plugins/lttng-utils/bin-info.h

   1 #ifndef _BABELTRACE_BIN_INFO_H
   2 #define _BABELTRACE_BIN_INFO_H
   3
   4 /*
   5  * Babeltrace - Executable and Shared Object Debug Info Reader
   6  *
   7  * Copyright 2015 Antoine Busque <abusque@efficios.com>
   8  *
   9  * Author: Antoine Busque <abusque@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  24  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  26  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  27  * SOFTWARE.
  28  */
  29
  30 #include <stdint.h>
  31 #include <stdbool.h>
  32 #include <gelf.h>
  33 #include <elfutils/libdw.h>
  34 #include <babeltrace/babeltrace-internal.h>
  35
  36 #define DEFAULT_DEBUG_DIR "/usr/lib/debug"
  37 #define DEBUG_SUBDIR ".debug/"
  38 #define BUILD_ID_SUBDIR ".build-id/"
  39 #define BUILD_ID_SUFFIX ".debug"
  40
  41 struct bin_info {
  42         /* Base virtual memory address. */
  43         uint64_t low_addr;
  44         /* Upper bound of exec address space. */
  45         uint64_t high_addr;
  46         /* Size of exec address space. */
  47         uint64_t memsz;
  48         /* Paths to ELF and DWARF files. */
  49         gchar *elf_path;
  50         gchar *dwarf_path;
  51         /* libelf and libdw objects representing the files. */
  52         Elf *elf_file;
  53         Dwarf *dwarf_info;
  54         /* Optional build ID info. */
  55         uint8_t *build_id;
  56         size_t build_id_len;
  57
  58         /* Optional debug link info. */
  59         gchar *dbg_link_filename;
  60         uint32_t dbg_link_crc;
  61         /* FDs to ELF and DWARF files. */
  62         int elf_fd;
  63         int dwarf_fd;
  64         /* Configuration. */
  65         gchar *debug_info_dir;
  66         /* Denotes whether the executable is position independent code. */
  67         bool is_pic:1;
  68         /* denotes whether the build id in the trace matches to one on disk. */
  69         bool file_build_id_matches:1;
  70         /*
  71          * Denotes whether the executable only has ELF symbols and no
  72          * DWARF info.
  73          */
  74         bool is_elf_only:1;
  75 };
  76
  77 struct source_location {
  78         uint64_t line_no;
  79         gchar *filename;
  80 };
  81
  82 /**
  83  * Initializes the bin_info framework. Call this before calling
  84  * anything else.
  85  *
  86  * @returns             0 on success, -1 on failure
  87  */
  88 BT_HIDDEN
  89 int bin_info_init(void);
  90
  91 /**
  92  * Instantiate a structure representing an ELF executable, possibly
  93  * with DWARF info, located at the given path.
  94  *
  95  * @param path          Path to the ELF file
  96  * @param low_addr      Base address of the executable
  97  * @param memsz In-memory size of the executable
  98  * @param is_pic        Whether the executable is position independent
  99  *                      code (PIC)
 100  * @param debug_info_dir Directory containing debug info or NULL.
 101  * @param target_prefix  Path to the root file system of the target
 102  *                       or NULL.
 103  * @returns             Pointer to the new bin_info on success,
 104  *                      NULL on failure.
 105  */
 106 BT_HIDDEN
 107 struct bin_info *bin_info_create(const char *path, uint64_t low_addr,
 108                 uint64_t memsz, bool is_pic, const char *debug_info_dir,
 109                 const char *target_prefix);
 110
 111 /**
 112  * Destroy the given bin_info instance
 113  *
 114  * @param bin   bin_info instance to destroy
 115  */
 116 BT_HIDDEN
 117 void bin_info_destroy(struct bin_info *bin);
 118
 119 /**
 120  * Sets the build ID information for a given bin_info instance.
 121  *
 122  * @param bin           The bin_info instance for which to set
 123  *                      the build ID
 124  * @param build_id      Array of bytes containing the actual ID
 125  * @param build_id_len  Length in bytes of the build_id
 126  * @returns             0 on success, -1 on failure
 127  */
 128 BT_HIDDEN
 129 int bin_info_set_build_id(struct bin_info *bin, uint8_t *build_id,
 130                 size_t build_id_len);
 131
 132 /**
 133  * Sets the debug link information for a given bin_info instance.
