From 9558ec02d0f7bbf30dc1f9ee4c0b06c9b0c49afe Mon Sep 17 00:00:00 2001

From: Erik Kurzinger <ekurzinger@nvidia.com>

Date: Fri, 14 Aug 2020 07:27:58 -0700

Subject: [PATCH] suspend lock in eglBindWaylandDisplayWL

When binding an external EGL display to a Wayland display, core EGL will

need to translate the external handle to an internal handle before

performing any API calls. This may occur, for example, when running a

nested Wayland compositor where the EGL display will be using

EGL_PLATFORM_WAYLAND as opposed to EGL_PLATFORM_DEVICE. Translating this

handle involves calling wlEglGetInternalHandleExport, which attempts to

acquire the external API lock. However, during eglBindWaylandDisplayWL this

lock is already held.  As a result, when wl_eglstream_display_bind calls

eglQueryString to retrieve the extension string, this lock acquisition will

fail causing a crash.

To fix this, wl_eglstream_display_bind should temporarily suspend the API

lock before calling eglQueryString.

---

 src/wayland-eglstream-server.c | 2 ++

 1 file changed, 2 insertions(+)

diff --git a/src/wayland-eglstream-server.c b/src/wayland-eglstream-server.c

index c37f8e6..331ad32 100644

--- a/src/wayland-eglstream-server.c

+++ b/src/wayland-eglstream-server.c

@@ -308,7 +308,9 @@ wl_eglstream_display_bind(WlEglPlatformData *data,

     wlStreamDpy->eglDisplay    = eglDisplay;

     wlStreamDpy->caps_override = 0;

+    wlExternalApiUnlock();

     exts = data->egl.queryString(eglDisplay, EGL_EXTENSIONS);

+    wlExternalApiLock();

 #define CACHE_EXT(_PREFIX_, _NAME_)                                      \

         wlStreamDpy->exts._NAME_ =                                       \