From e90c9a06872353395b0231caefcc3d065f50288e Mon Sep 17 00:00:00 2001
From: Rolf Neugebauer <rn@rneugeba.io>
Date: Sat, 27 Oct 2018 13:22:31 +0100
Subject: [PATCH] kernel: perf only for LTS and latest stable/disable for arm64

The logic for perf became too complex. Just build for latest LTS
and latest stable.

Disable for arm64 for now as it is broken for 4.19 due to a header
mismatch:

In file included from /linux/tools/arch/arm64/include/uapi/asm/unistd.h:20:0,
                 from libbpf.c:36:
/linux/tools/include/uapi/asm-generic/unistd.h:754:0: error: "__NR_fcntl" redefined [-Werror]

In file included from /usr/include/sys/syscall.h:4:0,
                 from /linux/tools/perf/perf-sys.h:7,
                 from libbpf.c:35:
/usr/include/bits/syscall.h:26:0: note: this is the location of the previous definition

Signed-off-by: Rolf Neugebauer <rn@rneugeba.io>
---
 kernel/Dockerfile | 8 +++++---
 kernel/Makefile   | 7 +++++--
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/kernel/Dockerfile b/kernel/Dockerfile
index 8d2d43cf0..5e453559a 100644
--- a/kernel/Dockerfile
+++ b/kernel/Dockerfile
@@ -175,9 +175,11 @@ RUN DVER=$(basename $(find /tmp/kernel-modules/lib/modules/ -mindepth 1 -maxdept
 RUN printf "KERNEL_SOURCE=${KERNEL_SOURCE}\n" > /out/kernel-source-info
 
 # perf
-# Skip for 4.4.x (the compile is broken and tedious to fix) and 4.9.x (the
-# compile broke with 4.9.93)
-RUN if [ "${KERNEL_SERIES}" != "4.4.x" ] && [ "${KERNEL_SERIES}" != "4.9.x" ]; then \
+# Only build perf for the latest LTS and the latest stable kernel.
+# There were intermittent breakage for 4.4.x and 4.9.x on some arches
+# Skip arm64 for now as perf for 4.19 fails to build.
+RUN if [ \( "${KERNEL_SERIES}" == "4.14.x" || "${KERNEL_SERIES}" == "4.19.x" \) \
+         && $(uname -m) != aarch64 ]; then \
        mkdir -p /build/perf && \
        make -C tools/perf LDFLAGS=-static O=/build/perf && \
        strip /build/perf/perf && \
diff --git a/kernel/Makefile b/kernel/Makefile
index daec2e486..10543c1c0 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -157,8 +157,10 @@ fetch: sources/linux-$(1).tar.xz
 # with DCT as part of the dependency on build_$(2)$(3)$(4) and then build
 # with DOCKER_CONTENT_TRUST explicitly set to 0
 
-ifneq ($(2), $(filter $(2),4.4.x 4.9.x))
-# perf does not build out of the box for 4.4.x and 4.9.x
+ifeq ($(2), $(filter $(2),4.14.x 4.19.x))
+# Only build perf for the latest LTS and the latest stable kernel.
+ifneq ($(ARCH),aarch64)
+# Skip arm64 for now as perf for 4.19 fails to build.
 build_perf_$(2)$(3)$(4): build_$(2)$(3)$(4)
 	docker pull $(ORG)/$(IMAGE_PERF):$(1)$(3)$(4)-$(TAG)$(SUFFIX) || \
 		 DOCKER_CONTENT_TRUST=0 docker build -f Dockerfile.perf \
@@ -192,6 +194,7 @@ forcebuild: forcebuild_perf_$(2)$(3)$(4)
 push: push_perf_$(2)$(3)$(4)
 forcepush: forcepush_perf_$(2)$(3)$(4)
 endif
+endif
 
 # For BCC, only build on x86 and only on latest LTS and latest stable.
 # That's 4.14.x and 4.19.x at time of authorship.