{ lib, stdenv, buildPackages, bc, bison, flex, perl, rsync, gmp, libmpc, mpfr, openssl, cpio, elfutils, hexdump, zstd, python3Minimal, zlib, pahole, kmod, fetchpatch, rustc-unwrapped, rust-bindgen-unwrapped, rustPlatform, }: let lib_ = lib; stdenv_ = stdenv; readConfig = configfile: let matchLine = line: let match = lib.match "(CONFIG_[^=]+)=([ym])" line; in lib.optional (match != null) { name = lib.elemAt match 0; value = lib.elemAt match 1; }; in lib.listToAttrs (lib.concatMap matchLine (lib.splitString "\n" (builtins.readFile configfile))); in lib.makeOverridable ( { # The kernel version version, # The kernel pname (should be set for variants) pname ? "linux", # Position of the Linux build expression pos ? null, # Additional kernel make flags extraMakeFlags ? [ ], # The name of the kernel module directory # Needs to be X.Y.Z[-extra], so pad with zeros if needed. modDirVersion ? null, # derive from version # The kernel source (tarball, git checkout, etc.) src, # a list of { name=..., patch=..., extraConfig=...} patches kernelPatches ? [ ], # The kernel .config file configfile, target ? if stdenv.hostPlatform.isx86 then "bzImage" else if stdenv.hostPlatform.isAarch32 then "zImage" else if stdenv.hostPlatform.isAarch64 || stdenv.hostPlatform.isRiscV then "Image" else if stdenv.hostPlatform.isLoongArch64 then "vmlinuz.efi" else "vmlinux", buildDTBs ? stdenv.hostPlatform.isAarch || stdenv.hostPlatform.isRiscV || stdenv.hostPlatform.isLoongArch64, # Manually specified nixexpr representing the config # If unspecified, this will be autodetected from the .config config ? lib.optionalAttrs (builtins.isPath configfile || allowImportFromDerivation) ( readConfig configfile ), # Custom seed used for CONFIG_GCC_PLUGIN_RANDSTRUCT if enabled. This is # automatically extended with extra per-version and per-config values. randstructSeed ? "", # Extra meta attributes extraMeta ? { }, # for module compatibility isZen ? false, # Whether to utilize the controversial import-from-derivation feature to parse the config allowImportFromDerivation ? false, features ? { }, lib ? lib_, stdenv ? stdenv_, }: let # Provide defaults. Note that we support `null` so that callers don't need to use optionalAttrs, # which can lead to unnecessary strictness and infinite recursions. modDirVersion_ = if modDirVersion == null then lib.versions.pad 3 version else modDirVersion; config_ = config; in let # Shadow the un-defaulted parameter; don't want null. modDirVersion = modDirVersion_; inherit (lib) hasAttr getAttr optional optionals optionalString maintainers teams platforms ; commonMakeFlags = import ./common-flags.nix { inherit lib stdenv buildPackages extraMakeFlags ; }; config = let attrName = attr: "CONFIG_" + attr; in { isSet = attr: hasAttr (attrName attr) config; getValue = attr: if config.isSet attr then getAttr (attrName attr) config else null; isYes = attr: (config.getValue attr) == "y"; isNo = attr: (config.getValue attr) == "n"; isModule = attr: (config.getValue attr) == "m"; isEnabled = attr: (config.isModule attr) || (config.isYes attr); isDisabled = attr: (!(config.isSet attr)) || (config.isNo attr); } // config_; isModular = config.isYes "MODULES"; withRust = config.isYes "RUST"; # Dependencies that are required to build kernel modules moduleBuildDependencies = [ pahole perl elfutils # module makefiles often run uname commands to find out the kernel version (buildPackages.deterministic-uname.override { inherit modDirVersion; }) ] ++ optional (lib.versionAtLeast version "5.13") zstd ++ optionals withRust [ rustc-unwrapped rust-bindgen-unwrapped ]; in stdenv.mkDerivation { inherit pname version src; __structuredAttrs = true; enableParallelBuilding = true; hardeningDisable = [ "bindnow" "format" "fortify" "stackprotector" "pic" ]; ${if isModular then "outputs" else null} = [ "out" "dev" "modules" ]; # We remove a bunch of stuff that is symlinked from other places to save space, # which trips the broken symlink check. So, just