egl-wayland/582b2d345abaa0e313cf16c902e602084ea59551.patch

From 582b2d345abaa0e313cf16c902e602084ea59551 Mon Sep 17 00:00:00 2001
From: Erik Kurzinger <ekurzinger@nvidia.com>
Date: Tue, 23 Nov 2021 14:15:14 -0500
Subject: [PATCH] egl-wayland: retrieve DRM device name before acquiring API
 lock

wlEglBindDisplaysHook acquires the external API lock before calling
wl_eglstream_display_bind, which in turn calls wl_drm_display_bind. That
function calls back into EGL to query the DRM device associated with the
given EGLDisplay.

Normally this is not a problem since the EGLDisplay passed to
eglBindWaylandDisplayWL will be an internal EGL_PLATFORM_DEVICE handle.
However, some applications, notably anything WebKit-based, will instead
pass in an external EGL_PLATFORM_WAYLAND handle. This means that the
eglQueryDisplayAttrib call by wl_drm_display_bind will require EGL to
call back into the egl-wayland library to look up the internal handle.
This is done by wlEglGetInternalHandleExport, which will attempt to
acquire the external API lock a second time, which will fail.

To avoid this, add a new function to wayland-drm.c which will retrieve
the DRM device name for the given EGLDisplay. wlEglBindDisplaysHook will
call this *before* acquiring the external API lock, and then pass it to
wl_drm_display_bind via wl_eglstream_display_bind so it can be saved in
the wl_eglstream_display struct.
---
 include/wayland-drm.h              |  7 ++++++-
 include/wayland-eglstream-server.h |  3 ++-
 src/wayland-drm.c                  | 33 +++++++++++++++---------------
 src/wayland-egldisplay.c           |  8 +++++---
 src/wayland-eglstream-server.c     |  5 +++--
 5 files changed, 32 insertions(+), 24 deletions(-)

diff --git a/include/wayland-drm.h b/include/wayland-drm.h
index be363c6..84d0f11 100644
--- a/include/wayland-drm.h
+++ b/include/wayland-drm.h
@@ -23,9 +23,14 @@
 #ifndef WAYLAND_DRM_H
 #define WAYLAND_DRM_H
 
+extern const char *
+wl_drm_get_dev_name(const WlEglPlatformData *data,
+                    EGLDisplay dpy);
+
 extern EGLBoolean
 wl_drm_display_bind(struct wl_display *display,
-                    struct wl_eglstream_display *wlStreamDpy);
+                    struct wl_eglstream_display *wlStreamDpy,
+                    const char *dev_name);
 extern void
 wl_drm_display_unbind(struct wl_eglstream_display *wlStreamDpy);
 
diff --git a/include/wayland-eglstream-server.h b/include/wayland-eglstream-server.h
index 76e772c..0f7d477 100644
--- a/include/wayland-eglstream-server.h
+++ b/include/wayland-eglstream-server.h
@@ -49,7 +49,8 @@ EGLBoolean
 wl_eglstream_display_bind(WlEglPlatformData *data,
                           struct wl_display *wlDisplay,
                           EGLDisplay eglDisplay,
-                          const char *exts);
+                          const char *exts,
+                          const char *dev_name);
 
 /*
  * wl_eglstream_display_unbind()
diff --git a/src/wayland-drm.c b/src/wayland-drm.c
index aa6de23..a08d82f 100644
--- a/src/wayland-drm.c
+++ b/src/wayland-drm.c
@@ -152,37 +152,36 @@ bind(struct wl_client *client, void *data, uint32_t version, uint32_t id)
         wl_resource_post_event(resource, WL_DRM_CAPABILITIES, 0);
 }
 
-EGLBoolean
-wl_drm_display_bind(struct wl_display *display,
-                    struct wl_eglstream_display *wlStreamDpy)
+const char *
+wl_drm_get_dev_name(const WlEglPlatformData *data,
+                    EGLDisplay dpy)
 {
-    EGLDisplay dpy = wlStreamDpy->eglDisplay;
     EGLDeviceEXT egl_dev;
     const char *dev_exts;
-    const char *dev_name;
 
