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2412 lines
69 KiB
2412 lines
69 KiB
/* Map in a shared object's segments from the file.
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Copyright (C) 1995-2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <elf.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <libintl.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <ldsodefs.h>
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#include <bits/wordsize.h>
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#include <sys/mman.h>
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#include <sys/param.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <gnu/lib-names.h>
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/* Type for the buffer we put the ELF header and hopefully the program
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header. This buffer does not really have to be too large. In most
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cases the program header follows the ELF header directly. If this
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is not the case all bets are off and we can make the header
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arbitrarily large and still won't get it read. This means the only
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question is how large are the ELF and program header combined. The
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ELF header 32-bit files is 52 bytes long and in 64-bit files is 64
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bytes long. Each program header entry is again 32 and 56 bytes
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long respectively. I.e., even with a file which has 10 program
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header entries we only have to read 372B/624B respectively. Add to
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this a bit of margin for program notes and reading 512B and 832B
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for 32-bit and 64-bit files respecitvely is enough. If this
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heuristic should really fail for some file the code in
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`_dl_map_object_from_fd' knows how to recover. */
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struct filebuf
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{
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ssize_t len;
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#if __WORDSIZE == 32
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# define FILEBUF_SIZE 512
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#else
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# define FILEBUF_SIZE 832
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#endif
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char buf[FILEBUF_SIZE] __attribute__ ((aligned (__alignof (ElfW(Ehdr)))));
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};
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#include "dynamic-link.h"
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#include <abi-tag.h>
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#include <stackinfo.h>
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#include <sysdep.h>
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#include <stap-probe.h>
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#include <libc-pointer-arith.h>
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#include <array_length.h>
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#include <dl-dst.h>
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#include <dl-load.h>
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#include <dl-map-segments.h>
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#include <dl-unmap-segments.h>
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#include <dl-machine-reject-phdr.h>
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#include <dl-sysdep-open.h>
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#include <dl-prop.h>
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#include <not-cancel.h>
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#include <endian.h>
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#if BYTE_ORDER == BIG_ENDIAN
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# define byteorder ELFDATA2MSB
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#elif BYTE_ORDER == LITTLE_ENDIAN
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# define byteorder ELFDATA2LSB
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#else
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# error "Unknown BYTE_ORDER " BYTE_ORDER
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# define byteorder ELFDATANONE
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#endif
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#define STRING(x) __STRING (x)
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int __stack_prot attribute_hidden attribute_relro
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#if _STACK_GROWS_DOWN && defined PROT_GROWSDOWN
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= PROT_GROWSDOWN;
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#elif _STACK_GROWS_UP && defined PROT_GROWSUP
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= PROT_GROWSUP;
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#else
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= 0;
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#endif
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/* This is the decomposed LD_LIBRARY_PATH search path. */
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static struct r_search_path_struct env_path_list attribute_relro;
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/* List of the hardware capabilities we might end up using. */
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static const struct r_strlenpair *capstr attribute_relro;
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static size_t ncapstr attribute_relro;
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static size_t max_capstrlen attribute_relro;
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/* Get the generated information about the trusted directories. Use
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an array of concatenated strings to avoid relocations. See
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gen-trusted-dirs.awk. */
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#include "trusted-dirs.h"
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static const char system_dirs[] = SYSTEM_DIRS;
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static const size_t system_dirs_len[] =
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{
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SYSTEM_DIRS_LEN
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};
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#define nsystem_dirs_len array_length (system_dirs_len)
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static bool
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is_trusted_path_normalize (const char *path, size_t len)
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{
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if (len == 0)
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return false;
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char *npath = (char *) alloca (len + 2);
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char *wnp = npath;
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while (*path != '\0')
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{
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if (path[0] == '/')
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{
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if (path[1] == '.')
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{
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if (path[2] == '.' && (path[3] == '/' || path[3] == '\0'))
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{
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while (wnp > npath && *--wnp != '/')
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;
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path += 3;
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continue;
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}
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else if (path[2] == '/' || path[2] == '\0')
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{
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path += 2;
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continue;
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}
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}
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if (wnp > npath && wnp[-1] == '/')
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{
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++path;
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continue;
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}
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}
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*wnp++ = *path++;
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}
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if (wnp == npath || wnp[-1] != '/')
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*wnp++ = '/';
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const char *trun = system_dirs;
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for (size_t idx = 0; idx < nsystem_dirs_len; ++idx)
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{
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if (wnp - npath >= system_dirs_len[idx]
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&& memcmp (trun, npath, system_dirs_len[idx]) == 0)
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/* Found it. */
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return true;
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trun += system_dirs_len[idx] + 1;
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}
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return false;
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}
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/* Given a substring starting at INPUT, just after the DST '$' start
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token, determine if INPUT contains DST token REF, following the
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ELF gABI rules for DSTs:
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* Longest possible sequence using the rules (greedy).
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* Must start with a $ (enforced by caller).
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* Must follow $ with one underscore or ASCII [A-Za-z] (caller
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follows these rules for REF) or '{' (start curly quoted name).
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* Must follow first two characters with zero or more [A-Za-z0-9_]
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(enforced by caller) or '}' (end curly quoted name).
