[PATCH bpf-next] samples/bpf: add -fno-asynchronous-unwind-tables to BPF Clang invocation

The samples/bpf Makefile currently compiles BPF files in a way that will
produce an .eh_frame section, which will in turn confuse libbpf and produce
errors when loading BPF programs, like:

libbpf: elf: skipping unrecognized data section(32) .eh_frame
libbpf: elf: skipping relo section(33) .rel.eh_frame for section(32) .eh_frame

Fix this by instruction Clang not to produce this section, as it's useless
for BPF anyway.

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Toke Høiland-Jørgensen <redacted>
---
 samples/bpf/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 520434ea966f..036998d11ded 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile

@@ -331,6 +331,7 @@ $(obj)/%.o: $(src)/%.c
 		-Wno-gnu-variable-sized-type-not-at-end \
 		-Wno-address-of-packed-member -Wno-tautological-compare \
 		-Wno-unknown-warning-option $(CLANG_ARCH_ARGS) \
+		-fno-asynchronous-unwind-tables \
 		-I$(srctree)/samples/bpf/ -include asm_goto_workaround.h \
 		-O2 -emit-llvm -Xclang -disable-llvm-passes -c $< -o - | \
 		$(OPT) -O2 -mtriple=bpf-pc-linux | $(LLVM_DIS) | \

-- 
2.32.0

Hello:

This patch was applied to bpf/bpf.git (refs/heads/master):

On Mon,  5 Jul 2021 12:38:41 +0200 you wrote:

The samples/bpf Makefile currently compiles BPF files in a way that will
produce an .eh_frame section, which will in turn confuse libbpf and produce
errors when loading BPF programs, like:

libbpf: elf: skipping unrecognized data section(32) .eh_frame
libbpf: elf: skipping relo section(33) .rel.eh_frame for section(32) .eh_frame

[...]

Here is the summary with links:
  - [bpf-next] samples/bpf: add -fno-asynchronous-unwind-tables to BPF Clang invocation
    https://git.kernel.org/bpf/bpf/c/5a0ae9872d5c

You are awesome, thank you!
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