The thread-id of 0 means any CPU but we then ignore the fact we find the first_cpu in this case who can have an index of 0. Instead of bailing out just test if we have managed to match up thread-id to a CPU.
Otherwise you get: gdb_handle_packet: command='vCont;C04:0;c' put_packet: reply='E22' Signed-off-by: Alex Bennée <alex.ben...@linaro.org> --- gdbstub.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/gdbstub.c b/gdbstub.c index a249846954..29c9ed3002 100644 --- a/gdbstub.c +++ b/gdbstub.c @@ -934,8 +934,8 @@ static int gdb_handle_vcont(GDBState *s, const char *p) * CPU first, and only then we can use its index. */ cpu = find_cpu(idx); - /* invalid CPU/thread specified */ - if (!idx || !cpu) { + /* invalid thread specified, cpu not found. */ + if (!cpu) { res = -EINVAL; goto out; } -- 2.13.0