net/rxrpc/skbuff.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* ar-skbuff.c: socket buffer destruction handling
   3  *
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/module.h>
  11 #include <linux/net.h>
  12 #include <linux/skbuff.h>
  13 #include <net/sock.h>
  14 #include <net/af_rxrpc.h>
  15 #include "ar-internal.h"
  16
  17 #define select_skb_count(op) (op >= rxrpc_skb_tx_cleaned ? &rxrpc_n_tx_skbs : &rxrpc_n_rx_skbs)
  18
  19 /*
  20  * Note the allocation or reception of a socket buffer.
  21  */
  22 void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
  23 {
  24         const void *here = __builtin_return_address(0);
  25         int n = atomic_inc_return(select_skb_count(op));
  26         trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
  27 }
  28
  29 /*
  30  * Note the re-emergence of a socket buffer from a queue or buffer.
  31  */
  32 void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
  33 {
  34         const void *here = __builtin_return_address(0);
  35         if (skb) {
  36                 int n = atomic_read(select_skb_count(op));
  37                 trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
  38         }
  39 }
  40
  41 /*
  42  * Note the addition of a ref on a socket buffer.
  43  */
  44 void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
  45 {
  46         const void *here = __builtin_return_address(0);
  47         int n = atomic_inc_return(select_skb_count(op));
  48         trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
  49         skb_get(skb);
  50 }
  51
  52 /*
  53  * Note the destruction of a socket buffer.
  54  */
  55 void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
  56 {
  57         const void *here = __builtin_return_address(0);
  58         if (skb) {
  59                 int n;
  60                 CHECK_SLAB_OKAY(&skb->users);
  61                 n = atomic_dec_return(select_skb_count(op));
  62                 trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
  63                 kfree_skb(skb);
  64         }
  65 }
  66
  67 /*
  68  * Clear a queue of socket buffers.
  69  */
  70 void rxrpc_purge_queue(struct sk_buff_head *list)
  71 {
  72         const void *here = __builtin_return_address(0);
  73         struct sk_buff *skb;
  74         while ((skb = skb_dequeue((list))) != NULL) {
  75                 int n = atomic_dec_return(select_skb_count(rxrpc_skb_rx_purged));
  76                 trace_rxrpc_skb(skb, rxrpc_skb_rx_purged,
  77                                 refcount_read(&skb->users), n, here);
  78                 kfree_skb(skb);
  79         }
  80 }