Re: [PATCH v13 05/10] bpf: Add bpf_lookup_*_key() and bpf_key_put() kfuncs

On Fri, 2022-08-26 at 00:25 -0700, Song Liu wrote:

On Fri, Aug 26, 2022 at 12:22 AM Roberto Sassu
[off-list ref] wrote:

quoted

On Thu, 2022-08-25 at 22:56 -0700, Song Liu wrote:

quoted

On Tue, Aug 23, 2022 at 8:02 AM Roberto Sassu
[off-list ref] wrote:

quoted

From: Roberto Sassu <roberto.sassu@huawei.com>

Add the bpf_lookup_user_key(), bpf_lookup_system_key() and
bpf_key_put()
kfuncs, to respectively search a key with a given key handle
serial
number
and flags, obtain a key from a pre-determined ID defined in
include/linux/verification.h, and cleanup.

Introduce system_keyring_id_check() to validate the keyring ID
parameter of
bpf_lookup_system_key().

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 include/linux/bpf.h          |   6 ++
 include/linux/verification.h |   8 +++
 kernel/trace/bpf_trace.c     | 135
+++++++++++++++++++++++++++++++++++
 3 files changed, 149 insertions(+)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 6041304b402e..991da09a5858 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h

@@ -2586,4 +2586,10 @@ static inline void

bpf_cgroup_atype_get(u32
attach_btf_id, int cgroup_atype) {}
 static inline void bpf_cgroup_atype_put(int cgroup_atype) {}
 #endif /* CONFIG_BPF_LSM */

+#ifdef CONFIG_KEYS

Do we need to declare struct key here?

quoted

+struct bpf_key {
+       struct key *key;
+       bool has_ref;
+};
+#endif /* CONFIG_KEYS */
 #endif /* _LINUX_BPF_H */

If there is a better place, I will move there.

I guess you misunderstood. I meant we need

struct key;

struct bpf_key {
       struct key *key;
       bool has_ref;
};

Otherwise, we may get some warning with certain config.

Argh, thanks!

Will add it.

Roberto