| 1 | #ifndef _BABELTRACE_SO_INFO_H |
| 2 | #define _BABELTRACE_SO_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 so_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 | /* Denotes whether the SO only has ELF symbols and no DWARF info. */ |
| 66 | bool is_elf_only:1; |
| 67 | }; |
| 68 | |
| 69 | struct source_location { |
| 70 | uint64_t line_no; |
| 71 | char *filename; |
| 72 | }; |
| 73 | |
| 74 | /** |
| 75 | * Initializes the so_info framework. Call this before calling |
| 76 | * anything else. |
| 77 | * |
| 78 | * @returns 0 on success, -1 on failure |
| 79 | */ |
| 80 | BT_HIDDEN |
| 81 | int so_info_init(void); |
| 82 | |
| 83 | /** |
| 84 | * Instantiate a structure representing an ELF executable, possibly |
| 85 | * with DWARF info, located at the given path. |
| 86 | * |
| 87 | * @param path Path to the ELF file |
| 88 | * @param low_addr Base address of the executable |
| 89 | * @param memsz In-memory size of the executable |
| 90 | * @param is_pic Whether the executable is position independent |
| 91 | * code (PIC) |
| 92 | * @returns Pointer to the new so_info on success, |
| 93 | * NULL on failure. |
| 94 | */ |
| 95 | BT_HIDDEN |
| 96 | struct so_info *so_info_create(const char *path, uint64_t low_addr, |
| 97 | uint64_t memsz, bool is_pic); |
| 98 | |
| 99 | /** |
| 100 | * Destroy the given so_info instance |
| 101 | * |
| 102 | * @param so so_info instance to destroy |
| 103 | */ |
| 104 | BT_HIDDEN |
| 105 | void so_info_destroy(struct so_info *so); |
| 106 | |
| 107 | /** |
| 108 | * Sets the build ID information for a given so_info instance. |
| 109 | * |
| 110 | * @param so The so_info instance for which to set |
| 111 | * the build ID |
| 112 | * @param build_id Array of bytes containing the actual ID |
| 113 | * @param build_id_len Length in bytes of the build_id |
| 114 | * @returns 0 on success, -1 on failure |
| 115 | */ |
| 116 | BT_HIDDEN |
| 117 | int so_info_set_build_id(struct so_info *so, uint8_t *build_id, |
| 118 | size_t build_id_len); |
| 119 | |
| 120 | /** |
| 121 | * Sets the debug link information for a given so_info instance. |
| 122 | * |
| 123 | * @param so The so_info instance for which to set |
| 124 | * the debug link |
| 125 | * @param filename Name of the separate debug info file |
| 126 | * @param crc Checksum for the debug info file |
| 127 | * @returns 0 on success, -1 on failure |
| 128 | */ |
| 129 | BT_HIDDEN |
| 130 | int so_info_set_debug_link(struct so_info *so, char *filename, uint32_t crc); |
| 131 | |
| 132 | /** |
| 133 | * Returns whether or not the given SO info \p so contains the address |
| 134 | * \p addr. |
| 135 | * |
| 136 | * @param so so_info instance |
| 137 | * @param addr Address to lookup |
| 138 | * @returns 1 if \p so contains \p addr, 0 if it does not, |
| 139 | * -1 on failure |
| 140 | */ |
| 141 | static inline |
| 142 | int so_info_has_address(struct so_info *so, uint64_t addr) |
| 143 | { |
| 144 | if (!so) { |
| 145 | return -1; |
| 146 | } |
| 147 | |
| 148 | return addr >= so->low_addr && addr < so->high_addr; |
| 149 | } |
| 150 | |
| 151 | /** |
| 152 | * Get the name of the function containing a given address within an |
| 153 | * executable. |
| 154 | * |
| 155 | * If no DWARF info is available, the function falls back to ELF |
| 156 | * symbols and the "function name" is in fact the name of the closest |
| 157 | * symbol, followed by the offset between the symbol and the address. |
| 158 | * |
| 159 | * On success, if found, the out parameter `func_name` is set. The ownership |
| 160 | * of `func_name` is passed to the caller. On failure, `func_name` remains |
| 161 | * unchanged. |
| 162 | * |
| 163 | * @param so so_info instance for the executable containing |
| 164 | * the address |
| 165 | * @param addr Virtual memory address for which to find the |
| 166 | * function name |
| 167 | * @param func_name Out parameter, the function name. |
| 168 | * @returns 0 on success, -1 on failure |
| 169 | */ |
| 170 | BT_HIDDEN |
| 171 | int so_info_lookup_function_name(struct so_info *so, uint64_t addr, |
| 172 | char **func_name); |
| 173 | |
| 174 | /** |
| 175 | * Get the source location (file name and line number) for a given |
| 176 | * address within an executable. |
| 177 | * |
| 178 | * If no DWARF info is available, the source location cannot be found |
| 179 | * and the function will return unsuccesfully. |
| 180 | * |
| 181 | * On success, if found, the out parameter `src_loc` is set. The ownership |
| 182 | * of `src_loc` is passed to the caller. On failure, `src_loc` remains |
| 183 | * unchanged. |
| 184 | * |
| 185 | * @param so so_info instance for the executable containing |
| 186 | * the address |
| 187 | * @param addr Virtual memory address for which to find the |
| 188 | * source location |
| 189 | * @param src_loc Out parameter, the source location |
| 190 | * @returns 0 on success, -1 on failure |
| 191 | */ |
| 192 | BT_HIDDEN |
| 193 | int so_info_lookup_source_location(struct so_info *so, uint64_t addr, |
| 194 | struct source_location **src_loc); |
| 195 | |
| 196 | /** |
| 197 | * Destroy the given source_location instance |
| 198 | * |
| 199 | * @param src_loc source_location instance to destroy |
| 200 | */ |
| 201 | BT_HIDDEN |
| 202 | void source_location_destroy(struct source_location *src_loc); |
| 203 | |
| 204 | #endif /* _BABELTRACE_SO_INFO_H */ |