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 #ifdef __cplusplus
  18 extern "C" {
  19 #endif
  20
  21 struct lttng_payload;
  22 struct lttng_payload_view;
  23 struct lttng_dynamic_buffer;
  24 struct mi_writer;
  25
  26 typedef bool (*userspace_probe_location_equal_cb)(
  27                 const struct lttng_userspace_probe_location *a,
  28                 const struct lttng_userspace_probe_location *b);
  29 typedef unsigned long (*userspace_probe_location_hash_cb)(
  30                 const struct lttng_userspace_probe_location *location);
  31 typedef enum lttng_error_code (*userspace_probe_location_mi)(
  32                 const struct lttng_userspace_probe_location *location,
  33                 struct mi_writer);
  34
  35 /*
  36  * No elf-specific comm structure is defined since no elf-specific payload is
  37  * currently needed.
  38  */
  39 struct lttng_userspace_probe_location_lookup_method_comm {
  40         /* enum lttng_userspace_probe_location_lookup_method_type */
  41         int8_t type;
  42         /* type-specific payload */
  43         char payload[];
  44 };
  45
  46 /* Common ancestor of all userspace probe location lookup methods. */
  47 struct lttng_userspace_probe_location_lookup_method {
  48         enum lttng_userspace_probe_location_lookup_method_type type;
  49 };
  50
  51 struct lttng_userspace_probe_location_lookup_method_elf {
  52         struct lttng_userspace_probe_location_lookup_method parent;
  53 };
  54
  55 struct lttng_userspace_probe_location_lookup_method_sdt {
  56         struct lttng_userspace_probe_location_lookup_method parent;
  57 };
  58
  59 struct lttng_userspace_probe_location_comm {
  60         /* enum lttng_userspace_probe_location_type */
  61         int8_t type;
  62         /*
  63          * Payload is composed of, in that order,
  64          *   - type-specific payload
  65          *   - struct lttng_userspace_probe_location_lookup_method_comm
  66          */
  67         char payload[];
  68 };
  69
  70 struct lttng_userspace_probe_location_function_comm {
  71         /* Both lengths include the trailing \0. */
  72         uint32_t function_name_len;
  73         uint32_t binary_path_len;
  74         /*
  75          * Payload is composed of, in that order,
  76          *   - function name (with trailing \0),
  77          *   - absolute binary path (with trailing \0)
  78          */
  79         char payload[];
  80 } LTTNG_PACKED;
  81
  82 struct lttng_userspace_probe_location_tracepoint_comm {
  83         /* The three lengths include the trailing \0. */
  84         uint32_t probe_name_len;
  85         uint32_t provider_name_len;
  86         uint32_t binary_path_len;
  87         /*
  88          * Payload is composed of, in that order,
  89          *   - probe name (with trailing \0),
  90          *   - provider name (with trailing \0),
  91          *   - absolute binary path (with trailing \0)
  92          */
  93         char payload[];
  94 } LTTNG_PACKED;
  95
  96 /* Common ancestor of all userspace probe locations. */
  97 struct lttng_userspace_probe_location {
  98         enum lttng_userspace_probe_location_type type;
  99         struct lttng_userspace_probe_location_lookup_method *lookup_method;
 100         userspace_probe_location_equal_cb equal;
 101         userspace_probe_location_hash_cb hash;
 102         userspace_probe_location_hash_cb mi;
 103 };
 104
 105 struct lttng_userspace_probe_location_function {
 106         struct lttng_userspace_probe_location parent;
 107         char *function_name;
 108         char *binary_path;
 109         /*
 110          * binary_fd is a file descriptor to the executable file. It's open
 111          * early on to keep the backing inode valid over the course of the
 112          * intrumentation and use. It prevents deletion and reuse races.
 113          */
 114         struct fd_handle *binary_fd_handle;
 115         enum lttng_userspace_probe_location_function_instrumentation_type instrumentation_type;
 116 };
 117
 118 struct lttng_userspace_probe_location_tracepoint {
 119         struct lttng_userspace_probe_location parent;
 120         char *probe_name;
 121         char *provider_name;
 122         char *binary_path;
 123         /*
 124          * binary_fd is a file descriptor to the executable file. It's open
 125          * early on to keep the backing inode valid over the course of the
 126          * intrumentation and use. It prevents deletion and reuse races.
 127          */
 128         struct fd_handle *binary_fd_handle;
 129 };
 130
 131 int lttng_userspace_probe_location_serialize(
 132                 const struct lttng_userspace_probe_location *location,
 133                 struct lttng_payload *payload);
 134
 135 int lttng_userspace_probe_location_create_from_payload(
 136                 struct lttng_payload_view *view,
 137                 struct lttng_userspace_probe_location **probe_location);
 138
 139 /*
 140  * Returns a version of the location that is serialized to a contiguous region
 141  * of memory. Pass NULL to buffer to only get the storage requirement of the
 142  * flattened userspace probe location.
 143  */
 144 int lttng_userspace_probe_location_flatten(
 145                 const struct lttng_userspace_probe_location *location,
 146                 struct lttng_dynamic_buffer *buffer);
 147
 148 struct lttng_userspace_probe_location *lttng_userspace_probe_location_copy(
 149                 const struct lttng_userspace_probe_location *location);
 150
 151 bool lttng_userspace_probe_location_lookup_method_is_equal(
 152                 const struct lttng_userspace_probe_location_lookup_method *a,
 153                 const struct lttng_userspace_probe_location_lookup_method *b);
 154
 155 bool lttng_userspace_probe_location_is_equal(
 156                 const struct lttng_userspace_probe_location *a,
 157                 const struct lttng_userspace_probe_location *b);
 158
 159 unsigned long lttng_userspace_probe_location_hash(
 160                 const struct lttng_userspace_probe_location *location);
 161
 162 enum lttng_error_code lttng_userspace_probe_location_mi_serialize(
 163                 const struct lttng_userspace_probe_location *location,
 164                 struct mi_writer *writer);
 165
 166 #ifdef __cplusplus
 167 }
 168 #endif
 169
 170 #endif /* LTTNG_USERSPACE_PROBE_INTERNAL_H */