| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright 2015 Antoine Busque <abusque@efficios.com> |
| 5 | * |
| 6 | * Babeltrace - Executable and Shared Object Debug Info Reader |
| 7 | */ |
| 8 | |
| 9 | #ifndef BABELTRACE_PLUGINS_LTTNG_UTILS_DEBUG_INFO_BIN_INFO_H |
| 10 | #define BABELTRACE_PLUGINS_LTTNG_UTILS_DEBUG_INFO_BIN_INFO_H |
| 11 | |
| 12 | #include <babeltrace2/babeltrace.h> |
| 13 | #include <stdint.h> |
| 14 | #include <stdbool.h> |
| 15 | #include <gelf.h> |
| 16 | #include <elfutils/libdw.h> |
| 17 | #include "common/macros.h" |
| 18 | #include "fd-cache/fd-cache.h" |
| 19 | |
| 20 | #define DEFAULT_DEBUG_DIR "/usr/lib/debug" |
| 21 | #define DEBUG_SUBDIR ".debug" |
| 22 | #define BUILD_ID_SUBDIR ".build-id" |
| 23 | #define BUILD_ID_SUFFIX ".debug" |
| 24 | #define BUILD_ID_PREFIX_DIR_LEN 2 |
| 25 | |
| 26 | struct bin_info { |
| 27 | bt_logging_level log_level; |
| 28 | |
| 29 | /* Used for logging; can be `NULL` */ |
| 30 | bt_self_component *self_comp; |
| 31 | |
| 32 | /* Base virtual memory address. */ |
| 33 | uint64_t low_addr; |
| 34 | /* Upper bound of exec address space. */ |
| 35 | uint64_t high_addr; |
| 36 | /* Size of exec address space. */ |
| 37 | uint64_t memsz; |
| 38 | /* Paths to ELF and DWARF files. */ |
| 39 | gchar *elf_path; |
| 40 | gchar *dwarf_path; |
| 41 | /* libelf and libdw objects representing the files. */ |
| 42 | Elf *elf_file; |
| 43 | Dwarf *dwarf_info; |
| 44 | /* Optional build ID info. */ |
| 45 | uint8_t *build_id; |
| 46 | size_t build_id_len; |
| 47 | |
| 48 | /* Optional debug link info. */ |
| 49 | gchar *dbg_link_filename; |
| 50 | uint32_t dbg_link_crc; |
| 51 | /* fd cache handles to ELF and DWARF files. */ |
| 52 | struct bt_fd_cache_handle *elf_handle; |
| 53 | struct bt_fd_cache_handle *dwarf_handle; |
| 54 | /* Configuration. */ |
| 55 | gchar *debug_info_dir; |
| 56 | /* Denotes whether the executable is position independent code. */ |
| 57 | bool is_pic:1; |
| 58 | /* Denotes whether the build id in the trace matches to one on disk. */ |
| 59 | bool file_build_id_matches:1; |
| 60 | /* |
| 61 | * Denotes whether the executable only has ELF symbols and no |
| 62 | * DWARF info. |
| 63 | */ |
| 64 | bool is_elf_only:1; |
| 65 | /* Weak ref. Owned by the iterator. */ |
| 66 | struct bt_fd_cache *fd_cache; |
| 67 | }; |
| 68 | |
| 69 | struct source_location { |
| 70 | uint64_t line_no; |
| 71 | gchar *filename; |
| 72 | }; |
| 73 | |
| 74 | /** |
| 75 | * Initializes the bin_info framework. Call this before calling |
| 76 | * anything else. |
| 77 | * |
| 78 | * @returns 0 on success, -1 on failure |
| 79 | */ |
| 80 | int bin_info_init(bt_logging_level log_level, |
| 81 | bt_self_component *self_comp); |
| 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 | * @param debug_info_dir Directory containing debug info or NULL. |
| 93 | * @param target_prefix Path to the root file system of the target |
| 94 | * or NULL. |
| 95 | * @returns Pointer to the new bin_info on success, |
| 96 | * NULL on failure. |
| 97 | */ |
| 98 | struct bin_info *bin_info_create(struct bt_fd_cache *fdc, const char *path, |
| 99 | uint64_t low_addr, uint64_t memsz, bool is_pic, |
| 100 | const char *debug_info_dir, const char *target_prefix, |
| 101 | bt_logging_level log_level, bt_self_component *self_comp); |
| 102 | |
| 103 | /** |
| 104 | * Destroy the given bin_info instance |
| 105 | * |
| 106 | * @param bin bin_info instance to destroy |
| 107 | */ |
| 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 | int bin_info_set_build_id(struct bin_info *bin, uint8_t *build_id, |
| 120 | size_t build_id_len); |
| 121 | |
| 122 | /** |
| 123 | * Sets the debug link information for a given bin_info instance. |
| 124 | * |
| 125 | * @param bin The bin_info instance for which to set |
| 126 | * the debug link |
| 127 | * @param filename Name of the separate debug info file |
