332 lines
10 KiB
C
332 lines
10 KiB
C
#undef I3__FILE__
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#define I3__FILE__ "sighandler.c"
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/*
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* vim:ts=4:sw=4:expandtab
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*
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* i3 - an improved dynamic tiling window manager
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* © 2009 Michael Stapelberg and contributors (see also: LICENSE)
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* © 2009 Jan-Erik Rediger
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*
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* sighandler.c: Interactive crash dialog upon SIGSEGV/SIGABRT/SIGFPE (offers
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* to restart inplace).
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*
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*/
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#include "all.h"
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#include <ev.h>
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#include <iconv.h>
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#include <signal.h>
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#include <sys/wait.h>
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#include <xcb/xcb_event.h>
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#include <X11/keysym.h>
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static void open_popups(void);
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static xcb_gcontext_t pixmap_gc;
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static xcb_pixmap_t pixmap;
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static int raised_signal;
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static char *crash_text[] = {
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"i3 just crashed.",
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"To debug this problem, either attach gdb now",
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"or press",
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"- 'b' to save a backtrace (needs GDB),",
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"- 'r' to restart i3 in-place or",
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"- 'f' to forget the current layout and restart"};
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static int crash_text_longest = 5;
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static int backtrace_string_index = 3;
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static int backtrace_done = 0;
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/*
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* Attach gdb to pid_parent and dump a backtrace to i3-backtrace.$pid in the
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* tmpdir
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*/
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static int backtrace(void) {
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char *tmpdir = getenv("TMPDIR");
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if (tmpdir == NULL)
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tmpdir = "/tmp";
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pid_t pid_parent = getpid();
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char *filename = NULL;
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int suffix = 0;
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struct stat bt;
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/* Find a unique filename for the backtrace (since the PID of i3 stays the
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* same), so that we don’t overwrite earlier backtraces. */
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do {
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FREE(filename);
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sasprintf(&filename, "%s/i3-backtrace.%d.%d.txt", tmpdir, pid_parent, suffix);
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suffix++;
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} while (stat(filename, &bt) == 0);
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pid_t pid_gdb = fork();
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if (pid_gdb < 0) {
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DLOG("Failed to fork for GDB\n");
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return -1;
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} else if (pid_gdb == 0) {
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/* child */
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int stdin_pipe[2],
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stdout_pipe[2];
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if (pipe(stdin_pipe) == -1) {
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ELOG("Failed to init stdin_pipe\n");
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return -1;
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}
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if (pipe(stdout_pipe) == -1) {
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ELOG("Failed to init stdout_pipe\n");
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return -1;
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}
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/* close standard streams in case i3 is started from a terminal; gdb
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* needs to run without controlling terminal for it to work properly in
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* this situation */
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close(STDIN_FILENO);
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close(STDOUT_FILENO);
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close(STDERR_FILENO);
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/* We provide pipe file descriptors for stdin/stdout because gdb < 7.5
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* crashes otherwise, see
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* http://sourceware.org/bugzilla/show_bug.cgi?id=14114 */
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dup2(stdin_pipe[0], STDIN_FILENO);
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dup2(stdout_pipe[1], STDOUT_FILENO);
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char *pid_s, *gdb_log_cmd;
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sasprintf(&pid_s, "%d", pid_parent);
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sasprintf(&gdb_log_cmd, "set logging file %s", filename);
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char *args[] = {
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"gdb",
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start_argv[0],
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"-p",
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pid_s,
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"-batch",
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"-nx",
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"-ex", gdb_log_cmd,
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"-ex", "set logging on",
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"-ex", "bt full",
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"-ex", "quit",
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NULL};
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execvp(args[0], args);
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DLOG("Failed to exec GDB\n");
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exit(1);
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}
