(td2,
 				    (u_long)(uintfptr_t)addr);
 				if (error)
 					goto out;
 			}
 			switch (req) {
 			case PT_TO_SCE:
 				p->p_ptevents |= PTRACE_SCE;
 				CTR4(KTR_PTRACE,
 		    "PT_TO_SCE: pid %d, events = %#x, PC = %#lx, sig = %d",
 				    p->p_pid, p->p_ptevents,
 				    (u_long)(uintfptr_t)addr, data);
 				break;
 			case PT_TO_SCX:
 				p->p_ptevents |= PTRACE_SCX;
 				CTR4(KTR_PTRACE,
 		    "PT_TO_SCX: pid %d, events = %#x, PC = %#lx, sig = %d",
 				    p->p_pid, p->p_ptevents,
 				    (u_long)(uintfptr_t)addr, data);
 				break;
 			case PT_SYSCALL:
 				p->p_ptevents |= PTRACE_SYSCALL;
 				CTR4(KTR_PTRACE,
 		    "PT_SYSCALL: pid %d, events = %#x, PC = %#lx, sig = %d",
 				    p->p_pid, p->p_ptevents,
 				    (u_long)(uintfptr_t)addr, data);
 				break;
 			case PT_CONTINUE:
 				CTR3(KTR_PTRACE,
 				    "PT_CONTINUE: pid %d, PC = %#lx, sig = %d",
 				    p->p_pid, (u_long)(uintfptr_t)addr, data);
 				break;
 			}
 			break;
 		case PT_DETACH:
 			/*
 			 * Reset the process parent.
 			 *
 			 * NB: This clears P_TRACED before reparenting
 			 * a detached process back to its original
 			 * parent.  Otherwise the debugee will be set
 			 * as an orphan of the debugger.
 			 */
 			p->p_flag &= ~(P_TRACED | P_WAITED);
 			if (p->p_oppid != p->p_pptr->p_pid) {
 				PROC_LOCK(p->p_pptr);
 				sigqueue_take(p->p_ksi);
 				PROC_UNLOCK(p->p_pptr);
 
 				pp = proc_realparent(p);
 				proc_reparent(p, pp, false);
 				if (pp == initproc)
 					p->p_sigparent = SIGCHLD;
 				CTR3(KTR_PTRACE,
 			    "PT_DETACH: pid %d reparented to pid %d, sig %d",
 				    p->p_pid, pp->p_pid, data);
 			} else
 				CTR2(KTR_PTRACE, "PT_DETACH: pid %d, sig %d",
 				    p->p_pid, data);
 			p->p_ptevents = 0;
 			FOREACH_THREAD_IN_PROC(p, td3) {
 				if ((td3->td_dbgflags & TDB_FSTP) != 0) {
 					sigqueue_delete(&td3->td_sigqueue,
 					    SIGSTOP);
 				}
 				td3->td_dbgflags &= ~(TDB_XSIG | TDB_FSTP |
 				    TDB_SUSPEND);
 			}
 
 			if ((p->p_flag2 & P2_PTRACE_FSTP) != 0) {
 				sigqueue_delete(&p->p_sigqueue, SIGSTOP);
 				p->p_flag2 &= ~P2_PTRACE_FSTP;
 			}
 
 			/* should we send SIGCHLD? */
 			/* childproc_continued(p); */
 			break;
 		}
 
 		sx_xunlock(&proctree_lock);
 		proctree_locked = 0;
 
 	sendsig:
 		MPASS(proctree_locked == 0);
 
 		/*
 		 * Clear the pending event for the thread that just
 		 * reported its event (p_xthread).  This may not be
 		 * the thread passed to PT_CONTINUE, PT_STEP, etc. if
 		 * the debugger is resuming a different thread.
 		 *
 		 * Deliver any pending signal via the reporting thread.
 		 */
 		MPASS(p->p_xthread != NULL);
 		p->p_xthread->td_dbgflags &= ~TDB_XSIG;
 		p->p_xthread->td_xsig = data;
 		p->p_xthread = NULL;
 		p->p_xsig = data;
 
 		/*
 		 * P_WKILLED is insurance that a PT_KILL/SIGKILL
 		 * always works immediately, even if another thread is
 		 * unsuspended first and attempts to handle a
 		 * different signal or if the POSIX.1b style signal
 		 * queue cannot accommodate any new signals.
 		 */
 		if (data == SIGKILL)
 			proc_wkilled(p);
 
