From 574f2cf39e37ac6ecdb6d9b8b38626b4d6502822 Mon Sep 17 00:00:00 2001
From: Ray Strode <rstrode@redhat.com>
Date: Mon, 25 Sep 2023 22:22:08 +0200
Subject: [PATCH 1/3] util: Add way to print backtraces
Now that mutter can use a realtime thread its very important that
it doesn't stall for too long, since that can result in the kernel
killing it. Ironically, a main reason mutter could stall is
kernel bugs.
When a stall happens, we need a way to see why. This commit adds
a new function, "meta_print_backtrace" to print backtrace of the
current process and the kernel (if possible).
A future commit will use this new function.
---
meson.build | 8 ++++
meson_options.txt | 6 +++
src/50-mutter.rules | 9 ++++
src/core/util-private.h | 2 +
src/core/util.c | 57 ++++++++++++++++++++++++
src/meson.build | 27 +++++++++++
src/mutter-backtrace | 17 +++++++
src/org.gnome.mutter.backtrace.policy.in | 17 +++++++
8 files changed, 143 insertions(+)
create mode 100644 src/50-mutter.rules
create mode 100755 src/mutter-backtrace
create mode 100644 src/org.gnome.mutter.backtrace.policy.in
diff --git a/meson.build b/meson.build
index d08401b3c..5482dfb9e 100644
--- a/meson.build
+++ b/meson.build
@@ -270,60 +270,67 @@ if have_wayland or have_native_backend
libdrm_dep = dependency('libdrm')
endif
have_egl_device = get_option('egl_device')
have_wayland_eglstream = get_option('wayland_eglstream')
if have_wayland_eglstream
wayland_eglstream_protocols_dep = dependency('wayland-eglstream-protocols')
dl_dep = cc.find_library('dl', required: true)
if not have_wayland
error('Wayland EGLStream support requires Wayland to be enabled')
endif
endif
have_sm = get_option('sm')
if have_sm
sm_dep = dependency('sm')
endif
have_libwacom = get_option('libwacom')
if have_libwacom
libwacom_dep = dependency('libwacom', version: libwacom_req)
endif
have_pango_ft2 = get_option('pango_ft2')
if have_pango_ft2
pangoft2_dep = dependency('pangoft2')
endif
+have_polkit = get_option('polkit')
+if have_polkit
+ polkit_dep = dependency('polkit-gobject-1')
+ polkit_policy_dir = polkit_dep.get_variable('policydir')
+ polkit_action_dir = polkit_dep.get_variable('actiondir')
+endif
+
have_startup_notification = get_option('startup_notification')
if have_startup_notification
if have_x11_client
libstartup_notification_dep = dependency('libstartup-notification-1.0',
version: libstartup_notification_req)
else
error('startup_notification requires X11 or Xwayland to be enabled')
endif
endif
have_remote_desktop = get_option('remote_desktop')
if have_remote_desktop
libpipewire_dep = dependency('libpipewire-0.3', version: libpipewire_req)
endif
have_introspection = get_option('introspection')
if have_introspection
gobject_introspection_dep = dependency('gobject-introspection-1.0')
introspection_args = [
'--quiet',
'-U_GNU_SOURCE',
]
endif
have_documentation = get_option('docs')
if have_documentation
gidocgen_dep = dependency('gi-docgen', version: '>= 2021.1',
fallback: ['gi-docgen', 'dummy_dep'])
endif
@@ -671,50 +678,51 @@ if have_documentation
subdir('doc/reference')
endif
gnome.post_install(
glib_compile_schemas: true,
)
meson.add_dist_script('meson/check-version.py', meson.project_version(), 'NEWS')
summary('prefix', prefix, section: 'Directories')
summary('libexecdir', libexecdir, section: 'Directories')
summary('pkgdatadir', pkgdatadir, section: 'Directories')
summary('buildtype', get_option('buildtype'), section: 'Build Configuration')
summary('debug', get_option('debug'), section: 'Build Configuration')
summary('OpenGL', have_gl, section: 'Rendering APIs')
summary('GLES2', have_gles2, section: 'Rendering APIs')
summary('EGL', have_egl, section: 'Rendering APIs')
summary('GLX', have_glx, section: 'Rendering APIs')
summary('Wayland', have_wayland, section: 'Options')
summary('Wayland EGLStream', have_wayland_eglstream, section: 'Options')