-    if (!wlStreamDpy->data->egl.queryDisplayAttrib(dpy,
-                                                   EGL_DEVICE_EXT,
-                                                   (EGLAttribKHR*)&egl_dev)) {
-        return EGL_FALSE;
+    if (!data->egl.queryDisplayAttrib(dpy, EGL_DEVICE_EXT,
+                                      (EGLAttribKHR*)&egl_dev)) {
+        return NULL;
     }
 
-
-    dev_exts = wlStreamDpy->data->egl.queryDeviceString(egl_dev,
-                                                        EGL_EXTENSIONS);
+    dev_exts = data->egl.queryDeviceString(egl_dev, EGL_EXTENSIONS);
 
     if (!dev_exts) {
-        return EGL_FALSE;
+        return NULL;
     }
 
     if (!wlEglFindExtension("EGL_EXT_device_drm_render_node", dev_exts)) {
-        return EGL_FALSE;
+        return NULL;
     }
 
-    dev_name =
-        wlStreamDpy->data->egl.queryDeviceString(egl_dev,
-                                                 EGL_DRM_RENDER_NODE_FILE_EXT);
+    return data->egl.queryDeviceString(egl_dev, EGL_DRM_RENDER_NODE_FILE_EXT);
+}
 
+EGLBoolean
+wl_drm_display_bind(struct wl_display *display,
+                    struct wl_eglstream_display *wlStreamDpy,
+                    const char *dev_name)
+{
     if (!dev_name) {
         return EGL_FALSE;
     }
diff --git a/src/wayland-egldisplay.c b/src/wayland-egldisplay.c
index 8b7394a..d285bf7 100644
--- a/src/wayland-egldisplay.c
+++ b/src/wayland-egldisplay.c
@@ -30,6 +30,7 @@
 #include "wayland-eglhandle.h"
 #include "wayland-eglutils.h"
 #include "wayland-drm-client-protocol.h"
+#include "wayland-drm.h"
 #include <string.h>
 #include <stdlib.h>
 #include <assert.h>
@@ -70,15 +71,16 @@ EGLBoolean wlEglIsValidNativeDisplayExport(void *data, void *nativeDpy)
 
 EGLBoolean wlEglBindDisplaysHook(void *data, EGLDisplay dpy, void *nativeDpy)
 {
-    /* Retrieve extension string before taking external API lock */
-    const char *exts = ((WlEglPlatformData *)data)->egl.queryString(dpy, EGL_EXTENSIONS);
+    /* Retrieve extension string and device name before taking external API lock */
+    const char *exts = ((WlEglPlatformData *)data)->egl.queryString(dpy, EGL_EXTENSIONS),
+               *dev_name = wl_drm_get_dev_name(data, dpy);
     EGLBoolean res = EGL_FALSE;
 
     wlExternalApiLock();
 
     res = wl_eglstream_display_bind((WlEglPlatformData *)data,
                                     (struct wl_display *)nativeDpy,
-                                    dpy, exts);
+                                    dpy, exts, dev_name);
 
     wlExternalApiUnlock();
 
diff --git a/src/wayland-eglstream-server.c b/src/wayland-eglstream-server.c
index b1baa08..1dfd7ce 100644
--- a/src/wayland-eglstream-server.c
+++ b/src/wayland-eglstream-server.c
@@ -289,7 +289,8 @@ EGLBoolean
 wl_eglstream_display_bind(WlEglPlatformData *data,
                           struct wl_display *wlDisplay,
                           EGLDisplay eglDisplay,
-                          const char *exts)
+                          const char *exts,
+                          const char *dev_name)
 {
     struct wl_eglstream_display *wlStreamDpy = NULL;
     char                        *env         = NULL;
@@ -355,7 +356,7 @@ wl_eglstream_display_bind(WlEglPlatformData *data,
                                            wl_eglstream_display_global_bind);
 
     /* Failure is not fatal */
-    wl_drm_display_bind(wlDisplay, wlStreamDpy);
+    wl_drm_display_bind(wlDisplay, wlStreamDpy, dev_name);
 
     wl_list_insert(&wlStreamDpyList, &wlStreamDpy->link);