Bug#1022787: libc6-dev: Lintian warns that all mips*el executables have executable stack

[Simon McVittie <smcv@debian.org>]

Package: libc6-dev
Version: 2.35-4
Severity: normal
X-Debbugs-Cc: debian-mips@lists.debian.org, lintian@packages.debian.org, jrtc27@debian.org
User: debian-mips@lists.debian.org
Usertags: mips mipsel

All mips*el executables and libraries appear to have an executable stack,
resulting in very large numbers of Lintian warnings, particularly for
packages with many small ELF objects like
<https://udd.debian.org/lintian/?packages=samba>.

Jessica Clarke looked into this and found that this is intentionally done
by glibc when targeting minimum kernel 4.8.0 or older with mips hardfloat:
https://github.com/bminor/glibc/blob/595c22ecd8e87a27fd19270ed30fdbae9ad25426/sysdeps/unix/sysv/linux/mips/configure.ac#L138-L143

Debian 9 had a kernel newer than 4.8.0, so I think Debian 12 probably
doesn't need to go that far into backwards compatibility? If the mips
porters agree, then glibc on mips*el should stop forcing an executable
stack, either by increasing the minimal kernel version or by patching
this out. That will provide some security hardening on mips*el.

Or, if the mips porters consider this backwards compatibility to be
more important than the security hardening of a non-executable stack,
then Lintian should stop issuing warnings about the executable stack on
mips*el to improve its signal/noise ratio.

Thanks,
    smcv