Hi All, A Fedora user has reported problems with MIT-SHM when the xserver is not running as root. Normal use works fine, but when doing a "su -" and then starting X apps as root MIT-SHM fails, see this screenshot:
https://bugzilla.redhat.com/attachment.cgi?id=977933 The culprit is this error: "Xerror: BadAccess (Attempt to access private resources denied)" Which makes sense, the shm segment is created by the app running as root, and the Xserver which is running as a normal user thus cannot access it, so far this has never been a problem because X was always running as root :) I'm tempted to call this a feature rather then a bug, and declaring this a Qt/KDE bug. I've written MIT SHM using X11 code in the past, and always installed an error handler, and did an XSync after the attach to check if the xshm-attach succeed, as it will also fail when running over the network. I guess qt/kde is using some other heuristic to determine if it is not running over a network, and assumes that things will just work when not running over the network, rather then doing "proper" error checking here. So to me it seems that Qt/KDE should do "proper" error checking here and simply fallback to a non shm path in this special case. Still I thought I would send a mail to the xorg-devel list before reporting this to the Qt guys, in case anyone has some clever ideas how to make this work with the xserver running as a regular user. Regards, Hans p.s. This is being tracked here for now: https://bugzilla.redhat.com/show_bug.cgi?id=1185893 _______________________________________________ xorg-devel@lists.x.org: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel