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