tree 5f460e51e72ef93f4103c39032f1aec298a638db
parent ddb7d1e975d224885397c002512ded987be3c3bc
author David Howells <dhowells@redhat.com> 1300467269 +0000
committer David Howells <dhowells@redhat.com> 1300467269 +0000

MN10300: gdbstub: Restrict single-stepping to non-preemptable non-SMP configs

Restrict single-stepping through the kernel using gdbstub to non-preemptable
non-SMP configs as gdbstub has to do software single-stepping by means of
temporary breakpoints.  Hardware single-stepping is unavailable as Panasonic
have not sufficiently documented the interface to it.

Software single-stepping through preemptable or SMP kernels runs into problems
as it makes it much more likely that the wrong thread will hit the temporary
breakpoints.  It seems impractical to work around the problem for the most
part.  It could be possible to make a UP preemptable kernel switch temporary
breakpoints in and out in switch_to().

Signed-off-by: David Howells <dhowells@redhat.com>