summary('X11', have_x11, section: 'Options')
summary('XWayland', have_xwayland, section: 'Options')
summary('Native Backend', have_native_backend, section: 'Options')
summary('EGL Device', have_egl_device, section: 'Options')
summary('Remote desktop', have_remote_desktop, section: 'Options')
summary('libgnome-desktop', have_gnome_desktop, section: 'Options')
summary('libdisplay-info', have_libdisplay_info, section: 'Options')
+summary('Polkit enhanced backtrace support', have_polkit, section: 'Options')
summary('Sound player', have_sound_player, section: 'Options')
summary('gudev', have_libgudev, section: 'Options')
summary('Wacom', have_libwacom, section: 'Options')
summary('SM', have_sm, section: 'Options')
summary('Startup notification', have_startup_notification, section: 'Options')
summary('Introspection', have_introspection, section: 'Options')
summary('Documentation', have_documentation, section: 'Options')
summary('Profiler', have_profiler, section: 'Options')
summary('Xwayland initfd', have_xwayland_initfd, section: 'Options')
summary('Xwayland listenfd', have_xwayland_listenfd, section: 'Options')
summary('Xwayland terminate delay', have_xwayland_terminate_delay, section: 'Options')
summary('Xwayland byte-swapped clients', have_xwayland_byte_swapped_clients, section: 'Options')
summary('Enabled', have_tests, section: 'Tests')
summary('Core tests', have_core_tests, section: 'Tests')
summary('Cogl tests', have_cogl_tests, section: 'Tests')
summary('Clutter tests', have_clutter_tests, section: 'Tests')
summary('KVM tests', get_option('kvm_tests'), section: 'Tests')
summary('Installed tests', have_installed_tests, section: 'Tests')
summary('Coverage', get_option('b_coverage'), section: 'Tests')
diff --git a/meson_options.txt b/meson_options.txt
index b5d215b24..b6b18ebdf 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -84,60 +84,66 @@ option('wayland_eglstream',
option('udev',
type: 'boolean',
value: true,
description: 'Enable udev support when using the X11 backend'
)
option('udev_dir',
type: 'string',
value: '',
description: 'Absolute path of the udev base directory'
)
option('libwacom',
type: 'boolean',
value: true,
description: 'Enable libwacom support'
)
option('sound_player',
type: 'boolean',
value: true,
description: 'Enable sound player support using libcanberra',
)
option('pango_ft2',
type: 'boolean',
value: true,
description: 'Enable PangoFt2 support'
)
+option('polkit',
+ type: 'boolean',
+ value: true,
+ description: 'Enable Polkit enhanced backtrace support'
+)
+
option('startup_notification',
type: 'boolean',
value: true,
description: 'Enable startup notification support'
)
option('sm',
type: 'boolean',
value: true,
description: 'Enable X11 session management support'
)
option('introspection',
type: 'boolean',
value: true,
description: 'Enable GObject introspection'
)
option('docs',
type: 'boolean',
value: false,
description: 'Enable gi-docgen documentation'
)
option('cogl_tests',
type: 'boolean',
value: true,
description: 'Enable cogl tests'
)
diff --git a/src/50-mutter.rules b/src/50-mutter.rules
new file mode 100644
index 000000000..d14735fe6
--- /dev/null
+++ b/src/50-mutter.rules
@@ -0,0 +1,9 @@
+polkit.addRule(function(action, subject) {
+ if (subject.isInGroup("wheel") &&
+ subject.active &&
+ subject.local &&
+ action.id == "org.gnome.mutter.backtrace") {
+ return polkit.Result.YES;
+ }
+});
+
diff --git a/src/core/util-private.h b/src/core/util-private.h
index 18ae68de7..32798ca4e 100644
--- a/src/core/util-private.h
+++ b/src/core/util-private.h
@@ -13,46 +13,48 @@
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <glib/gi18n-lib.h>
#include <sys/time.h>
#include "meta/util.h"
#include "meta/common.h"
/* META_EXPORT_TEST should be used to export symbols that are exported only
* for testability purposes */
