[Buildroot] [PATCHv6 2/5] package/bcc: new package

[Romain Naour <romain.naour@gmail.com>]

From: Jugurtha BELKALEM <jugurtha.belkalem@smile.fr>

bcc is a front-end tool for eBPF :
https://github.com/iovisor/bcc/blob/master/README.md.
eBPF is the most powerful Linux tracer, and bcc
allows to write eBPF scripts in C and PYTHON3.

bcc can help to troubleshoot issues quickly on
embedded systems (as long as Linux kernel
version >= 4.1).

bcc can also make it easy to create observabilty tools,
SDN configuration, ddos mitigation, intrusion detection
and secure containers. More information is available at:
https://ebpf.io/

BCC can be tested on the target :
$ mount -t debugfs none /sys/kernel/debug
$ cd /usr/share/bcc/tools
$ ./execsnoop

Signed-off-by: Jugurtha BELKALEM <jugurtha.belkalem@smile.fr>
Signed-off-by: Romain Naour <romain.naour@gmail.com>
Tested-by: Qais Yousef <qais.yousef@arm.com>
Cc: Qais Yousef <qais.yousef@arm.com>
---
v6
- Add missing python patch from Qais
- remove luajit patch since the luajit support is explicitely disabled
- keep tested-by from Qais since he tested bcc (but not the luajit support)
- drop the reviewed-by due to luajit and python changes
- Add Romain in DEVELOPERS file

v5
- Add a patch to disable luajit support
- remove iperf3, netperf, audit optional runtime dependencies (Qais)

v4
- Bump to version 0.17.0.
- Remove kernel dependency (Qais)
- Remove optional kernel option handling (Quais)
- Update ebpf url (Quais)
- Fix tools path in the commit log (Quais)
- Add full tar dependency (used to extract the kernel sources from IKHEADERS module) (Quais)
- Make luajit optional dependeny (Quais)
- Remove python module install hook (Quais)
- Keep BCC_LINUX_CONFIG_FIXUPS but only for kernel built by Buildroot.

V3
- Bump to version 0.16.0.
- Add required python dependency.
- Remove unnecessary and duplicated
  kernel flags (#Testing section) in bcc.mk.

V2
- Add eBPF's required Kernel flags.
- Fix submodule source fetch problem.
- Add toolchain dependency.
---
 DEVELOPERS                                    |  2 +
 package/Config.in                             |  1 +
 ...-an-option-to-disable-luajit-support.patch | 45 +++++++++++++++++++
 ...sts.txt-Fix-python-installation-path.patch | 34 ++++++++++++++
 package/bcc/Config.in                         | 39 ++++++++++++++++
 package/bcc/bcc.hash                          |  3 ++
 package/bcc/bcc.mk                            | 43 ++++++++++++++++++
 7 files changed, 167 insertions(+)
 create mode 100644 package/bcc/0001-CMake-add-an-option-to-disable-luajit-support.patch
 create mode 100644 package/bcc/0002-python-CMakeLists.txt-Fix-python-installation-path.patch
 create mode 100644 package/bcc/Config.in
 create mode 100644 package/bcc/bcc.hash
 create mode 100644 package/bcc/bcc.mk

diff --git a/DEVELOPERS b/DEVELOPERS
index 9406f30cd5..681c4e18db 100644
--- a/DEVELOPERS
+++ b/DEVELOPERS
@@ -1392,6 +1392,7 @@ N:	Joshua Henderson <joshua.henderson@microchip.com>
 F:	package/qt5/qt5wayland/
 
 N:	Jugurtha BELKALEM <jugurtha.belkalem@smile.fr>
+F:	package/bcc/
 F:	package/python-aiofiles/
 F:	package/python-crayons/
 F:	package/python-cycler/
@@ -2233,6 +2234,7 @@ F:	board/qemu/
 F:	configs/qemu_*
 F:	package/alure/
 F:	package/aubio/
+F:	package/bcc/
 F:	package/binutils/
 F:	package/bullet/
 F:	package/clang/
diff --git a/package/Config.in b/package/Config.in
index dc7139a49a..c04392126c 100644
--- a/package/Config.in
+++ b/package/Config.in
@@ -83,6 +83,7 @@ endmenu
 