skip it. We'll know if it explodes. dontCheckForBrokenSymlinks = true; patches = # kernelPatches can contain config changes and no actual patch lib.filter (p: p != null) (map (p: p.patch) kernelPatches) # Required for deterministic builds along with some postPatch magic. ++ optional (lib.versionOlder version "5.19") ./randstruct-provide-seed.patch ++ optional (lib.versionAtLeast version "5.19") ./randstruct-provide-seed-5.19.patch # Linux 5.12 marked certain PowerPC-only symbols as GPL, which breaks # OpenZFS; this was fixed in Linux 5.19 so we backport the fix # https://github.com/openzfs/zfs/pull/13367 ++ optional ( lib.versionAtLeast version "5.12" && lib.versionOlder version "5.19" && stdenv.hostPlatform.isPower ) (fetchpatch { url = "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/patch/?id=d9e5c3e9e75162f845880535957b7fd0b4637d23"; hash = "sha256-bBOyJcP6jUvozFJU0SPTOf3cmnTQ6ZZ4PlHjiniHXLU="; }); buildFlags = [ "KBUILD_BUILD_VERSION=1-NixOS" target "vmlinux" # for "perf" and things like that "scripts_gdb" ] ++ optional isModular "modules" ++ optionals buildDTBs [ "dtbs" "DTC_FLAGS=-@" ] ++ extraMakeFlags; installFlags = [ "INSTALL_PATH=${placeholder "out"}" ] ++ (optional isModular "INSTALL_MOD_PATH=${placeholder "modules"}") ++ optionals buildDTBs [ "dtbs_install" "INSTALL_DTBS_PATH=${placeholder "out"}/dtbs" ]; depsBuildBuild = [ buildPackages.stdenv.cc ]; nativeBuildInputs = [ bison flex perl bc openssl rsync gmp libmpc mpfr elfutils zstd python3Minimal kmod hexdump ] ++ optionals (lib.versionAtLeast version "5.2") [ cpio pahole zlib ] ++ optionals withRust [ rustc-unwrapped rust-bindgen-unwrapped ]; env = { RUST_LIB_SRC = lib.optionalString withRust rustPlatform.rustLibSrc; # avoid leaking Rust source file names into the final binary, which adds # a false dependency on rust-lib-src on targets with uncompressed kernels KRUSTFLAGS = lib.optionalString withRust "--remap-path-prefix ${rustPlatform.rustLibSrc}=/"; }; makeFlags = [ "O=$(buildRoot)" # We have a `modules` variable in the environment for our # split output, but the kernel Makefiles also define their # own `modules` variable. Their definition wins, but Make # remembers that the variable was originally from the # environment and exports it to all the build recipes. This # breaks the build with an “Argument list too long” error due # to passing the huge list of every module object file in the # environment of every process invoked by every build recipe. # # We use `--eval` here to undefine the inherited environment # variable before any Makefiles are read, ensuring that the # kernel’s definition creates a new, unexported variable. "--eval=undefine modules" ] ++ commonMakeFlags; postPatch = '' # Ensure that depmod gets resolved through PATH sed -i Makefile -e 's|= /sbin/depmod|= depmod|' # Some linux-hardened patches now remove certain files in the scripts directory, so the file may not exist. [[ -f scripts/ld-version.sh ]] && patchShebangs scripts/ld-version.sh # Set randstruct seed to a deterministic but diversified value. Note: # we could have instead patched gen-random-seed.sh to take input from # the buildFlags, but that would require also patching the kernel's # toplevel Makefile to add a variable export. This would be likely to # cause future patch conflicts. for file in scripts/gen-randstruct-seed.sh scripts/gcc-plugins/gen-random-seed.sh; do if [ -f "$file" ]; then substituteInPlace "$file" \ --replace NIXOS_RANDSTRUCT_SEED \ $(echo ${randstructSeed}${src} ${placeholder "configfile"} | sha256sum | cut -d ' ' -f 1 | tr -d '\n') break fi done patchShebangs scripts # also patch arch-specific install scripts for i in $(find arch -name install.sh); do patchShebangs "$i" done # unset $src because the build system tries to use it and spams a bunch of warnings # see: https://github.com/torvalds/linux/commit/b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0 unset src ''; configurePhase = '' runHook preConfigure mkdir build export