cask:ctld# pgrep -lf ctld
70090 /usr/sbin/ctld
cask:ctld# dtrace -n pid70090::login_negotiate:entry
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: adding breakpoint at 0x80062b000
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: adding breakpoint at 0x408d30
dtrace: removing breakpoint at 0x80062b000
dtrace: removing breakpoint at 0x408d30
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: adding breakpoint at 0x80062b000
dtrace: adding breakpoint at 0x408d30
dtrace: removing breakpoint at 0x80062b000
dtrace: removing breakpoint at 0x408d30
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: adding breakpoint at 0x80062b000
dtrace: ERROR: elf_getdata() failed: Invalid argument
dtrace: adding breakpoint at 0x408d30
dtrace: removing breakpoint at 0x80062b000
dtrace: removing breakpoint at 0x408d30
dtrace: adding breakpoint at 0x80062b000
dtrace: adding breakpoint at 0x408d30
dtrace: removing breakpoint at 0x80062b000
dtrace: removing breakpoint at 0x408d30
dtrace: description 'pid70090::login_negotiate:entry' matched 1 probe
^C

cask:ctld# ls ctld
ls: ctld: No such file or directory
cask:ctld# gdb /usr/sbin/ctld
GNU gdb (GDB) 7.11.1 [GDB v7.11.1 for FreeBSD]
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-portbld-freebsd12.0".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from /usr/sbin/ctld...Reading symbols from /usr/lib/debug//usr/sbin/ctld.debug...done.
done.
(gdb) l *login_negotiate
0x4126d0 is in login_negotiate (/root/ws/head/usr.sbin/ctld/login.c:675).
670		return (true);
671	}
672	
673	static void
674	login_negotiate(struct connection *conn, struct pdu *request)
675	{
676		struct pdu *response;
677		struct iscsi_bhs_login_response *bhslr2;
678		struct keys *request_keys, *response_keys;
679		int i;
(gdb) break login_negotiate
Breakpoint 1 at 0x4126e0: file /root/ws/head/usr.sbin/ctld/login.c, line 682.