net/sctp/objcnt.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* SCTP kernel implementation
   3  * (C) Copyright IBM Corp. 2001, 2004
   4  *
   5  * This file is part of the SCTP kernel implementation
   6  *
   7  * Support for memory object debugging.  This allows one to monitor the
   8  * object allocations/deallocations for types instrumented for this
   9  * via the proc fs.
  10  *
  11  * Please send any bug reports or fixes you make to the
  12  * email address(es):
  13  *    lksctp developers <linux-sctp@vger.kernel.org>
  14  *
  15  * Written or modified by:
  16  *    Jon Grimm             <jgrimm@us.ibm.com>
  17  */
  18
  19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/kernel.h>
  22 #include <net/sctp/sctp.h>
  23
  24 /*
  25  * Global counters to count raw object allocation counts.
  26  * To add new counters, choose a unique suffix for the variable
  27  * name as the helper macros key off this suffix to make
  28  * life easier for the programmer.
  29  */
  30
  31 SCTP_DBG_OBJCNT(sock);
  32 SCTP_DBG_OBJCNT(ep);
  33 SCTP_DBG_OBJCNT(transport);
  34 SCTP_DBG_OBJCNT(assoc);
  35 SCTP_DBG_OBJCNT(bind_addr);
  36 SCTP_DBG_OBJCNT(bind_bucket);
  37 SCTP_DBG_OBJCNT(chunk);
  38 SCTP_DBG_OBJCNT(addr);
  39 SCTP_DBG_OBJCNT(datamsg);
  40 SCTP_DBG_OBJCNT(keys);
  41
  42 /* An array to make it easy to pretty print the debug information
  43  * to the proc fs.
  44  */
  45 static struct sctp_dbg_objcnt_entry sctp_dbg_objcnt[] = {
  46         SCTP_DBG_OBJCNT_ENTRY(sock),
  47         SCTP_DBG_OBJCNT_ENTRY(ep),
  48         SCTP_DBG_OBJCNT_ENTRY(assoc),
  49         SCTP_DBG_OBJCNT_ENTRY(transport),
  50         SCTP_DBG_OBJCNT_ENTRY(chunk),
  51         SCTP_DBG_OBJCNT_ENTRY(bind_addr),
  52         SCTP_DBG_OBJCNT_ENTRY(bind_bucket),
  53         SCTP_DBG_OBJCNT_ENTRY(addr),
  54         SCTP_DBG_OBJCNT_ENTRY(datamsg),
  55         SCTP_DBG_OBJCNT_ENTRY(keys),
  56 };
  57
  58 /* Callback from procfs to read out objcount information.
  59  * Walk through the entries in the sctp_dbg_objcnt array, dumping
  60  * the raw object counts for each monitored type.
  61  */
  62 static int sctp_objcnt_seq_show(struct seq_file *seq, void *v)
  63 {
  64         int i;
  65
  66         i = (int)*(loff_t *)v;
  67         seq_setwidth(seq, 127);
  68         seq_printf(seq, "%s: %d", sctp_dbg_objcnt[i].label,
  69                                 atomic_read(sctp_dbg_objcnt[i].counter));
  70         seq_pad(seq, '\n');
  71         return 0;
  72 }
  73
  74 static void *sctp_objcnt_seq_start(struct seq_file *seq, loff_t *pos)
  75 {
  76         return (*pos >= ARRAY_SIZE(sctp_dbg_objcnt)) ? NULL : (void *)pos;
  77 }
  78
  79 static void sctp_objcnt_seq_stop(struct seq_file *seq, void *v)
  80 {
  81 }
  82
  83 static void *sctp_objcnt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  84 {
  85         ++*pos;
  86         return (*pos >= ARRAY_SIZE(sctp_dbg_objcnt)) ? NULL : (void *)pos;
  87 }
  88
  89 static const struct seq_operations sctp_objcnt_seq_ops = {
  90         .start = sctp_objcnt_seq_start,
  91         .next  = sctp_objcnt_seq_next,
  92         .stop  = sctp_objcnt_seq_stop,
  93         .show  = sctp_objcnt_seq_show,
  94 };
  95
  96 /* Initialize the objcount in the proc filesystem.  */
  97 void sctp_dbg_objcnt_init(struct net *net)
  98 {
  99         struct proc_dir_entry *ent;
 100
 101         ent = proc_create_seq("sctp_dbg_objcnt", 0,
 102                           net->sctp.proc_net_sctp, &sctp_objcnt_seq_ops);
 103         if (!ent)
 104                 pr_warn("sctp_dbg_objcnt: Unable to create /proc entry.\n");
 105 }