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/dynamic-buffer.h>
  15 #include <common/buffer-view.h>
  16
  17 typedef bool (*userspace_probe_location_equal_cb)(
  18                 const struct lttng_userspace_probe_location *a,
  19                 const struct lttng_userspace_probe_location *b);
  20
  21 /*
  22  * No elf-specific comm structure is defined since no elf-specific payload is
  23  * currently needed.
  24  */
  25 struct lttng_userspace_probe_location_lookup_method_comm {
  26         /* enum lttng_userspace_probe_location_lookup_method_type */
  27         int8_t type;
  28         /* type-specific payload */
  29         char payload[];
  30 };
  31
  32 /* Common ancestor of all userspace probe location lookup methods. */
  33 struct lttng_userspace_probe_location_lookup_method {
  34         enum lttng_userspace_probe_location_lookup_method_type type;
  35 };
  36
  37 struct lttng_userspace_probe_location_lookup_method_elf {
  38         struct lttng_userspace_probe_location_lookup_method parent;
  39 };
  40
  41 struct lttng_userspace_probe_location_lookup_method_sdt {
  42         struct lttng_userspace_probe_location_lookup_method parent;
  43 };
  44
  45 struct lttng_userspace_probe_location_comm {
  46         /* enum lttng_userspace_probe_location_type */
  47         int8_t type;
  48         /*
  49          * Payload is composed of, in that order,
  50          *   - type-specific payload
  51          *   - struct lttng_userspace_probe_location_lookup_method_comm
  52          */
  53         char payload[];
  54 };
  55
  56 struct lttng_userspace_probe_location_function_comm {
  57         /* Both lengths include the trailing \0. */
  58         uint32_t function_name_len;
  59         uint32_t binary_path_len;
  60         /*
  61          * Payload is composed of, in that order,
  62          *   - function name (with trailing \0),
  63          *   - absolute binary path (with trailing \0)
  64          */
  65         char payload[];
  66 } LTTNG_PACKED;
  67
  68 struct lttng_userspace_probe_location_tracepoint_comm {
  69         /* The three lengths include the trailing \0. */
  70         uint32_t probe_name_len;
  71         uint32_t provider_name_len;
  72         uint32_t binary_path_len;
  73         /*
  74          * Payload is composed of, in that order,
  75          *   - probe name (with trailing \0),
  76          *   - provider name (with trailing \0),
  77          *   - absolute binary path (with trailing \0)
  78          */
  79         char payload[];
  80 } LTTNG_PACKED;
  81
  82 /* Common ancestor of all userspace probe locations. */
  83 struct lttng_userspace_probe_location {
  84         enum lttng_userspace_probe_location_type type;
  85         struct lttng_userspace_probe_location_lookup_method *lookup_method;
  86         userspace_probe_location_equal_cb equal;
  87 };
  88
  89 struct lttng_userspace_probe_location_function {
  90         struct lttng_userspace_probe_location parent;
  91         char *function_name;
  92         char *binary_path;
  93         /*
  94          * binary_fd is a file descriptor to the executable file. It's open
  95          * early on to keep the backing inode valid over the course of the
  96          * intrumentation and use. It prevents deletion and reuse races.
  97          * Set to -1 if not open.
  98          */
  99         int binary_fd;
 100         enum lttng_userspace_probe_location_function_instrumentation_type instrumentation_type;
 101 };
 102
 103 struct lttng_userspace_probe_location_tracepoint {
 104         struct lttng_userspace_probe_location parent;
 105         char *probe_name;
 106         char *provider_name;
 107         char *binary_path;
 108         /*
 109          * binary_fd is a file descriptor to the executable file. It's open
 110          * early on to keep the backing inode valid over the course of the
 111          * intrumentation and use. It prevents deletion and reuse races.
 112          * Set to -1 if not open.
 113          */
 114         int binary_fd;
 115 };
 116
 117 LTTNG_HIDDEN
 118 int lttng_userspace_probe_location_serialize(
 119                 const struct lttng_userspace_probe_location *location,
 120                 struct lttng_dynamic_buffer *buffer,
 121                 int *binary_fd);
 122
 123 LTTNG_HIDDEN
 124 int lttng_userspace_probe_location_create_from_buffer(
 125                 const struct lttng_buffer_view *buffer,
 126                 struct lttng_userspace_probe_location **probe_location);
 127
 128 LTTNG_HIDDEN
 129 int lttng_userspace_probe_location_function_set_binary_fd(
 130                 struct lttng_userspace_probe_location *location, int binary_fd);
 131
 132 LTTNG_HIDDEN
 133 int lttng_userspace_probe_location_tracepoint_set_binary_fd(
 134                 struct lttng_userspace_probe_location *location, int binary_fd);
 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 LTTNG_HIDDEN
 142 int lttng_userspace_probe_location_flatten(
 143                 const struct lttng_userspace_probe_location *location,
 144                 struct lttng_dynamic_buffer *buffer);
 145
 146 LTTNG_HIDDEN
 147 struct lttng_userspace_probe_location *lttng_userspace_probe_location_copy(
 148                 const struct lttng_userspace_probe_location *location);
 149
 150 LTTNG_HIDDEN
 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 LTTNG_HIDDEN
 156 bool lttng_userspace_probe_location_is_equal(
 157                 const struct lttng_userspace_probe_location *a,
 158                 const struct lttng_userspace_probe_location *b);
 159
 160 #endif /* LTTNG_USERSPACE_PROBE_INTERNAL_H */