[PATCH] D56554: [ELF] Add '-z nognustack' opt to suppress emitting PT_GNU_STACK

[Rui Ueyama via Phabricator via cfe-commits]

ruiu added a comment.

GNU linkers assume that input object files that work with non-executable stack has a .note.GNU-stack section, and they emit a PT_GNU_STACK segment to mark the stack area non-executable if all input files have that marker section.

If restoring default means we implement that behavior, then lld shouldn't do that. That mechanism is error-prone, and the consequence of an error is disabling a major security measure. To be on the safe side, we simply emit unless it is explicitly to not do that by `-z execstack`.

If you add `-z nognustack` as an alias to `-z execstack` (and changing the behavior of `-z execstack` to not add the marker segment at all), I think I'm fine with that.


Repository:
  rLLD LLVM Linker

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  https://reviews.llvm.org/D56554/new/

https://reviews.llvm.org/D56554