[PATCH] package/bpftool: add a patch to fix cross compilation

[Shahab Vahedi]

If on the host machine the "co-re" is supported, bpftool will
build a bootstrap version of itself as well. In that case, the
cross compilation can fail. This commit adds a patch to remedy
that. The fix that you see here is already upsteamed [1].

[1]
https://lore.kernel.org/bpf/165477661272.11342.13015777410417612477.git-patchwork-notify@kernel.org/T/#t

Signed-off-by: Shahab Vahedi <shahab at synopsys.com>
---
 package/bpftool/0001-fix-bootsrap.patch | 32 +++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 package/bpftool/0001-fix-bootsrap.patch

diff --git a/package/bpftool/0001-fix-bootsrap.patch b/package/bpftool/0001-fix-bootsrap.patch
new file mode 100644
index 0000000000..03f4231cca
--- /dev/null
+++ b/package/bpftool/0001-fix-bootsrap.patch
@@ -0,0 +1,32 @@
+This is an adapted version of an upstreamed patch [1], else it won't be
+possible to cross compile bpftool if "clang-bpf-co-re" feature is enabled.
+
+[1] bpftool: Fix bootstrapping during a cross compilation
+https://lore.kernel.org/bpf/8d297f0c-cfd0-ef6f-3970-6dddb3d9a87a@synopsys.com/t/#u
+--- bpftool-v6.8.0/src/Makefile
++++ bpftool-v6.8.0/src/Makefile
+@@ -51,7 +51,7 @@
+ $(LIBBPF_BOOTSTRAP): $(wildcard $(BPF_DIR)/*.[ch] $(BPF_DIR)/Makefile) | $(LIBBPF_BOOTSTRAP_OUTPUT)
+ 	$(Q)$(MAKE) -C $(BPF_DIR) OBJDIR=$(patsubst %/,%,$(LIBBPF_BOOTSTRAP_OUTPUT)) \
+ 		PREFIX=$(LIBBPF_BOOTSTRAP_DESTDIR:/=) \
+-		ARCH= CROSS_COMPILE= CC=$(HOSTCC) LD=$(HOSTLD) $@ install_headers
++		ARCH= CROSS_COMPILE= CC=$(HOSTCC) LD=$(HOSTLD) AR=$(HOSTAR) $@ install_headers
+ 
+ $(LIBBPF_BOOTSTRAP_INTERNAL_HDRS): $(LIBBPF_BOOTSTRAP_HDRS_DIR)/%.h: $(BPF_DIR)/%.h | $(LIBBPF_BOOTSTRAP_HDRS_DIR)
+ 	$(call QUIET_INSTALL, $@)
+--- bpftool-v6.8.0/src/Makefile.include
++++ bpftool-v6.8.0/src/Makefile.include
+@@ -12,11 +12,13 @@
+ ifneq ($(LLVM),)
+   $(if $(findstring default,$(origin CC)),$(eval CC := clang$(LLVM_VERSION)))
+   $(if $(findstring default,$(origin LD)),$(eval LD := ld.lld$(LLVM_VERSION)))
++  HOSTAR ?= llvm-ar
+   HOSTCC ?= clang
+   HOSTLD ?= ld.lld
+ else
+   $(if $(findstring default,$(origin CC)),$(eval CC = $(CROSS_COMPILE)$(CC)))
+   $(if $(findstring default,$(origin LD)),$(eval LD = $(CROSS_COMPILE)$(LD)))
++  HOSTAR ?= ar
+   HOSTCC ?= gcc
+   HOSTLD ?= ld
+ endif