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If the sequence is a DST matching REF then the length of the DST
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(excluding the $ sign but including curly braces, if any) is
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returned, otherwise 0. */
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static size_t
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is_dst (const char *input, const char *ref)
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{
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bool is_curly = false;
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/* Is a ${...} input sequence? */
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if (input[0] == '{')
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{
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is_curly = true;
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++input;
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}
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/* Check for matching name, following closing curly brace (if
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required), or trailing characters which are part of an
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identifier. */
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size_t rlen = strlen (ref);
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if (strncmp (input, ref, rlen) != 0
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|| (is_curly && input[rlen] != '}')
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|| ((input[rlen] >= 'A' && input[rlen] <= 'Z')
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|| (input[rlen] >= 'a' && input[rlen] <= 'z')
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|| (input[rlen] >= '0' && input[rlen] <= '9')
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|| (input[rlen] == '_')))
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return 0;
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if (is_curly)
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/* Count the two curly braces. */
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return rlen + 2;
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else
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return rlen;
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}
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/* INPUT should be the start of a path e.g DT_RPATH or name e.g.
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DT_NEEDED. The return value is the number of known DSTs found. We
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count all known DSTs regardless of __libc_enable_secure; the caller
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is responsible for enforcing the security of the substitution rules
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(usually _dl_dst_substitute). */
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size_t
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_dl_dst_count (const char *input)
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{
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size_t cnt = 0;
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input = strchr (input, '$');
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/* Most likely there is no DST. */
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if (__glibc_likely (input == NULL))
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return 0;
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do
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{
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size_t len;
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++input;
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/* All DSTs must follow ELF gABI rules, see is_dst (). */
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if ((len = is_dst (input, "ORIGIN")) != 0
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|| (len = is_dst (input, "PLATFORM")) != 0
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|| (len = is_dst (input, "LIB")) != 0)
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++cnt;
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/* There may be more than one DST in the input. */
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input = strchr (input + len, '$');
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}
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while (input != NULL);
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return cnt;
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}
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/* Process INPUT for DSTs and store in RESULT using the information
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from link map L to resolve the DSTs. This function only handles one
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path at a time and does not handle colon-separated path lists (see
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fillin_rpath ()). Lastly the size of result in bytes should be at
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least equal to the value returned by DL_DST_REQUIRED. Note that it
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is possible for a DT_NEEDED, DT_AUXILIARY, and DT_FILTER entries to
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have colons, but we treat those as literal colons here, not as path
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list delimeters. */
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char *
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_dl_dst_substitute (struct link_map *l, const char *input, char *result)
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{
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/* Copy character-by-character from input into the working pointer
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looking for any DSTs. We track the start of input and if we are
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going to check for trusted paths, all of which are part of $ORIGIN
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handling in SUID/SGID cases (see below). In some cases, like when
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a DST cannot be replaced, we may set result to an empty string and
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return. */
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char *wp = result;
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const char *start = input;
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bool check_for_trusted = false;
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do
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{
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if (__glibc_unlikely (*input == '$'))
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{
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const char *repl = NULL;
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size_t len;
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++input;
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if ((len = is_dst (input, "ORIGIN")) != 0)
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{
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/* For SUID/GUID programs we normally ignore the path with
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$ORIGIN in DT_RUNPATH, or DT_RPATH. However, there is
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one exception to this rule, and it is:
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* $ORIGIN appears as the first path element, and is
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the only string in the path or is immediately
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followed by a path separator and the rest of the
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path,
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and ...
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* The path is rooted in a trusted directory.
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This exception allows such programs to reference
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shared libraries in subdirectories of trusted
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directories. The use case is one of general
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organization and deployment flexibility.
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Trusted directories are usually such paths as "/lib64"
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or "/usr/lib64", and the usual RPATHs take the form of
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[$ORIGIN/../$LIB/somedir]. */
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if (__glibc_unlikely (__libc_enable_secure)
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&& !(input == start + 1
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&& (input[len] == '\0' || input[len] == '/')))
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repl = (const char *) -1;
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else
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repl = l->l_origin;
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check_for_trusted = (__libc_enable_secure
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&& l->l_type == lt_executable);
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}
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else if ((len = is_dst (input, "PLATFORM")) != 0)
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repl = GLRO(dl_platform);
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else if ((len = is_dst (input, "LIB")) != 0)
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repl = DL_DST_LIB;
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if (repl != NULL && repl != (const char *) -1)
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{
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wp = __stpcpy (wp, repl);
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input += len;
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}
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else if (len != 0)
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{
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/* We found a valid DST that we know about, but we could
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not find a replacement value for it, therefore we
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cannot use this path and discard it. */
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*result = '\0';
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return result;
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}
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else
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/* No DST we recognize. */
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*wp++ = '$';
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}
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else
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{
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*wp++ = *input++;
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}
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}
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while (*input != '\0');
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/* In SUID/SGID programs, after $ORIGIN expansion the normalized
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path must be rooted in one of the trusted directories. The $LIB
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and $PLATFORM DST cannot in any way be manipulated by the caller
|
|
because they are fixed values that are set by the dynamic loader
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|
and therefore any paths using just $LIB or $PLATFORM need not be
|
|
checked for trust, the authors of the binaries themselves are
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trusted to have designed this correctly. Only $ORIGIN is tested in
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|
this way because it may be manipulated in some ways with hard
|
|
links. */
|
|
if (__glibc_unlikely (check_for_trusted)
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|
&& !is_trusted_path_normalize (result, wp - result))
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|
{
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|
*result = '\0';
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|
return result;
|
|
}
|
|
|
|
*wp = '\0';
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|
|
|
return result;
|
|
}
|
|
|
|
|
|
/* Return a malloc allocated copy of INPUT with all recognized DSTs
|
|
replaced. On some platforms it might not be possible to determine the
|
|
path from which the object belonging to the map is loaded. In this
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|
case the path containing the DST is left out. On error NULL
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|
is returned. */
|
|
static char *
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|
expand_dynamic_string_token (struct link_map *l, const char *input)
|
|
{
|
|
/* We make two runs over the string. First we determine how large the
|
|
resulting string is and then we copy it over. Since this is no
|
|
frequently executed operation we are looking here not for performance
|
|
but rather for code size. */
|
|
size_t cnt;
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|
size_t total;
|
|
char *result;
|
|
|
|
/* Determine the number of DSTs. */
|
|
cnt = _dl_dst_count (input);
|
|
|
|
/* If we do not have to replace anything simply copy the string. */
|
|
if (__glibc_likely (cnt == 0))
|
|
return __strdup (input);
|
|
|
|
/* Determine the length of the substituted string. */
|
|
total = DL_DST_REQUIRED (l, input, strlen (input), cnt);
|
|
|
|
/* Allocate the necessary memory. */
|
|
result = (char *) malloc (total + 1);
|
|
if (result == NULL)
|
|
return NULL;
|
|
|
|
return _dl_dst_substitute (l, input, result);
|
|
}
|
|
|
|
|
|
/* Add `name' to the list of names for a particular shared object.