#define META_EXPORT_TEST META_EXPORT
void meta_set_verbose (gboolean setting);
void meta_set_debugging (gboolean setting);
void meta_set_is_wayland_compositor (gboolean setting);
char * meta_generate_random_id (GRand *rand,
int length);
+void meta_print_backtrace (void);
+
void meta_init_debug_utils (void);
static inline int64_t
meta_timeval_to_microseconds (const struct timeval *tv)
{
return ((int64_t) tv->tv_sec) * G_USEC_PER_SEC + tv->tv_usec;
}
#define META_POINT_IN_RECT(xcoord, ycoord, rect) \
((xcoord) >= (rect).x && \
(xcoord) < ((rect).x + (rect).width) && \
(ycoord) >= (rect).y && \
(ycoord) < ((rect).y + (rect).height))
#define META_CONTAINER_OF(ptr, type, member) \
(type *) ((uint8_t *) (ptr) - G_STRUCT_OFFSET (type, member))
diff --git a/src/core/util.c b/src/core/util.c
index 05a0dea39..dc547713c 100644
--- a/src/core/util.c
+++ b/src/core/util.c
@@ -1,107 +1,110 @@
/*
* Copyright (C) 2001 Havoc Pennington
* Copyright (C) 2005 Elijah Newren
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#define _POSIX_C_SOURCE 200112L /* for fdopen() */
#include "config.h"
#include "core/display-private.h"
#include "core/util-private.h"
+#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
+#include <sys/wait.h>
#ifdef HAVE_SYS_PRCTL
#include <sys/prctl.h>
#endif
#include "clutter/clutter-mutter.h"
#include "cogl/cogl.h"
#include "meta/common.h"
#include "meta/main.h"
static const GDebugKey meta_debug_keys[] = {
{ "focus", META_DEBUG_FOCUS },
{ "workarea", META_DEBUG_WORKAREA },
{ "stack", META_DEBUG_STACK },
{ "sm", META_DEBUG_SM },
{ "events", META_DEBUG_EVENTS },
{ "window-state", META_DEBUG_WINDOW_STATE },
{ "window-ops", META_DEBUG_WINDOW_OPS },
{ "geometry", META_DEBUG_GEOMETRY },
{ "placement", META_DEBUG_PLACEMENT },
{ "ping", META_DEBUG_PING },
{ "keybindings", META_DEBUG_KEYBINDINGS },
{ "sync", META_DEBUG_SYNC },
{ "startup", META_DEBUG_STARTUP },
{ "prefs", META_DEBUG_PREFS },
{ "groups", META_DEBUG_GROUPS },
{ "resizing", META_DEBUG_RESIZING },
{ "shapes", META_DEBUG_SHAPES },
{ "edge-resistance", META_DEBUG_EDGE_RESISTANCE },
{ "dbus", META_DEBUG_DBUS },
{ "input", META_DEBUG_INPUT },
{ "wayland", META_DEBUG_WAYLAND },
{ "kms", META_DEBUG_KMS },
{ "screen-cast", META_DEBUG_SCREEN_CAST },
{ "remote-desktop", META_DEBUG_REMOTE_DESKTOP },
{ "backend", META_DEBUG_BACKEND },
{ "render", META_DEBUG_RENDER },
{ "color", META_DEBUG_COLOR },
{ "input-events", META_DEBUG_INPUT_EVENTS },
{ "eis", META_DEBUG_EIS },
};
static gint verbose_topics = 0;
static gboolean is_wayland_compositor = FALSE;
static int debug_paint_flags = 0;
static GLogLevelFlags mutter_log_level = G_LOG_LEVEL_MESSAGE;
+static char *backtrace_command = NULL;
#ifdef WITH_VERBOSE_MODE
static FILE* logfile = NULL;
static void
ensure_logfile (void)
{
if (logfile == NULL && g_getenv ("MUTTER_USE_LOGFILE"))
{
char *filename = NULL;
char *tmpl;
int fd;
GError *err;
tmpl = g_strdup_printf ("mutter-%d-debug-log-XXXXXX",
(int) getpid ());
err = NULL;
fd = g_file_open_tmp (tmpl,
&filename,
&err);
g_free (tmpl);
if (err != NULL)
{
meta_warning ("Failed to open debug log: %s",
err->message);
g_error_free (err);
return;
@@ -186,60 +189,70 @@ meta_remove_verbose_topic (MetaDebugTopic topic)
verbose_topics = 0;
else
verbose_topics &= ~topic;
}
void
meta_init_debug_utils (void)
{
const char *debug_env;
#ifdef HAVE_SYS_PRCTL
prctl (PR_SET_DUMPABLE, 1);
#endif
if (g_getenv ("MUTTER_VERBOSE"))
meta_set_verbose (TRUE);
debug_env = g_getenv ("MUTTER_DEBUG");
if (debug_env)
{
MetaDebugTopic topics;
topics = g_parse_debug_string (debug_env,
meta_debug_keys,
G_N_ELEMENTS (meta_debug_keys));
meta_add_verbose_topic (topics);
}
if (g_test_initialized ())
mutter_log_level = G_LOG_LEVEL_DEBUG;
+
+ /* If pkexec works we'll get a kernel backtrace too,
+ * but it may not work if the user isn't in the wheel group.
