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selftests/bpf: Fix stat probe in d_path test

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Some kernels builds might inline vfs_getattr call within fstat
syscall code path, so fentry/vfs_getattr trampoline is not called.

Add security_inode_getattr to allowlist and switch the d_path test stat
trampoline to security_inode_getattr.

Keeping dentry_open and filp_close, because they are in their own
files, so unlikely to be inlined, but in case they are, adding
security_file_open.

Adding flags that indicate trampolines were called and failing
the test if any of them got missed, so it's easier to identify
the issue next time.

Fixes: e4d1af4b16 ("selftests/bpf: Add test for d_path helper")
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200918112338.2618444-1-jolsa@kernel.org
This commit is contained in:
Jiri Olsa
2020-09-18 13:23:38 +02:00
committed by Alexei Starovoitov
parent c69d2ddb20
commit a8a717963f
3 changed files with 26 additions and 1 deletions
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9
tools/testing/selftests/bpf/progs/test_d_path.c
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@@ -15,7 +15,10 @@ char paths_close[MAX_FILES][MAX_PATH_LEN] = {};
int rets_stat[MAX_FILES] = {};
int rets_close[MAX_FILES] = {};
SEC("fentry/vfs_getattr")
int called_stat = 0;
int called_close = 0;
SEC("fentry/security_inode_getattr")
int BPF_PROG(prog_stat, struct path *path, struct kstat *stat,
__u32 request_mask, unsigned int query_flags)
{
@@ -23,6 +26,8 @@ int BPF_PROG(prog_stat, struct path *path, struct kstat *stat,
__u32 cnt = cnt_stat;
int ret;
called_stat = 1;
if (pid != my_pid)
return 0;
@@ -42,6 +47,8 @@ int BPF_PROG(prog_close, struct file *file, void *id)
__u32 cnt = cnt_close;
int ret;
called_close = 1;
if (pid != my_pid)
return 0;