From 1efaa85889051978f806c4ea7c6d4997329624e5 Mon Sep 17 00:00:00 2001
From: Robert Foss <rfoss@kernel.org>
Date: Mon, 31 Jul 2023 11:40:23 +0200
Subject: [PATCH] egl: Fix attrib_list[0] == EGL_NONE check

_eglGetSurfacelessDisplay(), _eglGetWaylandDisplay() and
_eglGetGbmDisplay() handle the attrib_list[0] == EGL_NONE
case incorrectly by returning an EGL_BAD_ATTRIBUTE error.

Fix this bug, and switch the functions to use switch/case
in order to have the same structure as the sibling
_eglGetXXXDisplay() functions which support multiple attributes.

Fixes: c237539d621 ("egl: Implement EGL_EXT_explicit_device")

Signed-off-by: Robert Foss <rfoss@kernel.org>
Reviewed-by: Eric Engestrom <eric@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24394>
---
 src/egl/main/egldisplay.c | 75 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 51 insertions(+), 24 deletions(-)

diff --git a/src/egl/main/egldisplay.c b/src/egl/main/egldisplay.c
index 2bfe271..1769e19 100644
--- a/src/egl/main/egldisplay.c
+++ b/src/egl/main/egldisplay.c
@@ -570,14 +570,23 @@ _eglGetGbmDisplay(struct gbm_device *native_display,
 
    /* This platform recognizes only EXT_explicit_device */
    if (attrib_list) {
-      if (attrib_list[0] != EGL_DEVICE_EXT) {
-         _eglError(EGL_BAD_ATTRIBUTE, "eglGetPlatformDisplay");
-         return NULL;
-      }
-      dev = _eglLookupDevice((void *)attrib_list[1]);
-      if (!dev) {
-         _eglError(EGL_BAD_DEVICE_EXT, "eglGetPlatformDisplay");
-         return NULL;
+      for (int i = 0; attrib_list[i] != EGL_NONE; i += 2) {
+         EGLAttrib attrib = attrib_list[i];
+         EGLAttrib value = attrib_list[i + 1];
+
+         switch (attrib) {
+         case EGL_DEVICE_EXT:
+            dev = _eglLookupDevice((void *)value);
+            if (!dev) {
+               _eglError(EGL_BAD_DEVICE_EXT, "eglGetPlatformDisplay");
+               return NULL;
+            }
+            break;
+
+         default:
+            _eglError(EGL_BAD_ATTRIBUTE, "eglGetPlatformDisplay");
+            return NULL;
+         }
       }
    }
 
@@ -600,14 +609,23 @@ _eglGetWaylandDisplay(struct wl_display *native_display,
 
    /* This platform recognizes only EXT_explicit_device */
    if (attrib_list) {
-      if (attrib_list[0] != EGL_DEVICE_EXT) {
-         _eglError(EGL_BAD_ATTRIBUTE, "eglGetPlatformDisplay");
-         return NULL;
-      }
-      dev = _eglLookupDevice((void *)attrib_list[1]);
-      if (!dev) {
-         _eglError(EGL_BAD_DEVICE_EXT, "eglGetPlatformDisplay");
-         return NULL;
+      for (int i = 0; attrib_list[i] != EGL_NONE; i += 2) {
+         EGLAttrib attrib = attrib_list[i];
+         EGLAttrib value = attrib_list[i + 1];
+
+         switch (attrib) {
+         case EGL_DEVICE_EXT:
+            dev = _eglLookupDevice((void *)value);
+            if (!dev) {
+               _eglError(EGL_BAD_DEVICE_EXT, "eglGetPlatformDisplay");
+               return NULL;
+            }
+            break;
+
+         default:
+            _eglError(EGL_BAD_ATTRIBUTE, "eglGetPlatformDisplay");
+            return NULL;
+         }
       }
    }
 
@@ -633,14 +651,23 @@ _eglGetSurfacelessDisplay(void *native_display, const EGLAttrib *attrib_list)
 
    /* This platform recognizes only EXT_explicit_device */
    if (attrib_list) {
-      if (attrib_list[0] != EGL_DEVICE_EXT) {
-         _eglError(EGL_BAD_ATTRIBUTE, "eglGetPlatformDisplay");
-         return NULL;
-      }
-      if ((native_display && native_display != (void *)attrib_list[1]) ||
-          (native_display != _eglLookupDevice(native_display))) {
-         _eglError(EGL_BAD_DEVICE_EXT, "eglGetPlatformDisplay");
-         return NULL;
+      for (int i = 0; attrib_list[i] != EGL_NONE; i += 2) {
+         EGLAttrib attrib = attrib_list[i];
+         EGLAttrib value = attrib_list[i + 1];
+
+         switch (attrib) {
+         case EGL_DEVICE_EXT:
+            if ((native_display && native_display != (void *)value) ||
+                (native_display != _eglLookupDevice(native_display))) {
+               _eglError(EGL_BAD_DEVICE_EXT, "eglGetPlatformDisplay");
+               return NULL;
+            }
+            break;
+
+         default:
+            _eglError(EGL_BAD_ATTRIBUTE, "eglGetPlatformDisplay");
+            return NULL;
+         }
       }
    }
 
-- 
2.7.4