libsysprof-profile: tail journald and append logs to capture

It can be handy to get system information from journald to correlate with
what is going on in applications. This simple journald tail GSource will
dispatch to our callback which can append the logs to the capture.

This uses a custom callback rather than the GSourceFunc because that seems
a bit annoying to use with recent GCC function equivalence checks.

config.h.meson

@@ -16,6 +16,8 @@
 
 #mesondefine HAVE_EXECINFO_H
 
+#mesondefine HAVE_LIBSYSTEMD
+
 #mesondefine HAVE_PERF_CLOCKID
 
 #mesondefine HAVE_POLKIT

meson.build

@@ -61,6 +61,7 @@ cxx = meson.get_compiler('cpp')
 
 glib_dep = dependency('glib-2.0', version: glib_req_version, required: need_glib)
 gtk_dep = dependency('gtk4', version: gtk_req_version, required: need_gtk)
+libsystemd_dep = dependency('libsystemd', required: false)
 
 config_h = configuration_data()
 config_h.set_quoted('SYMBOLIC_VERSION', symbolic_version)
@@ -104,6 +105,7 @@ config_h.set('LOCALEDIR', 'PACKAGE_LOCALE_DIR')
 config_h.set10('ENABLE_NLS', true)
 config_h.set_quoted('GETTEXT_PACKAGE', 'sysprof')
 config_h.set_quoted('PACKAGE_LOCALE_DIR', join_paths(get_option('prefix'), get_option('datadir'), 'locale'))
+config_h.set10('HAVE_LIBSYSTEMD', libsystemd_dep.found())
 
 polkit_agent_dep = dependency('polkit-agent-1', required: false)
 config_h.set10('HAVE_POLKIT_AGENT', polkit_agent_dep.found())

src/libsysprof-profile/meson.build

@@ -14,6 +14,7 @@ libsysprof_profile_public_sources = [
   'sysprof-recording.c',
   'sysprof-sampler.c',
   'sysprof-spawnable.c',
+  'sysprof-system-logs.c',
   'sysprof-tracer.c',
 ]
 
@@ -22,6 +23,7 @@ libsysprof_profile_private_sources = [
   'sysprof-controlfd-instrument.c',
   'sysprof-maps-parser.c',
   'sysprof-perf-event-stream.c',
+  'sysprof-journald-source.c',
   'sysprof-podman.c',
   'sysprof-polkit.c',
 ]
@@ -44,6 +46,7 @@ libsysprof_profile_public_headers = [
   'sysprof-recording.h',
   'sysprof-sampler.h',
   'sysprof-spawnable.h',
+  'sysprof-system-logs.h',
   'sysprof-tracer.h',
 ]
 
@@ -61,6 +64,7 @@ libsysprof_profile_deps = [
   dependency('json-glib-1.0'),
   dependency('libdex-1', version: dex_req_version),
   dependency('polkit-gobject-1', version: polkit_req_version),
+  libsystemd_dep,
 
