From: Florent Revest <[email protected]>
Iterators are currently used to expose kernel information to userspace
over fast procfs-like files but iterators could also be used to
manipulate local storage. For example, the task_file iterator could be
used to initialize a socket local storage with associations between
processes and sockets or to selectively delete local storage values.
This exposes both socket local storage helpers to all iterators.
Alternatively we could expose it to only certain iterators with strcmps
on prog->aux->attach_func_name.
Signed-off-by: Florent Revest <[email protected]>
---
net/core/bpf_sk_storage.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index a32037daa933..4edd033e899c 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -394,6 +394,7 @@ static bool bpf_sk_storage_tracing_allowed(const struct bpf_prog *prog)
* use the bpf_sk_storage_(get|delete) helper.
*/
switch (prog->expected_attach_type) {
+ case BPF_TRACE_ITER:
case BPF_TRACE_RAW_TP:
/* bpf_sk_storage has no trace point */
return true;
--
2.29.2.299.gdc1121823c-goog
On Thu, Nov 19, 2020 at 5:27 PM Florent Revest <[email protected]> wrote:
>
> From: Florent Revest <[email protected]>
>
> Iterators are currently used to expose kernel information to userspace
> over fast procfs-like files but iterators could also be used to
> manipulate local storage. For example, the task_file iterator could be
> used to initialize a socket local storage with associations between
> processes and sockets or to selectively delete local storage values.
>
> This exposes both socket local storage helpers to all iterators.
> Alternatively we could expose it to only certain iterators with strcmps
> on prog->aux->attach_func_name.
Since you mentioned the alternative here, maybe you can also
explain why you chose the current approach.
On Thu, Nov 19, 2020 at 05:26:52PM +0100, Florent Revest wrote:
> From: Florent Revest <[email protected]>
>
> Iterators are currently used to expose kernel information to userspace
> over fast procfs-like files but iterators could also be used to
> manipulate local storage. For example, the task_file iterator could be
> used to initialize a socket local storage with associations between
> processes and sockets or to selectively delete local storage values.
>
> This exposes both socket local storage helpers to all iterators.
> Alternatively we could expose it to only certain iterators with strcmps
> on prog->aux->attach_func_name.
I cannot see any hole to iter the bpf_sk_storage_map and also
bpf_sk_storage_get/delete() itself for now.
I have looked at other iters (e.g. tcp, udp, and sock_map iter).
It will be good if you can double check them also.
I think at least one more test on the tcp iter is needed.
Other than that,
Acked-by: Martin KaFai Lau <[email protected]>