loader: Factor out the common driver opening logic from each loader.

I copied the code from egl_dri2.c, but the functionality was equivalent
between all the loaders other than their particular environment variables.

v2: Drop the logging function equivalent to loader_default_logger()
    (requested by Eric, Emil).  Move the SCons workaround across.  Drop
    the now-unused driGetDriverExtensions() declaration that was lost in a
    rebase.

Reviewed-by: Eric Engestrom <eric.engestrom@intel.com> (v1)
Reviewed-by: Emil Velikov <emil.velikov@collabora.com> (v1)

src/egl/Makefile.am

@@ -119,8 +119,7 @@ AM_CFLAGS += \
 	-I$(top_srcdir)/src/egl/drivers/dri2 \
 	-I$(top_srcdir)/src/gbm/backends/dri \
 	-I$(top_builddir)/src/egl/wayland/wayland-drm \
-	-I$(top_srcdir)/src/egl/wayland/wayland-drm \
+	-I$(top_srcdir)/src/egl/wayland/wayland-drm
-	-DDEFAULT_DRIVER_DIR=\"$(DRI_DRIVER_SEARCH_DIR)\"
 
 nodist_libEGL_common_la_SOURCES = \
 	$(dri2_backend_GENERATED_FILES)

src/egl/drivers/dri2/egl_dri2.c

@@ -483,75 +483,14 @@ static const __DRIextension **
 dri2_open_driver(_EGLDisplay *disp)
 {
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
-   const __DRIextension **extensions = NULL;
+   static const char *search_path_vars[] = {
-   char path[PATH_MAX], *search_paths, *next, *end;
+      "LIBGL_DRIVERS_PATH",
-   char *get_extensions_name;
+      NULL,
-   const __DRIextension **(*get_extensions)(void);
+   };
 
-   search_paths = NULL;
+   return loader_open_driver(dri2_dpy->driver_name,
-   if (geteuid() == getuid()) {
+                             &dri2_dpy->driver,
-      /* don't allow setuid apps to use LIBGL_DRIVERS_PATH */
+                             search_path_vars);
-      search_paths = getenv("LIBGL_DRIVERS_PATH");
-   }
-   if (search_paths == NULL)
-      search_paths = DEFAULT_DRIVER_DIR;
-
-   dri2_dpy->driver = NULL;
-   end = search_paths + strlen(search_paths);
-   for (char *p = search_paths; p < end; p = next + 1) {
-      int len;
-      next = strchr(p, ':');
-      if (next == NULL)
-         next = end;
-
-      len = next - p;
-#if GLX_USE_TLS
-      snprintf(path, sizeof path,
-               "%.*s/tls/%s_dri.so", len, p, dri2_dpy->driver_name);
-      dri2_dpy->driver = dlopen(path, RTLD_NOW | RTLD_GLOBAL);
-#endif
-      if (dri2_dpy->driver == NULL) {
-         snprintf(path, sizeof path,
-                  "%.*s/%s_dri.so", len, p, dri2_dpy->driver_name);
-         dri2_dpy->driver = dlopen(path, RTLD_NOW | RTLD_GLOBAL);
-         if (dri2_dpy->driver == NULL)
-            _eglLog(_EGL_DEBUG, "failed to open %s: %s\n", path, dlerror());
-      }
-      /* not need continue to loop all paths once the driver is found */
-      if (dri2_dpy->driver != NULL)
-         break;
-   }
-
-   if (dri2_dpy->driver == NULL) {
-      _eglLog(_EGL_WARNING,
-              "DRI2: failed to open %s (search paths %s)",
-              dri2_dpy->driver_name, search_paths);
-      return NULL;
-   }
-
-   _eglLog(_EGL_DEBUG, "DRI2: dlopen(%s)", path);
-
-   get_extensions_name = loader_get_extensions_name(dri2_dpy->driver_name);
-   if (get_extensions_name) {
-      get_extensions = dlsym(dri2_dpy->driver, get_extensions_name);
-      if (get_extensions) {
-         extensions = get_extensions();
-      } else {
-         _eglLog(_EGL_DEBUG, "driver does not expose %s(): %s\n",
-                 get_extensions_name, dlerror());
-      }
-      free(get_extensions_name);
-   }
-
-   if (!extensions)
-      extensions = dlsym(dri2_dpy->driver, __DRI_DRIVER_EXTENSIONS);
-   if (extensions == NULL) {
-      _eglLog(_EGL_WARNING,
-              "DRI2: driver exports no extensions (%s)", dlerror());
-      dlclose(dri2_dpy->driver);
-   }
-
-   return extensions;
 }
 
