+#undef I3__FILE__
+#define I3__FILE__ "sighandler.c"
/*
* vim:ts=4:sw=4:expandtab
*
#include <ev.h>
#include <iconv.h>
#include <signal.h>
+#include <sys/wait.h>
#include <xcb/xcb_event.h>
#include <X11/keysym.h>
+static void open_popups(void);
+
static xcb_gcontext_t pixmap_gc;
static xcb_pixmap_t pixmap;
static int raised_signal;
"i3 just crashed.",
"To debug this problem, either attach gdb now",
"or press",
- "- 'e' to exit and get a core-dump,",
+ "- 'b' to save a backtrace (needs GDB),",
"- 'r' to restart i3 in-place or",
"- 'f' to forget the current layout and restart"
};
static int crash_text_longest = 5;
+static int backtrace_string_index = 3;
+static int backtrace_done = 0;
+
+/*
+ * Attach gdb to pid_parent and dump a backtrace to i3-backtrace.$pid in the
+ * tmpdir
+ */
+static int backtrace(void) {
+ char *tmpdir = getenv("TMPDIR");
+ if (tmpdir == NULL)
+ tmpdir = "/tmp";
+
+ pid_t pid_parent = getpid();
+
+ char *filename = NULL;
+ int suffix = 0;
+ struct stat bt;
+ /* Find a unique filename for the backtrace (since the PID of i3 stays the
+ * same), so that we don’t overwrite earlier backtraces. */
+ do {
+ FREE(filename);
+ sasprintf(&filename, "%s/i3-backtrace.%d.%d.txt", tmpdir, pid_parent, suffix);
+ suffix++;
+ } while (stat(filename, &bt) == 0);
+
+ pid_t pid_gdb = fork();
+ if (pid_gdb < 0) {
+ DLOG("Failed to fork for GDB\n");
+ return -1;
+ } else if (pid_gdb == 0) {
+ /* child */
+ int stdin_pipe[2],
+ stdout_pipe[2];
+
+ pipe(stdin_pipe);
+ pipe(stdout_pipe);
+
+ /* close standard streams in case i3 is started from a terminal; gdb
+ * needs to run without controlling terminal for it to work properly in
+ * this situation */
+ close(STDIN_FILENO);
+ close(STDOUT_FILENO);
+ close(STDERR_FILENO);
+
+ /* We provide pipe file descriptors for stdin/stdout because gdb < 7.5
+ * crashes otherwise, see
+ * http://sourceware.org/bugzilla/show_bug.cgi?id=14114 */
+ dup2(stdin_pipe[0], STDIN_FILENO);
+ dup2(stdout_pipe[1], STDOUT_FILENO);
+
+ char *pid_s, *gdb_log_cmd;
+ sasprintf(&pid_s, "%d", pid_parent);
+ sasprintf(&gdb_log_cmd, "set logging file %s", filename);
+
+ char *args[] = {
+ "gdb",
+ start_argv[0],
+ "-p",
+ pid_s,
+ "-batch",
+ "-nx",
+ "-ex", gdb_log_cmd,
+ "-ex", "set logging on",
+ "-ex", "bt full",
+ "-ex", "quit",
+ NULL
+ };
+ execvp(args[0], args);
+ DLOG("Failed to exec GDB\n");
+ exit(1);
+ }
+ int status = 0;
+
+ waitpid(pid_gdb, &status, 0);
+
+ /* see if the backtrace was succesful or not */
+ if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+ DLOG("GDB did not run properly\n");
+ return -1;
+ } else if (stat(filename, &bt) == -1) {
+ DLOG("GDB executed successfully, but no backtrace was generated\n");
+ return -1;
+ }
+ return 1;
+}
/*
* Draw the window containing the info text
*
*/
-static int sig_draw_window(xcb_window_t win, int width, int height, int font_height) {
+static int sig_draw_window(xcb_window_t win, int width, int height, int font_height, i3String **crash_text_i3strings) {
/* re-draw the background */
xcb_rectangle_t border = { 0, 0, width, height},
inner = { 2, 2, width - 4, height - 4};
/* restore font color */
set_font_colors(pixmap_gc, get_colorpixel("#FFFFFF"), get_colorpixel("#000000"));
- for (int i = 0; i < sizeof(crash_text) / sizeof(char*); i++) {
- draw_text(crash_text[i], strlen(crash_text[i]), false, pixmap, pixmap_gc,
- 8, 3 + (i - 1) * font_height, width - 16);
+ char *bt_colour = "#FFFFFF";
+ if (backtrace_done < 0)
+ bt_colour = "#AA0000";
+ else if (backtrace_done > 0)
+ bt_colour = "#00AA00";
+
+ for (int i = 0; crash_text_i3strings[i] != NULL; ++i) {
+ /* fix the colour for the backtrace line when it finished */
+ if (i == backtrace_string_index)
+ set_font_colors(pixmap_gc, get_colorpixel(bt_colour), get_colorpixel("#000000"));
+
