On Tue, Oct 05, 2021 at 04:17:51PM -0400, Jeffrey Walton wrote: > On Tue, Oct 5, 2021 at 4:00 PM Lennart Sorensen > <lsore...@csclub.uwaterloo.ca> wrote: > > > > ... > > This fixnum idea in gcl is broken. It must go away. Pointers are for > > addresses and nothing else. > > +1. Tagged pointers caused a lot of problems porting some packages to > Aarch64. Tagged pointers were blocking a number of web related > packages. It also caused a number of CVEs, like CVE-2020-9391.
And I found this post: https://lore.kernel.org/lkml/20081006132651.gg3...@one.firstfloor.org/ where Andi Kleen calls the need for ADDR_LIMIT_3GB "a kludge for bug-to-bug compatibility with old binaries (that is where the 3GB personality came from to work around bugs in some old JVMs that could not deal with a full 4GB address space), it shouldn't be really used for anything new." And that was 13 years ago. Seems some code still isn't fixed. Not working with a full 4GB address space is considered a bug and should be treated as such. -- Len Sorensen