 menu "Debugging, profiling and benchmark"
 	source "package/babeltrace2/Config.in"
+	source "package/bcc/Config.in"
 	source "package/blktrace/Config.in"
 	source "package/bonnie/Config.in"
 	source "package/cache-calibrator/Config.in"
diff --git a/package/bcc/0001-CMake-add-an-option-to-disable-luajit-support.patch b/package/bcc/0001-CMake-add-an-option-to-disable-luajit-support.patch
new file mode 100644
index 0000000000..93d3e16a7f
--- /dev/null
+++ b/package/bcc/0001-CMake-add-an-option-to-disable-luajit-support.patch
@@ -0,0 +1,45 @@
+From b61c5eb0b2c385a6d3bbabf2396cb363588b32ab Mon Sep 17 00:00:00 2001
+From: Romain Naour <romain.naour@gmail.com>
+Date: Sun, 6 Dec 2020 17:15:25 +0100
+Subject: [PATCH] CMake: add an option to disable luajit support
+
+bcc luajit support is optional and should be disabled
+when luajit is not available.
+
+This option allow to explicitely disable luajit when
+cross-compiling.
+
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
+---
+ CMakeLists.txt     | 2 ++
+ src/CMakeLists.txt | 2 ++
+ 2 files changed, 4 insertions(+)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 74fe4f19..c87b28c4 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -40,6 +40,8 @@ option(ENABLE_LLVM_SHARED "Enable linking LLVM as a shared library" OFF)
+ option(ENABLE_CLANG_JIT "Enable Loading BPF through Clang Frontend" ON)
+ option(ENABLE_USDT "Enable User-level Statically Defined Tracing" ON)
+ option(ENABLE_MAN "Build man pages" ON)
++cmake_dependent_option(ENABLE_LUAJIT "Use Luajit" ON "ENABLE_CLANG_JIT" OFF)
++
+ CMAKE_DEPENDENT_OPTION(ENABLE_CPP_API "Enable C++ API" ON "ENABLE_USDT" OFF)
+ 
+ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
+diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
+index 37b7e289..78c5fe58 100644
+--- a/src/CMakeLists.txt
++++ b/src/CMakeLists.txt
+@@ -17,5 +17,7 @@ add_subdirectory(cc)
+ endif()
+ if(ENABLE_CLANG_JIT)
+ add_subdirectory(python)
++if(ENABLE_LUAJIT)
+ add_subdirectory(lua)
+ endif()
++endif()
+-- 
+2.25.4
+
diff --git a/package/bcc/0002-python-CMakeLists.txt-Fix-python-installation-path.patch b/package/bcc/0002-python-CMakeLists.txt-Fix-python-installation-path.patch
new file mode 100644
index 0000000000..507a5aced7
--- /dev/null
+++ b/package/bcc/0002-python-CMakeLists.txt-Fix-python-installation-path.patch
@@ -0,0 +1,34 @@
+From 15d8445905b6023eb369083392dd1018d31e9664 Mon Sep 17 00:00:00 2001
+From: Qais Yousef <qais.yousef@arm.com>
+Date: Fri, 18 Dec 2020 16:36:15 +0000
+Subject: [PATCH] python/CMakeLists.txt: Fix python installation path
+
+The check for /etc/debian_version is unfriendly to cross build
+environment like buildroot. It tries to identify the distro of the host,
+but since we're in cross build environment this obviously breaks.
+
+Remove this check for now.
+
+Signed-off-by: Qais Yousef <qais.yousef@arm.com>
+---
+ src/python/CMakeLists.txt | 4 ----
+ 1 file changed, 4 deletions(-)
+
+diff --git a/src/python/CMakeLists.txt b/src/python/CMakeLists.txt
+index fa602397..797e0d14 100644
+--- a/src/python/CMakeLists.txt
++++ b/src/python/CMakeLists.txt
+@@ -5,10 +5,6 @@ if(NOT PYTHON_CMD)
+   set(PYTHON_CMD "python")
+ endif()
+ 
+-if(EXISTS "/etc/debian_version")
+-  set(PYTHON_FLAGS "${PYTHON_FLAGS} --install-layout deb")
+-endif()
+-
+ file(GLOB_RECURSE PYTHON_SOURCES RELATIVE ${CMAKE_CURRENT_SOURCE_DIR}
+   ${CMAKE_CURRENT_SOURCE_DIR}/*.py)
+ file(GLOB_RECURSE PYTHON_INCLUDES RELATIVE ${CMAKE_CURRENT_SOURCE_DIR}
+-- 
+2.25.1
+
diff --git a/package/bcc/Config.in b/package/bcc/Config.in
new file mode 100644
index 0000000000..087d0cb932
--- /dev/null
+++ b/package/bcc/Config.in
@@ -0,0 +1,39 @@
+config BR2_PACKAGE_BCC
