From: Feng Zhou zhoufeng.zf@bytedance.com
Adding verifier test for accessing u32 pointer argument in tracing programs.
The test program loads 1nd argument of bpf_fentry_test9 function which is u32 pointer and checks that verifier allows that.
Co-developed-by: Chengming Zhou zhouchengming@bytedance.com Signed-off-by: Chengming Zhou zhouchengming@bytedance.com Signed-off-by: Feng Zhou zhoufeng.zf@bytedance.com --- net/bpf/test_run.c | 8 +++++++- .../testing/selftests/bpf/verifier/btf_ctx_access.c | 13 +++++++++++++ 2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index f1652f5fbd2e..68bdfc041a7b 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -541,6 +541,11 @@ int noinline bpf_fentry_test8(struct bpf_fentry_test_t *arg) return (long)arg->a; }
+__bpf_kfunc u32 bpf_fentry_test9(u32 *a) +{ + return *a; +} + __bpf_kfunc int bpf_modify_return_test(int a, int *b) { *b += 1; @@ -855,7 +860,8 @@ int bpf_prog_test_run_tracing(struct bpf_prog *prog, bpf_fentry_test5(11, (void *)12, 13, 14, 15) != 65 || 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_test8(&arg) != 0 || + bpf_fentry_test9(&retval) != 0) goto out; break; case BPF_MODIFY_RETURN: diff --git a/tools/testing/selftests/bpf/verifier/btf_ctx_access.c b/tools/testing/selftests/bpf/verifier/btf_ctx_access.c index 6340db6b46dc..0484d3de040d 100644 --- a/tools/testing/selftests/bpf/verifier/btf_ctx_access.c +++ b/tools/testing/selftests/bpf/verifier/btf_ctx_access.c @@ -10,3 +10,16 @@ .expected_attach_type = BPF_TRACE_FENTRY, .kfunc = "bpf_modify_return_test", }, + +{ + "btf_ctx_access u32 pointer accept", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0), /* load 1nd argument value (u32 pointer) */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_TRACING, + .expected_attach_type = BPF_TRACE_FENTRY, + .kfunc = "bpf_fentry_test9", +},