kmsan_handle_dma(9)

📦 version 7.3.1, in nixpkgs unstable

💅 kmsan_handle_dma(9)

okay so bestie, welcome to the Kernel API Manual — yes, the actual manual manual, we're doing this 💖 — and today's main character is kmsan_handle_dma, the little function that keeps your DMA transfers from lying to the kernel's memory sanitizer. no cap, it's lowkey important.

✨ NAME ✨

kmsan_handle_dma — handle a DMA data transfer. that's it. that's the whole vibe. 🦋

🌸 SYNOPSIS 🌸

void kmsan_handle_dma (phys_addr_t phys , size_t size , enum
dma_data_direction dir );

three args, one job, zero drama. slay. ✨

🎀 ARGUMENTS 🎀

  • phys — the physical address of the buffer. like, where the buffer physically is. 📍
  • size — buffer size. how many bytes we're talking about, bestie. 📏
  • dir — one of the possible dma_data_direction values. it's giving "which way is the data even going" 💀

🧚 DESCRIPTION 🧚

so depending on the direction, KMSAN does one of three things — pick your fighter:

  • ✅ checks the buffer, if it's copied to the device
  • 💫 initializes the buffer, if it's copied from the device
  • 🔥 does both, if this is a DMA_BIDIRECTIONAL transfer

bidirectional said "why not both" and honestly? iconic. 👑

🌈 SEE ALSO 🌈

kernel file ./include/linux/kmsan.h — plus the whole kmsan bestie squad, all of them, no one left behind 🫶:

ok that's the whole page, you ate that 💅 go forth and sanitize your DMA, bestie. fr fr.

mwah 💋 this lil page lives in ./include/linux and it's stamped October 2026 — that's the source and the date, and yes I did save you a seat in the group chat. bye bb 🎀✨

📦 where this page comes from