On 9/24/19 9:43 AM, Yonghong Song wrote:
On 9/24/19 8:26 AM, Shuah Khan wrote:
Hi Alexei and Daniel,
bpf test doesn't build on Linux 5.4 mainline. Do you know what's
happening here.
make -C tools/testing/selftests/bpf/
-c progs/test_core_reloc_ptr_as_arr.c -o - || echo "clang failed") | \
llc -march=bpf -mcpu=generic -filetype=obj -o
/mnt/data/lkml/linux_5.4/tools/testing/selftests/bpf/test_core_reloc_ptr_as_arr.o
progs/test_core_reloc_ptr_as_arr.c:25:6: error: use of unknown builtin
'__builtin_preserve_access_index' [-Wimplicit-function-declaration]
if (BPF_CORE_READ(&out->a, &in[2].a))
^
./bpf_helpers.h:533:10: note: expanded from macro 'BPF_CORE_READ'
__builtin_preserve_access_index(src))
^
progs/test_core_reloc_ptr_as_arr.c:25:6: warning: incompatible integer to
pointer conversion passing 'int' to parameter of type 'const void *'
[-Wint-conversion]
if (BPF_CORE_READ(&out->a, &in[2].a))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./bpf_helpers.h:533:10: note: expanded from macro 'BPF_CORE_READ'
__builtin_preserve_access_index(src))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning and 1 error generated.
llc: error: llc: <stdin>:1:1: error: expected top-level entity
clang failed
Also
make TARGETS=bpf kselftest fails as well. Dependency between
tools/lib/bpf and the test. How can we avoid this type of
dependency or resolve it in a way it doesn't result in build
failures?
Thanks, Shuah.
The clang __builtin_preserve_access_index() intrinsic is
introduced in LLVM9 (which just released last week) and
the builtin and other CO-RE features are only supported
in LLVM10 (current development branch) with more bug fixes
and added features.
I think we should do a feature test for llvm version and only
enable these tests when llvm version >= 10.
Yes. If new tests depend on a particular llvm revision, the failing
the build is a regression. I would like to see older tests that don't
have dependency build and run.
thanks,
-- Shuah
