From cdd5b09bcbc0c2ee8bfbdaacfe35c61fb297b8a1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Mon, 16 Dec 2019 11:38:19 +0100 Subject: [PATCH] samples/bpf: Set -fno-stack-protector when building BPF programs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 450278977acbf494a20367c22fbb38729772d1fc ] It seems Clang can in some cases turn on stack protection by default, which doesn't work with BPF. This was reported once before[0], but it seems the flag to explicitly turn off the stack protector wasn't added to the Makefile, so do that now. The symptom of this is compile errors like the following: error: :0:0: in function bpf_prog1 i32 (%struct.__sk_buff*): A call to built-in function '__stack_chk_fail' is not supported. [0] https://www.spinics.net/lists/netdev/msg556400.html Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191216103819.359535-1-toke@redhat.com Signed-off-by: Sasha Levin --- samples/bpf/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index e7ad48c605e0..6d1df7117e11 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -219,6 +219,7 @@ BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \ readelf -S ./llvm_btf_verify.o | grep BTF; \ /bin/rm -f ./llvm_btf_verify.o) +BPF_EXTRA_CFLAGS += -fno-stack-protector ifneq ($(BTF_LLVM_PROBE),) EXTRA_CFLAGS += -g else