src/plugins/lttng-utils/debug-info/bin-info.h

   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_BIN_INFO_H
  10 #define _BABELTRACE_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_BIN_INFO_H */