 		/*
 		 * Unsuspend all threads.  To leave a thread
 		 * suspended, use PT_SUSPEND to suspend it before
 		 * continuing the process.
 		 */
 		PROC_SLOCK(p);
 		p->p_flag &= ~(P_STOPPED_TRACE | P_STOPPED_SIG | P_WAITED);
 		thread_unsuspend(p);
 		PROC_SUNLOCK(p);
 		itimer_proc_continue(p);
 		kqtimer_proc_continue(p);
 		break;
 
 	case PT_WRITE_I:
 	case PT_WRITE_D:
 		td2->td_dbgflags |= TDB_USERWR;
 		PROC_UNLOCK(p);
 		error = 0;
 		if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data,
 		    sizeof(int)) != sizeof(int))
 			error = ENOMEM;
 		else
 			CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x",
 			    p->p_pid, addr, data);
 		PROC_LOCK(p);
 		break;
 
 	case PT_READ_I:
 	case PT_READ_D:
 		PROC_UNLOCK(p);
 		error = tmp = 0;
 		if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp,
 		    sizeof(int)) != sizeof(int))
 			error = ENOMEM;
 		else
 			CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x",
 			    p->p_pid, addr, tmp);
 		td->td_retval[0] = tmp;
 		PROC_LOCK(p);
 		break;
 
 	case PT_IO:
 		piod = addr;
 		iov.iov_base = piod->piod_addr;
 		iov.iov_len = piod->piod_len;
 		uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs;
 		uio.uio_resid = piod->piod_len;
 		uio.uio_iov = &iov;
 		uio.uio_iovcnt = 1;
 		uio.uio_segflg = UIO_USERSPACE;
 		uio.uio_td = td;
 		switch (piod->piod_op) {
 		case PIOD_READ_D:
 		case PIOD_READ_I:
 			CTR3(KTR_PTRACE, "PT_IO: pid %d: READ (%p, %#x)",
 			    p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
 			uio.uio_rw = UIO_READ;
 			break;
 		case PIOD_WRITE_D:
 		case PIOD_WRITE_I:
 			CTR3(KTR_PTRACE, "PT_IO: pid %d: WRITE (%p, %#x)",
 			    p->p_pid, (uintptr_t)uio.uio_offset, uio.uio_resid);
 			td2->td_dbgflags |= TDB_USERWR;
 			uio.uio_rw = UIO_WRITE;
 			break;
 		default:
 			error = EINVAL;
 			goto out;
 		}
 		PROC_UNLOCK(p);
 		error = proc_rwmem(p, &uio);
 		piod->piod_len -= uio.uio_resid;
 		PROC_LOCK(p);
 		break;
 
 	case PT_KILL:
 		CTR1(KTR_PTRACE, "PT_KILL: pid %d", p->p_pid);
 		data = SIGKILL;
 		goto sendsig;	/* in PT_CONTINUE above */
 
 	case PT_SETREGS:
 		CTR2(KTR_PTRACE, "PT_SETREGS: tid %d (pid %d)", td2->td_tid,
 		    p->p_pid);
 		td2->td_dbgflags |= TDB_USERWR;
 		error = PROC_WRITE(regs, td2, addr);
 		break;
 
 	case PT_GETREGS:
 		CTR2(KTR_PTRACE, "PT_GETREGS: tid %d (pid %d)", td2->td_tid,
 		    p->p_pid);
 		error = PROC_READ(regs, td2, addr);
 		break;
 
 	case PT_SETFPREGS:
 		CTR2(KTR_PTRACE, "PT_SETFPREGS: tid %d (pid %d)", td2->td_tid,
 		    p->p_pid);
 		td2->td_dbgflags |= TDB_USERWR;
 		error = PROC_WRITE(fpregs, td2, addr);
 		break;
 
 	case PT_GETFPREGS:
 		CTR2(KTR_PTRACE, "PT_GETFPREGS: tid %d (pid %d)", td2->td_tid,
 		    p->p_pid);
 		error = PROC_READ(fpregs, td2, addr);
 		break;
 
 	case PT_SETDBREGS:
 		CTR2(KTR_PTRACE, "PT_SETDBREGS: tid %d (pid %d)", td2->td_tid,
 		    p->p_pid);
 		td2->td_dbgflags |= TDB_USERWR;
 		error = PROC_WRITE(dbregs, td2, addr);
 		break;
 
 	case PT_GETDBREGS:
 		CTR2(KTR_PTRACE, "PT_GETDBREGS: tid %d (pid %d)", td2->td_tid,
 		    p->p_pid);
 		error = PROC_READ(dbregs, td2, addr);
 		break;
 
