On Thu, Apr 02, 2020 at 06:20:57PM +0200, Sedat Dilek wrote: > On Fri, Feb 28, 2020 at 1:22 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > > > Hi! > > > > A recent bug was solved for builds linked with ld.lld, and tracking > > it down took way longer than it needed to (a year). Ultimately, it > > boiled down to differences between ld.bfd and ld.lld's handling of > > orphan sections. Similarly, the recent FGKASLR series brough up orphan > > section handling too[2]. In both cases, it would have been nice if the > > linker was running with --orphan-handling=warn so that surprise sections > > wouldn't silently get mapped into the kernel image at locations up to > > the whim of the linker's orphan handling logic. Instead, all desired > > sections should be explicitly identified in the linker script (to be > > either kept or discarded) with any orphans throwing a warning. The > > powerpc architecture actually already does this, so this series seeks > > to extend this coverage to x86, arm64, and arm. > > > > This series depends on tip/x86/boot (where recent .eh_frame fixes[3] > > landed), and has a minor conflict[4] with the ARM tree (related to > > the earlier mentioned bug). As it uses refactorings in the asm-generic > > linker script, and makes changes to kbuild, I think the cleanest place > > for this series to land would also be through -tip. Once again (like > > my READ_IMPLIES_EXEC series), I'm looking to get maintainer Acks so > > this can go all together with the least disruption. Splitting it up by > > architecture seems needlessly difficult. > > > > Thanks! > > > > Hi Kees, > > what is the status of this patchset? > Looks like it is not in tip or linux-next Git. Based on the feedback, I have 3 TODO items: - track down and eliminate (or explain) the source of the .got.plt on arm64 - enable orphan warnings for _all_ architectures - refactor final link logic to perform the orphan warning in a clean way I'm working through these (and other work) still. I'm hoping to have another version up some time next week. -- Kees Cook
