include/lttng/userspace-probe.h

   1 /*
   2  * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This library is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This library is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this library; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 #ifndef LTTNG_USERSPACE_PROBE_H
  19 #define LTTNG_USERSPACE_PROBE_H
  20
  21 #ifdef __cplusplus
  22 extern "C" {
  23 #endif
  24
  25 /*
  26  * Userspace probe lookup methods specifies how the userspace probe location
  27  * specified by the user should be interpreted.
  28  */
  29 struct lttng_userspace_probe_location_lookup_method;
  30
  31 enum lttng_userspace_probe_location_lookup_method_type {
  32         LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_UNKNOWN           = -1,
  33         LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_DEFAULT  = 0,
  34         LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF      = 1,
  35         LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT    = 2,
  36 };
  37
  38 /*
  39  * Get the type of a lookup method.
  40  */
  41 extern enum lttng_userspace_probe_location_lookup_method_type
  42 lttng_userspace_probe_location_lookup_method_get_type(
  43                 const struct lttng_userspace_probe_location_lookup_method *lookup_method);
  44
  45 /*
  46  * Destroy a lookup method.
  47  */
  48 extern void lttng_userspace_probe_location_lookup_method_destroy(
  49                 struct lttng_userspace_probe_location_lookup_method *lookup_method);
  50
  51 /*
  52  * Create a tracepoint ELF function lookup method struct.
  53  * Return NULL on failure.
  54  */
  55 extern struct lttng_userspace_probe_location_lookup_method *
  56 lttng_userspace_probe_location_lookup_method_function_elf_create(void);
  57
  58 /*
  59  * Create a tracepoint SDT tracepoint lookup method struct.
  60  * Return NULL on failure.
  61  */
  62 extern struct lttng_userspace_probe_location_lookup_method *
  63 lttng_userspace_probe_location_lookup_method_tracepoint_sdt_create(void);
  64
  65
  66 /*
  67  * Contains all the information needed to compute the instrumentation point in
  68  * the binary. It is used in conjonction with a lookup method.
  69  */
  70 struct lttng_userspace_probe_location;
  71
  72 enum lttng_userspace_probe_location_type {
  73         LTTNG_USERSPACE_PROBE_LOCATION_TYPE_UNKNOWN     = -1,
  74         /* Traces a function's entry and exit. */
  75         LTTNG_USERSPACE_PROBE_LOCATION_TYPE_FUNCTION    = 0,
  76         /* Trace a single point. */
  77         LTTNG_USERSPACE_PROBE_LOCATION_TYPE_TRACEPOINT  = 1,
  78 };
  79
  80 /*
  81  * Get the type of the userspace probe location.
  82  */
  83 extern enum lttng_userspace_probe_location_type
  84 lttng_userspace_probe_location_get_type(
  85                 const struct lttng_userspace_probe_location *location);
  86
  87 /*
  88  * Destroy the userspace probe location.
  89  */
  90 extern void lttng_userspace_probe_location_destroy(
  91                 struct lttng_userspace_probe_location *location);
  92
  93 /*
  94  * Create a probe location of the function type.
  95  * Receives the target binary file path and function to instrument.
  96  * On failure, NULL is returned.
  97  *
  98  * The ownership of the lookup method is transferred to the created probe
  99  * location.
 100  */
 101 extern struct lttng_userspace_probe_location *
 102 lttng_userspace_probe_location_function_create(const char *binary_path,
 103                 const char *function_name,
 104                 struct lttng_userspace_probe_location_lookup_method *lookup_method);
 105
 106 /*
 107  * Get the target binary path of the probe location of the function type.
 108  */
 109 extern const char *lttng_userspace_probe_location_function_get_binary_path(
 110                 const struct lttng_userspace_probe_location *location);
 111
 112 /*
 113  * Get the target function type of the probe location of the function type.
 114  */
 115 extern const char *lttng_userspace_probe_location_function_get_function_name(
 116                 const struct lttng_userspace_probe_location *location);
 117
 118 /*
 119  * Get the FD to the target binary file to the probe location of the function
 120  * type.
 121  */
 122 extern int lttng_userspace_probe_location_function_get_binary_fd(
 123                 const struct lttng_userspace_probe_location *location);
 124
 125 /*
 126  * Get the lookup method of the given userspace probe location.
 127  * Returns NULL if the probe location type is unsupported.
 128  *
 129  * The ownership of the lookup method is NOT transferred to the caller.
 130  */
 131 extern const struct lttng_userspace_probe_location_lookup_method *
 132 lttng_userspace_probe_location_get_lookup_method(
 133                 const struct lttng_userspace_probe_location *location);
 134
 135 /*
 136  * Create a probe location of the tracepoint type.
 137  * Receives the target binary file path, probename and probe provider to
 138  * instrument.
 139  * On failure, NULL is returned.
 140  *
 141  * The ownership of the lookup method is transferred to the created probe
 142  * location.
 143  */
 144 extern struct lttng_userspace_probe_location *
 145 lttng_userspace_probe_location_tracepoint_create(const char *binary_path,
 146                 const char *probe_name, const char *provider_name,
 147                 struct lttng_userspace_probe_location_lookup_method *lookup_method);
 148
 149 /*
 150  * Get the target binary path of the probe location of the tracepoint type.
 151  */
 152 extern const char *lttng_userspace_probe_location_tracepoint_get_binary_path(
 153                 const struct lttng_userspace_probe_location *location);
 154
 155 /*
 156  * Get the target probe name of the probe location of the tracepoint type.
 157  */
 158 extern const char *lttng_userspace_probe_location_tracepoint_get_probe_name(
 159                 const struct lttng_userspace_probe_location *location);
 160
 161 /*
 162  * Get the target probe provider name of the probe location of the tracepoint
 163  * type.
 164  */
 165 extern const char *lttng_userspace_probe_location_tracepoint_get_provider_name(
 166                 const struct lttng_userspace_probe_location *location);
 167
 168 /*
 169  * Get the FD to the target binary file to the probe location of the tracepoint
 170  * type.
 171  */
 172 extern int lttng_userspace_probe_location_tracepoint_get_binary_fd(
 173                 const struct lttng_userspace_probe_location *location);
 174
 175 #ifdef __cplusplus
 176 }
 177 #endif
 178
 179 #endif /* LTTNG_USERSPACE_PROBE_H */