 134  *
 135  * @param bin           The bin_info instance for which to set
 136  *                      the debug link
 137  * @param filename      Name of the separate debug info file
 138  * @param crc           Checksum for the debug info file
 139  * @returns             0 on success, -1 on failure
 140  */
 141 BT_HIDDEN
 142 int bin_info_set_debug_link(struct bin_info *bin, const char *filename,
 143                 uint32_t crc);
 144
 145 /**
 146  * Returns whether or not the given bin info \p bin contains the
 147  * address \p addr.
 148  *
 149  * @param bin           bin_info instance
 150  * @param addr          Address to lookup
 151  * @returns             1 if \p bin contains \p addr, 0 if it does not,
 152  *                      -1 on failure
 153  */
 154 static inline
 155 int bin_info_has_address(struct bin_info *bin, uint64_t addr)
 156 {
 157         if (!bin) {
 158                 return -1;
 159         }
 160
 161         return addr >= bin->low_addr && addr < bin->high_addr;
 162 }
 163
 164 /**
 165  * Get the name of the function containing a given address within an
 166  * executable.
 167  *
 168  * If no DWARF info is available, the function falls back to ELF
 169  * symbols and the "function name" is in fact the name of the closest
 170  * symbol, followed by the offset between the symbol and the address.
 171  *
 172  * On success, if found, the out parameter `func_name` is set. The ownership
 173  * of `func_name` is passed to the caller. On failure, `func_name` remains
 174  * unchanged.
 175  *
 176  * @param bin           bin_info instance for the executable containing
 177  *                      the address
 178  * @param addr          Virtual memory address for which to find the
 179  *                      function name
 180  * @param func_name     Out parameter, the function name.
 181  * @returns             0 on success, -1 on failure
 182  */
 183 BT_HIDDEN
 184 int bin_info_lookup_function_name(struct bin_info *bin, uint64_t addr,
 185                 char **func_name);
 186
 187 /**
 188  * Get the source location (file name and line number) for a given
 189  * address within an executable.
 190  *
 191  * If no DWARF info is available, the source location cannot be found
 192  * and the function will return unsuccessfully.
 193  *
 194  * On success, if found, the out parameter `src_loc` is set. The ownership
 195  * of `src_loc` is passed to the caller. On failure, `src_loc` remains
 196  * unchanged.
 197  *
 198  * @param bin           bin_info instance for the executable containing
 199  *                      the address
 200  * @param addr          Virtual memory address for which to find the
 201  *                      source location
 202  * @param src_loc       Out parameter, the source location
 203  * @returns             0 on success, -1 on failure
 204  */
 205 BT_HIDDEN
 206 int bin_info_lookup_source_location(struct bin_info *bin, uint64_t addr,
 207                 struct source_location **src_loc);
 208 /**
 209  * Get a string representing the location within the binary of a given
 210  * address.
 211  *
 212  * In the  case of a PIC binary, the location is relative (+0x1234).
 213  * For a non-PIC binary, the location is absolute (@0x1234)
 214  *
 215  * On success, the out parameter `bin_loc` is set. The ownership is
 216  * passed to the caller. On failure, `bin_loc` remains unchanged.
 217  *
 218  * @param bin           bin_info instance for the executable containing
 219  *                      the address
 220  * @param addr          Virtual memory address for which to find the
 221  *                      binary location
 222  * @param bin_loc       Out parameter, the binary location
 223  * @returns             0 on success, -1 on failure
 224  */
 225 BT_HIDDEN
 226 int bin_info_get_bin_loc(struct bin_info *bin, uint64_t addr, char **bin_loc);
 227
 228 /**
 229  * Destroy the given source_location instance
 230  *
 231  * @param src_loc       source_location instance to destroy
 232  */
 233 BT_HIDDEN
 234 void source_location_destroy(struct source_location *src_loc);
 235
 236 #endif  /* _BABELTRACE_BIN_INFO_H */