From 2c4c7fbfa907d330317340c5d43ae93d46107e19 Mon Sep 17 00:00:00 2001
From: Lucas Fryzek <lfryzek@igalia.com>
Date: Wed, 28 May 2025 08:24:39 -0400
Subject: [PATCH] egl/dri: Check that xshm can be attached

Cc: mesa-stable
Co-authored-by: Carlos Lopez <clopez@igalia.com>
(cherry picked from commit 5f481dd89db04a2c3ae35402efdf2def005f4008)

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/40359>
---
 .pick_status.json                   |  2 +-
 src/egl/drivers/dri2/platform_x11.c | 35 +++--------------------------
 2 files changed, 4 insertions(+), 33 deletions(-)

diff --git a/.pick_status.json b/.pick_status.json
index 883b185b45b..eeeb68ed42a 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -2414,7 +2414,7 @@
         "description": "egl/dri: Check that xshm can be attached",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null,
         "notes": null
diff --git a/src/egl/drivers/dri2/platform_x11.c b/src/egl/drivers/dri2/platform_x11.c
index 25d6ed20754..579433e17d5 100644
--- a/src/egl/drivers/dri2/platform_x11.c
+++ b/src/egl/drivers/dri2/platform_x11.c
@@ -51,7 +51,9 @@
 #include "util/log.h"
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <sys/ipc.h>
 #include "x11_dri3.h"
+#include "x11_display.h"
 #include "kopper_interface.h"
 #include "loader.h"
 #include "platform_x11.h"
@@ -1123,37 +1125,6 @@ dri2_x11_setup_swap_interval(_EGLDisplay *disp)
    dri2_setup_swap_interval(disp, arbitrary_max_interval);
 }
 
-static bool
-check_xshm(struct dri2_egl_display *dri2_dpy)
-{
-   xcb_void_cookie_t cookie;
-   xcb_generic_error_t *error;
-   int ret = true;
-   xcb_query_extension_cookie_t shm_cookie;
-   xcb_query_extension_reply_t *shm_reply;
-   bool has_mit_shm;
-
-   shm_cookie = xcb_query_extension(dri2_dpy->conn, 7, "MIT-SHM");
-   shm_reply = xcb_query_extension_reply(dri2_dpy->conn, shm_cookie, NULL);
-
-   has_mit_shm = shm_reply && shm_reply->present;
-   free(shm_reply);
-   if (!has_mit_shm)
-      return false;
-
-   cookie = xcb_shm_detach_checked(dri2_dpy->conn, 0);
-   if ((error = xcb_request_check(dri2_dpy->conn, cookie))) {
-      /* BadRequest means we're a remote client. If we were local we'd
-       * expect BadValue since 'info' has an invalid segment name.
-       */
-      if (error->error_code == BadRequest)
-         ret = false;
-      free(error);
-   }
-
-   return ret;
-}
-
 static bool
 platform_x11_finalize(_EGLDisplay *disp, bool force_zink)
 {
@@ -1220,7 +1191,7 @@ dri2_initialize_x11_swrast(_EGLDisplay *disp)
 {
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
 
-   if (check_xshm(dri2_dpy)) {
+   if (x11_xcb_display_supports_xshm(dri2_dpy->conn)) {
       dri2_dpy->loader_extensions = swrast_loader_shm_extensions;
    } else {
       dri2_dpy->loader_extensions = swrast_loader_extensions;