selftests/bpf: Fix endianness issues in atomic tests

2021-02-10T19:55:22Z

Atomic tests store a DW, but then load it back as a W from the same address. This doesn't work on big-endian systems, and since the point of those tests is not testing narrow loads, fix simply by loading a DW. Fixes: 98d666d05a1d ("bpf: Add tests for new BPF atomic operations") Signed-off-by: Ilya Leoshkevich Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210210020713.77911-1-iii@linux.ibm.com

bpf: Add tests for new BPF atomic operations

2021-01-15T02:34:29Z

The prog_test that's added depends on Clang/LLVM features added by Yonghong in commit 286daafd6512 (was https://reviews.llvm.org/D72184). Note the use of a define called ENABLE_ATOMICS_TESTS: this is used to: - Avoid breaking the build for people on old versions of Clang - Avoid needing separate lists of test objects for no_alu32, where atomics are not supported even if Clang has the feature. The atomics_test.o BPF object is built unconditionally both for test_progs and test_progs-no_alu32. For test_progs, if Clang supports atomics, ENABLE_ATOMICS_TESTS is defined, so it includes the proper test code. Otherwise, progs and global vars are defined anyway, as stubs; this means that the skeleton user code still builds. The atomics_test.o userspace object is built once and used for both test_progs and test_progs-no_alu32. A variable called skip_tests is defined in the BPF object's data section, which tells the userspace object whether to skip the atomics test. Signed-off-by: Brendan Jackman Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210114181751.768687-11-jackmanb@google.com

kernel.git/tools/testing/selftests/bpf/verifier/atomic_xor.c, branch master

selftests/bpf: Fix endianness issues in atomic tests

bpf: Add tests for new BPF atomic operations