 	case PT_LWPINFO:
 		if (data <= 0 || data > sizeof(*pl)) {
 			error = EINVAL;
 			break;
 		}
 		pl = addr;
 		bzero(pl, sizeof(*pl));
 		pl->pl_lwpid = td2->td_tid;
 		pl->pl_event = PL_EVENT_NONE;
 		pl->pl_flags = 0;
 		if (td2->td_dbgflags & TDB_XSIG) {
 			pl->pl_event = PL_EVENT_SIGNAL;
 			if (td2->td_si.si_signo != 0 &&
 			    data >= offsetof(struct ptrace_lwpinfo, pl_siginfo)
 			    + sizeof(pl->pl_siginfo)){
 				pl->pl_flags |= PL_FLAG_SI;
 				pl->pl_siginfo = td2->td_si;
 			}
 		}
 		if (td2->td_dbgflags & TDB_SCE)
 			pl->pl_flags |= PL_FLAG_SCE;
 		else if (td2->td_dbgflags & TDB_SCX)
 			pl->pl_flags |= PL_FLAG_SCX;
 		if (td2->td_dbgflags & TDB_EXEC)
 			pl->pl_flags |= PL_FLAG_EXEC;
 		if (td2->td_dbgflags & TDB_FORK) {
 			pl->pl_flags |= PL_FLAG_FORKED;
 			pl->pl_child_pid = td2->td_dbg_forked;
 			if (td2->td_dbgflags & TDB_VFORK)
 				pl->pl_flags |= PL_FLAG_VFORKED;
 		} else if ((td2->td_dbgflags & (TDB_SCX | TDB_VFORK)) ==
 		    TDB_VFORK)
 			pl->pl_flags |= PL_FLAG_VFORK_DONE;
 		if (td2->td_dbgflags & TDB_CHILD)
 			pl->pl_flags |= PL_FLAG_CHILD;
 		if (td2->td_dbgflags & TDB_BORN)
 			pl->pl_flags |= PL_FLAG_BORN;
 		if (td2->td_dbgflags & TDB_EXIT)
 			pl->pl_flags |= PL_FLAG_EXITED;
 		pl->pl_sigmask = td2->td_sigmask;
 		pl->pl_siglist = td2->td_siglist;
 		strcpy(pl->pl_tdname, td2->td_name);
 		if ((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) != 0) {
 			pl->pl_syscall_code = td2->td_sa.code;
 			pl->pl_syscall_narg = td2->td_sa.callp->sy_narg;
 		} else {
 			pl->pl_syscall_code = 0;
 			pl->pl_syscall_narg = 0;
 		}
 		CTR6(KTR_PTRACE,
     "PT_LWPINFO: tid %d (pid %d) event %d flags %#x child pid %d syscall %d",
 		    td2->td_tid, p->p_pid, pl->pl_event, pl->pl_flags,
 		    pl->pl_child_pid, pl->pl_syscall_code);
 		break;
 
 	case PT_GETNUMLWPS:
 		CTR2(KTR_PTRACE, "PT_GETNUMLWPS: pid %d: %d threads", p->p_pid,
 		    p->p_numthreads);
 		td->td_retval[0] = p->p_numthreads;
 		break;
 
 	case PT_GETLWPLIST:
 		CTR3(KTR_PTRACE, "PT_GETLWPLIST: pid %d: data %d, actual %d",
 		    p->p_pid, data, p->p_numthreads);
 		if (data <= 0) {
 			error = EINVAL;
 			break;
 		}
 		num = imin(p->p_numthreads, data);
 		PROC_UNLOCK(p);
 		buf = malloc(num * sizeof(lwpid_t), M_TEMP, M_WAITOK);
 		tmp = 0;
 		PROC_LOCK(p);
 		FOREACH_THREAD_IN_PROC(p, td2) {
 			if (tmp >= num)
 				break;
 			buf[tmp++] = td2->td_tid;
 		}
 		PROC_UNLOCK(p);
 		error = copyout(buf, addr, tmp * sizeof(lwpid_t));
 		free(buf, M_TEMP);
 		if (!error)
 			td->td_retval[0] = tmp;
 		PROC_LOCK(p);
 		break;
 
 	case PT_VM_TIMESTAMP:
 		CTR2(KTR_PTRACE, "PT_VM_TIMESTAMP: pid %d: timestamp %d",
 		    p->p_pid, p->p_vmspace->vm_map.timestamp);
 		td->td_retval[0] = p->p_vmspace->vm_map.timestamp;
 		break;
 
 	case PT_VM_ENTRY:
 		PROC_UNLOCK(p);
 		error = ptrace_vm_entry(td, p, addr);
 		PROC_LOCK(p);
 		break;
 
 	default:
 #ifdef __HAVE_PTRACE_MACHDEP
 		if (req >= PT_FIRSTMACH) {
 			PROC_UNLOCK(p);
 			error = cpu_ptrace(td2, req, addr, data);
 			PROC_LOCK(p);
 		} else
 #endif
 			/* Unknown request. */
 			error = EINVAL;
 		break;
 	}
 
 out:
 	/* Drop our hold on this process now that the request has completed. */
 	_PRELE(p);
 fail:
 	PROC_UNLOCK(p);
 	if (proctree_locked)
 		sx_xunlock(&proctree_lock);
 	return (error);
 }
 #undef PROC_READ
 #undef PROC_WRITE