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| author | Shuran Liu <electronlsr@gmail.com> | 2025-12-06 22:12:10 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-12-10 01:36:26 -0800 |
| commit | 79e247d6608848c09038d0b1e7d256432624fd84 (patch) | |
| tree | f9e8465d16c593b1c345407724303a753a1b6e57 /tools/testing/selftests/bpf/progs/test_d_path.c | |
| parent | ac44dcc788b950606793e8f9690c30925f59df02 (diff) | |
| download | linux-next-79e247d6608848c09038d0b1e7d256432624fd84.tar.gz linux-next-79e247d6608848c09038d0b1e7d256432624fd84.zip | |
selftests/bpf: add regression test for bpf_d_path()
Add a regression test for bpf_d_path() to cover incorrect verifier
assumptions caused by an incorrect function prototype. The test
attaches to the fallocate hook, calls bpf_d_path() and verifies that
a simple prefix comparison on the returned pathname behaves correctly
after the fix in patch 1. It ensures the verifier does not assume
the buffer remains unwritten.
Co-developed-by: Zesen Liu <ftyg@live.com>
Signed-off-by: Zesen Liu <ftyg@live.com>
Co-developed-by: Peili Gao <gplhust955@gmail.com>
Signed-off-by: Peili Gao <gplhust955@gmail.com>
Co-developed-by: Haoran Ni <haoran.ni.cs@gmail.com>
Signed-off-by: Haoran Ni <haoran.ni.cs@gmail.com>
Signed-off-by: Shuran Liu <electronlsr@gmail.com>
Link: https://lore.kernel.org/r/20251206141210.3148-3-electronlsr@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_d_path.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_d_path.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_d_path.c b/tools/testing/selftests/bpf/progs/test_d_path.c index 84e1f883f97b..561b2f861808 100644 --- a/tools/testing/selftests/bpf/progs/test_d_path.c +++ b/tools/testing/selftests/bpf/progs/test_d_path.c @@ -17,6 +17,7 @@ int rets_close[MAX_FILES] = {}; int called_stat = 0; int called_close = 0; +int path_match_fallocate = 0; SEC("fentry/security_inode_getattr") int BPF_PROG(prog_stat, struct path *path, struct kstat *stat, @@ -62,4 +63,26 @@ int BPF_PROG(prog_close, struct file *file, void *id) return 0; } +SEC("fentry/vfs_fallocate") +int BPF_PROG(prog_fallocate, struct file *file, int mode, loff_t offset, loff_t len) +{ + pid_t pid = bpf_get_current_pid_tgid() >> 32; + int ret = 0; + char path_fallocate[MAX_PATH_LEN] = {}; + + if (pid != my_pid) + return 0; + + ret = bpf_d_path(&file->f_path, + path_fallocate, MAX_PATH_LEN); + if (ret < 0) + return 0; + + if (!path_fallocate[0]) + return 0; + + path_match_fallocate = 1; + return 0; +} + char _license[] SEC("license") = "GPL"; |