 EGLBoolean

src/egl/meson.build

@@ -93,9 +93,6 @@ if with_dri2
     'drivers/dri2/egl_dri2.h',
     'drivers/dri2/egl_dri2_fallbacks.h',
   )
-  c_args_for_egl += [
-    '-DDEFAULT_DRIVER_DIR="@0@"'.format(dri_search_path),
-  ]
 
   if with_platform_x11
     files_egl += files('drivers/dri2/platform_x11.c')

src/gbm/Makefile.am

@@ -42,7 +42,6 @@ libgbm_la_SOURCES += \
 	$(gbm_dri_FILES)
 
 AM_CFLAGS += \
-	-DDEFAULT_DRIVER_DIR='"$(DRI_DRIVER_SEARCH_DIR)"' \
 	$(LIBDRM_CFLAGS) \
 	$(PTHREADSTUBS_CFLAGS)
 

src/gbm/backends/dri/gbm_dri.c

@@ -304,28 +304,6 @@ dri_bind_extensions(struct gbm_dri_device *dri,
 static const __DRIextension **
 dri_open_driver(struct gbm_dri_device *dri)
 {
-   const __DRIextension **extensions = NULL;
-   char path[PATH_MAX], *search_paths, *p, *next, *end;
-   char *get_extensions_name;
-
-   search_paths = NULL;
-   /* don't allow setuid apps to use LIBGL_DRIVERS_PATH or GBM_DRIVERS_PATH */
-   if (geteuid() == getuid()) {
-      /* Read GBM_DRIVERS_PATH first for compatibility, but LIBGL_DRIVERS_PATH
-       * is recommended over GBM_DRIVERS_PATH.
-       */
-      search_paths = getenv("GBM_DRIVERS_PATH");
-
-      /* Read LIBGL_DRIVERS_PATH if GBM_DRIVERS_PATH was not set.
-       * LIBGL_DRIVERS_PATH is recommended over GBM_DRIVERS_PATH.
-       */
-      if (search_paths == NULL) {
-         search_paths = getenv("LIBGL_DRIVERS_PATH");
-      }
-   }
-   if (search_paths == NULL)
-      search_paths = DEFAULT_DRIVER_DIR;
-
    /* Temporarily work around dri driver libs that need symbols in libglapi
     * but don't automatically link it in.
     */
@@ -334,56 +312,18 @@ dri_open_driver(struct gbm_dri_device *dri)
     */
    dlopen("libglapi.so.0", RTLD_LAZY | RTLD_GLOBAL);
 
-   dri->driver = NULL;
+   static const char *search_path_vars[] = {
-   end = search_paths + strlen(search_paths);
+      /* Read GBM_DRIVERS_PATH first for compatibility, but LIBGL_DRIVERS_PATH
-   for (p = search_paths; p < end && dri->driver == NULL; p = next + 1) {
+       * is recommended over GBM_DRIVERS_PATH.
-      int len;
+       */
-      next = strchr(p, ':');
+      "GBM_DRIVERS_PATH"
-      if (next == NULL)
+      /* Read LIBGL_DRIVERS_PATH if GBM_DRIVERS_PATH was not set.
-         next = end;
+       * LIBGL_DRIVERS_PATH is recommended over GBM_DRIVERS_PATH.
-
+       */
-      len = next - p;
+      "LIBGL_DRIVERS_PATH",
-#if GLX_USE_TLS
+      NULL
-      snprintf(path, sizeof path,
+   };
-               "%.*s/tls/%s_dri.so", len, p, dri->driver_name);
+   return loader_open_driver(dri->driver_name, &dri->driver, search_path_vars);
-      dri->driver = dlopen(path, RTLD_NOW | RTLD_GLOBAL);
-#endif
-      if (dri->driver == NULL) {
-         snprintf(path, sizeof path,
-                  "%.*s/%s_dri.so", len, p, dri->driver_name);
-         dri->driver = dlopen(path, RTLD_NOW | RTLD_GLOBAL);
-      }
-      /* not need continue to loop all paths once the driver is found */
-      if (dri->driver != NULL)
-         break;
-   }
-
-   if (dri->driver == NULL) {
-      fprintf(stderr, "gbm: failed to open any driver (search paths %s)\n",
-              search_paths);
-      fprintf(stderr, "gbm: Last dlopen error: %s\n", dlerror());
-      return NULL;
-   }
-
-   get_extensions_name = loader_get_extensions_name(dri->driver_name);
-   if (get_extensions_name) {
-      const __DRIextension **(*get_extensions)(void);
-
-      get_extensions = dlsym(dri->driver, get_extensions_name);
-      free(get_extensions_name);
-
-      if (get_extensions)
-         extensions = get_extensions();
-   }
-
-   if (!extensions)
-      extensions = dlsym(dri->driver, __DRI_DRIVER_EXTENSIONS);
-   if (extensions == NULL) {
-      fprintf(stderr, "gbm: driver exports no extensions (%s)", dlerror());
-      dlclose(dri->driver);
-   }
-
-   return extensions;
 }
 
