2 #define I3__FILE__ "sighandler.c"
4 * vim:ts=4:sw=4:expandtab
6 * i3 - an improved dynamic tiling window manager
7 * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
8 * © 2009-2010 Jan-Erik Rediger
10 * sighandler.c: Interactive crash dialog upon SIGSEGV/SIGABRT/SIGFPE (offers
11 * to restart inplace).
21 #include <xcb/xcb_event.h>
23 #include <X11/keysym.h>
25 static void open_popups(void);
27 static xcb_gcontext_t pixmap_gc;
28 static xcb_pixmap_t pixmap;
29 static int raised_signal;
31 static char *crash_text[] = {
33 "To debug this problem, either attach gdb now",
35 "- 'b' to save a backtrace (needs GDB),",
36 "- 'r' to restart i3 in-place or",
37 "- 'f' to forget the current layout and restart"
39 static int crash_text_longest = 5;
40 static int backtrace_string_index = 3;
41 static int backtrace_done = 0;
44 * Attach gdb to pid_parent and dump a backtrace to i3-backtrace.$pid in the
47 static int backtrace(void) {
48 char *tmpdir = getenv("TMPDIR");
52 pid_t pid_parent = getpid();
54 char *filename = NULL;
55 sasprintf(&filename, "%s/i3-backtrace.%d.txt", tmpdir, pid_parent);
57 pid_t pid_gdb = fork();
59 DLOG("Failed to fork for GDB\n");
61 } else if (pid_gdb == 0) {
69 /* close standard streams in case i3 is started from a terminal; gdb
70 * needs to run without controlling terminal for it to work properly in
76 /* We provide pipe file descriptors for stdin/stdout because gdb < 7.5
77 * crashes otherwise, see
78 * http://sourceware.org/bugzilla/show_bug.cgi?id=14114 */
79 dup2(stdin_pipe[0], STDIN_FILENO);
80 dup2(stdout_pipe[1], STDOUT_FILENO);
82 char *pid_s, *gdb_log_cmd;
83 sasprintf(&pid_s, "%d", pid_parent);
84 sasprintf(&gdb_log_cmd, "set logging file %s", filename);
94 "-ex", "set logging on",
99 execvp(args[0], args);
100 DLOG("Failed to exec GDB\n");
106 waitpid(pid_gdb, &status, 0);
108 /* see if the backtrace was succesful or not */
109 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
110 DLOG("GDB did not run properly\n");
112 } else if (stat(filename, &bt) == -1) {
113 DLOG("GDB executed succesfully, but no backtrace was generated\n");
120 * Draw the window containing the info text
123 static int sig_draw_window(xcb_window_t win, int width, int height, int font_height, i3String **crash_text_i3strings) {
124 /* re-draw the background */
125 xcb_rectangle_t border = { 0, 0, width, height},
126 inner = { 2, 2, width - 4, height - 4};
127 xcb_change_gc(conn, pixmap_gc, XCB_GC_FOREGROUND, (uint32_t[]){ get_colorpixel("#FF0000") });
128 xcb_poly_fill_rectangle(conn, pixmap, pixmap_gc, 1, &border);
129 xcb_change_gc(conn, pixmap_gc, XCB_GC_FOREGROUND, (uint32_t[]){ get_colorpixel("#000000") });
130 xcb_poly_fill_rectangle(conn, pixmap, pixmap_gc, 1, &inner);
132 /* restore font color */
133 set_font_colors(pixmap_gc, get_colorpixel("#FFFFFF"), get_colorpixel("#000000"));
135 char *bt_colour = "#FFFFFF";
136 if (backtrace_done < 0)
137 bt_colour = "#AA0000";
138 else if (backtrace_done > 0)
139 bt_colour = "#00AA00";
141 for (int i = 0; crash_text_i3strings[i] != NULL; ++i) {
142 /* fix the colour for the backtrace line when it finished */
143 if (i == backtrace_string_index)
144 set_font_colors(pixmap_gc, get_colorpixel(bt_colour), get_colorpixel("#000000"));
146 draw_text(crash_text_i3strings[i], pixmap, pixmap_gc,
147 8, 5 + i * font_height, width - 16);
149 /* and reset the colour again for other lines */
150 if (i == backtrace_string_index)
151 set_font_colors(pixmap_gc, get_colorpixel("#FFFFFF"), get_colorpixel("#000000"));
154 /* Copy the contents of the pixmap to the real window */
155 xcb_copy_area(conn, pixmap, win, pixmap_gc, 0, 0, 0, 0, width, height);
162 * Handles keypresses of 'b', 'r' and 'f' to get a backtrace or restart i3
165 static int sig_handle_key_press(void *ignored, xcb_connection_t *conn, xcb_key_press_event_t *event) {
166 uint16_t state = event->state;
168 /* Apparantly, after activating numlock once, the numlock modifier
169 * stays turned on (use xev(1) to verify). So, to resolve useful
