From df844fd46b98c2efde8f4ac2d50d59bc90c4c679 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 23 Aug 2016 15:27:24 +0100 Subject: [PATCH] rxrpc: Use a tracepoint for skb accounting debugging Use a tracepoint to log various skb accounting points to help in debugging refcounting errors. Signed-off-by: David Howells --- include/trace/events/rxrpc.h | 56 ++++++++++++++++++++++++++++++++ net/rxrpc/af_rxrpc.c | 1 + net/rxrpc/ar-internal.h | 45 ++++---------------------- net/rxrpc/call_accept.c | 1 + net/rxrpc/call_event.c | 3 ++ net/rxrpc/conn_event.c | 2 ++ net/rxrpc/local_event.c | 1 + net/rxrpc/output.c | 1 + net/rxrpc/recvmsg.c | 1 + net/rxrpc/skbuff.c | 62 ++++++++++++++++++++++++++++++++++++ 10 files changed, 135 insertions(+), 38 deletions(-) create mode 100644 include/trace/events/rxrpc.h diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h new file mode 100644 index 000000000000..15283ee3e41a --- /dev/null +++ b/include/trace/events/rxrpc.h @@ -0,0 +1,56 @@ +/* AF_RXRPC tracepoints + * + * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM rxrpc + +#if !defined(_TRACE_RXRPC_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_RXRPC_H + +#include + +TRACE_EVENT(rxrpc_skb, + TP_PROTO(struct sk_buff *skb, int op, int usage, int mod_count, + const void *where), + + TP_ARGS(skb, op, usage, mod_count, where), + + TP_STRUCT__entry( + __field(struct sk_buff *, skb ) + __field(int, op ) + __field(int, usage ) + __field(int, mod_count ) + __field(const void *, where ) + ), + + TP_fast_assign( + __entry->skb = skb; + __entry->op = op; + __entry->usage = usage; + __entry->mod_count = mod_count; + __entry->where = where; + ), + + TP_printk("s=%p %s u=%d m=%d p=%pSR", + __entry->skb, + (__entry->op == 0 ? "NEW" : + __entry->op == 1 ? "SEE" : + __entry->op == 2 ? "GET" : + __entry->op == 3 ? "FRE" : + "PUR"), + __entry->usage, + __entry->mod_count, + __entry->where) + ); + +#endif /* _TRACE_RXRPC_H */ + +/* This part must be outside protection */ +#include diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index 88effadd4b16..c7cf356b42b8 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -22,6 +22,7 @@ #include #include #include +#define CREATE_TRACE_POINTS #include "ar-internal.h" MODULE_DESCRIPTION("RxRPC network protocol"); diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 648060a5df35..8cb517fbbd23 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -479,6 +479,8 @@ static inline void rxrpc_abort_call(struct rxrpc_call *call, u32 abort_code) write_unlock_bh(&call->state_lock); } +#include + /* * af_rxrpc.c */ @@ -752,6 +754,11 @@ int rxrpc_init_server_conn_security(struct rxrpc_connection *); * skbuff.c */ void rxrpc_packet_destructor(struct sk_buff *); +void rxrpc_new_skb(struct sk_buff *); +void rxrpc_see_skb(struct sk_buff *); +void rxrpc_get_skb(struct sk_buff *); +void rxrpc_free_skb(struct sk_buff *); +void rxrpc_purge_queue(struct sk_buff_head *); /* * sysctl.c @@ -899,44 +906,6 @@ do { \ #endif /* __KDEBUGALL */ -/* - * socket buffer accounting / leak finding - */ -static inline void __rxrpc_new_skb(struct sk_buff *skb, const char *fn) -{ - //_net("new skb %p %s [%d]", skb, fn, atomic_read(&rxrpc_n_skbs)); - //atomic_inc(&rxrpc_n_skbs); -} - -#define rxrpc_new_skb(skb) __rxrpc_new_skb((skb), __func__) - -static inline void __rxrpc_kill_skb(struct sk_buff *skb, const char *fn) -{ - //_net("kill skb %p %s [%d]", skb, fn, atomic_read(&rxrpc_n_skbs)); - //atomic_dec(&rxrpc_n_skbs); -} - -#define rxrpc_kill_skb(skb) __rxrpc_kill_skb((skb), __func__) - -static inline void __rxrpc_free_skb(struct sk_buff *skb, const char *fn) -{ - if (skb) { - CHECK_SLAB_OKAY(&skb->users); - //_net("free skb %p %s [%d]", - // skb, fn, atomic_read(&rxrpc_n_skbs)); - //atomic_dec(&rxrpc_n_skbs); - kfree_skb(skb); - } -} - -#define rxrpc_free_skb(skb) __rxrpc_free_skb((skb), __func__) - -static inline void rxrpc_purge_queue(struct sk_buff_head *list) -{ - struct sk_buff *skb; - while ((skb = skb_dequeue((list))) != NULL) - rxrpc_free_skb(skb); -} #define rxrpc_get_call(CALL) \ do { \ diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c index 9bae21e66d65..669ac79d3b44 100644 --- a/net/rxrpc/call_accept.c +++ b/net/rxrpc/call_accept.c @@ -203,6 +203,7 @@ void rxrpc_accept_incoming_calls(struct rxrpc_local *local) _net("incoming call skb %p", skb); + rxrpc_see_skb(skb); sp = rxrpc_skb(skb); /* Set up a response