 static int

src/gbm/meson.build

@@ -37,7 +37,6 @@ incs_gbm = [
 if with_dri2
   files_gbm += files('backends/dri/gbm_dri.c', 'backends/dri/gbm_driint.h')
   deps_gbm += dep_libdrm # TODO: pthread-stubs
-  args_gbm += '-DDEFAULT_DRIVER_DIR="@0@"'.format(dri_search_path)
 endif
 if with_platform_wayland
   deps_gbm += dep_wayland_server

src/glx/Makefile.am

@@ -40,7 +40,6 @@ AM_CFLAGS = \
 	$(VISIBILITY_CFLAGS) \
 	$(EXTRA_DEFINES_XF86VIDMODE) \
 	-D_REENTRANT \
-	-DDEFAULT_DRIVER_DIR=\"$(DRI_DRIVER_SEARCH_DIR)\" \
 	$(DEFINES) \
 	$(LIBDRM_CFLAGS) \
 	$(DRI2PROTO_CFLAGS) \

src/glx/SConscript

@@ -26,8 +26,6 @@ env.Append(CPPDEFINES = [
     '_REENTRANT',
 ])
 
-env.Append(CPPDEFINES = ['DEFAULT_DRIVER_DIR=\\"/usr/local/lib/dri\\"'])
-
 env.Prepend(LIBS = [
     libloader,
     mesautil,

src/glx/dri_common.c

@@ -77,9 +77,6 @@ dri_message(int level, const char *f, ...)
 #define GL_LIB_NAME "libGL.so.1"
 #endif
 
-static const __DRIextension **
-driGetDriverExtensions(void *handle, const char *driver_name);
-
 /**
  * Try to \c dlopen the named driver.
  *
@@ -97,98 +94,23 @@ driGetDriverExtensions(void *handle, const char *driver_name);
 _X_HIDDEN const __DRIextension **
 driOpenDriver(const char *driverName, void **out_driver_handle)
 {
-   void *glhandle, *handle;
+   void *glhandle;
-   const char *libPaths, *p, *next;
-   char realDriverName[200];
-   int len;
 
    /* Attempt to make sure libGL symbols will be visible to the driver */
    glhandle = dlopen(GL_LIB_NAME, RTLD_NOW | RTLD_GLOBAL);
 
-   libPaths = NULL;
+   static const char *search_path_vars[] = {
-   if (geteuid() == getuid()) {
+      "LIBGL_DRIVERS_PATH",
-      /* don't allow setuid apps to use LIBGL_DRIVERS_PATH */
+      "LIBGL_DRIVERS_DIR", /* deprecated */
-      libPaths = getenv("LIBGL_DRIVERS_PATH");
+      NULL
-      if (!libPaths)
+   };
-         libPaths = getenv("LIBGL_DRIVERS_DIR");        /* deprecated */
-   }
-   if (libPaths == NULL)
-      libPaths = DEFAULT_DRIVER_DIR;
 
