Re: GNU Guile 3.0.9rc1 available for testing!

[Greg Troxel]

Ludovic Courtès <ludo@gnu.org> writes:

> My understanding is that the expectation of being able to later mprotect
> that mapping to make it writable is a valid one per POSIX.  Quoth
> <https://pubs.opengroup.org/onlinepubs/9699919799/functions/mprotect.html>:
>
>   If PROT_WRITE is specified, the application shall ensure that it has
>   opened the mapped objects in the specified address range with write
>   permission, unless MAP_PRIVATE was specified in the original mapping,
>   regardless of whether the file descriptors used to map the objects
>   have since been closed.
>
> Here the original file descriptors are O_RDONLY, but the mapping is
> MAP_PRIVATE.
>
> I’m not sure how to best address that.
>
> Thoughts?

Thanks.  Definitely, let's keep this separate from 3.0.9.  It is not new
and it is easy for me to keep the workaround in pkgsrc.   I will consult
with our POSIX lawyers and see what comes of that.   If it turns out, as
seems likely, that this is a NetBSD bug, it will almost certainly be
fixed.

Either way, it might be good to have an ifdef with the workaround,  but
maybe with pkgsrc and few building not from pkgsrc, especially on
systems that wouldn't get the likely fix, it might be better to just not
do anything.  I think we should wait until we understand the POSIX
issues better.