Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx> writes: > The current stable LLVM BPF backend fails to compile the BPF selftests > due to a compiler bug. The bug has been fixed in trunk, but that fix > hasn't landed in the binary packages I'm using yet (Fedora arm64). > Without this workaround the tests don't compile for me. > > This patch triggers a preprocessor warning on LLVM versions that > definitely have the bug. The test may be conservative (ie, I'm not sure > if 9.1 will have the fix), but it should at least make the current set > of stable releases work together. > > See https://reviews.llvm.org/D69438 for more information on the fix. I > obtained the workaround from > https://lore.kernel.org/linux-kselftest/aed8eda7-df20-069b-ea14-f06628984566@xxxxxxxxx/T/ > > Fixes: 20a9ad2e7136 ("selftests/bpf: add CO-RE relocs array tests") > Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx> Having to depend on the latest trunk llvm to compile the selftests is definitely unfortunate. I believe there are some tests that won't work at all without trunk llvm (the fentry/fexit stuff comes to mind; although I'm not sure if they'll fail to compile, just fail to run?). Could we extend this type of checking to any such case? -Toke