|
|
`name' is expected to have been allocated with malloc and will
|
|
be freed if the shared object already has this name.
|
|
Returns false if the object already had this name. */
|
|
static void
|
|
add_name_to_object (struct link_map *l, const char *name)
|
|
{
|
|
struct libname_list *lnp, *lastp;
|
|
struct libname_list *newname;
|
|
size_t name_len;
|
|
|
|
lastp = NULL;
|
|
for (lnp = l->l_libname; lnp != NULL; lastp = lnp, lnp = lnp->next)
|
|
if (strcmp (name, lnp->name) == 0)
|
|
return;
|
|
|
|
name_len = strlen (name) + 1;
|
|
newname = (struct libname_list *) malloc (sizeof *newname + name_len);
|
|
if (newname == NULL)
|
|
{
|
|
/* No more memory. */
|
|
_dl_signal_error (ENOMEM, name, NULL, N_("cannot allocate name record"));
|
|
return;
|
|
}
|
|
/* The object should have a libname set from _dl_new_object. */
|
|
assert (lastp != NULL);
|
|
|
|
newname->name = memcpy (newname + 1, name, name_len);
|
|
newname->next = NULL;
|
|
newname->dont_free = 0;
|
|
lastp->next = newname;
|
|
}
|
|
|
|
/* Standard search directories. */
|
|
static struct r_search_path_struct rtld_search_dirs attribute_relro;
|
|
|
|
static size_t max_dirnamelen;
|
|
|
|
static struct r_search_path_elem **
|
|
fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
|
|
const char *what, const char *where, struct link_map *l)
|
|
{
|
|
char *cp;
|
|
size_t nelems = 0;
|
|
|
|
while ((cp = __strsep (&rpath, sep)) != NULL)
|
|
{
|
|
struct r_search_path_elem *dirp;
|
|
char *to_free = NULL;
|
|
size_t len = 0;
|
|
|
|
/* `strsep' can pass an empty string. */
|
|
if (*cp != '\0')
|
|
{
|
|
to_free = cp = expand_dynamic_string_token (l, cp);
|
|
|
|
/* expand_dynamic_string_token can return NULL in case of empty
|
|
path or memory allocation failure. */
|
|
if (cp == NULL)
|
|
continue;
|
|
|
|
/* Compute the length after dynamic string token expansion and
|
|
ignore empty paths. */
|
|
len = strlen (cp);
|
|
if (len == 0)
|
|
{
|
|
free (to_free);
|
|
continue;
|
|
}
|
|
|
|
/* Remove trailing slashes (except for "/"). */
|
|
while (len > 1 && cp[len - 1] == '/')
|
|
--len;
|
|
|
|
/* Now add one if there is none so far. */
|
|
if (len > 0 && cp[len - 1] != '/')
|
|
cp[len++] = '/';
|
|
}
|
|
|
|
/* See if this directory is already known. */
|
|
for (dirp = GL(dl_all_dirs); dirp != NULL; dirp = dirp->next)
|
|
if (dirp->dirnamelen == len && memcmp (cp, dirp->dirname, len) == 0)
|
|
break;
|
|
|
|
if (dirp != NULL)
|
|
{
|
|
/* It is available, see whether it's on our own list. */
|
|
size_t cnt;
|
|
for (cnt = 0; cnt < nelems; ++cnt)
|
|
if (result[cnt] == dirp)
|
|
break;
|
|
|
|
if (cnt == nelems)
|
|
result[nelems++] = dirp;
|
|
}
|
|
else
|
|
{
|
|
size_t cnt;
|
|
enum r_dir_status init_val;
|
|
size_t where_len = where ? strlen (where) + 1 : 0;
|
|
|
|
/* It's a new directory. Create an entry and add it. */
|
|
dirp = (struct r_search_path_elem *)
|
|
malloc (sizeof (*dirp) + ncapstr * sizeof (enum r_dir_status)
|
|
+ where_len + len + 1);
|
|
if (dirp == NULL)
|
|
_dl_signal_error (ENOMEM, NULL, NULL,
|
|
N_("cannot create cache for search path"));
|
|
|
|
dirp->dirname = ((char *) dirp + sizeof (*dirp)
|
|
+ ncapstr * sizeof (enum r_dir_status));
|
|
*((char *) __mempcpy ((char *) dirp->dirname, cp, len)) = '\0';
|
|
dirp->dirnamelen = len;
|
|
|
|
if (len > max_dirnamelen)
|
|
max_dirnamelen = len;
|
|
|
|
/* We have to make sure all the relative directories are
|
|
never ignored. The current directory might change and
|
|
all our saved information would be void. */
|
|
init_val = cp[0] != '/' ? existing : unknown;
|
|
for (cnt = 0; cnt < ncapstr; ++cnt)
|
|
dirp->status[cnt] = init_val;
|
|
|
|
dirp->what = what;
|
|
if (__glibc_likely (where != NULL))
|
|
dirp->where = memcpy ((char *) dirp + sizeof (*dirp) + len + 1
|
|
+ (ncapstr * sizeof (enum r_dir_status)),
|
|
where, where_len);
|
|
else
|
|
dirp->where = NULL;
|
|
|
|
dirp->next = GL(dl_all_dirs);
|
|
GL(dl_all_dirs) = dirp;
|