| 128 | * @param crc Checksum for the debug info file |
| 129 | * @returns 0 on success, -1 on failure |
| 130 | */ |
| 131 | int bin_info_set_debug_link(struct bin_info *bin, const char *filename, |
| 132 | uint32_t crc); |
| 133 | |
| 134 | /** |
| 135 | * Returns whether or not the given bin info \p bin contains the |
| 136 | * address \p addr. |
| 137 | * |
| 138 | * @param bin bin_info instance |
| 139 | * @param addr Address to lookup |
| 140 | * @returns 1 if \p bin contains \p addr, 0 if it does not, |
| 141 | * -1 on failure |
| 142 | */ |
| 143 | static inline |
| 144 | int bin_info_has_address(struct bin_info *bin, uint64_t addr) |
| 145 | { |
| 146 | if (!bin) { |
| 147 | return -1; |
| 148 | } |
| 149 | |
| 150 | return addr >= bin->low_addr && addr < bin->high_addr; |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * Get the name of the function containing a given address within an |
| 155 | * executable. |
| 156 | * |
| 157 | * If no DWARF info is available, the function falls back to ELF |
| 158 | * symbols and the "function name" is in fact the name of the closest |
| 159 | * symbol, followed by the offset between the symbol and the address. |
| 160 | * |
| 161 | * On success, if found, the out parameter `func_name` is set. The ownership |
| 162 | * of `func_name` is passed to the caller. On failure, `func_name` remains |
| 163 | * unchanged. |
| 164 | * |
| 165 | * @param bin bin_info instance for the executable containing |
| 166 | * the address |
| 167 | * @param addr Virtual memory address for which to find the |
| 168 | * function name |
| 169 | * @param func_name Out parameter, the function name. |
| 170 | * @returns 0 on success, -1 on failure |
| 171 | */ |
| 172 | int bin_info_lookup_function_name(struct bin_info *bin, uint64_t addr, |
| 173 | char **func_name); |
| 174 | |
| 175 | /** |
| 176 | * Get the source location (file name and line number) for a given |
| 177 | * address within an executable. |
| 178 | * |
| 179 | * If no DWARF info is available, the source location cannot be found |
| 180 | * and the function will return unsuccessfully. |
| 181 | * |
| 182 | * On success, if found, the out parameter `src_loc` is set. The ownership |
| 183 | * of `src_loc` is passed to the caller. On failure, `src_loc` remains |
| 184 | * unchanged. |
| 185 | * |
| 186 | * @param bin bin_info instance for the executable containing |
| 187 | * the address |
| 188 | * @param addr Virtual memory address for which to find the |
| 189 | * source location |
| 190 | * @param src_loc Out parameter, the source location |
| 191 | * @returns 0 on success, -1 on failure |
| 192 | */ |
| 193 | int bin_info_lookup_source_location(struct bin_info *bin, uint64_t addr, |
| 194 | struct source_location **src_loc); |
| 195 | /** |
| 196 | * Get a string representing the location within the binary of a given |
| 197 | * address. |
| 198 | * |
| 199 | * In the case of a PIC binary, the location is relative (+0x1234). |
| 200 | * For a non-PIC binary, the location is absolute (@0x1234) |
| 201 | * |
| 202 | * On success, the out parameter `bin_loc` is set. The ownership is |
| 203 | * passed to the caller. On failure, `bin_loc` remains unchanged. |
| 204 | * |
| 205 | * @param bin bin_info instance for the executable containing |
| 206 | * the address |
| 207 | * @param addr Virtual memory address for which to find the |
| 208 | * binary location |
| 209 | * @param bin_loc Out parameter, the binary location |
| 210 | * @returns 0 on success, -1 on failure |
| 211 | */ |
| 212 | int bin_info_get_bin_loc(struct bin_info *bin, uint64_t addr, char **bin_loc); |
| 213 | |
| 214 | /** |
| 215 | * Destroy the given source_location instance |
| 216 | * |
| 217 | * @param src_loc source_location instance to destroy |
| 218 | */ |
| 219 | void source_location_destroy(struct source_location *src_loc); |
| 220 | |
| 221 | #endif /* BABELTRACE_PLUGINS_LTTNG_UTILS_DEBUG_INFO_BIN_INFO_H */ |