170 * keysyms, we remove the numlock flag from the event state */
171 state &= ~xcb_numlock_mask;
173 xcb_keysym_t sym = xcb_key_press_lookup_keysym(keysyms, event, state);
176 DLOG("User issued core-dump command.\n");
178 /* fork and exec/attach GDB to the parent to get a backtrace in the
180 backtrace_done = backtrace();
182 /* re-open the windows to indicate that it's finished */
196 * Opens the window we use for input/output and maps it
199 static xcb_window_t open_input_window(xcb_connection_t *conn, Rect screen_rect, uint32_t width, uint32_t height) {
200 xcb_window_t win = xcb_generate_id(conn);
205 mask |= XCB_CW_BACK_PIXEL;
208 mask |= XCB_CW_OVERRIDE_REDIRECT;
211 /* center each popup on the specified screen */
212 uint32_t x = screen_rect.x + ((screen_rect.width / 2) - (width / 2)),
213 y = screen_rect.y + ((screen_rect.height / 2) - (height / 2));
215 xcb_create_window(conn,
216 XCB_COPY_FROM_PARENT,
217 win, /* the window id */
218 root, /* parent == root */
219 x, y, width, height, /* dimensions */
220 0, /* border = 0, we draw our own */
221 XCB_WINDOW_CLASS_INPUT_OUTPUT,
222 XCB_WINDOW_CLASS_COPY_FROM_PARENT, /* copy visual from parent */
226 /* Map the window (= make it visible) */
227 xcb_map_window(conn, win);
232 static void open_popups() {
233 /* width and height of the popup window, so that the text fits in */
234 int crash_text_num = sizeof(crash_text) / sizeof(char*);
235 int height = 13 + (crash_text_num * config.font.height);
237 int crash_text_length = sizeof(crash_text) / sizeof(char*);
238 i3String **crash_text_i3strings = smalloc(sizeof(i3String *) * (crash_text_length + 1));
239 /* Pre-compute i3Strings for our text */
240 for (int i = 0; i < crash_text_length; ++i) {
241 crash_text_i3strings[i] = i3string_from_utf8(crash_text[i]);
243 crash_text_i3strings[crash_text_length] = NULL;
244 /* calculate width for longest text */
245 int font_width = predict_text_width(crash_text_i3strings[crash_text_longest]);
246 int width = font_width + 20;
248 /* Open a popup window on each virtual screen */
251 TAILQ_FOREACH(screen, &outputs, outputs) {
254 win = open_input_window(conn, screen->rect, width, height);
257 pixmap = xcb_generate_id(conn);
258 pixmap_gc = xcb_generate_id(conn);
259 xcb_create_pixmap(conn, root_depth, pixmap, win, width, height);
260 xcb_create_gc(conn, pixmap_gc, pixmap, 0, 0);
262 /* Grab the keyboard to get all input */
263 xcb_grab_keyboard(conn, false, win, XCB_CURRENT_TIME, XCB_GRAB_MODE_ASYNC, XCB_GRAB_MODE_ASYNC);
265 /* Grab the cursor inside the popup */
266 xcb_grab_pointer(conn, false, win, XCB_NONE, XCB_GRAB_MODE_ASYNC,
267 XCB_GRAB_MODE_ASYNC, win, XCB_NONE, XCB_CURRENT_TIME);
269 sig_draw_window(win, width, height, config.font.height, crash_text_i3strings);
276 * It creates a window asking the user to restart in-place
277 * or exit to generate a core dump
280 void handle_signal(int sig, siginfo_t *info, void *data) {
281 DLOG("i3 crashed. SIG: %d\n", sig);
283 struct sigaction action;
284 action.sa_handler = SIG_DFL;
285 sigaction(sig, &action, NULL);
290 xcb_generic_event_t *event;
291 /* Yay, more own eventhandlers… */
292 while ((event = xcb_wait_for_event(conn))) {
293 /* Strip off the highest bit (set if the event is generated) */
294 int type = (event->response_type & 0x7F);
295 if (type == XCB_KEY_PRESS) {
296 sig_handle_key_press(NULL, conn, (xcb_key_press_event_t*)event);
303 * Setup signal handlers to safely handle SIGSEGV and SIGFPE
306 void setup_signal_handler(void) {
307 struct sigaction action;
309 action.sa_sigaction = handle_signal;
310 action.sa_flags = SA_NODEFER | SA_RESETHAND | SA_SIGINFO;
311 sigemptyset(&action.sa_mask);
313 /* Catch all signals with default action "Core", see signal(7) */
314 if (sigaction(SIGQUIT, &action, NULL) == -1 ||
315 sigaction(SIGILL, &action, NULL) == -1 ||
316 sigaction(SIGABRT, &action, NULL) == -1 ||
317 sigaction(SIGFPE, &action, NULL) == -1 ||
318 sigaction(SIGSEGV, &action, NULL) == -1)
319 ELOG("Could not setup signal handler");