K 10
svn:author
V 3
kib
K 8
svn:date
V 27
2019-11-12T15:56:27.252897Z
K 7
svn:log
V 402
i386: stop guessing the address of the trap frame in ddb backtrace.

Save the address of the trap frame in %ebp on kernel entry.  This
automatically provides it in struct i386_frame.f_frame to unwinder.

While there, more accurately handle the terminating frames,

Reviewed by:	avg, markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D22321

END