[PATCH] rtld: Check __libc_enable_secure before honoring LD_PREFER_MAP_32BIT_EXEC

[Florian Weimer]

Given the patch is a clear improvement over what we have today, would
you please repost it with the following changes:

Please try to add CVE-2019-19126 to the commit subject, along with the
bug number.  The latter has to be of the form “(bug 25204)” or
“[BZ #25204]”, so that our tooling recongizes it.

Please mention the commit which introduced the flow in the commit
message, e.g. “commit b9eb92ab05204df772eb4929eccd018637c9f3e9
("Add Prefer_MAP_32BIT_EXEC to map executable pages with MAP_32BIT")”.

It would be nice if you could write a short entry for NEWS, in the
Security related changes section for the 2.31 release.

If you do not want to make these changes, I can make them for you before
pushing the patch.

Thanks,
Florian