Well, the initial idea to only support either writable xor executable
areas was indeed motivated by security reasons. Then came Jiri and he
needed the forbidden combination for the loader: when loading executable
code, you first need to read it from a file and then write it to the
target address space area. In this regard, as_area_change_flags() can be
considered a workaround or a sort of a hack.

OK, but isn't this a little bit strange? If there are no purely technical reasons which would forbid creating W+E areas in as_area_create() directly, if there are legitimate reasons to support them and if it is even possible to setup such an area by two calls (instead of one call -- just a trivial obstruction), then why not simply allow to create such an area directly in as_area_create()?

I mean, this is no longer a security measure (because you are free to achieve the unsafe state), is is only an obfuscation.


M.D.

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