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