-   handle = NULL;
+   const __DRIextension **extensions =
-   for (p = libPaths; *p; p = next) {
+      loader_open_driver(driverName, out_driver_handle, search_path_vars);
-      next = strchr(p, ':');
-      if (next == NULL) {
-         len = strlen(p);
-         next = p + len;
-      }
-      else {
-         len = next - p;
-         next++;
-      }
-
-#ifdef GLX_USE_TLS
-      snprintf(realDriverName, sizeof realDriverName,
-               "%.*s/tls/%s_dri.so", len, p, driverName);
-      InfoMessageF("OpenDriver: trying %s\n", realDriverName);
-      handle = dlopen(realDriverName, RTLD_NOW | RTLD_GLOBAL);
-#endif
-
-      if (handle == NULL) {
-         snprintf(realDriverName, sizeof realDriverName,
-                  "%.*s/%s_dri.so", len, p, driverName);
-         InfoMessageF("OpenDriver: trying %s\n", realDriverName);
-         handle = dlopen(realDriverName, RTLD_NOW | RTLD_GLOBAL);
-      }
-
-      if (handle != NULL)
-         break;
-      else
-         InfoMessageF("dlopen %s failed (%s)\n", realDriverName, dlerror());
-   }
-
-   if (!handle)
-      ErrorMessageF("unable to load driver: %s_dri.so\n", driverName);
 
    if (glhandle)
       dlclose(glhandle);
 
-   const __DRIextension **extensions = driGetDriverExtensions(handle,
-                                                              driverName);
-   if (!extensions) {
-      dlclose(handle);
-      handle = NULL;
-   }
-
-   *out_driver_handle = handle;
-   return extensions;
-}
-
-static const __DRIextension **
-driGetDriverExtensions(void *handle, const char *driver_name)
-{
-   const __DRIextension **extensions = NULL;
-   const __DRIextension **(*get_extensions)(void);
-   char *get_extensions_name = loader_get_extensions_name(driver_name);
-
-   if (get_extensions_name) {
-      get_extensions = dlsym(handle, get_extensions_name);
-      if (get_extensions) {
-         free(get_extensions_name);
-         return get_extensions();
-      } else {
-         InfoMessageF("driver does not expose %s(): %s\n",
-                      get_extensions_name, dlerror());
-         free(get_extensions_name);
-      }
-   }
-
-   extensions = dlsym(handle, __DRI_DRIVER_EXTENSIONS);
-   if (extensions == NULL) {
-      ErrorMessageF("driver exports no extensions (%s)\n", dlerror());
-      return NULL;
-   }
-
    return extensions;
 }
 

src/glx/meson.build

@@ -134,7 +134,6 @@ endif
 
 gl_lib_cargs = [
   '-D_REENTRANT',
-  '-DDEFAULT_DRIVER_DIR="@0@"'.format(dri_search_path),
 ]
 
 if dep_xxf86vm.found()

src/loader/Makefile.am

@@ -28,6 +28,7 @@ noinst_LTLIBRARIES = libloader.la
 AM_CPPFLAGS = \
 	-I$(top_builddir)/src/util/ \
 	-DUSE_DRICONF \
+	-DDEFAULT_DRIVER_DIR=\"$(DRI_DRIVER_SEARCH_DIR)\" \
 	$(DEFINES) \
 	-I$(top_srcdir)/include \
 	-I$(top_srcdir)/include/drm-uapi \

src/loader/SConscript

@@ -12,6 +12,8 @@ if env['drm']:
     env.PkgUseModules('DRM')
     env.Append(CPPDEFINES = ['HAVE_LIBDRM'])
 
+env.Append(CPPDEFINES = ['DEFAULT_DRIVER_DIR=\\"/usr/local/lib/dri\\"'])
+
 # parse Makefile.sources
 sources = env.ParseSourceList('Makefile.sources', 'LOADER_C_FILES')
 

src/loader/loader.c

@@ -26,6 +26,7 @@
  *    Rob Clark <robclark@freedesktop.org>
  */
 
+#include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/stat.h>
@@ -35,6 +36,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <sys/param.h>
 #ifdef MAJOR_IN_MKDEV
 #include <sys/mkdev.h>
 #endif
@@ -510,3 +512,91 @@ loader_get_extensions_name(const char *driver_name)
 