   liblinereader_static_dep,
   libsysprof_capture_dep,

src/libsysprof-profile/sysprof-journald-source.c

@@ -0,0 +1,107 @@
+/* sysprof-journald-source.c
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * 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 3 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/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include <systemd/sd-journal.h>
+
+#include "sysprof-journald-source.h"
+
+typedef struct _SysprofJournaldSource
+{
+  GSource                    parent_instance;
+  sd_journal                *journal;
+  SysprofJournaldSourceFunc  func;
+  gpointer                   func_data;
+  GDestroyNotify             func_data_destroy;
+} SysprofJournaldSource;
+
+static void
+sysprof_journald_source_finalize (GSource *source)
+{
+  SysprofJournaldSource *self = (SysprofJournaldSource *)source;
+
+  if (self->func_data_destroy)
+    self->func_data_destroy (self->func_data);
+
+  g_clear_pointer (&self->journal, sd_journal_close);
+}
+
+static gboolean
+sysprof_journald_source_dispatch (GSource     *source,
+                                  GSourceFunc  callback,
+                                  gpointer     user_data)
+{
+  SysprofJournaldSource *self = (SysprofJournaldSource *)source;
+
+  if (sd_journal_process (self->journal) == SD_JOURNAL_APPEND)
+    {
+      if (sd_journal_next (self->journal) > 0)
+        return self->func (self->func_data, self->journal);
+    }
+
+  return G_SOURCE_CONTINUE;
+}
+
+static GSourceFuncs sysprof_journald_source_funcs = {
+  .dispatch = sysprof_journald_source_dispatch,
+  .finalize = sysprof_journald_source_finalize,
+};
+
+GSource *
+sysprof_journald_source_new (SysprofJournaldSourceFunc func,
+                             gpointer                  func_data,
+                             GDestroyNotify            func_data_destroy)
+{
+  SysprofJournaldSource *self;
+  sd_journal *journal = NULL;
+  int fd;
+
+  if (sd_journal_open (&journal, 0) < 0)
+    return NULL;
+
+  if (sd_journal_seek_tail (journal) < 0)
+    goto failure;
+
+  if (sd_journal_previous (journal) < 0)
+    goto failure;
+
+  if (sd_journal_next (journal) < 0)
+    goto failure;
+
+  if (-1 == (fd = sd_journal_get_fd (journal)))
+    goto failure;
+
+  self = (SysprofJournaldSource *)g_source_new (&sysprof_journald_source_funcs,
+                                                sizeof (SysprofJournaldSource));
+  self->journal = journal;
+  self->func = func;
+  self->func_data = func_data;
+  self->func_data_destroy = func_data_destroy;
+
+  g_source_add_unix_fd ((GSource *)self, fd, sd_journal_get_events (journal));
+
+  return (GSource *)self;
+
+failure:
+  g_clear_pointer (&journal, sd_journal_close);
+
+  return NULL;
+}

src/libsysprof-profile/sysprof-journald-source.h

@@ -0,0 +1,36 @@
+/* sysprof-journald-source.h
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * 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 3 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/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <glib-object.h>
+
+#include <systemd/sd-journal.h>
+
+G_BEGIN_DECLS
+
+typedef gboolean (*SysprofJournaldSourceFunc) (gpointer    user_data,
+                                               sd_journal *journal);
+
+GSource *sysprof_journald_source_new (SysprofJournaldSourceFunc func,
+                                      gpointer                  func_data,
+                                      GDestroyNotify            func_data_destroy);
+
+G_END_DECLS

src/libsysprof-profile/sysprof-profile.h

@@ -40,6 +40,7 @@ G_BEGIN_DECLS
 # include "sysprof-recording.h"
 # include "sysprof-sampler.h"
 # include "sysprof-spawnable.h"
+# include "sysprof-system-logs.h"
 # include "sysprof-tracer.h"
 #undef SYSPROF_PROFILE_INSIDE
 

