include/bpf.mk: check minimum required clang version

Avoid spurious runtime errors caused by loading eBPF modules
built with an old clang version

Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Felix Fietkau 2021-11-09 20:59:15 +01:00
parent 8a6b1a8d29
commit 694aed607f

View File

@ -1,6 +1,8 @@
BPF_DEPENDS := @HAS_BPF_TOOLCHAIN
LLVM_VER:=
CLANG_MIN_VER:=12
ifneq ($(CONFIG_USE_LLVM_HOST),)
BPF_TOOLCHAIN_HOST_PATH:=$(call qstrip,$(CONFIG_BPF_TOOLCHAIN_HOST_PATH))
ifneq ($(BPF_TOOLCHAIN_HOST_PATH),)
@ -61,6 +63,14 @@ BPF_CFLAGS := \
-Wno-unused-label \
-O2 -emit-llvm -Xclang -disable-llvm-passes
ifeq ($(DUMP),)
CLANG_VER:=$(shell clang -dM -E - < /dev/null | grep __clang_major__ | cut -d' ' -f3)
CLANG_VER_VALID:=$(shell [ "$(CLANG_VER)" -ge "$(CLANG_MIN_VER)" ] && echo 1 )
ifeq ($(CLANG_VER_VALID),)
$(error ERROR: LLVM/clang version too old. Minimum required: $(CLANG_MIN_VER), found: $(CLANG_VER))
endif
endif
define CompileBPF
$(CLANG) -g -target $(BPF_ARCH)-linux-gnu $(BPF_CFLAGS) $(2) \
-c $(1) -o $(patsubst %.c,%.bc,$(1))