From 450278977acbf494a20367c22fbb38729772d1fc Mon Sep 17 00:00:00 2001 From: =?utf8?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=utf8 Content-Transfer-Encoding: 8bit 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 --- samples/bpf/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 227077a..5b89c03 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -236,6 +236,7 @@ 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),) BPF_EXTRA_CFLAGS += -g else -- 2.7.4