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
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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 :)
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Miscellaneous fixes and improvements: These are fixes and improvements that don’t fit into a particular category but are important to ClangBuiltLinux.
kbuild: Fix '-S -c' in x86 stack protector scripts(v1,stable backport)
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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…ASoC: fsl: lpc3xxx-i2s: Avoid using ret uninitialized in lpc32xx_i2s_probe()(v1)power: supply: cros_charge-control: Avoid accessing attributes out of bounds(v1)ACPI: HMAT: Mark hmat_set_default_dram_perf() as __init(v1,v2)Bluetooth: btmtk: Mark all stub functions as inline(v1)drm/amd/display: Reapply 2fde4fdddc1f(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.
Re: [PATCH] cpumask: Switch from inline to __always_inlineRe: [PATCH v3 2/2] rust: add flags for shadow call stack sanitizerRe: [PATCH v3 1/2] rust: SHADOW_CALL_STACK is incompatible with RustRe: [PATCH] kbuild: add script and target to generate pacman packageRe: [RFC PATCH] selftests: introduce and use SELFTESTS_CC_IS_CLANG instead of LLVMRe: [PATCH 1/3] kbuild: raise the minimum GNU Make requirement to 4.0Re: [PATCH 2/3] modpost: remove self-definitions of R_ARM_* macrosRe: [PATCH 3/3] modpost: rename R_ARM_THM_CALL to R_ARM_THM_PC22Re: [PATCH] kbuild: deb-pkg: use default string when variable is unset or nullRe: [PATCH v2] kbuild: add script and target to generate pacman packageRe: [PATCH] kbuild: rpm-pkg: avoid the warnings with dtb's listed twiceRe: [PATCH v6] kbuild: add script and target to generate pacman packageRe: [PATCH v7] kbuild: add script and target to generate pacman packageRe: [PATCH] drm/xe: Fix warning on unreachable statementRe: [PATCH]: kbuild doc typo fixRe: [PATCH] fuse: fs-verity: aoid out-of-range comparisonRe: [PATCH] ARM: assembler: Drop obsolete VFP accessor fallbackRe: [PATCH] Remove *.orig pattern from .gitignore
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.
ld.lld: error: drivers/gpu/drm/amd/amdgpu/amdgpu.o:(.debug_info+0x7d117f5): unknown relocation (33554442) against symbolGCC images appear to be used for clang builds-Wframe-larger-than in drivers/gpu/drm/amd/amdgpu/vcn_v5_0_0.cRe: [PATCH v2 17/20] mm/zsmalloc: convert get/set_first_obj_offset() to take zpdescRe: [PATCH v2 01/10] riscv: Implement cmpxchg32/64() using ZacasRe: Plumbers Testing MC potential topic: specialised toolchainsRe: [PATCH] infiniband/hw/ocrdma: increase frame warning limit in verifier when using KASAN or KCSANRe: [PATCH] mm/slub: quiet the clang warning with -Wunused-function enabledExcessive stack usage with array bounds sanitizer when targeting PowerPC in Linux kernel's drivers/gpu/drm/amd/amdgpu/vcn_v5_0_0.cRe: [PATCH V6 2/5] mailbox: Add support for QTI CPUCP mailbox controllerRe: [PATCH v12 4/8] platform: cznic: turris-omnia-mcu: Add support for poweroff and wakeupRe: [PATCH] misc: Kconfig: add a new dependency for MARVELL_CN10K_DPICrash when booting UML after e3c92e81711d14b46c3121d36bc8e152cb843923Re: [linux-next:master 12947/13217] drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:1088:6: error: call to '__compiletime_assert_749' declared with 'error' attribute: FIELD_PREP: value too large for the fieldHigh stack usage in Linux kernel's drivers/gpu/drm/omapdrm/dss/dispc.cRe: [soc:sophgo/dt 1/1] arch/riscv/boot/dts/sophgo/sg2042.dtsi:7:10: fatal error: 'dt-bindings/clock/sophgo,sg2042-clkgen.h' file not foundRe: ld.lld: error: undefined symbol: iosf_mbi_availableRemove support for 3DNow!, both intrinsics and builtins.[LD/LTO] Error when building Linux 6.7 with Clang-18 and ThinLTOIt seems like --targets option is brokenCrash in net/core/dev.c when assertions are enabled after commit 13cabc47f8aeAssertion failure in Hexagon constant-extender optimization from Hexagon Linux kernel[LoongArch] Remove spurious mask operations from andn->icmp on 16 and 8 bit values[Clang] Loop over FieldDecls instead of all Decls"value is too large for field of 1 byte" after commit 1a47f3f3db665Re: [tip:x86/microcode 1/1] arch/x86/kernel/cpu/microcode/amd.c:714:6: warning: variable 'equiv_id' is used uninitialized whenever 'if' condition is falseRe: [PATCH v3 2/3] dma-mapping: replace zone_dma_bits by zone_dma_limit[llvm][CodeGen] Fixed max cycle calculation with zero-cost instructions for window scheduler
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.
Update patches (July 1, 2024)Disable CONFIG_DRM_WERROR for certain Fedora configurationspatches: stable: Drop merged __counted_by patches from 6.9.8patches: mainline: Drop radeon __counted_by patchboot-qemu.py: Handle LoongArch's EFI firmware location changeUpdate DEFAULT_KERNEL_FOR_PGO to 6.10.0Disable CONFIG_DRM_OMAP with LoongArch configurationsUpdate builds for 6.10 final releasetc_build: Improve source set up loggingUpdate korg-clang-18 to 18.1.8 and add korg-clang-19
Behind the scenes
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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 Raspberry Pi 4, a Raspberry Pi 3, a SolidRun Honeycomb LX2, an Ampere Altra Developer Platform, two Intel-based desktops, an AMD-based desktop, and an Intel-based laptop. 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.
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I continue to upload prebuilt, fast versions of LLVM for kernel developers and our continuous integration to use.
Special thanks
Special thanks to Google and the Linux Foundation for sponsoring my work.