From 96e3f4e3c32865fecdb266c2a41532337c75e316 Mon Sep 17 00:00:00 2001 From: Kevin Buettner Date: Mon, 27 Feb 2023 16:11:37 -0700 Subject: Forced quit cases handled by resetting sync_quit_force_run During my audit of the use of gdb_exception with regard to QUIT processing, I found a try/catch in the scoped_switch_fork_info destructor. Static analysis found this call path from the destructor to maybe_quit(): scoped_switch_fork_info::~scoped_switch_fork_info() -> remove_breakpoints() -> remove_breakpoint(bp_location*) -> remove_breakpoint_1(bp_location*, remove_bp_reason) -> memory_validate_breakpoint(gdbarch*, bp_target_info*) -> target_read_memory(unsigned long, unsigned char*, long) -> target_read(target_ops*, target_object, char const*, unsigned char*, unsigned long, long) -> maybe_quit() Since it's not safe to do a 'throw' from a destructor, we simply call set_quit_flag and, for gdb_exception_forced_quit, also set sync_quit_force_run. This will cause the appropriate exception to be rethrown at the next QUIT check. Another case is the try / catch in tui_getc() in tui-io.c. The existing catch swallows the exception. I've added a catch for 'gdb_exception_forced_quit', which also swallows the exception, but also sets sync_quit_force_run and calls set_quit_flag in order to restart forced quit processing at the next QUIT check. This is required because it isn't safe to throw into/through readline. Thanks to Pedro Alves for suggesting this idea. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=26761 Tested-by: Tom de Vries Approved-By: Pedro Alves --- gdb/tui/tui-io.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'gdb/tui/tui-io.c') diff --git a/gdb/tui/tui-io.c b/gdb/tui/tui-io.c index a17cf38..7752701 100644 --- a/gdb/tui/tui-io.c +++ b/gdb/tui/tui-io.c @@ -1271,6 +1271,14 @@ tui_getc (FILE *fp) { return tui_getc_1 (fp); } + catch (const gdb_exception_forced_quit &ex) + { + /* As noted below, it's not safe to let an exception escape + to newline, so, for this case, reset the quit flag for + later QUIT checking. */ + set_force_quit_flag (); + return 0; + } catch (const gdb_exception &ex) { /* Just in case, don't ever let an exception escape to readline. -- cgit v1.1