|
|
|
/* Put it in the result array. */
|
|
result[nelems++] = dirp;
|
|
}
|
|
free (to_free);
|
|
}
|
|
|
|
/* Terminate the array. */
|
|
result[nelems] = NULL;
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
static bool
|
|
decompose_rpath (struct r_search_path_struct *sps,
|
|
const char *rpath, struct link_map *l, const char *what)
|
|
{
|
|
/* Make a copy we can work with. */
|
|
const char *where = l->l_name;
|
|
char *cp;
|
|
struct r_search_path_elem **result;
|
|
size_t nelems;
|
|
/* Initialize to please the compiler. */
|
|
const char *errstring = NULL;
|
|
|
|
/* First see whether we must forget the RUNPATH and RPATH from this
|
|
object. */
|
|
if (__glibc_unlikely (GLRO(dl_inhibit_rpath) != NULL)
|
|
&& !__libc_enable_secure)
|
|
{
|
|
const char *inhp = GLRO(dl_inhibit_rpath);
|
|
|
|
do
|
|
{
|
|
const char *wp = where;
|
|
|
|
while (*inhp == *wp && *wp != '\0')
|
|
{
|
|
++inhp;
|
|
++wp;
|
|
}
|
|
|
|
if (*wp == '\0' && (*inhp == '\0' || *inhp == ':'))
|
|
{
|
|
/* This object is on the list of objects for which the
|
|
RUNPATH and RPATH must not be used. */
|
|
sps->dirs = (void *) -1;
|
|
return false;
|
|
}
|
|
|
|
while (*inhp != '\0')
|
|
if (*inhp++ == ':')
|
|
break;
|
|
}
|
|
while (*inhp != '\0');
|
|
}
|
|
|
|
/* Ignore empty rpaths. */
|
|
if (*rpath == '\0')
|
|
{
|
|
sps->dirs = (struct r_search_path_elem **) -1;
|
|
return false;
|
|
}
|
|
|
|
/* Make a writable copy. */
|
|
char *copy = __strdup (rpath);
|
|
if (copy == NULL)
|
|
{
|
|
errstring = N_("cannot create RUNPATH/RPATH copy");
|
|
goto signal_error;
|
|
}
|
|
|
|
/* Count the number of necessary elements in the result array. */
|
|
nelems = 0;
|
|
for (cp = copy; *cp != '\0'; ++cp)
|
|
if (*cp == ':')
|
|
++nelems;
|
|
|
|
/* Allocate room for the result. NELEMS + 1 is an upper limit for the
|
|
number of necessary entries. */
|
|
result = (struct r_search_path_elem **) malloc ((nelems + 1 + 1)
|
|
* sizeof (*result));
|
|
if (result == NULL)
|
|
{
|
|
free (copy);
|
|
errstring = N_("cannot create cache for search path");
|
|
signal_error:
|
|
_dl_signal_error (ENOMEM, NULL, NULL, errstring);
|
|
}
|
|
|
|
fillin_rpath (copy, result, ":", what, where, l);
|
|
|
|
/* Free the copied RPATH string. `fillin_rpath' make own copies if
|
|
necessary. */
|
|
free (copy);
|
|
|
|
/* There is no path after expansion. */
|
|
if (result[0] == NULL)
|
|
{
|
|
free (result);
|
|
sps->dirs = (struct r_search_path_elem **) -1;
|
|
return false;
|
|
}
|
|
|
|
sps->dirs = result;
|
|
/* The caller will change this value if we haven't used a real malloc. */
|
|
sps->malloced = 1;
|
|
return true;
|
|
}
|
|
|
|
/* Make sure cached path information is stored in *SP
|
|
and return true if there are any paths to search there. */
|
|
static bool
|
|
cache_rpath (struct link_map *l,
|
|
struct r_search_path_struct *sp,
|
|
int tag,
|
|
const char *what)
|
|
{
|
|
if (sp->dirs == (void *) -1)
|
|
return false;
|
|
|
|
if (sp->dirs != NULL)
|
|
return true;
|
|
|
|
if (l->l_info[tag] == NULL)
|
|
{
|
|
/* There is no path. */
|
|
sp->dirs = (void *) -1;
|
|
return false;
|
|
}
|
|
|
|
/* Make sure the cache information is available. */
|
|
return decompose_rpath (sp, (const char *) (D_PTR (l, l_info[DT_STRTAB])
|
|
+ l->l_info[tag]->d_un.d_val),
|
|
l, what);
|
|
}
|
|
|
|
|
|
void
|
|
_dl_init_paths (const char *llp)
|
|
{
|
|
size_t idx;
|
|
const char *strp;
|
|
struct r_search_path_elem *pelem, **aelem;
|
|
size_t round_size;
|
|
struct link_map __attribute__ ((unused)) *l = NULL;
|
|
/* Initialize to please the compiler. */
|
|
const char *errstring = NULL;
|
|
|
|
/* Fill in the information about the application's RPATH and the
|
|
directories addressed by the LD_LIBRARY_PATH environment variable. */
|
|
|
|
/* Get the capabilities. */
|
|
capstr = _dl_important_hwcaps (GLRO(dl_platform), GLRO(dl_platformlen),
|
|
&ncapstr, &max_capstrlen);
|
|
|
|
/* First set up the rest of the default search directory entries. */
