Current verifier checks for the arg to be nullable after checking for certain pointer types. It prevents programs to pass NULL to kfunc args even if they are marked as nullable. This patchset adjusts verifier and changes bpf crypto kfuncs to allow null for IV parameter which is optional for some ciphers. Benchmark shows ~4% improvements when there is no need to initialise 0-sized dynptr. v3: - add special selftest for nullable parameters v2: - adjust kdoc accordingly Vadim Fedorenko (5): bpf: verifier: make kfuncs args nullalble bpf: crypto: make state and IV dynptr nullable selftests: bpf: crypto: use NULL instead of 0-sized dynptr selftests: bpf: crypto: adjust bench to use nullable IV selftests: bpf: add testmod kfunc for nullable params kernel/bpf/crypto.c | 26 +++++------ kernel/bpf/verifier.c | 6 +-- .../selftests/bpf/bpf_testmod/bpf_testmod.c | 6 +++ .../bpf/bpf_testmod/bpf_testmod_kfunc.h | 1 + .../bpf/prog_tests/kfunc_param_nullable.c | 11 +++++ .../selftests/bpf/progs/crypto_bench.c | 10 ++--- .../selftests/bpf/progs/crypto_sanity.c | 16 ++----- .../bpf/progs/test_kfunc_param_nullable.c | 43 +++++++++++++++++++ 8 files changed, 85 insertions(+), 34 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/kfunc_param_nullable.c create mode 100644 tools/testing/selftests/bpf/progs/test_kfunc_param_nullable.c -- 2.43.0
