On 2026-03-10 at 11:24:21 -0700, Andrew Morton wrote: >On Tue, 10 Mar 2026 17:51:19 +0000 Maciej Wieczor-Retman ><[email protected]> wrote: > >> >> [1] Currently inline mode doesn't work on x86 due to things missing in >> the compiler. I have written a patch for clang that seems to fix the >> inline mode and I was able to boot and check that all patches regarding >> the inline mode work as expected. My hope is to post the patch to LLVM >> once this series is completed, and then make inline mode available in >> the kernel config. >> >> [2] While I was able to boot the inline tag-based kernel with my >> compiler changes in a simulated environment, due to toolchain >> difficulties I couldn't get it to boot on the machine I had access to. >> Also boot time results from the simulation seem too good to be true, and >> they're much too worse for the generic case to be believable. Therefore >> I'm posting only results from the physical server platform. >> >> ======= Compilation >> Clang was used to compile the series (make LLVM=1) since gcc doesn't >> seem to have support for KASAN tag-based compiler instrumentation on >> x86. Patchset does seem to compile with gcc without an issue but doesn't >> boot afterwards. > >So LLVM works partially and gcc doesn't work at all?
The non-working options are disabled in Kconfig so right now only outline KASAN with LLVM works fully. >Do we know which compiler people are using? Google tells me that >Android, ChromeOS, and OpenMandriva use LLVM. That's pretty thin. I don't have any numbers on this matter, from working on this I only got that there is much more KASAN traffic around clang. So I thought that most KASAN users prefer LLVM. >This is all rather problematic and it isn't clear (to me) how to >proceed at this time. Do we have any projections on when all this will >be fixed up? My understanding is that there is something off in gcc support. I recall Andrey Konovalov mentioning that gcc also doesn't work well with arm64's KASAN tag-based mode. As for LLVM inline support I do know the codebase a bit so I got some WIP patches there. But I wanted to see where this review process goes before posting to LLVM. >> The series is based on mm-new. > >I actually carry kexec patches in the mm-nonmm-[un]stable branches. >But the series applies OK anyway. Should I base this patchset on top of mm-nonmm-stable in the future? I was after one patch by Andrey Ryabinin that was in mm-new and I needed to rebase on top of it. -- Kind regards Maciej Wieczór-Retman
