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_comm {
  48         /* enum lttng_userspace_probe_location_type */
  49         int8_t type;
  50         /*
  51          * Payload is composed of, in that order,
  52          *   - type-specific payload
  53          *   - struct lttng_userspace_probe_location_lookup_method_comm
  54          */
  55         char payload[];
  56 };
  57
  58 struct lttng_userspace_probe_location_function_comm {
  59         /* Both lengths include the trailing \0. */
  60         uint32_t function_name_len;
  61         uint32_t binary_path_len;
  62         /*
  63          * Payload is composed of, in that order,
  64          *   - function name (with trailing \0),
  65          *   - absolute binary path (with trailing \0)
  66          */
  67         char payload[];
  68 } LTTNG_PACKED;
  69
  70 /* Common ancestor of all userspace probe locations. */
  71 struct lttng_userspace_probe_location {
  72         enum lttng_userspace_probe_location_type type;
  73         struct lttng_userspace_probe_location_lookup_method *lookup_method;
  74 };
  75
  76 struct lttng_userspace_probe_location_function {
  77         struct lttng_userspace_probe_location parent;
  78         char *function_name;
  79         char *binary_path;
  80         /*
  81          * binary_fd is a file descriptor to the executable file. It's open
  82          * early on to keep the backing inode valid over the course of the
  83          * intrumentation and use. It prevents deletion and reuse races.
  84          * Set to -1 if not open.
  85          */
  86         int binary_fd;
  87 };
  88
  89 LTTNG_HIDDEN
  90 int lttng_userspace_probe_location_serialize(
  91                 const struct lttng_userspace_probe_location *location,
  92                 struct lttng_dynamic_buffer *buffer,
  93                 int *binary_fd);
  94
  95 LTTNG_HIDDEN
  96 int lttng_userspace_probe_location_create_from_buffer(
  97                 const struct lttng_buffer_view *buffer,
  98                 struct lttng_userspace_probe_location **probe_location);
  99
 100 LTTNG_HIDDEN
 101 int lttng_userspace_probe_location_function_set_binary_fd(
 102                 struct lttng_userspace_probe_location *location, int binary_fd);
 103
 104 /*
 105  * Returns a version of the location that is serialized to a contiguous region
 106  * of memory. Pass NULL to buffer to only get the storage requirement of the
 107  * flattened userspace probe location.
 108  */
 109 LTTNG_HIDDEN
 110 int lttng_userspace_probe_location_flatten(
 111                 const struct lttng_userspace_probe_location *location,
 112                 struct lttng_dynamic_buffer *buffer);
 113
 114 #endif /* LTTNG_USERSPACE_PROBE_INTERNAL_H */