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