[Buildroot] [git commit branch/2022.02.x] package/libbpf: install in the correct lib directory

[Peter Korsgaard]

commit: https://git.buildroot.net/buildroot/commit/?id=7dfe00c8d346233280fbd877540e01f3749ea7a9
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/2022.02.x

The libbpf build system currently uses the output of "uname -m" to
determine if the library should be installed in "lib" or
"lib64". However, uname -m returns the architecture of the build
machine, which often has nothing to do with the target CPU
architecture.

A patch has been submitted and accepted upstream to address this
issue, by using the $(CC) -dumpmachine output instead. This ensures
libbpf is installed in either "lib" or "lib64" depending on the
bitness of the target CPU architecture.

Signed-off-by: Tobias Waldekranz <tobias at waldekranz.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
(cherry picked from commit c86b69a16dee0281d75890118110be934367430e)
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
 ...-Fix-cross-compilation-for-32-bit-targets.patch | 38 ++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/package/libbpf/0001-Makefile-Fix-cross-compilation-for-32-bit-targets.patch b/package/libbpf/0001-Makefile-Fix-cross-compilation-for-32-bit-targets.patch
new file mode 100644
index 0000000000..12c22f3147
--- /dev/null
+++ b/package/libbpf/0001-Makefile-Fix-cross-compilation-for-32-bit-targets.patch
@@ -0,0 +1,38 @@
+From 68e6f83f223ebf3fbf0d94c0f4592e5e6773f0c1 Mon Sep 17 00:00:00 2001
+From: Tobias Waldekranz <tobias at waldekranz.com>
+Date: Fri, 14 Oct 2022 21:14:14 +0200
+Subject: [PATCH] Makefile: Fix cross-compilation for 32-bit targets
+
+Determining the correct library installation path (lib vs. lib64)
+using uname(1) breaks in cross compilation scenarios where word widths
+differ between the host and target system.
+
+Instead, source the information from the compilers '-dumpmachine'
+option (supported by both GCC and Clang).
+
+We call this the "host" architecture, using the same nomenclature as
+Autotools (--host configure option).
+
+Upstream: https://github.com/libbpf/libbpf/commit/68e6f83f223ebf3fbf0d94c0f4592e5e6773f0c1
+Signed-off-by: Tobias Waldekranz <tobias at waldekranz.com>
+---
+ src/Makefile | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/src/Makefile b/src/Makefile
+index 3cd0854..d535f81 100644
+--- a/src/Makefile
++++ b/src/Makefile
+@@ -77,7 +77,8 @@ INSTALL = install
+ 
+ DESTDIR ?=
+ 
+-ifeq ($(filter-out %64 %64be %64eb %64le %64el s390x, $(shell uname -m)),)
++HOSTARCH = $(firstword $(subst -, ,$(shell $(CC) -dumpmachine)))
++ifeq ($(filter-out %64 %64be %64eb %64le %64el s390x, $(HOSTARCH)),)
+ 	LIBSUBDIR := lib64
+ else
+ 	LIBSUBDIR := lib
+-- 
+2.34.1
+