plugins/lttng-utils/debug-info/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 <babeltrace2/babeltrace-internal.h>
  35 #include <babeltrace2/fd-cache-internal.h>
  36
  37 #define DEFAULT_DEBUG_DIR "/usr/lib/debug"
  38 #define DEBUG_SUBDIR ".debug"
  39 #define BUILD_ID_SUBDIR ".build-id"
  40 #define BUILD_ID_SUFFIX ".debug"
  41 #define BUILD_ID_PREFIX_DIR_LEN 2
  42
  43 struct bin_info {
  44         /* Base virtual memory address. */
  45         uint64_t low_addr;
  46         /* Upper bound of exec address space. */
  47         uint64_t high_addr;
  48         /* Size of exec address space. */
  49         uint64_t memsz;
  50         /* Paths to ELF and DWARF files. */
  51         gchar *elf_path;
  52         gchar *dwarf_path;
  53         /* libelf and libdw objects representing the files. */
  54         Elf *elf_file;
  55         Dwarf *dwarf_info;
  56         /* Optional build ID info. */
  57         uint8_t *build_id;
  58         size_t build_id_len;
  59
  60         /* Optional debug link info. */
  61         gchar *dbg_link_filename;
  62         uint32_t dbg_link_crc;
  63         /* fd cache handles to ELF and DWARF files. */
  64         struct bt_fd_cache_handle *elf_handle;
  65         struct bt_fd_cache_handle *dwarf_handle;
  66         /* Configuration. */
  67         gchar *debug_info_dir;
  68         /* Denotes whether the executable is position independent code. */
  69         bool is_pic:1;
  70         /* Denotes whether the build id in the trace matches to one on disk. */
  71         bool file_build_id_matches:1;
  72         /*
  73          * Denotes whether the executable only has ELF symbols and no
  74          * DWARF info.
  75          */
  76         bool is_elf_only:1;
  77         /* Weak ref. Owned by the iterator. */
  78         struct bt_fd_cache *fd_cache;
  79 };
  80
  81 struct source_location {
  82         uint64_t line_no;
  83         gchar *filename;
  84 };
  85
  86 /**
  87  * Initializes the bin_info framework. Call this before calling
  88  * anything else.
  89  *
  90  * @returns             0 on success, -1 on failure
  91  */
  92 BT_HIDDEN
  93 int bin_info_init(void);
  94
  95 /**
  96  * Instantiate a structure representing an ELF executable, possibly
  97  * with DWARF info, located at the given path.
  98  *
  99  * @param path          Path to the ELF file
 100  * @param low_addr      Base address of the executable
 101  * @param memsz In-memory size of the executable
 102  * @param is_pic        Whether the executable is position independent
 103  *                      code (PIC)
 104  * @param debug_info_dir Directory containing debug info or NULL.
 105  * @param target_prefix  Path to the root file system of the target
 106  *                       or NULL.
 107  * @returns             Pointer to the new bin_info on success,
 108  *                      NULL on failure.
 109  */
 110 BT_HIDDEN
 111 struct bin_info *bin_info_create(struct bt_fd_cache *fdc, const char *path,
 112                 uint64_t low_addr, uint64_t memsz, bool is_pic,
 113                 const char *debug_info_dir, const char *target_prefix);
 114
 115 /**
 116  * Destroy the given bin_info instance
 117  *
 118  * @param bin   bin_info instance to destroy
 119  */
 120 BT_HIDDEN
 121 void bin_info_destroy(struct bin_info *bin);
 122
 123 /**
 124  * Sets the build ID information for a given bin_info instance.
 125  *
 126  * @param bin           The bin_info instance for which to set
 127  *                      the build ID
 128  * @param build_id      Array of bytes containing the actual ID
 129  * @param build_id_len  Length in bytes of the build_id
 130  * @returns             0 on success, -1 on failure
 131  */
 132 BT_HIDDEN
 133 int bin_info_set_build_id(struct bin_info *bin, uint8_t *build_id,
 134                 size_t build_id_len);
 135
 136 /**
 137  * Sets the debug link information for a given bin_info instance.
