include/lttng/userspace-probe-internal.h

   1 /*
   2  * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  * Copyright (C) 2018 Francis Deslauriers <francis.deslauriers@efficios.com>
   4  *
   5  * SPDX-License-Identifier: LGPL-2.1-only
   6  *
   7  */
   8
   9 #ifndef LTTNG_USERSPACE_PROBE_INTERNAL_H
  10 #define LTTNG_USERSPACE_PROBE_INTERNAL_H
  11
  12 #include <lttng/userspace-probe.h>
  13 #include <common/macros.h>
  14 #include <stdbool.h>
  15
  16 struct lttng_payload;
  17 struct lttng_payload_view;
  18 struct lttng_dynamic_buffer;
  19
  20 typedef bool (*userspace_probe_location_equal_cb)(
  21                 const struct lttng_userspace_probe_location *a,
  22                 const struct lttng_userspace_probe_location *b);
  23
  24 /*
  25  * No elf-specific comm structure is defined since no elf-specific payload is
  26  * currently needed.
  27  */
  28 struct lttng_userspace_probe_location_lookup_method_comm {
  29         /* enum lttng_userspace_probe_location_lookup_method_type */
  30         int8_t type;
  31         /* type-specific payload */
  32         char payload[];
  33 };
  34
  35 /* Common ancestor of all userspace probe location lookup methods. */
  36 struct lttng_userspace_probe_location_lookup_method {
  37         enum lttng_userspace_probe_location_lookup_method_type type;
  38 };
  39
  40 struct lttng_userspace_probe_location_lookup_method_elf {
  41         struct lttng_userspace_probe_location_lookup_method parent;
  42 };
  43
  44 struct lttng_userspace_probe_location_lookup_method_sdt {
  45         struct lttng_userspace_probe_location_lookup_method parent;
  46 };
  47
  48 struct lttng_userspace_probe_location_comm {
  49         /* enum lttng_userspace_probe_location_type */
  50         int8_t type;
  51         /*
  52          * Payload is composed of, in that order,
  53          *   - type-specific payload
  54          *   - struct lttng_userspace_probe_location_lookup_method_comm
  55          */
  56         char payload[];
  57 };
  58
  59 struct lttng_userspace_probe_location_function_comm {
  60         /* Both lengths include the trailing \0. */
  61         uint32_t function_name_len;
  62         uint32_t binary_path_len;
  63         /*
  64          * Payload is composed of, in that order,
  65          *   - function name (with trailing \0),
  66          *   - absolute binary path (with trailing \0)
  67          */
  68         char payload[];
  69 } LTTNG_PACKED;
  70
  71 struct lttng_userspace_probe_location_tracepoint_comm {
  72         /* The three lengths include the trailing \0. */
  73         uint32_t probe_name_len;
  74         uint32_t provider_name_len;
  75         uint32_t binary_path_len;
  76         /*
  77          * Payload is composed of, in that order,
  78          *   - probe name (with trailing \0),
  79          *   - provider name (with trailing \0),
  80          *   - absolute binary path (with trailing \0)
  81          */
  82         char payload[];
  83 } LTTNG_PACKED;
  84
  85 /* Common ancestor of all userspace probe locations. */
  86 struct lttng_userspace_probe_location {
  87         enum lttng_userspace_probe_location_type type;
  88         struct lttng_userspace_probe_location_lookup_method *lookup_method;
  89         userspace_probe_location_equal_cb equal;
  90 };
  91
  92 struct lttng_userspace_probe_location_function {
  93         struct lttng_userspace_probe_location parent;
  94         char *function_name;
  95         char *binary_path;
  96         /*
  97          * binary_fd is a file descriptor to the executable file. It's open
  98          * early on to keep the backing inode valid over the course of the
  99          * intrumentation and use. It prevents deletion and reuse races.
 100          * Set to -1 if not open.
 101          */
 102         int binary_fd;
 103         enum lttng_userspace_probe_location_function_instrumentation_type instrumentation_type;
 104 };
 105
 106 struct lttng_userspace_probe_location_tracepoint {
 107         struct lttng_userspace_probe_location parent;
 108         char *probe_name;
 109         char *provider_name;
 110         char *binary_path;
 111         /*
 112          * binary_fd is a file descriptor to the executable file. It's open
 113          * early on to keep the backing inode valid over the course of the
 114          * intrumentation and use. It prevents deletion and reuse races.
 115          * Set to -1 if not open.
 116          */
 117         int binary_fd;
 118 };
 119
 120 LTTNG_HIDDEN
 121 int lttng_userspace_probe_location_serialize(
 122                 const struct lttng_userspace_probe_location *location,
 123                 struct lttng_payload *payload);
 124
 125 LTTNG_HIDDEN
 126 int lttng_userspace_probe_location_create_from_payload(
 127                 struct lttng_payload_view *view,
 128                 struct lttng_userspace_probe_location **probe_location);
 129
 130 LTTNG_HIDDEN
 131 int lttng_userspace_probe_location_function_set_binary_fd(
 132                 struct lttng_userspace_probe_location *location, int binary_fd);
 133
 134 LTTNG_HIDDEN
 135 int lttng_userspace_probe_location_tracepoint_set_binary_fd(
 136                 struct lttng_userspace_probe_location *location, int binary_fd);
 137
 138 /*
 139  * Returns a version of the location that is serialized to a contiguous region
 140  * of memory. Pass NULL to buffer to only get the storage requirement of the
 141  * flattened userspace probe location.
 142  */
 143 LTTNG_HIDDEN
 144 int lttng_userspace_probe_location_flatten(
 145                 const struct lttng_userspace_probe_location *location,
 146                 struct lttng_dynamic_buffer *buffer);
 147
 148 LTTNG_HIDDEN
 149 struct lttng_userspace_probe_location *lttng_userspace_probe_location_copy(
 150                 const struct lttng_userspace_probe_location *location);
 151
 152 LTTNG_HIDDEN
 153 bool lttng_userspace_probe_location_lookup_method_is_equal(
 154                 const struct lttng_userspace_probe_location_lookup_method *a,
 155                 const struct lttng_userspace_probe_location_lookup_method *b);
 156
 157 LTTNG_HIDDEN
 158 bool lttng_userspace_probe_location_is_equal(
 159                 const struct lttng_userspace_probe_location *a,
 160                 const struct lttng_userspace_probe_location *b);
 161
 162 #endif /* LTTNG_USERSPACE_PROBE_INTERNAL_H */