src/libsysprof-profile/sysprof-system-logs.c

@@ -0,0 +1,194 @@
+/* sysprof-system-logs.c
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * 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 3 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/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include <errno.h>
+
+#include <glib/gi18n.h>
+#include <glib/gstdio.h>
+
+#include "sysprof-system-logs.h"
+#include "sysprof-instrument-private.h"
+#include "sysprof-recording-private.h"
+
+#ifdef HAVE_LIBSYSTEMD
+# include "sysprof-journald-source.h"
+#endif
+
+struct _SysprofSystemLogs
+{
+  SysprofInstrument parent_instance;
+};
+
+struct _SysprofSystemLogsClass
+{
+  SysprofInstrumentClass parent_class;
+};
+
+G_DEFINE_FINAL_TYPE (SysprofSystemLogs, sysprof_system_logs, SYSPROF_TYPE_INSTRUMENT)
+
+#ifdef HAVE_LIBSYSTEMD
+static char *
+journal_get_data (sd_journal *journal,
+                  const char *field)
+{
+  gconstpointer data = NULL;
+  const char *endptr;
+  const char *eq;
+  gsize length;
+  int ret;
+
+  g_assert (journal != NULL);
+  g_assert (field != NULL);
+
+  if ((ret = sd_journal_get_data (journal, field, &data, &length)) < 0)
+    return NULL;
+
+  endptr = (const char *)data + length;
+  if (!(eq = memchr (data, '=', length)))
+    return NULL;
+
+  eq++;
+
+  return g_strndup (eq, endptr - eq);
+}
+
+static gboolean
+sysprof_system_logs_callback (SysprofCaptureWriter *writer,
+                              sd_journal           *journal)
+{
+  g_autofree char *message = NULL;
+  g_autofree char *priority = NULL;
+  sd_id128_t boot_id;
+  guint64 usec;
+  int severity = 0;
+
+  g_assert (journal != NULL);
+  g_assert (writer != NULL);
+
+  if (sd_journal_get_monotonic_usec (journal, &usec, &boot_id) != 0 ||
+      !(message = journal_get_data (journal, "MESSAGE")))
+    return G_SOURCE_CONTINUE;
+
+  priority = journal_get_data (journal, "PRIORITY");
+
+  if (priority != NULL)
+    {
+      switch (priority[0])
+        {
+        case '0':
+        case '1':
+          severity = G_LOG_LEVEL_ERROR;
+          break;
+
+        case '2':
+          severity = G_LOG_LEVEL_CRITICAL;
+          break;
+
+        case '3':
+        case '4':
+          severity = G_LOG_LEVEL_WARNING;
+          break;
+
+        default:
+        case '5':
+          severity = G_LOG_LEVEL_MESSAGE;
+          break;
+
+        case '6':
+          severity = G_LOG_LEVEL_INFO;
+          break;
+
+        case '7':
+          severity = G_LOG_LEVEL_DEBUG;
+          break;
+        }
+    }
+
+  sysprof_capture_writer_add_log (writer, usec*1000, -1, -1, severity, "System Log", message);
+
+  return G_SOURCE_CONTINUE;
+}
+#endif
+
+#ifdef HAVE_LIBSYSTEMD
+static DexFuture *
+sysprof_system_logs_record_finished (DexFuture *future,
+                                     gpointer   user_data)
+{
+  GSource *source = user_data;
+  g_source_destroy (source);
+  return dex_future_new_for_boolean (TRUE);
+}
+#endif
+
+static DexFuture *
+sysprof_system_logs_record (SysprofInstrument *instrument,
+                            SysprofRecording  *recording,
+                            GCancellable      *cancellable)
+{
+#ifdef HAVE_LIBSYSTEMD
+  SysprofCaptureWriter *writer;
+  GSource *source;
+
+  g_assert (SYSPROF_IS_SYSTEM_LOGS (instrument));
+  g_assert (SYSPROF_IS_RECORDING (recording));
+  g_assert (G_IS_CANCELLABLE (cancellable));
+
+  writer = _sysprof_recording_writer (recording);
+
+  source = sysprof_journald_source_new ((SysprofJournaldSourceFunc)sysprof_system_logs_callback,
+                                        sysprof_capture_writer_ref (writer),
+                                        (GDestroyNotify)sysprof_capture_writer_unref);
+  g_source_set_static_name (source, "[sysprof-journald]");
+  g_source_set_priority (source, G_PRIORITY_LOW);
+  g_source_attach (source, NULL);
+
+  return dex_future_finally (dex_cancellable_new_from_cancellable (cancellable),
+                             sysprof_system_logs_record_finished,
+                             source,
+                             (GDestroyNotify)g_source_unref);
+#else
+  _sysprof_recording_diagnostic (recording,
+                                 _("System Logs"),
+                                 _("Recording system logs is not supported on your platform."));
+  return dex_future_new_for_boolean (TRUE);
+#endif
+}
+
+static void
+sysprof_system_logs_class_init (SysprofSystemLogsClass *klass)
+{
+  SysprofInstrumentClass *instrument_class = SYSPROF_INSTRUMENT_CLASS (klass);
+
+  instrument_class->record = sysprof_system_logs_record;
+}
+
+static void
+sysprof_system_logs_init (SysprofSystemLogs *self)
+{
+}
+
+SysprofInstrument *
+sysprof_system_logs_new (void)
+{
+  return g_object_new (SYSPROF_TYPE_SYSTEM_LOGS, NULL);
+}