buildRoot="$(pwd)/build" echo "manual-config configurePhase buildRoot=$buildRoot pwd=$PWD" if [ -f "$buildRoot/.config" ]; then echo "Could not link $buildRoot/.config : file exists" exit 1 fi ln -sv ${configfile} $buildRoot/.config # reads the existing .config file and prompts the user for options in # the current kernel source that are not found in the file. make "''${makeFlags[@]}" oldconfig runHook postConfigure make "''${makeFlags[@]}" prepare actualModDirVersion="$(cat $buildRoot/include/config/kernel.release)" if [ "$actualModDirVersion" != "${modDirVersion}" ]; then echo "Error: modDirVersion ${modDirVersion} specified in the Nix expression is wrong, it should be: $actualModDirVersion" exit 1 fi buildFlags+=("KBUILD_BUILD_TIMESTAMP=$(date -u -d @$SOURCE_DATE_EPOCH)") cd $buildRoot ''; postInstall = optionalString isModular '' mkdir -p $dev cp vmlinux $dev/ mkdir -p $dev/lib/modules/${modDirVersion}/build/scripts # Installing from source dir instead of $buildRoot so as to omit intermediate artifacts. cp -rL ../scripts/gdb/ $dev/lib/modules/${modDirVersion}/build/scripts # Installing `constants.py` from `$buildRoot` as it's generated. cp scripts/gdb/linux/constants.py $dev/lib/modules/${modDirVersion}/build/scripts/gdb/linux if [ -z "''${dontStrip-}" ]; then installFlags+=("INSTALL_MOD_STRIP=1") fi make modules_install "''${makeFlags[@]}" "''${installFlags[@]}" unlink $modules/lib/modules/${modDirVersion}/build mkdir -p $dev/lib/modules/${modDirVersion}/{build,source} # To save space, exclude a bunch of unneeded stuff when copying. (cd .. && rsync --archive --prune-empty-dirs \ --exclude='/build/' \ * $dev/lib/modules/${modDirVersion}/source/) cd $dev/lib/modules/${modDirVersion}/source cp $buildRoot/{.config,Module.symvers} $dev/lib/modules/${modDirVersion}/build make modules_prepare "''${makeFlags[@]}" O=$dev/lib/modules/${modDirVersion}/build # For reproducibility, removes accidental leftovers from a `cc1` call # from a `try-run` call from the Makefile rm -f $dev/lib/modules/${modDirVersion}/build/.[0-9]*.d # Keep some extra files on some arches (powerpc, aarch64) for f in arch/powerpc/lib/crtsavres.o arch/arm64/kernel/ftrace-mod.o; do if [ -f "$buildRoot/$f" ]; then mkdir -p "$(dirname $dev/lib/modules/${modDirVersion}/build/$f)" cp $buildRoot/$f $dev/lib/modules/${modDirVersion}/build/$f fi done # !!! No documentation on how much of the source tree must be kept # If/when kernel builds fail due to missing files, you can add # them here. Note that we may see packages requiring headers # from drivers/ in the future; it adds 50M to keep all of its # headers on 3.10 though. chmod u+w -R .. buildArchDir="$dev/lib/modules/${modDirVersion}/build/arch" # Remove unused arches for d in $(cd arch/; ls); do if [ -d "$buildArchDir/$d" ]; then continue; fi if [ -d "$buildArchDir/arm64" ] && [ "$d" = arm ]; then continue; fi rm -rf arch/$d done # Remove all driver-specific code (50M of which is headers) rm -fR drivers # Keep all headers find . -type f -name '*.h' -print0 | xargs -0 -r chmod u-w # Keep linker scripts (they are required for out-of-tree modules on aarch64) find . -type f -name '*.lds' -print0 | xargs -0 -r chmod u-w # Keep root and arch-specific Makefiles chmod u-w Makefile arch/*/Makefile* # Keep rust Makefile ${lib.optionalString withRust "chmod u-w rust/Makefile"} # Keep whole scripts dir chmod u-w -R scripts # Delete everything not kept find . -type f -perm -u=w -print0 | xargs -0 -r rm # Delete empty directories find -empty -type d -delete ''; preInstall = let # All we really need to do here is copy the final image and System.map to $out, # and use the kernel's modules_install, firmware_install, dtbs_install, etc. targets # for the rest. Easy, right? # # Unfortunately for us, the obvious way of getting the built image path, # make -s image_name, does not work correctly, because some architectures # (*cough* aarch64 *cough*) change KBUILD_IMAGE on the fly in their install targets, # so