|
|
aelem = rtld_search_dirs.dirs = (struct r_search_path_elem **)
|
|
malloc ((nsystem_dirs_len + 1) * sizeof (struct r_search_path_elem *));
|
|
if (rtld_search_dirs.dirs == NULL)
|
|
{
|
|
errstring = N_("cannot create search path array");
|
|
signal_error:
|
|
_dl_signal_error (ENOMEM, NULL, NULL, errstring);
|
|
}
|
|
|
|
round_size = ((2 * sizeof (struct r_search_path_elem) - 1
|
|
+ ncapstr * sizeof (enum r_dir_status))
|
|
/ sizeof (struct r_search_path_elem));
|
|
|
|
rtld_search_dirs.dirs[0] = malloc (nsystem_dirs_len * round_size
|
|
* sizeof (*rtld_search_dirs.dirs[0]));
|
|
if (rtld_search_dirs.dirs[0] == NULL)
|
|
{
|
|
errstring = N_("cannot create cache for search path");
|
|
goto signal_error;
|
|
}
|
|
|
|
rtld_search_dirs.malloced = 0;
|
|
pelem = GL(dl_all_dirs) = rtld_search_dirs.dirs[0];
|
|
strp = system_dirs;
|
|
idx = 0;
|
|
|
|
do
|
|
{
|
|
size_t cnt;
|
|
|
|
*aelem++ = pelem;
|
|
|
|
pelem->what = "system search path";
|
|
pelem->where = NULL;
|
|
|
|
pelem->dirname = strp;
|
|
pelem->dirnamelen = system_dirs_len[idx];
|
|
strp += system_dirs_len[idx] + 1;
|
|
|
|
/* System paths must be absolute. */
|
|
assert (pelem->dirname[0] == '/');
|
|
for (cnt = 0; cnt < ncapstr; ++cnt)
|
|
pelem->status[cnt] = unknown;
|
|
|
|
pelem->next = (++idx == nsystem_dirs_len ? NULL : (pelem + round_size));
|
|
|
|
pelem += round_size;
|
|
}
|
|
while (idx < nsystem_dirs_len);
|
|
|
|
max_dirnamelen = SYSTEM_DIRS_MAX_LEN;
|
|
*aelem = NULL;
|
|
|
|
#ifdef SHARED
|
|
/* This points to the map of the main object. */
|
|
l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
|
|
if (l != NULL)
|
|
{
|
|
assert (l->l_type != lt_loaded);
|
|
|
|
if (l->l_info[DT_RUNPATH])
|
|
{
|
|
/* Allocate room for the search path and fill in information
|
|
from RUNPATH. */
|
|
decompose_rpath (&l->l_runpath_dirs,
|
|
(const void *) (D_PTR (l, l_info[DT_STRTAB])
|
|
+ l->l_info[DT_RUNPATH]->d_un.d_val),
|
|
l, "RUNPATH");
|
|
/* During rtld init the memory is allocated by the stub malloc,
|
|
prevent any attempt to free it by the normal malloc. */
|
|
l->l_runpath_dirs.malloced = 0;
|
|
|
|
/* The RPATH is ignored. */
|
|
l->l_rpath_dirs.dirs = (void *) -1;
|
|
}
|
|
else
|
|
{
|
|
l->l_runpath_dirs.dirs = (void *) -1;
|
|
|
|
if (l->l_info[DT_RPATH])
|
|
{
|
|
/* Allocate room for the search path and fill in information
|
|
from RPATH. */
|
|
decompose_rpath (&l->l_rpath_dirs,
|
|
(const void *) (D_PTR (l, l_info[DT_STRTAB])
|
|
+ l->l_info[DT_RPATH]->d_un.d_val),
|
|
l, "RPATH");
|
|
/* During rtld init the memory is allocated by the stub
|
|
malloc, prevent any attempt to free it by the normal
|
|
malloc. */
|
|
l->l_rpath_dirs.malloced = 0;
|
|
}
|
|
else
|
|
l->l_rpath_dirs.dirs = (void *) -1;
|
|
}
|
|
}
|
|
#endif /* SHARED */
|
|
|
|
if (llp != NULL && *llp != '\0')
|
|
{
|
|
char *llp_tmp = strdupa (llp);
|
|
|
|
/* Decompose the LD_LIBRARY_PATH contents. First determine how many
|
|
elements it has. */
|
|
size_t nllp = 1;
|
|
for (const char *cp = llp_tmp; *cp != '\0'; ++cp)
|
|
if (*cp == ':' || *cp == ';')
|
|
++nllp;
|
|
|
|
env_path_list.dirs = (struct r_search_path_elem **)
|
|
malloc ((nllp + 1) * sizeof (struct r_search_path_elem *));
|
|
if (env_path_list.dirs == NULL)
|
|
{
|
|
errstring = N_("cannot create cache for search path");
|
|
goto signal_error;
|
|
}
|
|
|
|
(void) fillin_rpath (llp_tmp, env_path_list.dirs, ":;",
|
|
"LD_LIBRARY_PATH", NULL, l);
|
|
|
|
if (env_path_list.dirs[0] == NULL)
|
|
{
|
|
free (env_path_list.dirs);
|
|
env_path_list.dirs = (void *) -1;
|
|
}
|
|
|
|
env_path_list.malloced = 0;
|
|
}
|
|
else
|
|
env_path_list.dirs = (void *) -1;
|
|
}
|
|
|
|
|
|
static void
|
|
__attribute__ ((noreturn, noinline))
|
|
lose (int code, int fd, const char *name, char *realname, struct link_map *l,
|
|
const char *msg, struct r_debug *r, Lmid_t nsid)
|
|
{
|
|
/* The file might already be closed. */
|
|
if (fd != -1)
|
|
