Fix rxrpc call removal from the rxnet->calls list to use list_del_rcu() rather than list_del_init() to prevent stuffing up reading /proc/net/rxrpc/calls from potentially getting into an infinite loop. This, however, means that list_empty() no longer works on an entry that's been deleted from the list, making it harder to detect prior deletion. Fix this by: Firstly, make rxrpc_destroy_all_calls() only dump the first ten calls that are unexpectedly still on the list. Limiting the number of steps means there's no need to call cond_resched() or to remove calls from the list here, thereby eliminating the need for rxrpc_put_call() to check for that. rxrpc_put_call() can then be fixed to unconditionally delete the call from the list as it is the only place that the deletion occurs. Fixes: 2baec2c3f854 ("rxrpc: Support network namespacing") Closes: https://sashiko.dev/#/patchset/20260319150150.4189381-1-dhowells%40redhat.com Signed-off-by: David Howells cc: Marc Dionne cc: Jeffrey Altman cc: Linus Torvalds cc: Eric Dumazet cc: "David S. Miller" cc: Jakub Kicinski cc: Paolo Abeni cc: Simon Horman cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org cc: stable@kernel.org --- include/trace/events/rxrpc.h | 2 +- net/rxrpc/call_object.c | 24 +++++++++--------------- 2 files changed, 10 insertions(+), 16 deletions(-) diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h index 869f97c9bf73..a826cd80007b 100644 --- a/include/trace/events/rxrpc.h +++ b/include/trace/events/rxrpc.h @@ -347,7 +347,7 @@ EM(rxrpc_call_see_release, "SEE release ") \ EM(rxrpc_call_see_userid_exists, "SEE u-exists") \ EM(rxrpc_call_see_waiting_call, "SEE q-conn ") \ - E_(rxrpc_call_see_zap, "SEE zap ") + E_(rxrpc_call_see_still_live, "SEE !still-l") #define rxrpc_txqueue_traces \ EM(rxrpc_txqueue_await_reply, "AWR") \ diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c index 918f41d97a2f..59329cfe1532 100644 --- a/net/rxrpc/call_object.c +++ b/net/rxrpc/call_object.c @@ -654,11 +654,9 @@ void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why) if (dead) { ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE); - if (!list_empty(&call->link)) { - spin_lock(&rxnet->call_lock); - list_del_init(&call->link); - spin_unlock(&rxnet->call_lock); - } + spin_lock(&rxnet->call_lock); + list_del_rcu(&call->link); + spin_unlock(&rxnet->call_lock); rxrpc_cleanup_call(call); } @@ -730,24 +728,20 @@ void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet) _enter(""); if (!list_empty(&rxnet->calls)) { - spin_lock(&rxnet->call_lock); + int shown = 0; - while (!list_empty(&rxnet->calls)) { - call = list_entry(rxnet->calls.next, - struct rxrpc_call, link); - _debug("Zapping call %p", call); + spin_lock(&rxnet->call_lock); - rxrpc_see_call(call, rxrpc_call_see_zap); - list_del_init(&call->link); + list_for_each_entry(call, &rxnet->calls, link) { + rxrpc_see_call(call, rxrpc_call_see_still_live); pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n", call, refcount_read(&call->ref), rxrpc_call_states[__rxrpc_call_state(call)], call->flags, call->events); - spin_unlock(&rxnet->call_lock); - cond_resched(); - spin_lock(&rxnet->call_lock); + if (++shown >= 10) + break; } spin_unlock(&rxnet->call_lock);