drm_gem_mmap(9)

📦 version 7.3.1, in nixpkgs unstable

💅 drm_gem_mmap — memory map routine for GEM objects ✨

okay so this is drm_gem_mmap(9) from the Kernel API Manual, and bestie, it's literally the memory-map routine for GEM objects. let's get into it 🎀

🌸 SYNOPSIS 🌸

int drm_gem_mmap (struct file *filp , struct vm_area_struct *vma );

✨ ARGUMENTS ✨

  • filp — the DRM file pointer, aka the file you're coming in through 🫶
  • vma — the VMA for the area that's about to get mapped 💫

💖 DESCRIPTION 💖

so here's the vibe: if a driver supports GEM object mapping, then mmap calls on the DRM file descriptor will end up right here. like, this function is the main character they all report to 👑

what it does is look up the GEM object based on the offset that got passed in — and yes, vma->vm_pgoff will contain the fake offset we created, iykyk — and then it maps it with a call to drm_gem_mmap_obj.

🚨 important: if the caller is not granted access to the buffer object, the mmap will fail with EACCES. no access, no mapping, periodt. please see the vma manager for more information 🧚

🔥 SEE ALSO 🔥

Kernel file ./drivers/gpu/drm/drm_gem.c 💜

and that's the whole page, bestie — no cap, nothing skipped 💅

this lil drop came straight from the Kernel API Manual, living at ./drivers/gpu/drm, dated October 2026 — so yeah, shoutout to the drm_gem_mmap(9) era, she ate and left no crumbs 🍓✨

📦 where this page comes from