    return name;
 }
+
+/**
+ * Opens a DRI driver using its driver name, returning the __DRIextension
+ * entrypoints.
+ *
+ * \param driverName - a name like "i965", "radeon", "nouveau", etc.
+ * \param out_driver - Address where the dlopen() return value will be stored.
+ * \param search_path_vars - NULL-terminated list of env vars that can be used
+ * to override the DEFAULT_DRIVER_DIR search path.
+ */
+const struct __DRIextensionRec **
+loader_open_driver(const char *driver_name,
+                   void **out_driver_handle,
+                   const char **search_path_vars)
+{
+   char path[PATH_MAX], *search_paths, *next, *end;
+   char *get_extensions_name;
+   const struct __DRIextensionRec **extensions = NULL;
+   const struct __DRIextensionRec **(*get_extensions)(void);
+
+   search_paths = NULL;
+   if (geteuid() == getuid() && search_path_vars) {
+      for (int i = 0; search_path_vars[i] != NULL; i++) {
+         search_paths = getenv(search_path_vars[i]);
+         if (search_paths)
+            break;
+      }
+   }
+   if (search_paths == NULL)
+      search_paths = DEFAULT_DRIVER_DIR;
+
+   void *driver = NULL;
+   end = search_paths + strlen(search_paths);
+   for (char *p = search_paths; p < end; p = next + 1) {
+      int len;
+      next = strchr(p, ':');
+      if (next == NULL)
+         next = end;
+
+      len = next - p;
+#if GLX_USE_TLS
+      snprintf(path, sizeof(path), "%.*s/tls/%s_dri.so", len, p, driver_name);
+      driver = dlopen(path, RTLD_NOW | RTLD_GLOBAL);
+#endif
+      if (driver == NULL) {
+         snprintf(path, sizeof(path), "%.*s/%s_dri.so", len, p, driver_name);
+         driver = dlopen(path, RTLD_NOW | RTLD_GLOBAL);
+         if (driver == NULL)
+            log_(_LOADER_DEBUG, "MESA-LOADER: failed to open %s: %s\n",
+                 path, dlerror());
+      }
+      /* not need continue to loop all paths once the driver is found */
+      if (driver != NULL)
+         break;
+   }
+
+   if (driver == NULL) {
+      log_(_LOADER_WARNING, "MESA-LOADER: failed to open %s (search paths %s)\n",
+           driver_name, search_paths);
+      *out_driver_handle = NULL;
+      return NULL;
+   }
+
+   log_(_LOADER_DEBUG, "MESA-LOADER: dlopen(%s)\n", path);
+
+   get_extensions_name = loader_get_extensions_name(driver_name);
+   if (get_extensions_name) {
+      get_extensions = dlsym(driver, get_extensions_name);
+      if (get_extensions) {
+         extensions = get_extensions();
+      } else {
+         log_(_LOADER_DEBUG, "MESA-LOADER: driver does not expose %s(): %s\n",
+              get_extensions_name, dlerror());
+      }
+      free(get_extensions_name);
+   }
+
+   if (!extensions)
+      extensions = dlsym(driver, __DRI_DRIVER_EXTENSIONS);
+   if (extensions == NULL) {
+      log_(_LOADER_WARNING,
+           "MESA-LOADER: driver exports no extensions (%s)\n", dlerror());
+      dlclose(driver);
+   }
+
+   *out_driver_handle = driver;
+   return extensions;
+}

src/loader/loader.h

@@ -33,6 +33,8 @@
 extern "C" {
 #endif
 
+struct __DRIextensionRec;
+
 /* Helpers to figure out driver and device name, eg. from pci-id, etc. */
 
 int
@@ -47,6 +49,11 @@ loader_get_pci_id_for_fd(int fd, int *vendor_id, int *chip_id);
 char *
 loader_get_driver_for_fd(int fd);
 
+const struct __DRIextensionRec **
+loader_open_driver(const char *driver_name,
+                   void **out_driver_handle,
+                   const char **search_path_vars);
+
 char *
 loader_get_device_name_for_fd(int fd);
 

src/loader/meson.build

@@ -39,7 +39,9 @@ libloader = static_library(
   'loader',
   ['loader.c', 'loader.h', 'pci_id_driver_map.c', 'pci_id_driver_map.h',
    xmlpool_options_h],
-  c_args : [c_vis_args, '-DUSE_DRICONF'],
+  c_args : [c_vis_args, '-DUSE_DRICONF',
+            '-DDEFAULT_DRIVER_DIR="@0@"'.format(dri_search_path),
+],
   include_directories : [inc_include, inc_src, inc_util],
   dependencies : [dep_libdrm, dep_thread],
   build_by_default : false,