This is a note to let you know that I've just added the patch titled
bpf: Clarify error expectations from bpf_clone_redirect
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-clarify-error-expectations-from-bpf_clone_redire.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0668e6082eff2a8c141ab8c12c8cea0201def25e
Author: Stanislav Fomichev <sdf@xxxxxxxxxx>
Date: Mon Sep 11 12:47:30 2023 -0700
bpf: Clarify error expectations from bpf_clone_redirect
[ Upstream commit 7cb779a6867fea00b4209bcf6de2f178a743247d ]
Commit 151e887d8ff9 ("veth: Fixing transmit return status for dropped
packets") exposed the fact that bpf_clone_redirect is capable of
returning raw NET_XMIT_XXX return codes.
This is in the conflict with its UAPI doc which says the following:
"0 on success, or a negative error in case of failure."
Update the UAPI to reflect the fact that bpf_clone_redirect can
return positive error numbers, but don't explicitly define
their meaning.
Reported-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20230911194731.286342-1-sdf@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 6334aede67fc2..91c43f3756123 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -693,7 +693,9 @@ union bpf_attr {
* performed again, if the helper is used in combination with
* direct packet access.
* Return
- * 0 on success, or a negative error in case of failure.
+ * 0 on success, or a negative error in case of failure. Positive
+ * error indicates a potential drop or congestion in the target
+ * device. The particular positive error codes are not defined.
*
* u64 bpf_get_current_pid_tgid(void)
* Return
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 0c30ab898e2a5..37259bae15010 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -691,7 +691,9 @@ union bpf_attr {
* performed again, if the helper is used in combination with
* direct packet access.
* Return
- * 0 on success, or a negative error in case of failure.
+ * 0 on success, or a negative error in case of failure. Positive
+ * error indicates a potential drop or congestion in the target
+ * device. The particular positive error codes are not defined.
*
* u64 bpf_get_current_pid_tgid(void)
* Return
