cpukit: Add libdl with the Runtime Loader (RTL) code.

This is a merge of the RTL project.

cpukit/libdl/rap.c

@@ -0,0 +1,484 @@
+/*
+ *  COPYRIGHT (c) 2012 Chris Johns <chrisj@rtems.org>
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ */
+/**
+ * @file
+ *
+ * @ingroup rtems_rap
+ *
+ * @brief RTEMS Application Loader
+ *
+ * This is the RAP implementation.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <rtems/libio_.h>
+
+#include <dlfcn.h>
+#include <rtems/rtl/rap.h>
+#include <rtems/rtl/rtl.h>
+
+#include "rtl-find-file.h"
+
+/**
+ * The global RAP data. This structure is allocated on the heap when the first
+ * call to location an application and is never released.
+ */
+typedef struct rtems_rap_data_s
+{
+  rtems_id            lock;           /**< The RAP lock id */
+  rtems_chain_control apps;           /**< List if loaded application. */
+  int                 last_errno;     /**< Last error number. */
+  char                last_error[64]; /**< Last error string. */
+} rtems_rap_data_t;
+
+/**
+ * The RAP file data. This structure is allocated on the heap when a file is
+ * loaded.
+ */
+typedef struct rtems_rap_app_s
+{
+  rtems_chain_node node;         /**< The node's link in the chain. */
+  const char*      name;         /**< The file name */
+  void*            handle;       /**< The dlopen handle. */
+} rtems_rap_app_t;
+
+/**
+ * Semaphore configuration to create a mutex.
+ */
+#define RTEMS_MUTEX_ATTRIBS \
+  (RTEMS_PRIORITY | RTEMS_BINARY_SEMAPHORE | \
+   RTEMS_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL)
+
+/**
+ * RTL entry.
+ */
+#if (RTL_GLUE(__USER_LABEL_PREFIX__, 1) == RTL_GLUE(_, 1))
+  #define RTL_ENTRY_POINT "_rtems"
+#else
+  #define RTL_ENTRY_POINT "rtems"
+#endif
+
+/**
+ * Static RAP data is returned to the user when the loader is locked.
+ */
+static rtems_rap_data_t rap_;
+
+/**
+ * Verbose level for the RAP loader.
+ */
+static bool rap_verbose;
+
+/**
+ * RAP entry call signature.
+ */
+typedef int (*rtems_rap_entry_t)(int argc, const char* argv[]);
+
+/**
+ * Forward decl.
+ */
+static bool rtems_rap_unlock (void);
+
+static bool
+rtems_rap_data_init (void)
+{
+  /*
+   * Lock the RAP. We only create a lock if a call is made. First we test if a
+   * lock is present. If one is present we lock it. If not the libio lock is
+   * locked and we then test the lock again. If not present we create the lock
+   * then release libio lock.
+   */
+  if (!rap_.lock)
+  {
+    rtems_libio_lock ();
+
+    if (!rap_.lock)
+    {
+      rtems_status_code sc;
+      rtems_id          lock;
+
+      /*
+       * Create the RAP lock.
+       */
+      sc = rtems_semaphore_create (rtems_build_name ('R', 'A', 'P', '_'),
+                                   1, RTEMS_MUTEX_ATTRIBS,
+                                   RTEMS_NO_PRIORITY, &lock);
+      if (sc != RTEMS_SUCCESSFUL)
+        return false;
+
+      sc = rtems_semaphore_obtain (lock, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+      if (sc != RTEMS_SUCCESSFUL)
+      {
+        rtems_semaphore_delete (lock);
+        return false;
+      }
+
+      rap_.lock = lock;
+
+      /*
+       * Initialise the objects list and create any required services.
+       */
+      rtems_chain_initialize_empty (&rap_.apps);
+    }
+
+    rtems_libio_unlock ();
+
+    rtems_rap_unlock ();
+  }
+  return true;
+}
+
+static rtems_rap_data_t*
+rtems_rap_lock (void)
+{
+  rtems_status_code sc;
+
+  if (!rtems_rap_data_init ())
+    return NULL;
+
+  sc = rtems_semaphore_obtain (rap_.lock,
+                               RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+  if (sc != RTEMS_SUCCESSFUL)
+  {
+    errno = EINVAL;
+    return NULL;
+  }
+
+  return &rap_;
+}
+
+static bool
+rtems_rap_unlock (void)
+{
+  /*
+   * Not sure any error should be returned or an assert.