(void) __close_nocancel (fd);
|
|
if (l != NULL && l->l_origin != (char *) -1l)
|
|
free ((char *) l->l_origin);
|
|
free (l);
|
|
free (realname);
|
|
|
|
if (r != NULL)
|
|
{
|
|
r->r_state = RT_CONSISTENT;
|
|
_dl_debug_state ();
|
|
LIBC_PROBE (map_failed, 2, nsid, r);
|
|
}
|
|
|
|
_dl_signal_error (code, name, NULL, msg);
|
|
}
|
|
|
|
|
|
/* Process PT_GNU_PROPERTY program header PH in module L after
|
|
PT_LOAD segments are mapped. Only one NT_GNU_PROPERTY_TYPE_0
|
|
note is handled which contains processor specific properties. */
|
|
|
|
void
|
|
_dl_process_pt_gnu_property (struct link_map *l, const ElfW(Phdr) *ph)
|
|
{
|
|
const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr);
|
|
const ElfW(Addr) size = ph->p_memsz;
|
|
const ElfW(Addr) align = ph->p_align;
|
|
|
|
/* The NT_GNU_PROPERTY_TYPE_0 note must be aligned to 4 bytes in
|
|
32-bit objects and to 8 bytes in 64-bit objects. Skip notes
|
|
with incorrect alignment. */
|
|
if (align != (__ELF_NATIVE_CLASS / 8))
|
|
return;
|
|
|
|
const ElfW(Addr) start = (ElfW(Addr)) note;
|
|
unsigned int last_type = 0;
|
|
|
|
while ((ElfW(Addr)) (note + 1) - start < size)
|
|
{
|
|
/* Find the NT_GNU_PROPERTY_TYPE_0 note. */
|
|
if (note->n_namesz == 4
|
|
&& note->n_type == NT_GNU_PROPERTY_TYPE_0
|
|
&& memcmp (note + 1, "GNU", 4) == 0)
|
|
{
|
|
/* Check for invalid property. */
|
|
if (note->n_descsz < 8
|
|
|| (note->n_descsz % sizeof (ElfW(Addr))) != 0)
|
|
return;
|
|
|
|
/* Start and end of property array. */
|
|
unsigned char *ptr = (unsigned char *) (note + 1) + 4;
|
|
unsigned char *ptr_end = ptr + note->n_descsz;
|
|
|
|
do
|
|
{
|
|
unsigned int type = *(unsigned int *) ptr;
|
|
unsigned int datasz = *(unsigned int *) (ptr + 4);
|
|
|
|
/* Property type must be in ascending order. */
|
|
if (type < last_type)
|
|
return;
|
|
|
|
ptr += 8;
|
|
if ((ptr + datasz) > ptr_end)
|
|
return;
|
|
|
|
last_type = type;
|
|
|
|
/* Target specific property processing. */
|
|
if (_dl_process_gnu_property (l, type, datasz, ptr) == 0)
|
|
return;
|
|
|
|
/* Check the next property item. */
|
|
ptr += ALIGN_UP (datasz, sizeof (ElfW(Addr)));
|
|
}
|
|
while ((ptr_end - ptr) >= 8);
|
|
|
|
/* Only handle one NT_GNU_PROPERTY_TYPE_0. */
|
|
return;
|
|
}
|
|
|
|
note = ((const void *) note
|
|
+ ELF_NOTE_NEXT_OFFSET (note->n_namesz, note->n_descsz,
|
|
align));
|
|
}
|
|
}
|
|
|
|
|
|
/* Map in the shared object NAME, actually located in REALNAME, and already
|
|
opened on FD. */
|
|
|
|
#ifndef EXTERNAL_MAP_FROM_FD
|
|
static
|
|
#endif
|
|
struct link_map *
|
|
_dl_map_object_from_fd (const char *name, const char *origname, int fd,
|
|
struct filebuf *fbp, char *realname,
|
|
struct link_map *loader, int l_type, int mode,
|
|
void **stack_endp, Lmid_t nsid)
|
|
{
|
|
struct link_map *l = NULL;
|
|
const ElfW(Ehdr) *header;
|
|
const ElfW(Phdr) *phdr;
|
|
const ElfW(Phdr) *ph;
|
|
size_t maplength;
|
|
int type;
|
|
/* Initialize to keep the compiler happy. */
|
|
const char *errstring = NULL;
|
|
int errval = 0;
|
|
struct r_debug *r = _dl_debug_initialize (0, nsid);
|
|
bool make_consistent = false;
|
|
|
|
/* Get file information. To match the kernel behavior, do not fill
|
|
in this information for the executable in case of an explicit
|
|
loader invocation. */
|
|
struct r_file_id id;
|
|
if (mode & __RTLD_OPENEXEC)
|
|
{
|
|
assert (nsid == LM_ID_BASE);
|
|
memset (&id, 0, sizeof (id));
|
|
}
|
|
else
|
|
{
|
|
if (__glibc_unlikely (!_dl_get_file_id (fd, &id)))
|
|
{
|
|
errstring = N_("cannot stat shared object");
|
|
call_lose_errno:
|
|
errval = errno;
|
|
call_lose:
|
|
lose (errval, fd, name, realname, l, errstring,
|
|
make_consistent ? r : NULL, nsid);
|
|
}
|
|
|
|
/* Look again to see if the real name matched another already loaded. */
|
|
for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next)
|
|
if (!l->l_removed && _dl_file_id_match_p (&l->l_file_id, &id))
|
|
{
|
|
/* The object is already loaded.