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int status = 0;
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waitpid(pid_gdb, &status, 0);
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/* see if the backtrace was succesful or not */
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if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
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DLOG("GDB did not run properly\n");
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return -1;
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} else if (stat(filename, &bt) == -1) {
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DLOG("GDB executed successfully, but no backtrace was generated\n");
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return -1;
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}
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return 1;
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}
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/*
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* Draw the window containing the info text
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*
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*/
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static int sig_draw_window(xcb_window_t win, int width, int height, int font_height, i3String **crash_text_i3strings) {
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/* re-draw the background */
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xcb_rectangle_t border = {0, 0, width, height},
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inner = {2, 2, width - 4, height - 4};
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xcb_change_gc(conn, pixmap_gc, XCB_GC_FOREGROUND, (uint32_t[]){get_colorpixel("#FF0000")});
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xcb_poly_fill_rectangle(conn, pixmap, pixmap_gc, 1, &border);
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xcb_change_gc(conn, pixmap_gc, XCB_GC_FOREGROUND, (uint32_t[]){get_colorpixel("#000000")});
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xcb_poly_fill_rectangle(conn, pixmap, pixmap_gc, 1, &inner);
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/* restore font color */
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set_font_colors(pixmap_gc, get_colorpixel("#FFFFFF"), get_colorpixel("#000000"));
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char *bt_colour = "#FFFFFF";
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if (backtrace_done < 0)
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bt_colour = "#AA0000";
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else if (backtrace_done > 0)
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bt_colour = "#00AA00";
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for (int i = 0; crash_text_i3strings[i] != NULL; ++i) {
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/* fix the colour for the backtrace line when it finished */
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if (i == backtrace_string_index)
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set_font_colors(pixmap_gc, get_colorpixel(bt_colour), get_colorpixel("#000000"));
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draw_text(crash_text_i3strings[i], pixmap, pixmap_gc,
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8, 5 + i * font_height, width - 16);
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/* and reset the colour again for other lines */
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if (i == backtrace_string_index)
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set_font_colors(pixmap_gc, get_colorpixel("#FFFFFF"), get_colorpixel("#000000"));
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}
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/* Copy the contents of the pixmap to the real window */
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xcb_copy_area(conn, pixmap, win, pixmap_gc, 0, 0, 0, 0, width, height);
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xcb_flush(conn);
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return 1;
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}
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/*
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* Handles keypresses of 'b', 'r' and 'f' to get a backtrace or restart i3
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*
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*/
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static int sig_handle_key_press(void *ignored, xcb_connection_t *conn, xcb_key_press_event_t *event) {
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uint16_t state = event->state;
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/* Apparantly, after activating numlock once, the numlock modifier
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* stays turned on (use xev(1) to verify). So, to resolve useful
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* keysyms, we remove the numlock flag from the event state */
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state &= ~xcb_numlock_mask;
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xcb_keysym_t sym = xcb_key_press_lookup_keysym(keysyms, event, state);
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if (sym == 'b') {
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DLOG("User issued core-dump command.\n");
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/* fork and exec/attach GDB to the parent to get a backtrace in the
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* tmpdir */
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backtrace_done = backtrace();
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/* re-open the windows to indicate that it's finished */
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open_popups();
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}
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if (sym == 'r')
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i3_restart(false);
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if (sym == 'f')
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i3_restart(true);
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return 1;
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}
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/*
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* Opens the window we use for input/output and maps it
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*
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*/
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static xcb_window_t open_input_window(xcb_connection_t *conn, Rect screen_rect, uint32_t width, uint32_t height) {
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xcb_window_t win = xcb_generate_id(conn);
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uint32_t mask = 0;
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uint32_t values[2];
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mask |= XCB_CW_BACK_PIXEL;
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values[0] = 0;
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mask |= XCB_CW_OVERRIDE_REDIRECT;
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values[1] = 1;
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/* center each popup on the specified screen */
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uint32_t x = screen_rect.x + ((screen_rect.width / 2) - (width / 2)),
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y = screen_rect.y + ((screen_rect.height / 2) - (height / 2));
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xcb_create_window(conn,