+   */
+  rtems_status_code sc;
+  sc = rtems_semaphore_release (rap_.lock);
+  if ((sc != RTEMS_SUCCESSFUL) && (errno == 0))
+  {
+    errno = EINVAL;
+    return false;
+  }
+  return true;
+}
+
+static rtems_rap_app_t*
+rtems_rap_check_handle (void* handle)
+{
+  rtems_rap_app_t*  app;
+  rtems_chain_node* node;
+
+  app = handle;
+  node = rtems_chain_first (&rap_.apps);
+
+  while (!rtems_chain_is_tail (&rap_.apps, node))
+  {
+    rtems_rap_app_t* check = (rtems_rap_app_t*) node;
+    if (check == app)
+      return app;
+    node = rtems_chain_next (node);
+  }
+
+  return NULL;
+}
+
+static rtems_rap_app_t*
+rtems_rap_app_alloc (void)
+{
+  rtems_rap_app_t* app = malloc (sizeof (rtems_rap_app_t));
+  memset (app, 0, sizeof (rtems_rap_app_t));
+  rtems_chain_append (&rap_.apps, &app->node);
+  return app;
+}
+
+static void
+rtems_rap_app_free (rtems_rap_app_t* app)
+{
+  if (app->handle)
+  {
+    dlclose (app->handle);
+    app->handle = NULL;
+  }
+
+  if (!rtems_chain_is_node_off_chain (&app->node))
+    rtems_chain_extract (&app->node);
+}
+
+static bool
+rtems_rap_match_name (rtems_rap_app_t* app, const char* name)
+{
+  const char* a;
+
+  /*
+   * Assume the app name is absolute, ie points to the file on disk. This means
+   * there is at least one delimiter in the name.
+   */
+
+  if (strncmp (app->name, name, strlen (name)) == 0)
+    return true;
+
+  a = app->name + strlen (app->name) - 1;
+
+  while (a >= app->name)
+  {
+    if (rtems_filesystem_is_delimiter (*a))
+    {
+      const char* n = name;
+
+      ++a;
+
+      while (*a && *n)
+      {
+        if (*a == '.')
+        {
+          if (*n == '\0')
+            return true;
+        }
+
+        ++a;
+        ++n;
+      }
+
+      return false;
+    }
+
+    --a;
+  }
+
+  return false;
+}
+
+static void
+rtems_rap_get_rtl_error (void)
+{
+  rap_.last_errno =
+    rtems_rtl_get_error (rap_.last_error, sizeof (rap_.last_error));
+}
+
+static void
+rtems_rap_set_error (int error, const char* format, ...)
+{
+  rtems_rap_data_t* rap = rtems_rap_lock ();
+  va_list           ap;
+  va_start (ap, format);
+  rap->last_errno = error;
+  vsnprintf (rap->last_error, sizeof (rap->last_error), format, ap);
+  rtems_rap_unlock ();
+  va_end (ap);
+}
+
+bool
+rtems_rap_load (const char* name, int mode, int argc, const char* argv[])
+{
+  rtems_rap_data_t* rap = rtems_rap_lock ();
+
+  if (!rap)
+    return false;
+
+  if (rap_verbose)
+    printf ("rap: loading '%s'\n", name);
+
+  /*
+   * See if the app has already been loaded.
+   */
+  if (!rtems_rap_find (name))
+  {
+    rtems_rap_app_t*  app;
+    rtems_rap_entry_t init;
+    rtems_rap_entry_t fini;
+    size_t            size = 0;
+    int               r;
+
+    /*
+     * Allocate a new application descriptor and attempt to load it.
+     */
+    app = rtems_rap_app_alloc ();
+    if (app == NULL)
+    {
+      rtems_rap_set_error (ENOMEM, "no memory for application");
+      rtems_rap_unlock ();
+      return false;
+    }
+
+    /*
+     * Find the file in the file system using the search path.
