runtime/probes.c

   1 /* -*- linux-c -*-
   2  * Functions for Registering and Unregistering Probes
   3  * Copyright (C) 2005 Red Hat Inc.
   4  *
   5  * This file is part of systemtap, and is free software.  You can
   6  * redistribute it and/or modify it under the terms of the GNU General
   7  * Public License (GPL); either version 2, or (at your option) any
   8  * later version.
   9  */
  10
  11 #ifndef _PROBES_C_
  12 #define _PROBES_C
  13
  14 /** @file probes.c
  15  * @brief Functions to assist loading and unloading groups of probes.
  16  */
  17
  18 /** Unregister a group of jprobes.
  19  * @param probes Pointer to an array of struct jprobe.
  20  * @param num_probes Number of probes in the array.
  21  */
  22
  23 void _stp_unregister_jprobes (struct jprobe *probes, int num_probes)
  24 {
  25         int i;
  26         for (i = 0; i < num_probes; i++)
  27                 unregister_jprobe(&probes[i]);
  28         dbug("All jprobes removed\n");
  29 }
  30
  31 /** Register a group of jprobes.
  32  * @param probes Pointer to an array of struct jprobe.
  33  * @param num_probes Number of probes in the array.
  34  * @return 0 on success.
  35  */
  36
  37 int _stp_register_jprobes (struct jprobe *probes, int num_probes)
  38 {
  39         int i, ret ;
  40         unsigned long addr;
  41
  42         for (i = 0; i < num_probes; i++) {
  43                 addr =kallsyms_lookup_name((char *)probes[i].kp.addr);
  44                 if (addr == 0) {
  45                         _stp_warn("function %s not found!\n", (char *)probes[i].kp.addr);
  46                         ret = -1; /* FIXME */
  47                         goto out;
  48                 }
  49                 dbug("inserting jprobe at %s (%p)\n", probes[i].kp.addr, addr);
  50                 probes[i].kp.addr = (kprobe_opcode_t *)addr;
  51                 ret = register_jprobe(&probes[i]);
  52                 if (ret)
  53                         goto out;
  54         }
  55         return 0;
  56 out:
  57         _stp_warn("probe module initialization failed.  Exiting...\n");
  58         _stp_unregister_jprobes(probes, i);
  59         return ret;
  60 }
  61
  62 /** Unregister a group of kprobes.
  63  * @param probes Pointer to an array of struct kprobe.
  64  * @param num_probes Number of probes in the array.
  65  */
  66
  67 void _stp_unregister_kprobes (struct kprobe *probes, int num_probes)
  68 {
  69         int i;
  70         for (i = 0; i < num_probes; i++)
  71                 unregister_kprobe(&probes[i]);
  72         dbug("All kprobes removed\n");
  73 }
  74
  75
  76 #ifdef USE_RET_PROBES
  77 /** Unregister a group of return probes.
  78  * @param probes Pointer to an array of struct kretprobe.
  79  * @param num_probes Number of probes in the array.
  80  */
  81 void _stp_unregister_kretprobes (struct kretprobe *probes, int num_probes)
  82 {
  83         int i;
  84         for (i = 0; i < num_probes; i++)
  85                 unregister_kretprobe(&probes[i]);
  86         dbug("All return probes removed\n");
  87 }
  88 #endif
  89
  90 /** Register a group of kprobes.
  91  * @param probes Pointer to an array of struct kprobe.
  92  * @param num_probes Number of probes in the array.
  93  * @return 0 on success.
  94  */
  95 int _stp_register_kprobes (struct kprobe *probes, int num_probes)
  96 {
  97         int i, ret ;
  98         unsigned long addr;
  99
 100         for (i = 0; i < num_probes; i++) {
 101                 addr = kallsyms_lookup_name((char *)probes[i].addr);
 102                 if (addr == 0) {
 103                         _stp_warn("function %s not found!\n", (char *)probes[i].addr);
 104                         ret = -1;
 105                         goto out;
 106                 }
 107                 dbug("inserting kprobe at %s (%p)\n", probes[i].addr, addr);
 108                 probes[i].addr = (kprobe_opcode_t *)addr;
 109                 ret = register_kprobe(&probes[i]);
 110                 if (ret)
 111                         goto out;
 112         }
 113         return 0;
 114 out:
 115         _stp_warn("probe module initialization failed.  Exiting...\n");
 116         _stp_unregister_kprobes(probes, i);
 117         return ret;
 118 }
 119
 120 #ifdef USE_RET_PROBES
 121 /** Register a group of return probes.
 122  * @param probes Pointer to an array of struct kretprobe.
 123  * @param num_probes Number of probes in the array.
 124  * @return 0 on success.
 125  */
 126 int _stp_register_kretprobes (struct kretprobe *probes, int num_probes)
 127 {
 128         int i, ret ;
 129         unsigned long addr;
 130
 131         for (i = 0; i < num_probes; i++) {
 132                 addr = kallsyms_lookup_name((char *)probes[i].kp.addr);
 133                 if (addr == 0) {
 134                         _stp_warn("function %s not found!\n",
 135                                    (char *)probes[i].kp.addr);
 136                         ret = -1; /* FIXME */
 137                         goto out;
 138                 }
 139                 dbug("inserting kretprobe at %s (%p)\n", probes[i].kp.addr, addr);
 140                 probes[i].kp.addr = (kprobe_opcode_t *)addr;
 141                 ret = register_kretprobe(&probes[i]);
 142                 if (ret)
 143                         goto out;
 144         }
 145         return 0;
 146 out:
 147         _stp_warn("probe module initialization failed.  Exiting...\n");
 148         _stp_unregister_kretprobes(probes, i);
 149         return ret;
 150 }
 151 #endif
 152 #endif /* _PROBES_C */