gdb: FreeBSD

 
 21.1.7 FreeBSD
 --------------
 
 When the ABI of a system call is changed in the FreeBSD kernel, this is
 implemented by leaving a compatibility system call using the old ABI at
 the existing number and allocating a new system call number for the
 version using the new ABI. As a convenience, when a system call is
 caught by name (Seecatch syscall), compatibility system calls are
 also caught.
 
    For example, FreeBSD 12 introduced a new variant of the 'kevent'
 system call and catching the 'kevent' system call by name catches both
 variants:
 
      (gdb) catch syscall kevent
      Catchpoint 1 (syscalls 'freebsd11_kevent' [363] 'kevent' [560])
      (gdb)