+     */
+    if (!rtems_rtl_find_file (name, getenv ("PATH"), &app->name, &size))
+    {
+      rtems_rap_set_error (ENOENT, "file not found");
+      rtems_rap_app_free (app);
+      rtems_rap_unlock ();
+      return false;
+    }
+
+    app->handle = dlopen (app->name, RTLD_NOW | mode);
+    if (!app->handle)
+    {
+      rtems_rap_get_rtl_error ();
+      rtems_rap_app_free (app);
+      rtems_rap_unlock ();
+      return false;
+    }
+
+    init = dlsym (app->handle, RTL_ENTRY_POINT);
+    if (!init)
+    {
+      rtems_rap_get_rtl_error ();
+      rtems_rap_app_free (app);
+      rtems_rap_unlock ();
+      return false;
+    }
+
+    fini = dlsym (app->handle, RTL_ENTRY_POINT);
+    if (!fini)
+    {
+      rtems_rap_get_rtl_error ();
+      rtems_rap_app_free (app);
+      rtems_rap_unlock ();
+      return false;
+    }
+
+    r = init (argc, argv);
+    if (r != 0)
+    {
+      rtems_rap_set_error (r, "init call failure");
+      rtems_rap_app_free (app);
+      rtems_rap_unlock ();
+      return false;
+    }
+  }
+
+  rtems_rap_unlock ();
+
+  return true;
+}
+
+bool
+rtems_rap_unload (const char* name)
+{
+  rtems_rap_app_t*  app;
+  rtems_rap_entry_t fini;
+  int               r;
+
+  rtems_rap_lock ();
+
+  app = rtems_rap_find (name);
+
+  if (rap_verbose)
+    printf ("rap: unloading '%s'\n", name);
+
+  if (!app)
+  {
+    rtems_rap_set_error (ENOENT, "invalid handle");
+    rtems_rap_unlock ();
+    return false;
+  }
+
+  fini = dlsym (app->handle, RTL_ENTRY_POINT);
+  if (!fini)
+  {
+    rtems_rap_get_rtl_error ();
+    rtems_rap_unlock ();
+    return false;
+  }
+
+  r = fini (0, NULL);
+  if (r != 0)
+  {
+    rtems_rap_set_error (r, "fini failure");
+    rtems_rap_unlock ();
+    return false;
+  }
+
+  rtems_rap_app_free (app);
+  rtems_rap_unlock ();
+
+  return true;
+}
+
+void*
+rtems_rap_find (const char* name)
+{
+  rtems_rap_data_t* rap = rtems_rap_lock ();
+  rtems_chain_node* node;
+
+  node = rtems_chain_first (&rap->apps);
+
+  while (!rtems_chain_is_tail (&rap->apps, node))
+  {
+    rtems_rap_app_t* app = (rtems_rap_app_t*) node;
+    if (rtems_rap_match_name (app, name))
+    {
+      rtems_rap_unlock ();
+      return app;
+    }
+    node = rtems_chain_next (node);
+  }
+
+  rtems_rap_unlock ();
+
+  return NULL;
+}
+
+bool
+rtems_rap_iterate (rtems_rap_iterator_t iterator)
+{
+  rtems_rap_data_t* rap = rtems_rap_lock ();
+  rtems_chain_node* node;
+  bool              result = true;
+
+  node = rtems_chain_first (&rap->apps);
+
+  while (!rtems_chain_is_tail (&rap->apps, node))
+  {
+    rtems_rap_app_t* app = (rtems_rap_app_t*) node;
+    result = iterator (app);
+    if (!result)
+      break;
+    node = rtems_chain_next (node);
+  }
+
+  rtems_rap_unlock ();
+
+  return result;
+}
+
+const char*
+rtems_rap_name (void* handle)
+{
+  rtems_rap_app_t* app = rtems_rap_check_handle (handle);
+  if (app)
+    return app->name;
+  return NULL;
+}
+
+void*
+rtems_rap_dl_handle (void* handle)
+{
+  rtems_rap_app_t* app = rtems_rap_check_handle (handle);
+  if (app)
+    return app->handle;
+  return NULL;
+}
+
+int
+rtems_rap_get_error (char* message, size_t max_message)
+{
+  rtems_rap_data_t* rap = rtems_rap_lock ();
+  int               last_errno = rap->last_errno;
+  strncpy (message, rap->last_error, sizeof (rap->last_error));
+  rtems_rap_unlock ();
+  return last_errno;
+}