| /* Standard find_debuginfo callback for libdwfl. |
| Copyright (C) 2005 Red Hat, Inc. |
| |
| This program is Open Source software; you can redistribute it and/or |
| modify it under the terms of the Open Software License version 1.0 as |
| published by the Open Source Initiative. |
| |
| You should have received a copy of the Open Software License along |
| with this program; if not, you may obtain a copy of the Open Software |
| License version 1.0 from http://www.opensource.org/licenses/osl.php or |
| by writing the Open Source Initiative c/o Lawrence Rosen, Esq., |
| 3001 King Ranch Road, Ukiah, CA 95482. */ |
| |
| #include "libdwflP.h" |
| #include <stdio.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include "system.h" |
| |
| |
| #define DEFAULT_DEBUGINFO_PATH ":.debug:/usr/lib/debug" |
| |
| |
| /* Try to open64 [DIR/][SUBDIR/]DEBUGLINK, return file descriptor or -1. |
| On success, *DEBUGINFO_FILE_NAME has the malloc'd name of the open file. */ |
| static int |
| try_open (const char *dir, const char *subdir, const char *debuglink, |
| char **debuginfo_file_name) |
| { |
| char *fname = NULL; |
| if (dir == NULL && subdir == NULL) |
| fname = strdup (debuglink); |
| else if (subdir == NULL) |
| asprintf (&fname, "%s/%s", dir, debuglink); |
| else if (dir == NULL) |
| asprintf (&fname, "%s/%s", subdir, debuglink); |
| else |
| asprintf (&fname, "%s/%s/%s", dir, subdir, debuglink); |
| |
| if (fname == NULL) |
| return -1; |
| |
| int fd = open64 (fname, O_RDONLY); |
| if (fd < 0) |
| free (fname); |
| else |
| *debuginfo_file_name = fname; |
| |
| return fd; |
| } |
| |
| /* Return true iff the FD's contents CRC matches DEBUGLINK_CRC. */ |
| static inline bool |
| check_crc (int fd, GElf_Word debuglink_crc) |
| { |
| uint32_t file_crc; |
| return crc32_file (fd, &file_crc) == 0 && file_crc == debuglink_crc; |
| } |
| |
| int |
| dwfl_standard_find_debuginfo (Dwfl_Module *mod __attribute__ ((unused)), |
| void **userdata __attribute__ ((unused)), |
| const char *modname __attribute__ ((unused)), |
| GElf_Addr base __attribute__ ((unused)), |
| const char *file_name, |
| const char *debuglink_file, |
| GElf_Word debuglink_crc, |
| char **debuginfo_file_name) |
| { |
| bool cancheck = true; |
| |
| const char *file_basename = file_name == NULL ? NULL : basename (file_name); |
| if (debuglink_file == NULL) |
| { |
| if (file_basename == NULL) |
| { |
| errno = 0; |
| return -1; |
| } |
| |
| size_t len = strlen (file_basename); |
| char *localname = alloca (len + sizeof ".debug"); |
| memcpy (localname, file_basename, len); |
| memcpy (&localname[len], ".debug", sizeof ".debug"); |
| debuglink_file = localname; |
| cancheck = false; |
| } |
| |
| /* Look for a file named DEBUGLINK_FILE in the directories |
| indicated by the debug directory path setting. */ |
| |
| const Dwfl_Callbacks *const cb = mod->dwfl->callbacks; |
| char *path = strdupa ((cb->debuginfo_path ? *cb->debuginfo_path : NULL) |
| ?: DEFAULT_DEBUGINFO_PATH); |
| |
| /* A leading - or + in the whole path sets whether to check file CRCs. */ |
| bool defcheck = true; |
| if (path[0] == '-' || path[0] == '+') |
| { |
| defcheck = path[0] == '+'; |
| ++path; |
| } |
| |
| char *file_dirname = (file_basename == file_name ? NULL |
| : strndupa (file_name, file_basename - 1 - file_name)); |
| char *p; |
| while ((p = strsep (&path, ":")) != NULL) |
| { |
| /* A leading - or + says whether to check file CRCs for this element. */ |
| bool check = defcheck; |
| if (*p == '+' || *p == '-') |
| check = *p++ == '+'; |
| check = check && cancheck; |
| |
| const char *dir, *subdir; |
| switch (p[0]) |
| { |
| case '\0': |
| /* An empty entry says to try the main file's directory. */ |
| dir = file_dirname; |
| subdir = NULL; |
| break; |
| case '/': |
| /* An absolute path says to look there for a subdirectory |
| named by the main file's absolute directory. |
| This cannot be applied to a relative file name. */ |
| if (file_dirname == NULL || file_dirname[0] != '/') |
| continue; |
| dir = p; |
| subdir = file_dirname + 1; |
| break; |
| default: |
| /* A relative path says to try a subdirectory of that name |
| in the main file's directory. */ |
| dir = file_dirname; |
| subdir = p; |
| break; |
| } |
| |
| char *fname; |
| int fd = try_open (dir, subdir, debuglink_file, &fname); |
| if (fd < 0) |
| continue; |
| if (!check || check_crc (fd, debuglink_crc)) |
| { |
| *debuginfo_file_name = fname; |
| return fd; |
| } |
| free (fname); |
| close (fd); |
| } |
| |
| /* No dice. */ |
| errno = 0; |
| return -1; |
| } |
| INTDEF (dwfl_standard_find_debuginfo) |