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| author | Kui-Feng Lee <thinker.li@gmail.com> | 2024-02-09 05:37:50 +0300 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2024-02-14 02:16:44 +0300 |
| commit | 00f239eccf461a6403b3c16e767d04f3954cae98 (patch) | |
| tree | 2f57131d002ff067db53ab4a62ccd8d5f735ef54 /tools/testing/selftests/bpf/progs | |
| parent | 1611603537a4b88cec7993f32b70c03113801a46 (diff) | |
| download | linux-00f239eccf461a6403b3c16e767d04f3954cae98.tar.xz | |
selftests/bpf: Test PTR_MAYBE_NULL arguments of struct_ops operators.
Test if the verifier verifies nullable pointer arguments correctly for BPF
struct_ops programs.
"test_maybe_null" in struct bpf_testmod_ops is the operator defined for the
test cases here.
A BPF program should check a pointer for NULL beforehand to access the
value pointed by the nullable pointer arguments, or the verifier should
reject the programs. The test here includes two parts; the programs
checking pointers properly and the programs not checking pointers
beforehand. The test checks if the verifier accepts the programs checking
properly and rejects the programs not checking at all.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240209023750.1153905-5-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/struct_ops_maybe_null.c | 29 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/struct_ops_maybe_null_fail.c | 24 |
2 files changed, 53 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/struct_ops_maybe_null.c b/tools/testing/selftests/bpf/progs/struct_ops_maybe_null.c new file mode 100644 index 000000000000..b450f72e744a --- /dev/null +++ b/tools/testing/selftests/bpf/progs/struct_ops_maybe_null.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#include <vmlinux.h> +#include <bpf/bpf_tracing.h> +#include "../bpf_testmod/bpf_testmod.h" + +char _license[] SEC("license") = "GPL"; + +pid_t tgid = 0; + +/* This is a test BPF program that uses struct_ops to access an argument + * that may be NULL. This is a test for the verifier to ensure that it can + * rip PTR_MAYBE_NULL correctly. + */ +SEC("struct_ops/test_maybe_null") +int BPF_PROG(test_maybe_null, int dummy, + struct task_struct *task) +{ + if (task) + tgid = task->tgid; + + return 0; +} + +SEC(".struct_ops.link") +struct bpf_testmod_ops testmod_1 = { + .test_maybe_null = (void *)test_maybe_null, +}; + diff --git a/tools/testing/selftests/bpf/progs/struct_ops_maybe_null_fail.c b/tools/testing/selftests/bpf/progs/struct_ops_maybe_null_fail.c new file mode 100644 index 000000000000..6283099ec383 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/struct_ops_maybe_null_fail.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#include <vmlinux.h> +#include <bpf/bpf_tracing.h> +#include "../bpf_testmod/bpf_testmod.h" + +char _license[] SEC("license") = "GPL"; + +pid_t tgid = 0; + +SEC("struct_ops/test_maybe_null_struct_ptr") +int BPF_PROG(test_maybe_null_struct_ptr, int dummy, + struct task_struct *task) +{ + tgid = task->tgid; + + return 0; +} + +SEC(".struct_ops.link") +struct bpf_testmod_ops testmod_struct_ptr = { + .test_maybe_null = (void *)test_maybe_null_struct_ptr, +}; + |