From 10527fca66e39d7067986904161fa33741abcd26 Mon Sep 17 00:00:00 2001 From: Eli Zaretskii Date: Wed, 13 Feb 2019 17:39:31 +0200 Subject: [PATCH] Avoid crashes upon C-g in nested invocations of 'read_char' * src/keyboard.c (read_char, read_event_from_main_queue): Ensure the global value of getcjmp is restored when the stack is unwound by the likes of 'throw', by calling record_unwind_protect_ptr instead of restoring the value manually. (Bug#34394) (restore_getcjmp): Argument is now 'void *', to match the signature of record_unwind_protect_ptr. --- src/keyboard.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/src/keyboard.c b/src/keyboard.c index cd1747ea88c..1d67c3eaabd 100644 --- a/src/keyboard.c +++ b/src/keyboard.c @@ -360,7 +360,7 @@ static Lisp_Object make_lispy_focus_in (Lisp_Object); static Lisp_Object make_lispy_focus_out (Lisp_Object); static bool help_char_p (Lisp_Object); static void save_getcjmp (sys_jmp_buf); -static void restore_getcjmp (sys_jmp_buf); +static void restore_getcjmp (void *); static Lisp_Object apply_modifiers (int, Lisp_Object); static void restore_kboard_configuration (int); static void handle_interrupt (bool); @@ -2126,12 +2126,14 @@ read_event_from_main_queue (struct timespec *end_time, return c; /* Actually read a character, waiting if necessary. */ + ptrdiff_t count = SPECPDL_INDEX (); save_getcjmp (save_jump); + record_unwind_protect_ptr (restore_getcjmp, save_jump); restore_getcjmp (local_getcjmp); if (!end_time) timer_start_idle (); c = kbd_buffer_get_event (&kb, used_mouse_menu, end_time); - restore_getcjmp (save_jump); + unbind_to (count, Qnil); if (! NILP (c) && (kb != current_kboard)) { @@ -2620,10 +2622,12 @@ read_char (int commandflag, Lisp_Object map, { Lisp_Object tem0; + ptrdiff_t count = SPECPDL_INDEX (); save_getcjmp (save_jump); + record_unwind_protect_ptr (restore_getcjmp, save_jump); restore_getcjmp (local_getcjmp); tem0 = sit_for (Vecho_keystrokes, 1, 1); - restore_getcjmp (save_jump); + unbind_to (count, Qnil); if (EQ (tem0, Qt) && ! CONSP (Vunread_command_events)) echo_now (); @@ -2694,10 +2698,12 @@ read_char (int commandflag, Lisp_Object map, timeout = min (timeout, MOST_POSITIVE_FIXNUM / delay_level * 4); timeout = delay_level * timeout / 4; + ptrdiff_t count1 = SPECPDL_INDEX (); save_getcjmp (save_jump); + record_unwind_protect_ptr (restore_getcjmp, save_jump); restore_getcjmp (local_getcjmp); tem0 = sit_for (make_fixnum (timeout), 1, 1); - restore_getcjmp (save_jump); + unbind_to (count1, Qnil); if (EQ (tem0, Qt) && ! CONSP (Vunread_command_events)) @@ -3320,7 +3326,7 @@ save_getcjmp (sys_jmp_buf temp) } static void -restore_getcjmp (sys_jmp_buf temp) +restore_getcjmp (void *temp) { memcpy (getcjmp, temp, sizeof getcjmp); } -- 2.39.5