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 <common/fd-handle.h>
  15 #include <stdbool.h>
  16
  17 struct lttng_payload;
  18 struct lttng_payload_view;
  19 struct lttng_dynamic_buffer;
  20
  21 typedef bool (*userspace_probe_location_equal_cb)(
  22                 const struct lttng_userspace_probe_location *a,
  23                 const struct lttng_userspace_probe_location *b);
  24 typedef unsigned long (*userspace_probe_location_hash_cb)(
  25                 const struct lttng_userspace_probe_location *location);
  26
  27 /*
  28  * No elf-specific comm structure is defined since no elf-specific payload is
  29  * currently needed.
  30  */
  31 struct lttng_userspace_probe_location_lookup_method_comm {
  32         /* enum lttng_userspace_probe_location_lookup_method_type */
  33         int8_t type;
  34         /* type-specific payload */
  35         char payload[];
  36 };
  37
  38 /* Common ancestor of all userspace probe location lookup methods. */
  39 struct lttng_userspace_probe_location_lookup_method {
  40         enum lttng_userspace_probe_location_lookup_method_type type;
  41 };
  42
  43 struct lttng_userspace_probe_location_lookup_method_elf {
  44         struct lttng_userspace_probe_location_lookup_method parent;
  45 };
  46
  47 struct lttng_userspace_probe_location_lookup_method_sdt {
  48         struct lttng_userspace_probe_location_lookup_method parent;
  49 };
  50
  51 struct lttng_userspace_probe_location_comm {
  52         /* enum lttng_userspace_probe_location_type */
  53         int8_t type;
  54         /*
  55          * Payload is composed of, in that order,
  56          *   - type-specific payload
  57          *   - struct lttng_userspace_probe_location_lookup_method_comm
  58          */
  59         char payload[];
  60 };
  61
  62 struct lttng_userspace_probe_location_function_comm {
  63         /* Both lengths include the trailing \0. */
  64         uint32_t function_name_len;
  65         uint32_t binary_path_len;
  66         /*
  67          * Payload is composed of, in that order,
  68          *   - function name (with trailing \0),
  69          *   - absolute binary path (with trailing \0)
  70          */
  71         char payload[];
  72 } LTTNG_PACKED;
  73
  74 struct lttng_userspace_probe_location_tracepoint_comm {
  75         /* The three lengths include the trailing \0. */
  76         uint32_t probe_name_len;
  77         uint32_t provider_name_len;
  78         uint32_t binary_path_len;
  79         /*
  80          * Payload is composed of, in that order,
  81          *   - probe name (with trailing \0),
  82          *   - provider name (with trailing \0),
  83          *   - absolute binary path (with trailing \0)
  84          */
  85         char payload[];
  86 } LTTNG_PACKED;
  87
  88 /* Common ancestor of all userspace probe locations. */
  89 struct lttng_userspace_probe_location {
  90         enum lttng_userspace_probe_location_type type;
  91         struct lttng_userspace_probe_location_lookup_method *lookup_method;
  92         userspace_probe_location_equal_cb equal;
  93         userspace_probe_location_hash_cb hash;
  94 };
  95
  96 struct lttng_userspace_probe_location_function {
  97         struct lttng_userspace_probe_location parent;
  98         char *function_name;
  99         char *binary_path;
 100         /*
 101          * binary_fd is a file descriptor to the executable file. It's open
 102          * early on to keep the backing inode valid over the course of the
 103          * intrumentation and use. It prevents deletion and reuse races.
 104          */
 105         struct fd_handle *binary_fd_handle;
 106         enum lttng_userspace_probe_location_function_instrumentation_type instrumentation_type;
 107 };
 108
 109 struct lttng_userspace_probe_location_tracepoint {
 110         struct lttng_userspace_probe_location parent;
 111         char *probe_name;
 112         char *provider_name;
 113         char *binary_path;
 114         /*
 115          * binary_fd is a file descriptor to the executable file. It's open
 116          * early on to keep the backing inode valid over the course of the
 117          * intrumentation and use. It prevents deletion and reuse races.
 118          */
 119         struct fd_handle *binary_fd_handle;
 120 };
 121
 122 LTTNG_HIDDEN
 123 int lttng_userspace_probe_location_serialize(
 124                 const struct lttng_userspace_probe_location *location,
 125                 struct lttng_payload *payload);
 126
 127 LTTNG_HIDDEN
 128 int lttng_userspace_probe_location_create_from_payload(
 129                 struct lttng_payload_view *view,
 130                 struct lttng_userspace_probe_location **probe_location);
 131
 132 /*
 133  * Returns a version of the location that is serialized to a contiguous region
 134  * of memory. Pass NULL to buffer to only get the storage requirement of the
 135  * flattened userspace probe location.
 136  */
 137 LTTNG_HIDDEN
 138 int lttng_userspace_probe_location_flatten(
 139                 const struct lttng_userspace_probe_location *location,
 140                 struct lttng_dynamic_buffer *buffer);
 141
 142 LTTNG_HIDDEN
 143 struct lttng_userspace_probe_location *lttng_userspace_probe_location_copy(
 144                 const struct lttng_userspace_probe_location *location);
 145
 146 LTTNG_HIDDEN
 147 bool lttng_userspace_probe_location_lookup_method_is_equal(
 148                 const struct lttng_userspace_probe_location_lookup_method *a,
 149                 const struct lttng_userspace_probe_location_lookup_method *b);
 150
 151 LTTNG_HIDDEN
 152 bool lttng_userspace_probe_location_is_equal(
 153                 const struct lttng_userspace_probe_location *a,
 154                 const struct lttng_userspace_probe_location *b);
 155
 156 LTTNG_HIDDEN
 157 unsigned long lttng_userspace_probe_location_hash(
 158                 const struct lttng_userspace_probe_location *location);
 159
 160 #endif /* LTTNG_USERSPACE_PROBE_INTERNAL_H */