dma_buf_fd_install(9)

💅 dma_buf_fd_install(9) — the Kernel API Manual glow-up

okay bestie, so like… this is from the Kernel API Manual, and honestly? she's a short one but she's important. no cap.

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✨ NAME ✨

dma_buf_fd_install — installs a reserved fd for a dma-buf 🎀

like… it literally takes your little pre-booked fd and makes it real. main character energy tbh.

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🌸 SYNOPSIS 🌸

void dma_buf_fd_install (struct dma_buf *dmabuf , int fd );

that's it. that's the whole vibe. no return value, she just does the thing. 🦋

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💖 ARGUMENTS 💖

• dmabuf — [in] pointer to dma_buf. the actual buffer object in question, your little guy.
• fd — [in] fd reserved with get_unused_fd_flags. note the "reserved" — you already called dibs on this number and now you're cashing it in.

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👑 DESCRIPTION 👑

Publishes a previously reserved fd into the caller's fd table. lowkey iconic behaviour — the fd was in limbo and now she's officially published, like dropping a group chat screenshot to the story. ✨

⚠️ big important warning, seriously bestie: Must only be called after all fallible work (e.g. copy_to_user) has succeeded, as it cannot be undone safely once called. 😭 like, there's no undo button, no ctrl+z, no "wait nvm". once she's in the fd table, she's IN. so do all your risky stuff FIRST, then call this. periodt. 💀

The caller is responsible for having emitted the trace event (via dma_buf_fd or get_unused_fd_flags + this function) before calling this. so — trace event first, then this. the order is not a suggestion, it's the whole point. 🫶

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🦋 SEE ALSO 🦋

buckle up, this list is long, but she ate and left no crumbs 👑

• Kernel file ./drivers/dma-buf/dma-buf.c dma_buf_iter_begin(9), dma_buf_iter_next(9), implicit fence polling(9), dma_buf_set_name(9), dma buf device access(9), dma_buf_export(9), dma_buf_fd(9), dma_buf_get(9), dma_buf_put(9), locking convention(9), dma_buf_dynamic_attach(9), dma_buf_attach(9), dma_buf_detach(9), dma_buf_pin(9), dma_buf_unpin(9), dma_buf_map_attachment(9), dma_buf_map_attachment_unlocked(9), dma_buf_unmap_attachment(9), dma_buf_unmap_attachment_unlocked(9), dma_buf_attach_revocable(9), dma_buf_invalidate_mappings(9), cpu access(9), dma_buf_begin_cpu_access(9), dma_buf_end_cpu_access(9), dma_buf_mmap(9), dma_buf_vmap(9), dma_buf_vmap_unlocked(9), dma_buf_vunmap(9), dma_buf_vunmap_unlocked(9)

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🌈 and that's the page!! sourced straight out of ./drivers/dma-buf, dated October 2026, filed under dma_buf_fd_install(9) — go forth and install those fds responsibly, bestie 💜🍓🧚