Messages in this thread |  | | Date | Sat, 13 Oct 2001 21:05:21 +0200 | From | Jamie Lokier <> | Subject | Re: Security question: "Text file busy" overwriting executables but not shared libraries? |
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Pablo Alcaraz wrote: > Whatever will be the chosen solution, it would have to allow to > overwrite all the executables and libraries files (if we have enough > permissions).
Pablo, there's no need for this. Upgrades to libraries are done by removing the old file's name from its parent directory and placing the new file at that name, perhaps using an atomic rename. The old _file_ continues to exist even though its name has been deleted, until the last program using the library finishes using it, even though the old file does not have a name any more.
New programs that open the library will find the new file. Both files exist until the old file finally disappears. At no point is any file's contents overwritten.
This is why you can upgrade a running linux system including critical system libraries, and nothing crashes. Usually ;-)
-- Jamie - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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