we end up attempting to install the thing we didn't actually build. # # Thankfully, there's a way out that doesn't involve just hardcoding everything. # # The kernel has an install target, which runs a pretty simple shell script # (located at scripts/install.sh or arch/$arch/boot/install.sh, depending on # which kernel version you're looking at) that tries to do something sensible. # # (it would be great to hijack this script immediately, as it has all the # information we need passed to it and we don't need it to try and be smart, # but unfortunately, the exact location of the scripts differs between kernel # versions, and they're seemingly not considered to be public API at all) # # One of the ways it tries to discover what "something sensible" actually is # is by delegating to what's supposed to be a user-provided install script # located at ~/bin/installkernel. # # (the other options are: # - a distribution-specific script at /sbin/installkernel, # which we can't really create in the sandbox easily # - an architecture-specific script at arch/$arch/boot/install.sh, # which attempts to guess _something_ and usually guesses very wrong) # # More specifically, the install script exec's into ~/bin/installkernel, if one # exists, with the following arguments: # # $1: $KERNELRELEASE - full kernel version string # $2: $KBUILD_IMAGE - the final image path # $3: System.map - path to System.map file, seemingly hardcoded everywhere # $4: $INSTALL_PATH - path to the destination directory as specified in installFlags # # $2 is exactly what we want, so hijack the script and use the knowledge given to it # by the makefile overlords for our own nefarious ends. # # Note that the makefiles specifically look in ~/bin/installkernel, and # writeShellScriptBin writes the script to /bin/installkernel, # so HOME needs to be set to just the store path. # # FIXME: figure out a less roundabout way of doing this. installkernel = buildPackages.writeShellScriptBin "installkernel" '' cp -av $2 $4 cp -av $3 $4 ''; in '' installFlags+=("-j$NIX_BUILD_CORES") export HOME=${installkernel} ''; preFixup = '' if [ -z "''${dontStrip-}" -a -e $out/vmlinux ]; then $STRIP -v -S -p $out/vmlinux fi ''; requiredSystemFeatures = [ "big-parallel" ]; passthru = rec { inherit version modDirVersion config kernelPatches configfile target buildDTBs moduleBuildDependencies stdenv commonMakeFlags ; inherit isZen withRust # Forwarded into passthru so features survive kernel.override() call chains # used by the NixOS module system (see boot.kernelPackages apply in kernel.nix). features ; baseVersion = lib.head (lib.splitString "-rc" version); kernelOlder = lib.versionOlder baseVersion; kernelAtLeast = lib.versionAtLeast baseVersion; }; # Some image types need special install targets installTargets = [ ( if (target == "zImage" || target == "Image.gz" || target == "vmlinuz.efi") && builtins.elem stdenv.hostPlatform.linuxArch [ "arm" "arm64" "parisc" "riscv" ] then "zinstall" else "install" ) ]; karch = stdenv.hostPlatform.linuxArch; pos = lib.optionalDrvAttr (pos != null) pos; meta = { # https://github.com/NixOS/nixpkgs/pull/345534#issuecomment-2391238381 broken = withRust && lib.versionOlder version "6.12"; description = "The Linux kernel" + ( if kernelPatches == [ ] then "" else " (with patches: " + lib.concatStringsSep ", " (map (x: x.name) kernelPatches) + ")" ); license = lib.licenses.gpl2Only; homepage = "https://www.kernel.org/"; maintainers = [ maintainers.thoughtpolice ]; teams = [ teams.linux-kernel teams.security-review ]; platforms = platforms.linux; badPlatforms = lib.optionals (lib.versionOlder version "4.15") [ "riscv32-linux" "riscv64-linux" ] # Generic scripts/install.sh is only available on LoongArch64 since 6.16. ++ lib.optional (lib.versionOlder version "6.16") "loongarch64-linux"; timeout = 14400; # 4 hours identifiers.cpeParts = { part = "o"; vendor = "linux"; product = "linux_kernel"; inherit version; update = "*"; }; } // extraMeta; } )