mirror_ubuntu-kernels/tools/testing
Jakub Kicinski 52f671db18 net/sched: act_mirred: use the backlog for mirred ingress
The test Davide added in commit ca22da2fbd ("act_mirred: use the backlog
for nested calls to mirred ingress") hangs our testing VMs every 10 or so
runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by
lockdep.

The problem as previously described by Davide (see Link) is that
if we reverse flow of traffic with the redirect (egress -> ingress)
we may reach the same socket which generated the packet. And we may
still be holding its socket lock. The common solution to such deadlocks
is to put the packet in the Rx backlog, rather than run the Rx path
inline. Do that for all egress -> ingress reversals, not just once
we started to nest mirred calls.

In the past there was a concern that the backlog indirection will
lead to loss of error reporting / less accurate stats. But the current
workaround does not seem to address the issue.

Fixes: 53592b3640 ("net/sched: act_mirred: Implement ingress actions")
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Suggested-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/netdev/33dc43f587ec1388ba456b4915c75f02a8aae226.1663945716.git.dcaratti@redhat.com/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-16 10:13:31 +00:00
..
crypto/chacha20-s390
cxl tools/testing/cxl: Disable "missing prototypes / declarations" warnings 2024-01-22 10:41:59 -08:00
fault-injection
ktest
kunit kunit: tool: add test for parsing attributes 2023-12-18 13:21:15 -07:00
memblock mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
nvdimm tools/testing/nvdimm: Disable "missing prototypes / declarations" warnings 2024-01-22 10:41:59 -08:00
radix-tree maple_tree: fix warning comparing pointer to 0 2023-12-20 14:48:12 -08:00
scatterlist
selftests net/sched: act_mirred: use the backlog for mirred ingress 2024-02-16 10:13:31 +00:00
vsock vsock/test: two tests to check credit update logic 2023-12-15 10:37:35 +00:00