+ * If it fails, we fall back to running unprivileged to at
+ * least get a backtrace of the process.
+ */
+ if (backtrace_command == NULL)
+ backtrace_command = g_strdup_printf ("pkexec %1$s %2$d || %1$s %2$d",
+ MUTTER_LIBEXECDIR "/mutter-backtrace",
+ (int) getpid ());
}
gboolean
meta_is_wayland_compositor (void)
{
return is_wayland_compositor;
}
void
meta_set_is_wayland_compositor (gboolean value)
{
is_wayland_compositor = value;
}
char *
meta_g_utf8_strndup (const gchar *src,
gsize n)
{
const gchar *s = src;
while (n && *s)
{
s = g_utf8_next_char (s);
n--;
}
return g_strndup (src, s - src);
}
static int
utf8_fputs (const char *str,
@@ -513,60 +526,104 @@ MetaLocaleDirection
meta_get_locale_direction (void)
{
switch (clutter_get_text_direction ())
{
case CLUTTER_TEXT_DIRECTION_LTR:
return META_LOCALE_DIRECTION_LTR;
case CLUTTER_TEXT_DIRECTION_RTL:
return META_LOCALE_DIRECTION_RTL;
default:
g_assert_not_reached ();
return 0;
}
}
char *
meta_generate_random_id (GRand *rand,
int length)
{
char *id;
int i;
/* Generate a random string of printable ASCII characters. */
id = g_new0 (char, length + 1);
for (i = 0; i < length; i++)
id[i] = (char) g_rand_int_range (rand, 32, 127);
return id;
}
+static gboolean
+unix_signal_safe_run_command (const char *command)
+{
+ pid_t pid;
+ int status;
+ int ret;
+
+ pid = fork ();
+ if (pid == -1)
+ return FALSE;
+
+ if (pid == 0)
+ {
+ int stdin_fd;
+
+ const char *argv[] = {
+ "/bin/sh",
+ "-c",
+ command,
+ NULL
+ };
+
+ stdin_fd = open ("/dev/null", O_RDWR);
+ dup2 (stdin_fd, STDIN_FILENO);
+
+ execve (argv[0], (char **) argv, environ);
+
+ _exit (1);
+ }
+
+ do
+ {
+ ret = waitpid (pid, &status, 0);
+ }
+ while (ret != 0 && errno == EINTR);
+
+ return WIFEXITED (status) && WEXITSTATUS (status) == 0;
+}
+
+void
+meta_print_backtrace (void)
+{
+ unix_signal_safe_run_command (backtrace_command);
+}
void
meta_add_clutter_debug_flags (ClutterDebugFlag debug_flags,
ClutterDrawDebugFlag draw_flags,
ClutterPickDebugFlag pick_flags)
{
clutter_add_debug_flags (debug_flags, draw_flags, pick_flags);
}
void
meta_remove_clutter_debug_flags (ClutterDebugFlag debug_flags,
ClutterDrawDebugFlag draw_flags,
ClutterPickDebugFlag pick_flags)
{
clutter_remove_debug_flags (debug_flags, draw_flags, pick_flags);
}
/**
* meta_get_clutter_debug_flags:
* @debug_flags: (out) (optional): return location for debug flags
* @draw_flags: (out) (optional): return location for draw debug flags
* @pick_flags: (out) (optional): return location for pick debug flags
*/
void
meta_get_clutter_debug_flags (ClutterDebugFlag *debug_flags,
ClutterDrawDebugFlag *draw_flags,
ClutterPickDebugFlag *pick_flags)
{
clutter_get_debug_flags (debug_flags, draw_flags, pick_flags);
}
diff --git a/src/meson.build b/src/meson.build
index ca2ef166c..4aabb6a14 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -1197,60 +1197,87 @@ libmutter = shared_library(libmutter_name,
],
install_rpath: pkglibdir,
