ib_is_udata_in_empty(9)

🦋 ib_is_udata_in_empty(9) 🦋

okay so bestie, welcome to the Kernel API Manual — this is the page for ib_is_udata_in_empty(9), and honestly? she's a tiny little vibe-check function and I'm obsessed 💅

✨ NAME ✨

ib_is_udata_in_empty — the girl whose whole job is checking whether the udata input buffer is all zeros 🎀

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🌸 SYNOPSIS 🌸

int ib_is_udata_in_empty (struct ib_udata *udata );

💖 ARGUMENTS 💖

• udata — the system calls ib_udata struct, periodt ✨ that's the one thing you're handing her.

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🔥 DESCRIPTION 🔥

so here's the tea ☕ — you should use this one when the driver does not currently define a driver data struct. Like, there's no struct, nothing to validate, so she just peeks at the buffer and tells you what's up 👑

Here's the glow-up breakdown of her return values:

• 0 — the buffer is empty or all zeros, slay 💚
• -EOPNOTSUPP — there's non-zero data in there, so nope, not supported 😭
• a negative error code — something went wrong on failure, and that's the whole story 💀

ngl bestie, read those returns carefully — 0 and -EOPNOTSUPP are not the same thing, and a negative error code is its own separate third case. Don't conflate them, iykyk 🙈

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🌈 SEE ALSO 🌈

• Kernel file ./include/rdma/uverbs_ioctl.h
• uverbs_attr_get_uobjs_arr(9)
• ib_copy_validate_udata_in(9)
• ib_copy_validate_udata_in_cm(9)
• ib_respond_udata(9)
• ib_respond_empty_udata(9)
• ib_no_udata_io(9)

the whole friend group fr fr 🫶 go say hi to all of them 💜

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and that's the page, babes 🎀 this iconic little drop comes to you from ./include/rdma, dated October 2026 — main character energy from the kernel, always ⭐🧚‍♀️💜