Occasionally, I will forget to link something from the mailing list in this post. To see my full mailing list activity (patches, reviews, and reports), you can view it on lore.kernel.org.

Linux kernel patches

  • Build errors: These are patches to fix various build errors that I found through testing different configurations with LLVM or were exposed by our continuous integration setup. The kernel needs to build in order to be run :)

    • x86/mm: Ensure clear_page() variants always have __kcfi_typeid_ symbols (v1)
    • KMSAN: Restore dynamic check for '-fsanitize=kernel-memory' (v1)
    • Resolve ARM kCFI build failure in idpf xsk.c (v1)

  • Miscellaneous fixes and improvements: These are fixes and improvements that don’t fit into a particular category but are important to ClangBuiltLinux.

    • scripts/Makefile.extrawarn: Respect CONFIG_WERROR / W=e for hostprogs (v1)
    • kbuild: Fixes for fallout from recent modules.builtin.modinfo series (v1)
    • kbuild: Use '--strip-unneeded-symbol' for removing module device table symbols (v1)
    • powerpc/vmlinux.lds: Drop .interp description (v1)
    • jfs: Rename _inline to avoid conflict with clang's '-fms-extensions' (v1)
    • KMSAN: Restore dynamic check for '-fsanitize=kernel-memory' (v1)
    • kbuild: Rename Makefile.extrawarn to Makefile.warn (v1)
    • kbuild: uapi: Drop types.h check from headers_check.pl (v1)

  • Warning fixes: These are patches to fix various warnings that appear with LLVM. I used to go into detail about the different warnings and what they mean, but the important takeaway for this section is that the kernel should build warning free, as all developers should be using CONFIG_WERROR, which will turn these all into failures. Maybe these should be in the build failures section…

    • PCI: rcar-host: Add OF Kconfig dependency to avoid objtool no-cfi warning (v1, v2)
    • i2c: designware: Remove i2c_dw_remove_lock_support() (v1)
    • smb: client: Fix format specifiers for size_t in parse_dfs_referrals() (v1)
    • net/mlx5e: Return 1 instead of 0 in invalid case in mlx5e_mpwrq_umr_entry_size() (v1)
    • usb: uhci: Work around bogus clang shift overflow warning from DMA_BIT_MASK(64) (v1, v2)
    • HID: intel-ish-hid: Fix -Wcast-function-type-strict in devm_ishtp_alloc_workqueue() (v1)

Patch review and input

For the next sections, I link directly to my first response in the thread when possible but there are times where the link is to the main post. My responses can be seen inline by going to the bottom of the thread and clicking on my name.

Reviewing patches that are submitted is incredibly important, as it helps ensure good code quality due to catching mistakes before the patches get accepted and it can help get patches accepted faster, as some maintainers will blindly pick up patches that have been reviewed by someone that they trust.

Issue triage, input, and reporting

The unfortunate thing about working at the intersection of two projects is we will often find bugs that are not strictly related to the project, which require some triage and reporting back to the original author of the breakage so that they can be fixed and not impact our own testing. Some of these bugs fall into that category while others are issues strictly related to this project.

Tooling improvements

These are changes to various tools that we use, such as our continuous integration setup, booting utilities, toolchain building scripts, or other closely related projects such as AOSP’s distribution of LLVM and TuxMake.

Behind the scenes

  • Every day that there is a new linux-next release, I rebase and build a few different kernel trees then boot and runtime test them on several different machines, including a SolidRun Honeycomb LX2, an Ampere Altra Developer Platform, four Intel-based devices, and an AMD-based device. This is not always visible because I do not report anything unless there is something broken but it can take up to a few hours each day, depending on the amount of churn and issues uncovered.

  • I continue to upload prebuilt, fast versions of LLVM for kernel developers and our continuous integration to use.

  • [GIT PULL] Kbuild fixes for 6.18 #1

  • [GIT PULL] Kbuild fixes for 6.18 #2

Special thanks

Special thanks to Google and the Linux Foundation for sponsoring my work.