https://bugs.freedesktop.org/show_bug.cgi?id=90079
Bug ID: 90079 Summary: drmSetMaster and drmDropMaster need root privileges Product: DRI Version: unspecified Hardware: All OS: Linux (All) Status: NEW Severity: normal Priority: medium Component: libdrm Assignee: dri-devel@lists.freedesktop.org Reporter: g1938560@trbvm.com
I run a small, user-space program that renders images in my virtual console with drmModeSetCRTC and family. I also support virtual terminal switching with ioctl() on stuff from linux/vt.h and some basic signal handling.
Switching back to X server, however, just renders... nothing.
Apparently I'm supposed to call drmDropMaster so that X server can pick up from there. I get -1 and errno is set to Permission Denied. When run as root, it works as expected.
Is there any reason why these functions require root privileges? More importantly, is there any workaround for this so that my user space program can let X server draw its stuff once user switches back to X's virtual terminal?