 138  *
 139  * @param bin           The bin_info instance for which to set
 140  *                      the debug link
 141  * @param filename      Name of the separate debug info file
 142  * @param crc           Checksum for the debug info file
 143  * @returns             0 on success, -1 on failure
 144  */
 145 BT_HIDDEN
 146 int bin_info_set_debug_link(struct bin_info *bin, const char *filename,
 147                 uint32_t crc);
 148
 149 /**
 150  * Returns whether or not the given bin info \p bin contains the
 151  * address \p addr.
 152  *
 153  * @param bin           bin_info instance
 154  * @param addr          Address to lookup
 155  * @returns             1 if \p bin contains \p addr, 0 if it does not,
 156  *                      -1 on failure
 157  */
 158 static inline
 159 int bin_info_has_address(struct bin_info *bin, uint64_t addr)
 160 {
 161         if (!bin) {
 162                 return -1;
 163         }
 164
 165         return addr >= bin->low_addr && addr < bin->high_addr;
 166 }
 167
 168 /**
 169  * Get the name of the function containing a given address within an
 170  * executable.
 171  *
 172  * If no DWARF info is available, the function falls back to ELF
 173  * symbols and the "function name" is in fact the name of the closest
 174  * symbol, followed by the offset between the symbol and the address.
 175  *
 176  * On success, if found, the out parameter `func_name` is set. The ownership
 177  * of `func_name` is passed to the caller. On failure, `func_name` remains
 178  * unchanged.
 179  *
 180  * @param bin           bin_info instance for the executable containing
 181  *                      the address
 182  * @param addr          Virtual memory address for which to find the
 183  *                      function name
 184  * @param func_name     Out parameter, the function name.
 185  * @returns             0 on success, -1 on failure
 186  */
 187 BT_HIDDEN
 188 int bin_info_lookup_function_name(struct bin_info *bin, uint64_t addr,
 189                 char **func_name);
 190
 191 /**
 192  * Get the source location (file name and line number) for a given
 193  * address within an executable.
 194  *
 195  * If no DWARF info is available, the source location cannot be found
 196  * and the function will return unsuccessfully.
 197  *
 198  * On success, if found, the out parameter `src_loc` is set. The ownership
 199  * of `src_loc` is passed to the caller. On failure, `src_loc` remains
 200  * unchanged.
 201  *
 202  * @param bin           bin_info instance for the executable containing
 203  *                      the address
 204  * @param addr          Virtual memory address for which to find the
 205  *                      source location
 206  * @param src_loc       Out parameter, the source location
 207  * @returns             0 on success, -1 on failure
 208  */
 209 BT_HIDDEN
 210 int bin_info_lookup_source_location(struct bin_info *bin, uint64_t addr,
 211                 struct source_location **src_loc);
 212 /**
 213  * Get a string representing the location within the binary of a given
 214  * address.
 215  *
 216  * In the  case of a PIC binary, the location is relative (+0x1234).
 217  * For a non-PIC binary, the location is absolute (@0x1234)
 218  *
 219  * On success, the out parameter `bin_loc` is set. The ownership is
 220  * passed to the caller. On failure, `bin_loc` remains unchanged.
 221  *
 222  * @param bin           bin_info instance for the executable containing
 223  *                      the address
 224  * @param addr          Virtual memory address for which to find the
 225  *                      binary location
 226  * @param bin_loc       Out parameter, the binary location
 227  * @returns             0 on success, -1 on failure
 228  */
 229 BT_HIDDEN
 230 int bin_info_get_bin_loc(struct bin_info *bin, uint64_t addr, char **bin_loc);
 231
 232 /**
 233  * Destroy the given source_location instance
 234  *
 235  * @param src_loc       source_location instance to destroy
 236  */
 237 BT_HIDDEN
 238 void source_location_destroy(struct source_location *src_loc);
 239
 240 #endif  /* _BABELTRACE_BIN_INFO_H */