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  * This library is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   7  * as published by the Free Software Foundation.
   8  *
   9  * This library is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  12  * for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public License
  15  * along with this library; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #ifndef LTTNG_USERSPACE_PROBE_INTERNAL_H
  20 #define LTTNG_USERSPACE_PROBE_INTERNAL_H
  21
  22 #include <lttng/userspace-probe.h>
  23 #include <common/macros.h>
  24 #include <common/dynamic-buffer.h>
  25 #include <common/buffer-view.h>
  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 };
  93
  94 struct lttng_userspace_probe_location_function {
  95         struct lttng_userspace_probe_location parent;
  96         char *function_name;
  97         char *binary_path;
  98         /*
  99          * binary_fd is a file descriptor to the executable file. It's open
 100          * early on to keep the backing inode valid over the course of the
 101          * intrumentation and use. It prevents deletion and reuse races.
 102          * Set to -1 if not open.
 103          */
 104         int binary_fd;
 105         enum lttng_userspace_probe_location_function_instrumentation_type instrumentation_type;
 106 };
 107
 108 struct lttng_userspace_probe_location_tracepoint {
 109         struct lttng_userspace_probe_location parent;
 110         char *probe_name;
 111         char *provider_name;
 112         char *binary_path;
 113         /*
 114          * binary_fd is a file descriptor to the executable file. It's open
 115          * early on to keep the backing inode valid over the course of the
 116          * intrumentation and use. It prevents deletion and reuse races.
 117          * Set to -1 if not open.
 118          */
 119         int binary_fd;
 120 };
 121
 122 LTTNG_HIDDEN
 123 int lttng_userspace_probe_location_serialize(
 124                 const struct lttng_userspace_probe_location *location,
 125                 struct lttng_dynamic_buffer *buffer,
 126                 int *binary_fd);
 127
 128 LTTNG_HIDDEN
 129 int lttng_userspace_probe_location_create_from_buffer(
 130                 const struct lttng_buffer_view *buffer,
 131                 struct lttng_userspace_probe_location **probe_location);
 132
 133 LTTNG_HIDDEN
 134 int lttng_userspace_probe_location_function_set_binary_fd(
 135                 struct lttng_userspace_probe_location *location, int binary_fd);
 136
 137 LTTNG_HIDDEN
 138 int lttng_userspace_probe_location_tracepoint_set_binary_fd(
 139                 struct lttng_userspace_probe_location *location, int binary_fd);
 140
 141 /*
 142  * Returns a version of the location that is serialized to a contiguous region
 143  * of memory. Pass NULL to buffer to only get the storage requirement of the
 144  * flattened userspace probe location.
 145  */
 146 LTTNG_HIDDEN
 147 int lttng_userspace_probe_location_flatten(
 148                 const struct lttng_userspace_probe_location *location,
 149                 struct lttng_dynamic_buffer *buffer);
 150
 151 LTTNG_HIDDEN
 152 struct lttng_userspace_probe_location *lttng_userspace_probe_location_copy(
 153                 const struct lttng_userspace_probe_location *location);
 154
 155 #endif /* LTTNG_USERSPACE_PROBE_INTERNAL_H */