packet header in case we need it */ diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c index eaa8035dcb71..3d1267cea9ea 100644 --- a/net/rxrpc/call_event.c +++ b/net/rxrpc/call_event.c @@ -407,6 +407,7 @@ static int rxrpc_drain_rx_oos_queue(struct rxrpc_call *call) skb = skb_dequeue(&call->rx_oos_queue); if (skb) { + rxrpc_see_skb(skb); sp = rxrpc_skb(skb); _debug("drain OOS packet %d [%d]", @@ -427,6 +428,7 @@ static int rxrpc_drain_rx_oos_queue(struct rxrpc_call *call) /* find out what the next packet is */ skb = skb_peek(&call->rx_oos_queue); + rxrpc_see_skb(skb); if (skb) call->rx_first_oos = rxrpc_skb(skb)->hdr.seq; else @@ -576,6 +578,7 @@ process_further: if (!skb) return -EAGAIN; + rxrpc_see_skb(skb); _net("deferred skb %p", skb); sp = rxrpc_skb(skb); diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c index cee0f35bc1cf..c631d926f4db 100644 --- a/net/rxrpc/conn_event.c +++ b/net/rxrpc/conn_event.c @@ -277,6 +277,7 @@ void rxrpc_process_connection(struct work_struct *work) /* go through the conn-level event packets, releasing the ref on this * connection that each one has when we've finished with it */ while ((skb = skb_dequeue(&conn->rx_queue))) { + rxrpc_see_skb(skb); ret = rxrpc_process_event(conn, skb, &abort_code); switch (ret) { case -EPROTO: @@ -365,6 +366,7 @@ void rxrpc_reject_packets(struct rxrpc_local *local) whdr.type = RXRPC_PACKET_TYPE_ABORT; while ((skb = skb_dequeue(&local->reject_queue))) { + rxrpc_see_skb(skb); sp = rxrpc_skb(skb); switch (sa.sa.sa_family) { case AF_INET: diff --git a/net/rxrpc/local_event.c b/net/rxrpc/local_event.c index 31a3f86ef2f6..bcc6593b4cdb 100644 --- a/net/rxrpc/local_event.c +++ b/net/rxrpc/local_event.c @@ -93,6 +93,7 @@ void rxrpc_process_local_events(struct rxrpc_local *local) if (skb) { struct rxrpc_skb_priv *sp = rxrpc_skb(skb); + rxrpc_see_skb(skb); _debug("{%d},{%u}", local->debug_id, sp->hdr.type); switch (sp->hdr.type) { diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index 9e626f1e2668..e3a08d542fb7 100644 --- a/net/rxrpc/output.c +++ b/net/rxrpc/output.c @@ -548,6 +548,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx, skb = call->tx_pending; call->tx_pending = NULL; + rxrpc_see_skb(skb); copied = 0; do { diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c index 9ed66d533002..b964c2d49a88 100644 --- a/net/rxrpc/recvmsg.c +++ b/net/rxrpc/recvmsg.c @@ -111,6 +111,7 @@ int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, } peek_next_packet: + rxrpc_see_skb(skb); sp = rxrpc_skb(skb); call = sp->call; ASSERT(call != NULL); diff --git a/net/rxrpc/skbuff.c b/net/rxrpc/skbuff.c index 06c51d4b622d..d28058a97bc1 100644 --- a/net/rxrpc/skbuff.c +++ b/net/rxrpc/skbuff.c @@ -163,3 +163,65 @@ void rxrpc_kernel_free_skb(struct sk_buff *skb) rxrpc_free_skb(skb); } EXPORT_SYMBOL(rxrpc_kernel_free_skb); + +/* + * Note the existence of a new-to-us socket buffer (allocated or dequeued). + */ +void rxrpc_new_skb(struct sk_buff *skb) +{ + const void *here = __builtin_return_address(0); + int n = atomic_inc_return(&rxrpc_n_skbs); + trace_rxrpc_skb(skb, 0, atomic_read(&skb->users), n, here); +} + +/* + * Note the re-emergence of a socket buffer from a queue or buffer. + */ +void rxrpc_see_skb(struct sk_buff *skb) +{ + const void *here = __builtin_return_address(0); + if (skb) { + int n = atomic_read(&rxrpc_n_skbs); + trace_rxrpc_skb(skb, 1, atomic_read(&skb->users), n, here); + } +} + +/* + * Note the addition of a ref on a socket buffer. + */ +void rxrpc_get_skb(struct sk_buff *skb) +{ + const void *here = __builtin_return_address(0); + int n = atomic_inc_return(&rxrpc_n_skbs); + trace_rxrpc_skb(skb, 2, atomic_read(&skb->users), n, here); + skb_get(skb); +} + +/* + * Note the destruction of a socket buffer. + */ +void rxrpc_free_skb(struct sk_buff *skb) +{ + const void *here = __builtin_return_address(0); + if (skb) { + int n; + CHECK_SLAB_OKAY(&skb->users); + n = atomic_dec_return(&rxrpc_n_skbs); + trace_rxrpc_skb(skb, 3, atomic_read(&skb->users), n, here); + kfree_skb(skb); + } +} + +/* + * Clear a queue of socket buffers. + */ +void rxrpc_purge_queue(struct sk_buff_head *list) +{ + const void *here = __builtin_return_address(0); + struct sk_buff *skb; + while ((skb = skb_dequeue((list))) != NULL) { + int n = atomic_dec_return(&rxrpc_n_skbs); + trace_rxrpc_skb(skb, 4, atomic_read(&skb->users), n, here); + kfree_skb(skb); + } +} -- 2.20.1