/external/elfutils/libdwfl/find-debuginfo.c
C | 298 lines | 189 code | 24 blank | 85 comment | 59 complexity | db92077f6ec5d6425b48a618a4d10bed MD5 | raw file
- /* Standard find_debuginfo callback for libdwfl.
- Copyright (C) 2005, 2006, 2007, 2008 Red Hat, Inc.
- This file is part of Red Hat elfutils.
- Red Hat elfutils is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by the
- Free Software Foundation; version 2 of the License.
- Red Hat elfutils is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
- You should have received a copy of the GNU General Public License along
- with Red Hat elfutils; if not, write to the Free Software Foundation,
- Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
- In addition, as a special exception, Red Hat, Inc. gives You the
- additional right to link the code of Red Hat elfutils with code licensed
- under any Open Source Initiative certified open source license
- (http://www.opensource.org/licenses/index.php) which requires the
- distribution of source code with any binary distribution and to
- distribute linked combinations of the two. Non-GPL Code permitted under
- this exception must only link to the code of Red Hat elfutils through
- those well defined interfaces identified in the file named EXCEPTION
- found in the source code files (the "Approved Interfaces"). The files
- of Non-GPL Code may instantiate templates or use macros or inline
- functions from the Approved Interfaces without causing the resulting
- work to be covered by the GNU General Public License. Only Red Hat,
- Inc. may make changes or additions to the list of Approved Interfaces.
- Red Hat's grant of this exception is conditioned upon your not adding
- any new exceptions. If you wish to add a new Approved Interface or
- exception, please contact Red Hat. You must obey the GNU General Public
- License in all respects for all of the Red Hat elfutils code and other
- code used in conjunction with Red Hat elfutils except the Non-GPL Code
- covered by this exception. If you modify this file, you may extend this
- exception to your version of the file, but you are not obligated to do
- so. If you do not wish to provide this exception without modification,
- you must delete this exception statement from your version and license
- this file solely under the GPL without exception.
- Red Hat elfutils is an included package of the Open Invention Network.
- An included package of the Open Invention Network is a package for which
- Open Invention Network licensees cross-license their patents. No patent
- license is granted, either expressly or impliedly, by designation as an
- included package. Should you wish to participate in the Open Invention
- Network licensing program, please visit www.openinventionnetwork.com
- <http://www.openinventionnetwork.com>. */
- #include "libdwflP.h"
- #include <stdio.h>
- #include <fcntl.h>
- #include <unistd.h>
- #include "system.h"
- /* 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;
- if (dir == NULL && subdir == NULL)
- {
- fname = strdup (debuglink);
- if (fname == NULL)
- return -1;
- }
- else if ((subdir == NULL ? asprintf (&fname, "%s/%s", dir, debuglink)
- : dir == NULL ? asprintf (&fname, "%s/%s", subdir, debuglink)
- : asprintf (&fname, "%s/%s/%s", dir, subdir, debuglink)) < 0)
- return -1;
- int fd = TEMP_FAILURE_RETRY (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 (__libdwfl_crc32_file (fd, &file_crc) == 0
- && file_crc == debuglink_crc);
- }
- static bool
- validate (Dwfl_Module *mod, int fd, bool check, GElf_Word debuglink_crc)
- {
- /* If we have a build ID, check only that. */
