Commit 45027897 authored Dec 16, 2019 by Toke Høiland-Jørgensen Committed by Alexei Starovoitov Dec 16, 2019

samples/bpf: Set -fno-stack-protector when building BPF programs

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: <unknown>: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 <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191216103819.359535-1-toke@redhat.com

parent 5615ed47

samples/bpf/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

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