[PATCH 2/2] config: android-recommended: Disable BPF_UNPRIV_DEFAULT_OFF for netd

From: Marijn Suijten
Date: Wed Feb 02 2022 - 04:34:13 EST


From: Marijn Suijten <marijns95@xxxxxxxxx>

AOSP's `netd` process fails to start on Android S:

E ClatdController: getClatEgress4MapFd() failure: Operation not permitted
I netd : Initializing ClatdController: 410us
E netd : Failed to start trafficcontroller: (Status[code: 1, msg: "Pinned map not accessible or does not exist: (/sys/fs/bpf/map_netd_cookie_tag_map): Operation not permitted"])
E netd : CRITICAL: sleeping 60 seconds, netd exiting with failure, crash loop likely!

And on Android R:

I ClatdController: 4.9+ kernel and device shipped with P - clat ebpf might work.
E ClatdController: getClatEgressMapFd() failure: Operation not permitted
I netd : Initializing ClatdController: 1409us
E netd : Failed to start trafficcontroller: (Status[code: 1, msg: "Pinned map not accessible or does not exist: (/sys/fs/bpf/map_netd_cookie_tag_map): Operation not permitted"])

These permission issues are caused by 08389d888287 ("bpf: Add kconfig
knob for disabling unpriv bpf by default") because AOSP does not provide
netd the `SYS_ADMIN` capability, and also has no userspace support for
the `BPF` capability yet.

Cc: Amit Pundir <amit.pundir@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Suggested-by: John Stultz <john.stultz@xxxxxxxxxx>
[John suggested this in https://linaro.atlassian.net/browse/ACK-107?focusedCommentId=117382]
Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
---
kernel/configs/android-recommended.config | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/configs/android-recommended.config b/kernel/configs/android-recommended.config
index 22bd76e43aca..e400fbbc8aba 100644
--- a/kernel/configs/android-recommended.config
+++ b/kernel/configs/android-recommended.config
@@ -1,4 +1,5 @@
# KEEP ALPHABETICALLY SORTED
+# CONFIG_BPF_UNPRIV_DEFAULT_OFF is not set
# CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
# CONFIG_INPUT_MOUSE is not set
# CONFIG_LEGACY_PTYS is not set
--
2.35.1