install_dir: libdir,
install: true,
)
libmutter_dep = declare_dependency(
link_with: libmutter,
include_directories: mutter_includes,
sources: mutter_built_headers,
dependencies: [
libmutter_cogl_dep,
libmutter_clutter_dep,
mutter_deps,
],
)
mutter = executable('mutter',
sources: [
files('core/mutter.c'),
],
include_directories: mutter_includes,
c_args: [
mutter_c_args,
'-DG_LOG_DOMAIN="mutter"',
],
dependencies: [libmutter_dep],
install_dir: bindir,
install: true,
)
+
+install_data(
+ 'mutter-backtrace',
+ install_dir : libexecdir,
+ install_mode : 'rwxr-xr-x'
+)
+
+if have_polkit
+ backtrace_polkit_policy = configure_file(
+ input : 'org.gnome.mutter.backtrace.policy.in',
+ output : 'org.gnome.mutter.backtrace.policy',
+ configuration : {'LIBEXECDIR': libexecdir}
+ )
+
+ install_data(
+ backtrace_polkit_policy,
+ install_dir : polkit_policy_dir,
+ install_mode : 'rw-r--r--'
+ )
+
+ install_data(
+ '50-mutter.rules',
+ install_dir : polkit_action_dir,
+ install_mode : 'rw-r--r--'
+ )
+endif
+
if have_x11
executable('mutter-restart-helper',
sources: [
files('core/restart-helper.c'),
],
include_directories: [
top_includepath,
],
c_args: [
mutter_c_args,
'-DG_LOG_DOMAIN="mutter-restart-helper"',
],
dependencies: [
x11_dep,
xcomposite_dep,
],
install_dir: libexecdir,
install: true,
)
endif
if have_introspection
mutter_introspected_sources = []
foreach source : mutter_sources
if source.endswith('.c')
mutter_introspected_sources += source
endif
endforeach
libmutter_gir = gnome.generate_gir(libmutter,
diff --git a/src/mutter-backtrace b/src/mutter-backtrace
new file mode 100755
index 000000000..20c9d4e75
--- /dev/null
+++ b/src/mutter-backtrace
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+[ $# -ne 1 ] && exit 1
+
+gdb_command=(gdb -p "$1" -ex 'thread apply all bt full' -batch)
+
+if [ -n $PKEXEC_UID -a $(id -u) -eq 0 ]; then
+ cd /proc/$1/task
+ for thread in *; do
+ echo "Thread ${thread}:"
+ cat $thread/stack
+ done
+ pkexec --user $(id -u -n $PKEXEC_UID) "${gdb_command[@]}"
+ exit 0
+fi
+
+${gdb_command[@]}
diff --git a/src/org.gnome.mutter.backtrace.policy.in b/src/org.gnome.mutter.backtrace.policy.in
new file mode 100644
index 000000000..39985acb9
--- /dev/null
+++ b/src/org.gnome.mutter.backtrace.policy.in
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE policyconfig PUBLIC
+ "-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN"
+ "http://www.freedesktop.org/standards/PolicyKit/1/policyconfig.dtd">
+<policyconfig>
+ <action id="org.gnome.mutter.backtrace">
+ <message>Authentication is required to run mutter-backtrace</message>
+ <icon_name>dialog-password</icon_name>
+ <defaults>
+ <allow_any>auth_admin</allow_any>
+ <allow_inactive>auth_admin</allow_inactive>
+ <allow_active>auth_admin</allow_active>
+ </defaults>
+ <annotate key="org.freedesktop.policykit.exec.path">@LIBEXECDIR@/mutter-backtrace</annotate>
+ </action>
+</policyconfig>
+
--
2.41.0