Adding verifier test for accessing const void pointer argument in tracing programs.
The test program loads 1st argument of bpf_fentry_test10 function which is const void pointer and checks that verifier allows that.
Signed-off-by: KaFai Wan mannkafai@gmail.com Acked-by: Jiri Olsa jolsa@kernel.org --- net/bpf/test_run.c | 8 +++++++- .../selftests/bpf/progs/verifier_btf_ctx_access.c | 12 ++++++++++++ 2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 7cb192cbd65f..aaf13a7d58ed 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -569,6 +569,11 @@ __bpf_kfunc u32 bpf_fentry_test9(u32 *a) return *a; }
+int noinline bpf_fentry_test10(const void *a) +{ + return (long)a; +} + void noinline bpf_fentry_test_sinfo(struct skb_shared_info *sinfo) { } @@ -699,7 +704,8 @@ int bpf_prog_test_run_tracing(struct bpf_prog *prog, bpf_fentry_test6(16, (void *)17, 18, 19, (void *)20, 21) != 111 || bpf_fentry_test7((struct bpf_fentry_test_t *)0) != 0 || bpf_fentry_test8(&arg) != 0 || - bpf_fentry_test9(&retval) != 0) + bpf_fentry_test9(&retval) != 0 || + bpf_fentry_test10((void *)0) != 0) goto out; break; case BPF_MODIFY_RETURN: diff --git a/tools/testing/selftests/bpf/progs/verifier_btf_ctx_access.c b/tools/testing/selftests/bpf/progs/verifier_btf_ctx_access.c index 28b939572cda..03942cec07e5 100644 --- a/tools/testing/selftests/bpf/progs/verifier_btf_ctx_access.c +++ b/tools/testing/selftests/bpf/progs/verifier_btf_ctx_access.c @@ -65,4 +65,16 @@ __naked void ctx_access_u32_pointer_reject_8(void) " ::: __clobber_all); }
+SEC("fentry/bpf_fentry_test10") +__description("btf_ctx_access const void pointer accept") +__success __retval(0) +__naked void ctx_access_const_void_pointer_accept(void) +{ + asm volatile (" \ + r2 = *(u64 *)(r1 + 0); /* load 1st argument value (const void pointer) */\ + r0 = 0; \ + exit; \ +" ::: __clobber_all); +} + char _license[] SEC("license") = "GPL";