DRM_IOCTL_PR...HANDLE_TO_FD(9)

💅 DRM_IOCTL_PRIME_HANDLE_TO_FD 💅

okay bestie, welcome to the Kernel API Manual — yes, the whole manual, and yes this page is short but it's iconic. sit down, sip ur matcha, we're learning how to turn a GEM handle into a DMA-BUF file descriptor 🦋

---

✨ NAME ✨

DRM_IOCTL_PRIME_HANDLE_TO_FD — Convert a GEM handle to a DMA-BUF FD.

like, the whole personality of this ioctl is right there in the name ngl 💖

---

🎀 SYNOPSIS 🎀

DRM_IOCTL_PRIME_HANDLE_TO_FD

that's it. that's the synopsis. she's lowkey minimal and we respect it ✨

---

🌸 DESCRIPTION 🌸

so here's the vibe: user-space fills in drm_prime_handle.handle with the GEM handle it wants to export, plus drm_prime_handle.flags, and the kernel hands back a DMA-BUF file descriptor in drm_prime_handle.fd. literally that's the trade, handle in, fd out, no cap 🔥

the export can fail for any driver-specific reason — for example because export is not supported for this specific GEM handle (but it might be for others 👀). so like, don't assume one failure means all failures, bestie, it's per-handle energy.

support for exporting DMA-BUFs is advertised via DRM_PRIME_CAP_EXPORT. that's ur vibe check before u even try 🫶

---

🧚 SEE ALSO 🧚

go off, cross-references, we love a thorough girlie:

• Kernel file ./tools/perf/trace/beauty/include/uapi/drm/drm.h struct
• drm_gem_close(9)
• struct drm_gem_flink(9)
• struct drm_gem_open(9)
• struct drm_gem_change_handle(9)
• DRM_CAP_DUMB_BUFFER(9)
• DRM_CAP_VBLANK_HIGH_CRTC(9)
• DRM_CAP_DUMB_PREFERRED_DEPTH(9)
• DRM_CAP_DUMB_PREFER_SHADOW(9)
• DRM_CAP_PRIME(9)
• DRM_PRIME_CAP_IMPORT(9)
• DRM_PRIME_CAP_EXPORT(9)
• DRM_CAP_TIMESTAMP_MONOTONIC(9)
• DRM_CAP_ASYNC_PAGE_FLIP(9)
• DRM_CAP_CURSOR_WIDTH(9)
• DRM_CAP_CURSOR_HEIGHT(9)
• DRM_CAP_ADDFB2_MODIFIERS(9)
• DRM_CAP_PAGE_FLIP_TARGET(9)
• DRM_CAP_CRTC_IN_VBLANK_EVENT(9)
• DRM_CAP_SYNCOBJ(9)
• DRM_CAP_SYNCOBJ_TIMELINE(9)
• DRM_CAP_ATOMIC_ASYNC_PAGE_FLIP(9)
• DRM_CLIENT_CAP_STEREO_3D(9)
• DRM_CLIENT_CAP_UNIVERSAL_PLANES(9)
• DRM_CLIENT_CAP_ATOMIC(9)
• DRM_CLIENT_CAP_ASPECT_RATIO(9)
• DRM_CLIENT_CAP_WRITEBACK_CONNECTORS(9)
• DRM_CLIENT_CAP_CURSOR_PLANE_HOTSPOT(9)
• DRM_CLIENT_CAP_PLANE_COLOR_PIPELINE(9)
• struct drm_syncobj_eventfd(9)
• DRM_IOCTL_GEM_CLOSE(9)
• DRM_IOCTL_PRIME_FD_TO_HANDLE(9)
• DRM_IOCTL_MODE_RMFB(9)
• DRM_IOCTL_MODE_CREATE_DUMB(9)
• DRM_IOCTL_MODE_GETFB2(9)
• DRM_IOCTL_SYNCOBJ_EVENTFD(9)
• DRM_IOCTL_MODE_CLOSEFB(9)
• DRM_IOCTL_SET_CLIENT_NAME(9)
• DRM_IOCTL_GEM_CHANGE_HANDLE(9)
• struct drm_event(9)
• DRM_EVENT_VBLANK(9)
• DRM_EVENT_FLIP_COMPLETE(9)
• DRM_EVENT_CRTC_SEQUENCE(9)

---

and that's the page, bestie, u ate that 💅 this lil gem came from ./tools/perf/trace/beauty/incl... and it's dated October 2026 — go forth and export ur handles responsibly, mwah 🎀💖🌟