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         /* 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, const char *filename,
 134                 uint32_t crc);
 135
 136 /**
 137  * Returns whether or not the given bin info \p bin contains the
 138  * address \p addr.
 139  *
 140  * @param bin           bin_info instance
 141  * @param addr          Address to lookup
 142  * @returns             1 if \p bin contains \p addr, 0 if it does not,
 143  *                      -1 on failure
 144  */
 145 static inline
 146 int bin_info_has_address(struct bin_info *bin, uint64_t addr)
 147 {
 148         if (!bin) {
 149                 return -1;
 150         }
 151
 152         return addr >= bin->low_addr && addr < bin->high_addr;
 153 }
 154
 155 /**
 156  * Get the name of the function containing a given address within an
 157  * executable.
 158  *
 159  * If no DWARF info is available, the function falls back to ELF
 160  * symbols and the "function name" is in fact the name of the closest
 161  * symbol, followed by the offset between the symbol and the address.
 162  *
 163  * On success, if found, the out parameter `func_name` is set. The ownership
 164  * of `func_name` is passed to the caller. On failure, `func_name` remains
 165  * unchanged.
 166  *
 167  * @param bin           bin_info instance for the executable containing
 168  *                      the address
 169  * @param addr          Virtual memory address for which to find the
 170  *                      function name
 171  * @param func_name     Out parameter, the function name.
 172  * @returns             0 on success, -1 on failure
 173  */
 174 BT_HIDDEN
 175 int bin_info_lookup_function_name(struct bin_info *bin, uint64_t addr,
 176                 char **func_name);
 177
 178 /**
 179  * Get the source location (file name and line number) for a given
 180  * address within an executable.
 181  *
 182  * If no DWARF info is available, the source location cannot be found
 183  * and the function will return unsuccessfully.
 184  *
 185  * On success, if found, the out parameter `src_loc` is set. The ownership
 186  * of `src_loc` is passed to the caller. On failure, `src_loc` remains
 187  * unchanged.
 188  *
 189  * @param bin           bin_info instance for the executable containing
 190  *                      the address
 191  * @param addr          Virtual memory address for which to find the
 192  *                      source location
 193  * @param src_loc       Out parameter, the source location
 194  * @returns             0 on success, -1 on failure
 195  */
 196 BT_HIDDEN
 197 int bin_info_lookup_source_location(struct bin_info *bin, uint64_t addr,
 198                 struct source_location **src_loc);
 199 /**
 200  * Get a string representing the location within the binary of a given
 201  * address.
 202  *
 203  * In the  case of a PIC binary, the location is relative (+0x1234).
 204  * For a non-PIC binary, the location is absolute (@0x1234)
 205  *
 206  * On success, the out parameter `bin_loc` is set. The ownership is
 207  * passed to the caller. On failure, `bin_loc` remains unchanged.
 208  *
 209  * @param bin           bin_info instance for the executable containing
 210  *                      the address
 211  * @param addr          Virtual memory address for which to find the
 212  *                      binary location
 213  * @param bin_loc       Out parameter, the binary location
 214  * @returns             0 on success, -1 on failure
 215  */
 216 BT_HIDDEN
 217 int bin_info_get_bin_loc(struct bin_info *bin, uint64_t addr, char **bin_loc);
 218
 219 /**
 220  * Destroy the given source_location instance
 221  *
 222  * @param src_loc       source_location instance to destroy
 223  */
 224 BT_HIDDEN
 225 void source_location_destroy(struct source_location *src_loc);
 226
 227 #endif  /* _BABELTRACE_BIN_INFO_H */