From 7df2ae88facad7e8e186261750645ce51a898993 Mon Sep 17 00:00:00 2001 From: Simon Ser Date: Fri, 3 Sep 2021 10:03:27 +0200 Subject: [PATCH] render/allocator: use legacy authentication for primary nodes Closes: https://github.com/swaywm/wlroots/issues/3156 --- render/allocator/allocator.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/render/allocator/allocator.c b/render/allocator/allocator.c index affc928e..23b2aca5 100644 --- a/render/allocator/allocator.c +++ b/render/allocator/allocator.c @@ -35,8 +35,31 @@ static int reopen_drm_node(int drm_fd) { int new_fd = open(name, O_RDWR | O_CLOEXEC); if (new_fd < 0) { wlr_log_errno(WLR_ERROR, "Failed to open DRM node '%s'", name); + free(name); + return -1; } + free(name); + + // If we're using a DRM primary node (e.g. because we're running under the + // DRM backend, or because we're on split render/display machine), we need + // to use the legacy DRM authentication mechanism to have the permission to + // manipulate buffers. + if (drmGetNodeTypeFromFd(new_fd) == DRM_NODE_PRIMARY) { + drm_magic_t magic; + if (drmGetMagic(new_fd, &magic) < 0) { + wlr_log_errno(WLR_ERROR, "drmGetMagic failed"); + close(new_fd); + return -1; + } + + if (drmAuthMagic(drm_fd, magic) < 0) { + wlr_log_errno(WLR_ERROR, "drmAuthMagic failed"); + close(new_fd); + return -1; + } + } + return new_fd; }