[lld] r340902 - Always add a .note.GNU-stack section if -r.

[Joerg Sonnenberger via llvm-commits]

On Thu, Aug 30, 2018 at 10:07:34AM +0900, Rui Ueyama via llvm-commits wrote:
> On Thu, Aug 30, 2018 at 7:16 AM Joerg Sonnenberger <joerg at bec.de> wrote:
> 
> > On Wed, Aug 29, 2018 at 07:27:09AM -0000, Rui Ueyama via llvm-commits
> > wrote:
> > > Author: ruiu
> > > Date: Wed Aug 29 00:27:09 2018
> > > New Revision: 340902
> > >
> > > URL: http://llvm.org/viewvc/llvm-project?rev=340902&view=rev
> > > Log:
> > > Always add a .note.GNU-stack section if -r.
> > >
> > > With this patch, lld creates a .note.GNU_stack and adds that to an
> > > output file if it is creating a re-linkable object file (i.e. if -r
> > > is given). If we don't do this, and if you use GNU linkers as a final
> > > linker, they create an executable whose stack area is executable,
> > > which is considered pretty bad these days.
> >
> > It should only be done if at least one of the input files had the note.
> >
> 
> I consider .note.GNU-stack a pointless feature at the moment; it could make
> your program's stack area executable in an obscure way. You should pass `-z
> execstack` to the final link command line if your program really need an
> executable stack.

I consider the whole note pointless. That's exactly why I am complaining
about adding this junk when it is not necessary or desirable. Not every
OS follows the stupid glibc model of making the stack executable unless
told otherwise.

Joerg