include/lttng/userspace-probe.h

   1 /*
   2  * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #ifndef LTTNG_USERSPACE_PROBE_H
   9 #define LTTNG_USERSPACE_PROBE_H
  10
  11 #include <lttng/lttng-export.h>
  12
  13 #ifdef __cplusplus
  14 extern "C" {
  15 #endif
  16
  17 /*
  18  * Userspace probe lookup methods specifies how the userspace probe location
  19  * specified by the user should be interpreted.
  20  */
  21 struct lttng_userspace_probe_location_lookup_method;
  22
  23 enum lttng_userspace_probe_location_lookup_method_type {
  24         LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_UNKNOWN = -1,
  25         LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_DEFAULT = 0,
  26         LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF = 1,
  27         LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT = 2,
  28 };
  29
  30 /*
  31  * Get the type of a lookup method.
  32  */
  33 LTTNG_EXPORT extern enum lttng_userspace_probe_location_lookup_method_type
  34 lttng_userspace_probe_location_lookup_method_get_type(
  35         const struct lttng_userspace_probe_location_lookup_method *lookup_method);
  36
  37 /*
  38  * Destroy a lookup method.
  39  */
  40 LTTNG_EXPORT extern void lttng_userspace_probe_location_lookup_method_destroy(
  41         struct lttng_userspace_probe_location_lookup_method *lookup_method);
  42
  43 /*
  44  * Create a tracepoint ELF function lookup method struct.
  45  * Return NULL on failure.
  46  */
  47 LTTNG_EXPORT extern struct lttng_userspace_probe_location_lookup_method *
  48 lttng_userspace_probe_location_lookup_method_function_elf_create(void);
  49
  50 /*
  51  * Create a tracepoint SDT tracepoint lookup method struct.
  52  * Return NULL on failure.
  53  */
  54 LTTNG_EXPORT extern struct lttng_userspace_probe_location_lookup_method *
  55 lttng_userspace_probe_location_lookup_method_tracepoint_sdt_create(void);
  56
  57 /*
  58  * Contains all the information needed to compute the instrumentation point in
  59  * the binary. It is used in conjonction with a lookup method.
  60  */
  61 struct lttng_userspace_probe_location;
  62
  63 enum lttng_userspace_probe_location_status {
  64         LTTNG_USERSPACE_PROBE_LOCATION_STATUS_OK = 0,
  65         /* Invalid parameters provided. */
  66         LTTNG_USERSPACE_PROBE_LOCATION_STATUS_INVALID = -1,
  67 };
  68
  69 enum lttng_userspace_probe_location_type {
  70         LTTNG_USERSPACE_PROBE_LOCATION_TYPE_UNKNOWN = -1,
  71         /* Function. */
  72         LTTNG_USERSPACE_PROBE_LOCATION_TYPE_FUNCTION = 0,
  73         /* SDT probe's callsites. */
  74         LTTNG_USERSPACE_PROBE_LOCATION_TYPE_TRACEPOINT = 1,
  75 };
  76
  77 /*
  78  * Get the type of the userspace probe location.
  79  */
  80 LTTNG_EXPORT extern enum lttng_userspace_probe_location_type
  81 lttng_userspace_probe_location_get_type(const struct lttng_userspace_probe_location *location);
  82
  83 /*
  84  * Destroy the userspace probe location.
  85  */
  86 LTTNG_EXPORT extern void
  87 lttng_userspace_probe_location_destroy(struct lttng_userspace_probe_location *location);
  88
  89 enum lttng_userspace_probe_location_function_instrumentation_type {
  90         LTTNG_USERSPACE_PROBE_LOCATION_FUNCTION_INSTRUMENTATION_TYPE_UNKNOWN = -1,
  91         /* Only instrument the function's entry. */
  92         LTTNG_USERSPACE_PROBE_LOCATION_FUNCTION_INSTRUMENTATION_TYPE_ENTRY = 0,
  93 };
  94
  95 /*
  96  * Create a probe location of the function type.
  97  * Receives the target binary file path and function to instrument.
  98  * On failure, NULL is returned.
  99  *
 100  * The ownership of the lookup method is transferred to the created probe
 101  * location.
 102  */
 103 LTTNG_EXPORT extern struct lttng_userspace_probe_location *
 104 lttng_userspace_probe_location_function_create(
 105         const char *binary_path,
 106         const char *function_name,
 107         struct lttng_userspace_probe_location_lookup_method *lookup_method);
 108
 109 /*
 110  * Get the target binary path of the probe location of the function type.
