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Comment by eddyb | Hacker News Reader

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AFAIK Linux doesn't use zero-terminated strings anywhere in its syscalls, or at least not in those like write, where you pass a size alongside the buffer.

However (almost?) all syscalls dealing with filesystem paths take null-terminated strings. See for example the implementation of the open() syscall:

https://github.com/torvalds/linux/blob/fb65d872d7a8dc629837a...

(Hence the need for the strncpy_from_user()-function: https://github.com/torvalds/linux/blob/fb65d872d7a8dc629837a...)

Ahh, I totally missed the path arguments, my bad.

write() syscall writes a sequence of bytes (not string) therefore cannot use zero-terminated convention.

open takes a NUL-terminated filename.

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