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author | Andrii Nakryiko <andrii@kernel.org> | 2023-12-11 20:41:31 +0300 |
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committer | Alexei Starovoitov <ast@kernel.org> | 2023-12-12 06:16:32 +0300 |
commit | e72c1ccfd449598f7eda10d3bb7441d501ddcfc3 (patch) | |
tree | 7a2c8fc5c837b5a8a74a5360c5129adf9a1a9b0f /tools/testing/selftests/bpf/prog_tests | |
parent | 2ebe81c814355d000fe49d9c4213983844dcb32b (diff) | |
download | linux-e72c1ccfd449598f7eda10d3bb7441d501ddcfc3.tar.xz |
selftests/bpf: validate eliminated global subprog is not freplaceable
Add selftest that establishes dead code-eliminated valid global subprog
(global_dead) and makes sure that it's not possible to freplace it, as
it's effectively not there. This test will fail with unexpected success
before 2afae08c9dcb ("bpf: Validate global subprogs lazily").
v2->v3:
- add missing err assignment (Alan);
- undo unnecessary signature changes in verifier_global_subprogs.c (Eduard);
v1->v2:
- don't rely on assembly output in verifier log, which changes between
compiler versions (CI).
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20231211174131.2324306-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests')
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/global_func_dead_code.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/global_func_dead_code.c b/tools/testing/selftests/bpf/prog_tests/global_func_dead_code.c new file mode 100644 index 000000000000..65309894b27a --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/global_func_dead_code.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */ + +#include <test_progs.h> +#include "verifier_global_subprogs.skel.h" +#include "freplace_dead_global_func.skel.h" + +void test_global_func_dead_code(void) +{ + struct verifier_global_subprogs *tgt_skel = NULL; + struct freplace_dead_global_func *skel = NULL; + char log_buf[4096]; + int err, tgt_fd; + + /* first, try to load target with good global subprog */ + tgt_skel = verifier_global_subprogs__open(); + if (!ASSERT_OK_PTR(tgt_skel, "tgt_skel_good_open")) + return; + + bpf_program__set_autoload(tgt_skel->progs.chained_global_func_calls_success, true); + + err = verifier_global_subprogs__load(tgt_skel); + if (!ASSERT_OK(err, "tgt_skel_good_load")) + goto out; + + tgt_fd = bpf_program__fd(tgt_skel->progs.chained_global_func_calls_success); + + /* Attach to good non-eliminated subprog */ + skel = freplace_dead_global_func__open(); + if (!ASSERT_OK_PTR(skel, "skel_good_open")) + goto out; + + err = bpf_program__set_attach_target(skel->progs.freplace_prog, tgt_fd, "global_good"); + ASSERT_OK(err, "attach_target_good"); + + err = freplace_dead_global_func__load(skel); + if (!ASSERT_OK(err, "skel_good_load")) + goto out; + + freplace_dead_global_func__destroy(skel); + + /* Try attaching to dead code-eliminated subprog */ + skel = freplace_dead_global_func__open(); + if (!ASSERT_OK_PTR(skel, "skel_dead_open")) + goto out; + + bpf_program__set_log_buf(skel->progs.freplace_prog, log_buf, sizeof(log_buf)); + err = bpf_program__set_attach_target(skel->progs.freplace_prog, tgt_fd, "global_dead"); + ASSERT_OK(err, "attach_target_dead"); + + err = freplace_dead_global_func__load(skel); + if (!ASSERT_ERR(err, "skel_dead_load")) + goto out; + + ASSERT_HAS_SUBSTR(log_buf, "Subprog global_dead doesn't exist", "dead_subprog_missing_msg"); + +out: + verifier_global_subprogs__destroy(tgt_skel); + freplace_dead_global_func__destroy(skel); +} |