include/lttng/userspace-probe-internal.hpp

   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 <common/fd-handle.hpp>
  13 #include <common/macros.hpp>
  14
  15 #include <lttng/lttng-error.h>
  16 #include <lttng/userspace-probe.h>
  17
  18 #include <stdbool.h>
  19
  20 struct lttng_payload;
  21 struct lttng_payload_view;
  22 struct lttng_dynamic_buffer;
  23 struct mi_writer;
  24
  25 using userspace_probe_location_equal_cb = bool (*)(const struct lttng_userspace_probe_location *,
  26                                                    const struct lttng_userspace_probe_location *);
  27 using userspace_probe_location_hash_cb =
  28         unsigned long (*)(const struct lttng_userspace_probe_location *);
  29 using userspace_probe_location_mi =
  30         enum lttng_error_code (*)(const struct lttng_userspace_probe_location *, struct mi_writer);
  31
  32 /*
  33  * No elf-specific comm structure is defined since no elf-specific payload is
  34  * currently needed.
  35  */
  36 struct lttng_userspace_probe_location_lookup_method_comm {
  37         /* enum lttng_userspace_probe_location_lookup_method_type */
  38         int8_t type;
  39         /* type-specific payload */
  40         char payload[];
  41 };
  42
  43 /* Common ancestor of all userspace probe location lookup methods. */
  44 struct lttng_userspace_probe_location_lookup_method {
  45         enum lttng_userspace_probe_location_lookup_method_type type;
  46 };
  47
  48 struct lttng_userspace_probe_location_lookup_method_elf {
  49         struct lttng_userspace_probe_location_lookup_method parent;
  50 };
  51
  52 struct lttng_userspace_probe_location_lookup_method_sdt {
  53         struct lttng_userspace_probe_location_lookup_method parent;
  54 };
  55
  56 struct lttng_userspace_probe_location_comm {
  57         /* enum lttng_userspace_probe_location_type */
  58         int8_t type;
  59         /*
  60          * Payload is composed of, in that order,
  61          *   - type-specific payload
  62          *   - struct lttng_userspace_probe_location_lookup_method_comm
  63          */
  64         char payload[];
  65 };
  66
  67 struct lttng_userspace_probe_location_function_comm {
  68         /* Both lengths include the trailing \0. */
  69         uint32_t function_name_len;
  70         uint32_t binary_path_len;
  71         /*
  72          * Payload is composed of, in that order,
  73          *   - function name (with trailing \0),
  74          *   - absolute binary path (with trailing \0)
  75          */
  76         char payload[];
  77 } LTTNG_PACKED;
  78
  79 struct lttng_userspace_probe_location_tracepoint_comm {
  80         /* The three lengths include the trailing \0. */
  81         uint32_t probe_name_len;
  82         uint32_t provider_name_len;
  83         uint32_t binary_path_len;
  84         /*
  85          * Payload is composed of, in that order,
  86          *   - probe name (with trailing \0),
  87          *   - provider name (with trailing \0),
  88          *   - absolute binary path (with trailing \0)
  89          */
  90         char payload[];
  91 } LTTNG_PACKED;
  92
  93 /* Common ancestor of all userspace probe locations. */
  94 struct lttng_userspace_probe_location {
  95         enum lttng_userspace_probe_location_type type;
  96         struct lttng_userspace_probe_location_lookup_method *lookup_method;
  97         userspace_probe_location_equal_cb equal;
  98         userspace_probe_location_hash_cb hash;
  99         userspace_probe_location_hash_cb mi;
 100 };
 101
 102 struct lttng_userspace_probe_location_function {
 103         struct lttng_userspace_probe_location parent;
 104         char *function_name;
 105         char *binary_path;
 106         /*
 107          * binary_fd is a file descriptor to the executable file. It's open
 108          * early on to keep the backing inode valid over the course of the
 109          * intrumentation and use. It prevents deletion and reuse races.
 110          */
 111         struct fd_handle *binary_fd_handle;
 112         enum lttng_userspace_probe_location_function_instrumentation_type instrumentation_type;
 113 };
 114
 115 struct lttng_userspace_probe_location_tracepoint {
 116         struct lttng_userspace_probe_location parent;
 117         char *probe_name;
 118         char *provider_name;
 119         char *binary_path;
 120         /*
 121          * binary_fd is a file descriptor to the executable file. It's open
 122          * early on to keep the backing inode valid over the course of the
 123          * intrumentation and use. It prevents deletion and reuse races.
 124          */
 125         struct fd_handle *binary_fd_handle;
 126 };
 127
 128 int lttng_userspace_probe_location_serialize(
 129                 const struct lttng_userspace_probe_location *location,
 130                 struct lttng_payload *payload);
 131
 132 int lttng_userspace_probe_location_create_from_payload(
 133                 struct lttng_payload_view *view,
 134                 struct lttng_userspace_probe_location **probe_location);
 135
 136 /*
 137  * Returns a version of the location that is serialized to a contiguous region
 138  * of memory. Pass NULL to buffer to only get the storage requirement of the
 139  * flattened userspace probe location.
 140  */
 141 int lttng_userspace_probe_location_flatten(
 142                 const struct lttng_userspace_probe_location *location,
 143                 struct lttng_dynamic_buffer *buffer);
 144
 145 struct lttng_userspace_probe_location *lttng_userspace_probe_location_copy(
 146                 const struct lttng_userspace_probe_location *location);
 147
 148 bool lttng_userspace_probe_location_lookup_method_is_equal(
 149                 const struct lttng_userspace_probe_location_lookup_method *a,
 150                 const struct lttng_userspace_probe_location_lookup_method *b);
 151
 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 unsigned long lttng_userspace_probe_location_hash(
 157                 const struct lttng_userspace_probe_location *location);
 158
 159 enum lttng_error_code lttng_userspace_probe_location_mi_serialize(
 160                 const struct lttng_userspace_probe_location *location,
 161                 struct mi_writer *writer);
 162
 163 #endif /* LTTNG_USERSPACE_PROBE_INTERNAL_H */