drm_compat_ioctl(9)

💅 drm_compat_ioctl(9) — the Kernel API Manual moment

Okay bestie, so this one lives in the Kernel API Manual (section 9, iykyk) and it's called drm_compat_ioctl — literally the 32-bit IOCTL compatibility handler for DRM drivers. Say that five times fast, I dare you. 🫶

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✨ NAME ✨

drm_compat_ioctl — the 32bit IOCTL compatibility handler for DRM drivers. That's the whole vibe. 🌸

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🦋 SYNOPSIS 🦋

long drm_compat_ioctl (struct file *filp , unsigned int cmd , unsigned
long arg );

Yes the line break in the middle of unsigned long is real, it's giving "the manpage just woke up and chose chaos." Copy it exactly, no cap. 💀

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🎀 ARGUMENTS 🎀

• filp — the file this ioctl is called on. That's your main character file pointer right there. 👑
• cmd — the ioctl cmd number. Just the number, doing number things. 🔢
• arg — the user argument. Comes straight from userspace, handle with care bestie. 🙈

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💖 DESCRIPTION 💖

So here's the tea: this is the compatibility handler for 32 bit userspace running on 64 kernels. Think of it as the translator bestie standing between your tiny 32-bit app and your very grown-up 64-bit kernel — matching energy, matched structures, no awkwardness. 🌈

The way that all the actual IOCTL handling gets forwarded to drm_ioctl?? Obsessed. This function doesn't do the work itself, it just marshalls structures as appropriate and passes things along like the world's most supportive group chat admin. 🧚

⚠️ Important caveat, and I'm gonna say it clearly: this only handles DRM core IOCTLs. If the driver has botched IOCTL itself, it must handle those by wrapping this function. Not me making up rules — that's literally the spec. 💅

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⭐ RETURN ⭐

Zero on success, negative error code on failure. That's it, that's the whole mood. Success = 0, failure = negative, periodt. ✨

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🔥 SEE ALSO 🔥

• Kernel file ./drivers/gpu/drm/drm_ioc32.c — go read it, it's iconic, iykyk. 📖

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That's the whole page, bestie — no crumbs left behind, every flag and caveat accounted for. 🍓

💜 Sourced from ./drivers/gpu/drm, dated October 2026, and filed under drm_compat_ioctl(9). Bye bestie, go wrap your botched IOCTLs responsibly! 🎀🦋✨