|
|
Just bump its reference count and return it. */
|
|
__close_nocancel (fd);
|
|
|
|
/* If the name is not in the list of names for this object add
|
|
it. */
|
|
free (realname);
|
|
add_name_to_object (l, name);
|
|
|
|
return l;
|
|
}
|
|
}
|
|
|
|
#ifdef SHARED
|
|
/* When loading into a namespace other than the base one we must
|
|
avoid loading ld.so since there can only be one copy. Ever. */
|
|
if (__glibc_unlikely (nsid != LM_ID_BASE)
|
|
&& (_dl_file_id_match_p (&id, &GL(dl_rtld_map).l_file_id)
|
|
|| _dl_name_match_p (name, &GL(dl_rtld_map))))
|
|
{
|
|
/* This is indeed ld.so. Create a new link_map which refers to
|
|
the real one for almost everything. */
|
|
l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
|
|
if (l == NULL)
|
|
goto fail_new;
|
|
|
|
/* Refer to the real descriptor. */
|
|
l->l_real = &GL(dl_rtld_map);
|
|
|
|
/* No need to bump the refcount of the real object, ld.so will
|
|
never be unloaded. */
|
|
__close_nocancel (fd);
|
|
|
|
/* Add the map for the mirrored object to the object list. */
|
|
_dl_add_to_namespace_list (l, nsid);
|
|
|
|
return l;
|
|
}
|
|
#endif
|
|
|
|
if (mode & RTLD_NOLOAD)
|
|
{
|
|
/* We are not supposed to load the object unless it is already
|
|
loaded. So return now. */
|
|
free (realname);
|
|
__close_nocancel (fd);
|
|
return NULL;
|
|
}
|
|
|
|
/* Print debugging message. */
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
|
|
_dl_debug_printf ("file=%s [%lu]; generating link map\n", name, nsid);
|
|
|
|
/* This is the ELF header. We read it in `open_verify'. */
|
|
header = (void *) fbp->buf;
|
|
|
|
/* Signal that we are going to add new objects. */
|
|
if (r->r_state == RT_CONSISTENT)
|
|
{
|
|
#ifdef SHARED
|
|
/* Auditing checkpoint: we are going to add new objects. */
|
|
if ((mode & __RTLD_AUDIT) == 0
|
|
&& __glibc_unlikely (GLRO(dl_naudit) > 0))
|
|
{
|
|
struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
|
|
/* Do not call the functions for any auditing object. */
|
|
if (head->l_auditing == 0)
|
|
{
|
|
struct audit_ifaces *afct = GLRO(dl_audit);
|
|
for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
|
|
{
|
|
if (afct->activity != NULL)
|
|
afct->activity (&link_map_audit_state (head, cnt)->cookie,
|
|
LA_ACT_ADD);
|
|
|
|
afct = afct->next;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* Notify the debugger we have added some objects. We need to
|
|
call _dl_debug_initialize in a static program in case dynamic
|
|
linking has not been used before. */
|
|
r->r_state = RT_ADD;
|
|
_dl_debug_state ();
|
|
LIBC_PROBE (map_start, 2, nsid, r);
|
|
make_consistent = true;
|
|
}
|
|
else
|
|
assert (r->r_state == RT_ADD);
|
|
|
|
/* Enter the new object in the list of loaded objects. */
|
|
l = _dl_new_object (realname, name, l_type, loader, mode, nsid);
|
|
if (__glibc_unlikely (l == NULL))
|
|
{
|
|
#ifdef SHARED
|
|
fail_new:
|
|
#endif
|
|
errstring = N_("cannot create shared object descriptor");
|
|
goto call_lose_errno;
|
|
}
|
|
|
|
/* Extract the remaining details we need from the ELF header
|
|
and then read in the program header table. */
|
|
l->l_entry = header->e_entry;
|
|
type = header->e_type;
|
|
l->l_phnum = header->e_phnum;
|
|
|
|
maplength = header->e_phnum * sizeof (ElfW(Phdr));
|
|
if (header->e_phoff + maplength <= (size_t) fbp->len)
|
|
phdr = (void *) (fbp->buf + header->e_phoff);
|
|
else
|
|
{
|
|
phdr = alloca (maplength);
|
|
if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength,
|
|
header->e_phoff) != maplength)
|
|
{
|
|
errstring = N_("cannot read file data");
|
|
goto call_lose_errno;
|
|
}
|
|
}
|
|
|
|
/* On most platforms presume that PT_GNU_STACK is absent and the stack is
|
|
* executable. Other platforms default to a nonexecutable stack and don't
|
|
* need PT_GNU_STACK to do so. */
|
|
uint_fast16_t stack_flags = DEFAULT_STACK_PERMS;
|
|
|
|
{
|
|
/* Scan the program header table, collecting its load commands. */
|
|
struct loadcmd loadcmds[l->l_phnum];
|
|
size_t nloadcmds = 0;
|
|
bool has_holes = false;
|
|
|
|
/* The struct is initialized to zero so this is not necessary:
|
|
l->l_ld = 0;
|
|
l->l_phdr = 0;
|
|
l->l_addr = 0; */
|
|
for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
|
|
switch (ph->p_type)
|
|
{
|
|
/* These entries tell us where to find things once the file's
|
|
segments are mapped in. We record the addresses it says
|
|
verbatim, and later correct for the run-time load address. */
|
|
case PT_DYNAMIC:
|
|
if (ph->p_filesz)
|
|
{
|
|
/* Debuginfo only files from "objcopy --only-keep-debug"
|
|
contain a PT_DYNAMIC segment with p_filesz == 0. Skip
|
|
such a segment to avoid a crash later. */
|
|
l->l_ld = (void *) ph->p_vaddr;
|
|
l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
|
|
}
|
|
break;
|
|
|
|
case PT_PHDR:
|
|
l->l_phdr = (void *) ph->p_vaddr;
|
|
break;
|
|
|
|
case PT_LOAD:
|
|
/* A load command tells us to map in part of the file.