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XCB_COPY_FROM_PARENT,
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win, /* the window id */
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root, /* parent == root */
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x, y, width, height, /* dimensions */
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0, /* border = 0, we draw our own */
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XCB_WINDOW_CLASS_INPUT_OUTPUT,
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XCB_WINDOW_CLASS_COPY_FROM_PARENT, /* copy visual from parent */
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mask,
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values);
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/* Map the window (= make it visible) */
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xcb_map_window(conn, win);
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return win;
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}
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static void open_popups() {
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/* width and height of the popup window, so that the text fits in */
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int crash_text_num = sizeof(crash_text) / sizeof(char *);
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int height = 13 + (crash_text_num * config.font.height);
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int crash_text_length = sizeof(crash_text) / sizeof(char *);
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i3String **crash_text_i3strings = smalloc(sizeof(i3String *) * (crash_text_length + 1));
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/* Pre-compute i3Strings for our text */
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for (int i = 0; i < crash_text_length; ++i) {
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crash_text_i3strings[i] = i3string_from_utf8(crash_text[i]);
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}
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crash_text_i3strings[crash_text_length] = NULL;
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/* calculate width for longest text */
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int font_width = predict_text_width(crash_text_i3strings[crash_text_longest]);
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int width = font_width + 20;
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/* Open a popup window on each virtual screen */
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Output *screen;
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xcb_window_t win;
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TAILQ_FOREACH(screen, &outputs, outputs) {
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if (!screen->active)
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continue;
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win = open_input_window(conn, screen->rect, width, height);
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/* Create pixmap */
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pixmap = xcb_generate_id(conn);
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pixmap_gc = xcb_generate_id(conn);
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xcb_create_pixmap(conn, root_depth, pixmap, win, width, height);
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xcb_create_gc(conn, pixmap_gc, pixmap, 0, 0);
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/* Grab the keyboard to get all input */
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xcb_grab_keyboard(conn, false, win, XCB_CURRENT_TIME, XCB_GRAB_MODE_ASYNC, XCB_GRAB_MODE_ASYNC);
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/* Grab the cursor inside the popup */
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xcb_grab_pointer(conn, false, win, XCB_NONE, XCB_GRAB_MODE_ASYNC,
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XCB_GRAB_MODE_ASYNC, win, XCB_NONE, XCB_CURRENT_TIME);
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sig_draw_window(win, width, height, config.font.height, crash_text_i3strings);
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xcb_flush(conn);
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}
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}
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/*
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* Handle signals
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* It creates a window asking the user to restart in-place
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* or exit to generate a core dump
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*
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*/
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void handle_signal(int sig, siginfo_t *info, void *data) {
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DLOG("i3 crashed. SIG: %d\n", sig);
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struct sigaction action;
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action.sa_handler = SIG_DFL;
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sigaction(sig, &action, NULL);
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raised_signal = sig;
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open_popups();
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xcb_generic_event_t *event;
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/* Yay, more own eventhandlers… */
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while ((event = xcb_wait_for_event(conn))) {
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/* Strip off the highest bit (set if the event is generated) */
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int type = (event->response_type & 0x7F);
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if (type == XCB_KEY_PRESS) {
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sig_handle_key_press(NULL, conn, (xcb_key_press_event_t *)event);
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}
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free(event);
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}
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}
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/*
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* Setup signal handlers to safely handle SIGSEGV and SIGFPE
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*
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*/
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void setup_signal_handler(void) {
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struct sigaction action;
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action.sa_sigaction = handle_signal;
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action.sa_flags = SA_NODEFER | SA_RESETHAND | SA_SIGINFO;
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sigemptyset(&action.sa_mask);
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/* Catch all signals with default action "Core", see signal(7) */
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if (sigaction(SIGQUIT, &action, NULL) == -1 ||
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sigaction(SIGILL, &action, NULL) == -1 ||
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sigaction(SIGABRT, &action, NULL) == -1 ||
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sigaction(SIGFPE, &action, NULL) == -1 ||
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sigaction(SIGSEGV, &action, NULL) == -1)
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ELOG("Could not setup signal handler");
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}
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