- if (mod->build_id_len > 0)
- {
- /* We need to open an Elf handle on the file so we can check its
- build ID note for validation. Backdoor the handle into the
- module data structure since we had to open it early anyway. */
- mod->debug.elf = elf_begin (fd, ELF_C_READ_MMAP_PRIVATE, NULL);
- if (likely (__libdwfl_find_build_id (mod, false, mod->debug.elf) == 2))
- /* Also backdoor the gratuitous flag. */
- mod->debug.valid = true;
- else
- {
- /* A mismatch! */
- elf_end (mod->debug.elf);
- mod->debug.elf = NULL;
- mod->debug.valid = false;
- }
- return mod->debug.valid;
- }
- return !check || check_crc (fd, debuglink_crc);
- }
- static int
- find_debuginfo_in_path (Dwfl_Module *mod, const char *file_name,
- const char *debuglink_file, GElf_Word debuglink_crc,
- char **debuginfo_file_name)
- {
- bool cancheck = debuglink_crc != (GElf_Word) 0;
- 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;
- /* ANDROID_CHANGE_BEGIN */
- #if defined(__BIONIC__) || defined(__APPLE__)
- char *path = strdup ((cb->debuginfo_path ? *cb->debuginfo_path : NULL)
- ?: DEFAULT_DEBUGINFO_PATH);
- #else
- char *path = strdupa ((cb->debuginfo_path ? *cb->debuginfo_path : NULL)
- ?: DEFAULT_DEBUGINFO_PATH);
- #endif
- /* ANDROID_CHANGE_END */
- /* 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;
- }
- /* ANDROID_CHANGE_BEGIN */
- #if defined(__BIONIC__) || defined(__APPLE__)
- char *file_dirname = (file_basename == file_name ? NULL
- : strndup (file_name, file_basename - 1 - file_name));
- #else
- char *file_dirname = (file_basename == file_name ? NULL
- : strndupa (file_name, file_basename - 1 - file_name));
- #endif
- /* ANDROID_CHANGE_END */
- 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;
- }
- /* ANDROID_CHANGE_BEGIN */
- char *fname = NULL;
- /* ANDROID_CHANGE_END */
- int fd = try_open (dir, subdir, debuglink_file, &fname);
- if (fd < 0)
- switch (errno)
- {
- case ENOENT:
- case ENOTDIR:
- continue;
- default:
- /* ANDROID_CHANGE_BEGIN */
- #ifdef __BIONIC__
- free(path);
- free(file_dirname);
- #endif
- /* ANDROID_CHANGE_END */
- return -1;
- }
- if (validate (mod, fd, check, debuglink_crc))
- {
- *debuginfo_file_name = fname;
- /* ANDROID_CHANGE_BEGIN */
- #ifdef __BIONIC__
- free(path);
- free(file_dirname);
- #endif
- /* ANDROID_CHANGE_END */
- return fd;
- }
- free (fname);
- close (fd);
- }
- /* ANDROID_CHANGE_BEGIN */
- #ifdef __BIONIC__
- free(path);
- free(file_dirname);
- #endif
- /* ANDROID_CHANGE_END */
- /* No dice. */
- errno = 0;
- return -1;
- }
- int
- dwfl_standard_find_debuginfo (Dwfl_Module *mod,
- 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)
- {
- /* First try by build ID if we have one. If that succeeds or fails
- other than just by finding nothing, that's all we do. */
- const unsigned char *bits;
- GElf_Addr vaddr;
- if (INTUSE(dwfl_module_build_id) (mod, &bits, &vaddr) > 0)
- {
- int fd = INTUSE(dwfl_build_id_find_debuginfo) (mod,
- NULL, NULL, 0,
- NULL, NULL, 0,
- debuginfo_file_name);
- if (fd >= 0 || errno != 0)
- return fd;
- }
- /* Failing that, search the path by name. */
- int fd = find_debuginfo_in_path (mod, file_name,
- debuglink_file, debuglink_crc,
- debuginfo_file_name);
- if (fd < 0 && errno == 0)
- {
- /* If FILE_NAME is a symlink, the debug file might be associated
- with the symlink target name instead. */
- char *canon = canonicalize_file_name (file_name);
- if (canon != NULL && strcmp (file_name, canon))
- fd = find_debuginfo_in_path (mod, canon,
- debuglink_file, debuglink_crc,
- debuginfo_file_name);
- free (canon);
- }
- return fd;
- }
- INTDEF (dwfl_standard_find_debuginfo)