[sysprof/wip/chergert/sysprof-3] sysprofd: add comm and do some postprocessing

[Christian Hergert <chergert src gnome org>]

commit c79d3aa0bb1b321f6c90e9635a44951e20b4baa7
Author: Christian Hergert <chergert redhat com>
Date:   Fri May 10 18:18:39 2019 -0700

    sysprofd: add comm and do some postprocessing

 src/org.gnome.Sysprof3.Service.xml |  1 +
 src/sysprofd/ipc-service-impl.c    | 72 +++++++++++++++++++++++++++++++++++---
 2 files changed, 69 insertions(+), 4 deletions(-)
---
diff --git a/src/org.gnome.Sysprof3.Service.xml b/src/org.gnome.Sysprof3.Service.xml
index 1be4e13..d39f68c 100644
--- a/src/org.gnome.Sysprof3.Service.xml
+++ b/src/org.gnome.Sysprof3.Service.xml
@@ -62,6 +62,7 @@
 
       - pid: (int32): the process identifier, always included
       - cmdline: (string): Provides the command line
+      - comm: (string): Provide the comm, useful when cmdline is empty
       - maps: (string): Provide the contents of /proc/pid/maps
       - statm: (string): Provide the contents of /proc/pid/statm
       - mountinfo: (string): Provide the contents of/proc/pid/mountinfo
diff --git a/src/sysprofd/ipc-service-impl.c b/src/sysprofd/ipc-service-impl.c
index 961239c..b1be108 100644
--- a/src/sysprofd/ipc-service-impl.c
+++ b/src/sysprofd/ipc-service-impl.c
@@ -189,17 +189,76 @@ ipc_service_impl_g_authorize_method (GDBusInterfaceSkeleton *skeleton,
   return ret;
 }
 
+static gboolean
+needs_escape (const gchar *str)
+{
+  for (; *str; str++)
+    {
+      if (g_ascii_isspace (*str) || *str == '\'' || *str == '"')
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
 static void
 postprocess_cmdline (gchar **str,
                      gsize   len)
 {
+  g_autoptr(GPtrArray) parts = g_ptr_array_new_with_free_func (g_free);
+  g_autofree gchar *instr = NULL;
+  const gchar *begin = NULL;
+
+  if (len == 0)
+    return;
+
+  instr = *str;
+
+  for (gsize i = 0; i < len; i++)
+    {
+      if (!begin && instr[i])
+        {
+          begin = &instr[i];
+        }
+      else if (begin && instr[i] == '\0')
+        {
+          if (needs_escape (begin))
+            g_ptr_array_add (parts, g_shell_quote (begin));
+          else
+            g_ptr_array_add (parts, g_strdup (begin));
+
+          begin = NULL;
+        }
+    }
+
+  /* If the last byte was not \0, as can happen with prctl(), then we need
+   * to add it here manually.
+   */
+  if (begin)
+    {
+      if (needs_escape (begin))
+        g_ptr_array_add (parts, g_shell_quote (begin));
+      else
+        g_ptr_array_add (parts, g_strdup (begin));
+    }
+
+  g_ptr_array_add (parts, NULL);
+
+  *str = g_strjoinv (" ", (gchar **)parts->pdata);
+}
+
+static void
+postprocess_rstrip (gchar **str,
+                    gsize   len)
+{
+  g_strchomp (*str);
 }
 
 static void
 add_pid_proc_file_to (gint          pid,
                       const gchar  *name,
                       GVariantDict *dict,
-                     void (*postprocess) (gchar **, gsize))
+                      void (*postprocess) (gchar **, gsize))
 {
   g_autofree gchar *path = NULL;
   g_autofree gchar *contents = NULL;
@@ -229,6 +288,7 @@ ipc_service_impl_handle_get_process_info (IpcService            *service,
   gsize n_processes = 0;
   gboolean want_statm;
   gboolean want_cmdline;
+  gboolean want_comm;
   gboolean want_maps;
   gboolean want_mountinfo;
 
@@ -240,6 +300,7 @@ ipc_service_impl_handle_get_process_info (IpcService            *service,
   want_cmdline = !!strstr (attributes, "cmdline");
   want_maps = !!strstr (attributes, "maps");
   want_mountinfo = !!strstr (attributes, "mountinfo");
+  want_comm = !!strstr (attributes, "comm");
 
   g_variant_builder_init (&builder, G_VARIANT_TYPE ("aa{sv}"));
 
@@ -254,16 +315,19 @@ ipc_service_impl_handle_get_process_info (IpcService            *service,
           g_variant_dict_insert (&dict, "pid", "i", pid, NULL);
 
           if (want_statm)
-            add_pid_proc_file_to (pid, "statm", &dict, NULL);
+            add_pid_proc_file_to (pid, "statm", &dict, postprocess_rstrip);
 
           if (want_cmdline)
             add_pid_proc_file_to (pid, "cmdline", &dict, postprocess_cmdline);
 
+          if (want_comm)
+            add_pid_proc_file_to (pid, "comm", &dict, postprocess_rstrip);
+
           if (want_maps)
-            add_pid_proc_file_to (pid, "maps", &dict, NULL);
+            add_pid_proc_file_to (pid, "maps", &dict, postprocess_rstrip);
 
           if (want_mountinfo)
-            add_pid_proc_file_to (pid, "mountinfo", &dict, NULL);
+            add_pid_proc_file_to (pid, "mountinfo", &dict, postprocess_rstrip);
 
           g_variant_builder_add_value (&builder, g_variant_dict_end (&dict));
         }