+	bool "bcc"
+	depends on BR2_PACKAGE_LLVM_ARCH_SUPPORTS
+	depends on BR2_TOOLCHAIN_USES_GLIBC # hardcode GNU tuple (x86_64-unknown-linux-gnu)
+	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_8 # clang
+	depends on BR2_INSTALL_LIBSTDCPP # clang
+	select BR2_PACKAGE_BUSYBOX_SHOW_OTHERS # to select tar package
+	select BR2_PACKAGE_CLANG
+	select BR2_PACKAGE_ELFUTILS
+	select BR2_PACKAGE_FLEX # needs FlexLexer.h
+	select BR2_PACKAGE_LLVM_BPF
+	select BR2_PACKAGE_PYTHON3
+	select BR2_PACKAGE_TAR # Decompress kernel headers required by BCC
+	help
+	  BPF Compiler Collection (BCC)
+
+	  BCC is a toolkit for creating efficient kernel tracing and
+	  manipulation programs, and includes several useful tools and
+	  examples. It makes use of extended BPF (Berkeley Packet
+	  Filters), formally known as eBPF, a new feature that was
+	  first added to Linux 3.15. Much of what BCC uses requires
+	  Linux 4.1 and above.
+
+	  Note: Before using bcc, you need either need to :
+	  - For kernel_ver = [4.1, 5.2) : Copy kernel source code
+	  to target folder /lib/module/<kernel_ver>/build.
+	  - Or kernel_ver >= 5.2 : Compile kernel with CONFIG_IKHEADERS
+	  and use generated headers under /sys/kernel/kheaders.tar.xz
+	  to populate /lib/module/<kernel_ver>/build.
+
+	  That's because the clang frontend build eBPF code at runtime.
+
+	  https://github.com/iovisor/bcc
+	  http://www.ebpf.io
+
+comment "bcc needs a glibc toolchain, C++, gcc >= 4.8, host gcc >= 4.8"
+	depends on BR2_PACKAGE_LLVM_ARCH_SUPPORTS
+	depends on !BR2_TOOLCHAIN_USES_GLIBC || !BR2_INSTALL_LIBSTDCPP \
+		|| !BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
diff --git a/package/bcc/bcc.hash b/package/bcc/bcc.hash
new file mode 100644
index 0000000000..a9ca0a36cd
--- /dev/null
+++ b/package/bcc/bcc.hash
@@ -0,0 +1,3 @@
+# locally calculated
+sha256  7a3ef28a493dcd7ee0797ebca8f13b30ffca08efc93ff73ff8fa9ba0234d7947  bcc-v0.17.0.tar.gz
+sha256  b40930bbcf80744c86c46a12bc9da056641d722716c378f5659b9e555ef833e1  LICENSE.txt
diff --git a/package/bcc/bcc.mk b/package/bcc/bcc.mk
new file mode 100644
index 0000000000..bafa9e2096
--- /dev/null
+++ b/package/bcc/bcc.mk
@@ -0,0 +1,43 @@
+################################################################################
+#
+# bcc
+#
+################################################################################
+
+BCC_VERSION = v0.17.0
+BCC_SITE = https://github.com/iovisor/bcc.git
+BCC_SITE_METHOD = git
+BCC_GIT_SUBMODULES = YES
+BCC_LICENSE = Apache-2.0
+BCC_LICENSE_FILES = LICENSE.txt
+# libbcc.so and libbcc_bpf.so
+BCC_INSTALL_STAGING = YES
+BCC_DEPENDENCIES = host-bison host-flex clang elfutils flex llvm python3 tar
+
+# ENABLE_LLVM_SHARED=ON to use llvm.so.
+# Force REVISION otherwise bcc will use git describe to generate a version number.
+BCC_CONF_OPTS = -DENABLE_LLVM_SHARED=ON \
+	-DREVISION=$(BCC_VERSION) \
+	-DENABLE_CLANG_JIT=ON \
+	-DENABLE_MAN=OFF \
+	-DENABLE_LUAJIT=OFF
+
+define BCC_LINUX_CONFIG_FIXUPS
+	# Enable kernel support for eBPF
+	$(call KCONFIG_ENABLE_OPT,CONFIG_BPF)
+	$(call KCONFIG_ENABLE_OPT,CONFIG_BPF_SYSCALL)
+	$(call KCONFIG_ENABLE_OPT,CONFIG_NET_CLS_BPF)
+	$(call KCONFIG_ENABLE_OPT,CONFIG_NET_ACT_BPF)
+	$(call KCONFIG_ENABLE_OPT,CONFIG_BPF_JIT)
+	# [for Linux kernel versions 4.1 through 4.6]
+	$(call KCONFIG_ENABLE_OPT,CONFIG_HAVE_BPF_JIT)
+	# [for Linux kernel versions 4.7 and later]
+	$(call KCONFIG_ENABLE_OPT,CONFIG_HAVE_EBPF_JIT)
+	$(call KCONFIG_ENABLE_OPT,CONFIG_BPF_EVENTS)
+	# [for Linux kernel versions 5.2 and later]
+	$(call KCONFIG_ENABLE_OPT,CONFIG_IKHEADERS)
+	# bcc needs debugfs at runtime
+	$(call KCONFIG_ENABLE_OPT,CONFIG_DEBUG_FS)
+endef
+
+$(eval $(cmake-package))
-- 
2.25.4