From d041e7d2bf3e25e09bd5850a8de15b6dbd0ffdc5 Mon Sep 17 00:00:00 2001
From: Rolf Neugebauer <rn@rneugeba.io>
Date: Wed, 6 Mar 2019 00:37:31 +0000
Subject: [PATCH] kernel: Factor our perf build from main kernel build

The build of the perf utility has been quite bothersome,
with different arches and kernel versions failing.

Since we now have the ful kernel source in the package,
factor out the actual build into Dockerfile.perf

Signed-off-by: Rolf Neugebauer <rn@rneugeba.io>
---
 kernel/Dockerfile      | 10 ----------
 kernel/Dockerfile.perf | 41 +++++++++++++++++++++++++++++++++++++----
 2 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/kernel/Dockerfile b/kernel/Dockerfile
index fdcec0302..a625e1eb7 100644
--- a/kernel/Dockerfile
+++ b/kernel/Dockerfile
@@ -172,16 +172,6 @@ RUN DVER=$(basename $(find /tmp/kernel-modules/lib/modules/ -mindepth 1 -maxdept
 
 RUN printf "KERNEL_SOURCE=${KERNEL_SOURCE}\n" > /out/kernel-source-info
 
-# perf
-# Only build perf for the latest LTS and the latest stable kernel.
-# Skip arm64 for now as perf for 4.19.x fails to build.
-RUN if [ "${KERNEL_SERIES}" != 4.9.x ] && [ $(uname -m) != aarch64 ]; then \
-       mkdir -p /build/perf && \
-       make -C tools/perf LDFLAGS=-static O=/build/perf && \
-       strip /build/perf/perf && \
-       cp /build/perf/perf /out; \
-     fi
-
 # Download Intel ucode and create a CPIO archive for it
 ENV UCODE_URL=https://downloadmirror.intel.com/28039/eng/microcode-20180807.tgz
 RUN set -e && \
diff --git a/kernel/Dockerfile.perf b/kernel/Dockerfile.perf
index 5f08e7a97..ee20a3637 100644
--- a/kernel/Dockerfile.perf
+++ b/kernel/Dockerfile.perf
@@ -1,10 +1,43 @@
-# This Dockerfile extracts the perf utility from a kernel package and
-# places it into a scratch image
+# This Dockerfile extracts the source code and headers from a kernel package,
+# builds the perf utility, and places it into a scratch image
 ARG IMAGE
-FROM ${IMAGE} AS kernel
+FROM ${IMAGE} AS ksrc
+
+FROM linuxkit/alpine:518c2ed0f398c5508969ac5e033607201fb419ed AS build
+RUN apk add \
+    argp-standalone \
+    bash \
+    bc \
+    binutils-dev \
+    bison \
+    build-base \
+    diffutils \
+    flex \
+    gmp-dev \
+    installkernel \
+    kmod \
+    libelf-dev \
+    mpc1-dev \
+    mpfr-dev \
+    sed \
+    tar \
+    xz \
+    xz-dev \
+    zlib-dev
+
+COPY --from=ksrc /linux.tar.xz /kernel-headers.tar /
+RUN tar xf linux.tar.xz && \
+    tar xf kernel-headers.tar
+
+WORKDIR /linux
+
+RUN mkdir -p /out && \
+    make -C tools/perf LDFLAGS=-static && \
+    strip tools/perf/perf && \
+    cp tools/perf/perf /out
 
 FROM scratch
 ENTRYPOINT []
 CMD []
 WORKDIR /
-COPY --from=kernel /perf /usr/bin/perf
+COPY --from=build /out/perf /usr/bin/perf