+ draw_text(crash_text_i3strings[i], pixmap, pixmap_gc,
+ 8, 5 + i * font_height, width - 16);
+
+ /* and reset the colour again for other lines */
+ if (i == backtrace_string_index)
+ set_font_colors(pixmap_gc, get_colorpixel("#FFFFFF"), get_colorpixel("#000000"));
}
/* Copy the contents of the pixmap to the real window */
}
/*
- * Handles keypresses of 'e' or 'r' to exit or restart i3
+ * Handles keypresses of 'b', 'r' and 'f' to get a backtrace or restart i3
*
*/
static int sig_handle_key_press(void *ignored, xcb_connection_t *conn, xcb_key_press_event_t *event) {
xcb_keysym_t sym = xcb_key_press_lookup_keysym(keysyms, event, state);
- if (sym == 'e') {
- DLOG("User issued exit-command, raising error again.\n");
- raise(raised_signal);
- exit(1);
+ if (sym == 'b') {
+ DLOG("User issued core-dump command.\n");
+
+ /* fork and exec/attach GDB to the parent to get a backtrace in the
+ * tmpdir */
+ backtrace_done = backtrace();
+
+ /* re-open the windows to indicate that it's finished */
+ open_popups();
}
if (sym == 'r')
return win;
}
-/*
- * Handle signals
- * It creates a window asking the user to restart in-place
- * or exit to generate a core dump
- *
- */
-void handle_signal(int sig, siginfo_t *info, void *data) {
- DLOG("i3 crashed. SIG: %d\n", sig);
-
- struct sigaction action;
- action.sa_handler = SIG_DFL;
- sigaction(sig, &action, NULL);
- raised_signal = sig;
-
+static void open_popups() {
/* width and height of the popup window, so that the text fits in */
int crash_text_num = sizeof(crash_text) / sizeof(char*);
int height = 13 + (crash_text_num * config.font.height);
+ int crash_text_length = sizeof(crash_text) / sizeof(char*);
+ i3String **crash_text_i3strings = smalloc(sizeof(i3String *) * (crash_text_length + 1));
+ /* Pre-compute i3Strings for our text */
+ for (int i = 0; i < crash_text_length; ++i) {
+ crash_text_i3strings[i] = i3string_from_utf8(crash_text[i]);
+ }
+ crash_text_i3strings[crash_text_length] = NULL;
/* calculate width for longest text */
- size_t text_len = strlen(crash_text[crash_text_longest]);
- xcb_char2b_t *longest_text = convert_utf8_to_ucs2(crash_text[crash_text_longest], &text_len);
- int font_width = predict_text_width((char *)longest_text, text_len, true);
+ int font_width = predict_text_width(crash_text_i3strings[crash_text_longest]);
int width = font_width + 20;
/* Open a popup window on each virtual screen */
xcb_grab_pointer(conn, false, win, XCB_NONE, XCB_GRAB_MODE_ASYNC,
XCB_GRAB_MODE_ASYNC, win, XCB_NONE, XCB_CURRENT_TIME);
- sig_draw_window(win, width, height, config.font.height);
+ sig_draw_window(win, width, height, config.font.height, crash_text_i3strings);
xcb_flush(conn);
}
+}
+
+/*
+ * Handle signals
+ * It creates a window asking the user to restart in-place
+ * or exit to generate a core dump
+ *
+ */
+void handle_signal(int sig, siginfo_t *info, void *data) {
+ DLOG("i3 crashed. SIG: %d\n", sig);
+
+ struct sigaction action;
+ action.sa_handler = SIG_DFL;
+ sigaction(sig, &action, NULL);
+ raised_signal = sig;
+
+ open_popups();
xcb_generic_event_t *event;
/* Yay, more own eventhandlers… */
* Setup signal handlers to safely handle SIGSEGV and SIGFPE
*
*/
-void setup_signal_handler() {
+void setup_signal_handler(void) {
struct sigaction action;
action.sa_sigaction = handle_signal;
action.sa_flags = SA_NODEFER | SA_RESETHAND | SA_SIGINFO;
sigemptyset(&action.sa_mask);
- if (sigaction(SIGSEGV, &action, NULL) == -1 ||
+ /* Catch all signals with default action "Core", see signal(7) */
+ if (sigaction(SIGQUIT, &action, NULL) == -1 ||
+ sigaction(SIGILL, &action, NULL) == -1 ||
sigaction(SIGABRT, &action, NULL) == -1 ||
- sigaction(SIGFPE, &action, NULL) == -1)
+ sigaction(SIGFPE, &action, NULL) == -1 ||
+ sigaction(SIGSEGV, &action, NULL) == -1)
ELOG("Could not setup signal handler");
}