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 :)

    • drm/tidss: dispc: Explicitly include bitfield.h (v1)
    • mfd: tps6594: Explicitly include bitfield.h (v1)
    • md/md-llbitmap: Use DIV_ROUND_UP_SECTOR_T (v1)
    • tpm: loongson: Add bufsiz parameter to tpm_loongson_send() (v1)
    • nfsd: Avoid strlen conflict in nfsd4_encode_components_esc() (v1, v2, v3)
    • Fixes for pmac32_defconfig after fb.h removal from backlight.h (v1)

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

    • nilfs2: fix CFI failure when accessing /sys/fs/nilfs2/features/* (v1)

  • Stable backports and fixes: It is important to make sure that the stable trees are as free from issues as possible, as those are the trees that devices and users use; for example, Android and Chrome OS regularly merge from stable, so if there is a problem that will impact those trees that we fixed in mainline, it should be backported.

    • [PATCH 5.4 only] powerpc: boot: Remove unnecessary zero in label in udelay() (v1, v2)
    • [PATCH 6.6 ONLY] s390/cpum_cf: Fix uninitialized warning after backport of ce971233242b (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…

    • compiler-clang.h: Define __SANITIZE_*__ macros only when undefined (v1)
    • objtool: Ignore __pi___cfi_ prefixed symbols (v1)
    • drm/pixpaper: Fix return type of pixpaper_mode_valid() (v1)
    • drm/omap: Mark dispc_save_context() with noinline_for_stack (v1)
    • mei: late_bind: Fix -Wincompatible-function-pointer-types-strict (v1)
    • btrfs: Fix PAGE_SIZE format specifier in open_ctree() (v1)
    • Kconfig fixes for QCOM clk drivers when targeting ARCH=arm (v1)

LLVM patches

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

Special thanks

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