 111  */
 112 LTTNG_EXPORT extern const char *lttng_userspace_probe_location_function_get_binary_path(
 113         const struct lttng_userspace_probe_location *location);
 114
 115 /*
 116  * Get the target function type of the probe location of the function type.
 117  */
 118 LTTNG_EXPORT extern const char *lttng_userspace_probe_location_function_get_function_name(
 119         const struct lttng_userspace_probe_location *location);
 120
 121 /*
 122  * Get the FD to the target binary file to the probe location of the function
 123  * type. The FD is only valid for the duration of the lifetime of `location`.
 124  */
 125 LTTNG_EXPORT extern int lttng_userspace_probe_location_function_get_binary_fd(
 126         const struct lttng_userspace_probe_location *location);
 127
 128 /*
 129  * Get the instrumentation type of the function probe location.
 130  */
 131 LTTNG_EXPORT extern enum lttng_userspace_probe_location_function_instrumentation_type
 132 lttng_userspace_probe_location_function_get_instrumentation_type(
 133         const struct lttng_userspace_probe_location *location);
 134
 135 /*
 136  * Get the instrumentation type of the function probe location.
 137  * Defaults to
 138  * LTTNG_USERSPACE_PROBE_LOCATION_FUNCTION_INSTRUMENTATION_TYPE_ENTRY.
 139  *
 140  * Returns LTTNG_USERSPACE_PROBE_LOCATION_STATUS_OK on success,
 141  * LTTNG_USERSPACE_PROBE_LOCATION_STATUS_INVALID if invalid parameters
 142  * are provided.
 143  */
 144 LTTNG_EXPORT extern enum lttng_userspace_probe_location_status
 145 lttng_userspace_probe_location_function_set_instrumentation_type(
 146         const struct lttng_userspace_probe_location *location,
 147         enum lttng_userspace_probe_location_function_instrumentation_type instrumentation_type);
 148
 149 /*
 150  * Get the lookup method of the given userspace probe location.
 151  * Returns NULL if the probe location type is unsupported.
 152  *
 153  * The ownership of the lookup method is NOT transferred to the caller.
 154  */
 155 LTTNG_EXPORT extern const struct lttng_userspace_probe_location_lookup_method *
 156 lttng_userspace_probe_location_get_lookup_method(
 157         const struct lttng_userspace_probe_location *location);
 158
 159 /*
 160  * Create a probe location of the tracepoint type.
 161  * Receives the target binary file path, probename and probe provider to
 162  * instrument.
 163  * On failure, NULL is returned.
 164  *
 165  * The ownership of the lookup method is transferred to the created probe
 166  * location.
 167  */
 168 LTTNG_EXPORT extern struct lttng_userspace_probe_location *
 169 lttng_userspace_probe_location_tracepoint_create(
 170         const char *binary_path,
 171         const char *probe_name,
 172         const char *provider_name,
 173         struct lttng_userspace_probe_location_lookup_method *lookup_method);
 174
 175 /*
 176  * Get the target binary path of the probe location of the tracepoint type.
 177  */
 178 LTTNG_EXPORT extern const char *lttng_userspace_probe_location_tracepoint_get_binary_path(
 179         const struct lttng_userspace_probe_location *location);
 180
 181 /*
 182  * Get the target probe name of the probe location of the tracepoint type.
 183  */
 184 LTTNG_EXPORT extern const char *lttng_userspace_probe_location_tracepoint_get_probe_name(
 185         const struct lttng_userspace_probe_location *location);
 186
 187 /*
 188  * Get the target probe provider name of the probe location of the tracepoint
 189  * type.
 190  */
 191 LTTNG_EXPORT extern const char *lttng_userspace_probe_location_tracepoint_get_provider_name(
 192         const struct lttng_userspace_probe_location *location);
 193
 194 /*
 195  * Get the FD to the target binary file to the probe location of the tracepoint
 196  * type. The FD is only valid for the duration of the lifetime of `location`.
 197  */
 198 LTTNG_EXPORT extern int lttng_userspace_probe_location_tracepoint_get_binary_fd(
 199         const struct lttng_userspace_probe_location *location);
 200
 201 #ifdef __cplusplus
 202 }
 203 #endif
 204
 205 #endif /* LTTNG_USERSPACE_PROBE_H */