From 9ccabccd15603dbf9fe988c86708fe644d1398a7 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Thu, 16 Nov 2017 18:44:44 +0000 Subject: Python unwinder sniffer: PyExc_KeyboardInterrupt -> Quit If you happen to press Ctrl-C while GDB is running the Python unwinder machinery, the Ctrl-C is swallowed by the Python unwinder machinery. For example, with: break foo commands > c > end and while (1) foo (); and then let the inferior hit "foo" repeatedly, sometimes Ctrl-C results in: ~~~ 23 usleep (100); Breakpoint 2, foo () at gdb.base/bp-cmds-continue-ctrl-c.c:23 23 usleep (100); ^C Breakpoint 2, Python Exception : foo () at gdb.base/bp-cmds-continue-ctrl-c.c:23 23 usleep (100); Breakpoint 2, foo () at gdb.base/bp-cmds-continue-ctrl-c.c:23 23 usleep (100); Breakpoint 2, foo () at gdb.base/bp-cmds-continue-ctrl-c.c:23 23 usleep (100); ~~~ Notice the Python exception above. The interesting thing here is that GDB continues as if nothing happened, doesn't really stop and give back control to the user. Instead, the Ctrl-C aborted the Python unwinder sniffer and GDB moved on to just use another unwinder. Fix this by translating a PyExc_KeyboardInterrupt back into a Quit exception once back in GDB. This was exposed by the new gdb.base/bp-cmds-continue-ctrl-c.exp testcase added later in the series. gdb/ChangeLog: 2017-11-16 Pedro Alves * python/py-unwind.c (pyuw_sniffer): Translate PyExc_KeyboardInterrupt to a GDB Quit exception. --- gdb/python/py-unwind.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'gdb/python') diff --git a/gdb/python/py-unwind.c b/gdb/python/py-unwind.c index acfce7d..b578373 100644 --- a/gdb/python/py-unwind.c +++ b/gdb/python/py-unwind.c @@ -539,6 +539,13 @@ pyuw_sniffer (const struct frame_unwind *self, struct frame_info *this_frame, pyo_pending_frame.get (), NULL)); if (pyo_unwind_info == NULL) { + /* If the unwinder is cancelled due to a Ctrl-C, then propagate + the Ctrl-C as a GDB exception instead of swallowing it. */ + if (PyErr_ExceptionMatches (PyExc_KeyboardInterrupt)) + { + PyErr_Clear (); + quit (); + } gdbpy_print_stack (); return 0; } -- cgit v1.1