Re: Security question: "Text file busy" overwriting executables but not shared libraries?

Jamie Lokier
2001-10-13T14:53:59Z

Linus Torvalds wrote:
> Trust me. The people who came up with MAP_COPY were stupid. Really. It's
> an idiotic concept, and it's not worth implementing.

I can think of an efficiency-related use for MAP_COPY, and it has
nothing to do with shared libraries:

- An editor using mmap() to read a file.

The existing semantics require that you either call read() and waste
(potentially shared) memory to do this, or use MAP_PRIVATE and then
deliberately page in and dirty all of the file's pages.

Neither of these seem to be the most efficient way to launch an editor.

cheers,
-- Jamie