unsafe_memcpy(9)

💖 NAME 💖

okay so bestie, welcome to the unsafe_memcpy(9) page from the Kernel API Manual — yes, the manual name is folded in right here at the top, because we're cute like that 💅

• unsafe_memcpy — a memcpy implementation with no FORTIFY bounds checking. literally what it says on the tin, no cap ✨

✨ SYNOPSIS ✨

unsafe_memcpy (dst , src , bytes , justification );

🦋 ARGUMENTS 🦋

• dst — destination memory address to write to 💖
• src — source memory address to read from 🎀
• bytes — how many bytes to write to dst from src 🫶
• justification — free-form text or comment describing why the use is needed 📝

🌸 DESCRIPTION 🌸

okay so real talk: use this for corner cases where the compiler cannot do the right thing, or during transitions between APIs, etc. 🧚

it should be used very rarely, and it includes a place for justification detailing where bounds checking has happened, and why existing solutions cannot be employed. 👑

💀 heads up, bestie: this one has no FORTIFY bounds checking, and the page says it should be used very rarely. not a default flex, fr fr.

💜 SEE ALSO 💜

• Kernel file ./include/linux/fortify-string.h 🦋
• strnlen(9), strlen(9), strlcat(9), strcat(9), strncat(9), strcpy(9) — the whole friend group, iykyk 💅

mwah 💋 this page came from the ./include/linux source, dated October 2026, and it's literally unsafe_memcpy(9). bye bestie, go be iconic 🫶