src/libsysprof-profile/sysprof-system-logs.h

@@ -0,0 +1,43 @@
+/* sysprof-system-logs.h
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * 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 3 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/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include "sysprof-instrument.h"
+
+G_BEGIN_DECLS
+
+#define SYSPROF_TYPE_SYSTEM_LOGS         (sysprof_system_logs_get_type())
+#define SYSPROF_IS_SYSTEM_LOGS(obj)      G_TYPE_CHECK_INSTANCE_TYPE(obj, SYSPROF_TYPE_SYSTEM_LOGS)
+#define SYSPROF_SYSTEM_LOGS(obj)         G_TYPE_CHECK_INSTANCE_CAST(obj, SYSPROF_TYPE_SYSTEM_LOGS, SysprofSystemLogs)
+#define SYSPROF_SYSTEM_LOGS_CLASS(klass) G_TYPE_CHECK_CLASS_CAST(klass, SYSPROF_TYPE_SYSTEM_LOGS, SysprofSystemLogsClass)
+
+typedef struct _SysprofSystemLogs      SysprofSystemLogs;
+typedef struct _SysprofSystemLogsClass SysprofSystemLogsClass;
+
+SYSPROF_AVAILABLE_IN_ALL
+GType              sysprof_system_logs_get_type (void) G_GNUC_CONST;
+SYSPROF_AVAILABLE_IN_ALL
+SysprofInstrument *sysprof_system_logs_new      (void);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (SysprofSystemLogs, g_object_unref)
+
+G_END_DECLS
+

src/libsysprof-profile/tests/test-profiler.c

@@ -178,6 +178,7 @@ main (int   argc,
   sysprof_profiler_add_instrument (profiler, sysprof_energy_usage_new ());
   sysprof_profiler_add_instrument (profiler, sysprof_memory_usage_new ());
   sysprof_profiler_add_instrument (profiler, sysprof_network_usage_new ());
+  sysprof_profiler_add_instrument (profiler, sysprof_system_logs_new ());
 
   if (power_profile)
     sysprof_profiler_add_instrument (profiler, sysprof_power_profile_new (power_profile));

src/sysprof/sysprof-greeter.c

@@ -44,6 +44,7 @@ struct _SysprofGreeter
   GtkSwitch          *record_disk_usage;
   GtkSwitch          *record_network_usage;
   GtkSwitch          *record_compositor;
+  GtkSwitch          *record_system_logs;
 };
 
 enum {
@@ -91,6 +92,9 @@ sysprof_greeter_create_profiler (SysprofGreeter *self)
                                                                      "org.gnome.Shell",
                                                                      "/org/gnome/Sysprof3/Profiler"));
 
+  if (gtk_switch_get_active (self->record_system_logs))
+    sysprof_profiler_add_instrument (profiler, sysprof_system_logs_new ());
+
   return g_steal_pointer (&profiler);
 }
 
@@ -282,6 +286,7 @@ sysprof_greeter_class_init (SysprofGreeterClass *klass)
   gtk_widget_class_bind_template_child (widget_class, SysprofGreeter, record_disk_usage);
   gtk_widget_class_bind_template_child (widget_class, SysprofGreeter, record_network_usage);
   gtk_widget_class_bind_template_child (widget_class, SysprofGreeter, record_page);
+  gtk_widget_class_bind_template_child (widget_class, SysprofGreeter, record_system_logs);
   gtk_widget_class_bind_template_child (widget_class, SysprofGreeter, sample_native_stacks);
   gtk_widget_class_bind_template_child (widget_class, SysprofGreeter, toolbar);
   gtk_widget_class_bind_template_child (widget_class, SysprofGreeter, view_stack);

src/sysprof/sysprof-greeter.ui

@@ -223,6 +223,24 @@
                         </child>
                       </object>
                     </child>
+                    <child>
+                      <object class="AdwPreferencesGroup">
+                        <property name="title" translatable="yes">System</property>
+                        <child>
+                          <object class="AdwActionRow">
+                            <property name="activatable-widget">record_system_logs</property>
+                            <property name="title" translatable="yes">System Logs</property>
+                            <property name="subtitle" translatable="yes">Watch the system log for new messages and record them</property>
+                            <child type="suffix">
+                              <object class="GtkSwitch" id="record_system_logs">
+                                <property name="active">true</property>
+                                <property name="valign">center</property>
+                              </object>
+                            </child>
+                          </object>
+                        </child>
+                      </object>
+                    </child>
                   </object>
                 </property>
               </object>