When the program starts executing due to a gdb command such as
is output. When the program stops,
is output. Before the
stopped annotation, a variety of
annotations describe how the program stopped.
^Z^Zsignalled, the annotation continues:
intro-text ^Z^Zsignal-name name ^Z^Zsignal-name-end middle-text ^Z^Zsignal-string string ^Z^Zsignal-string-end end-text
where name is the name of the signal, such as
SIGSEGV, and string is the explanation of the signal, such
Illegal Instruction or
Segmentation fault. The arguments
intro-text, middle-text, and end-text are for the
user's benefit and have no particular format.
signalled, but gdb is just saying that the program received the signal, not that it was terminated with it.