|
|
We record the load commands and process them all later. */
|
|
if (__glibc_unlikely ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0))
|
|
{
|
|
errstring = N_("ELF load command alignment not page-aligned");
|
|
goto call_lose;
|
|
}
|
|
if (__glibc_unlikely (((ph->p_vaddr - ph->p_offset)
|
|
& (ph->p_align - 1)) != 0))
|
|
{
|
|
errstring
|
|
= N_("ELF load command address/offset not properly aligned");
|
|
goto call_lose;
|
|
}
|
|
|
|
struct loadcmd *c = &loadcmds[nloadcmds++];
|
|
c->mapstart = ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize));
|
|
c->mapend = ALIGN_UP (ph->p_vaddr + ph->p_filesz, GLRO(dl_pagesize));
|
|
c->dataend = ph->p_vaddr + ph->p_filesz;
|
|
c->allocend = ph->p_vaddr + ph->p_memsz;
|
|
c->mapoff = ALIGN_DOWN (ph->p_offset, GLRO(dl_pagesize));
|
|
|
|
/* Determine whether there is a gap between the last segment
|
|
and this one. */
|
|
if (nloadcmds > 1 && c[-1].mapend != c->mapstart)
|
|
has_holes = true;
|
|
|
|
/* Optimize a common case. */
|
|
#if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
|
|
c->prot = (PF_TO_PROT
|
|
>> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
|
|
#else
|
|
c->prot = 0;
|
|
if (ph->p_flags & PF_R)
|
|
c->prot |= PROT_READ;
|
|
if (ph->p_flags & PF_W)
|
|
c->prot |= PROT_WRITE;
|
|
if (ph->p_flags & PF_X)
|
|
c->prot |= PROT_EXEC;
|
|
#endif
|
|
break;
|
|
|
|
case PT_TLS:
|
|
if (ph->p_memsz == 0)
|
|
/* Nothing to do for an empty segment. */
|
|
break;
|
|
|
|
l->l_tls_blocksize = ph->p_memsz;
|
|
l->l_tls_align = ph->p_align;
|
|
if (ph->p_align == 0)
|
|
l->l_tls_firstbyte_offset = 0;
|
|
else
|
|
l->l_tls_firstbyte_offset = ph->p_vaddr & (ph->p_align - 1);
|
|
l->l_tls_initimage_size = ph->p_filesz;
|
|
/* Since we don't know the load address yet only store the
|
|
offset. We will adjust it later. */
|
|
l->l_tls_initimage = (void *) ph->p_vaddr;
|
|
|
|
/* l->l_tls_modid is assigned below, once there is no
|
|
possibility for failure. */
|
|
|
|
if (l->l_type != lt_library
|
|
&& GL(dl_tls_dtv_slotinfo_list) == NULL)
|
|
{
|
|
#ifdef SHARED
|
|
/* We are loading the executable itself when the dynamic
|
|
linker was executed directly. The setup will happen
|
|
later. */
|
|
assert (l->l_prev == NULL || (mode & __RTLD_AUDIT) != 0);
|
|
#else
|
|
assert (false && "TLS not initialized in static application");
|
|
#endif
|
|
}
|
|
break;
|
|
|
|
case PT_GNU_STACK:
|
|
stack_flags = ph->p_flags;
|
|
break;
|
|
|
|
case PT_GNU_RELRO:
|
|
l->l_relro_addr = ph->p_vaddr;
|
|
l->l_relro_size = ph->p_memsz;
|
|
break;
|
|
}
|
|
|
|
if (__glibc_unlikely (nloadcmds == 0))
|
|
{
|
|
/* This only happens for a bogus object that will be caught with
|
|
another error below. But we don't want to go through the
|
|
calculations below using NLOADCMDS - 1. */
|
|
errstring = N_("object file has no loadable segments");
|
|
goto call_lose;
|
|
}
|
|
|
|
/* dlopen of an executable is not valid because it is not possible
|
|
to perform proper relocations, handle static TLS, or run the
|
|
ELF constructors. For PIE, the check needs the dynamic
|
|
section, so there is another check below. */
|
|
if (__glibc_unlikely (type != ET_DYN)
|
|
&& __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0))
|
|
{
|
|
/* This object is loaded at a fixed address. This must never
|
|
happen for objects loaded with dlopen. */
|
|
errstring = N_("cannot dynamically load executable");
|
|
goto call_lose;
|
|
}
|
|
|
|
/* Length of the sections to be loaded. */
|
|
maplength = loadcmds[nloadcmds - 1].allocend - loadcmds[0].mapstart;
|
|
|
|
/* Now process the load commands and map segments into memory.
|
|
This is responsible for filling in:
|
|
l_map_start, l_map_end, l_addr, l_contiguous, l_text_end, l_phdr
|
|
*/
|
|
errstring = _dl_map_segments (l, fd, header, type, loadcmds, nloadcmds,
|
|
maplength, has_holes, loader);
|
|
if (__glibc_unlikely (errstring != NULL))
|
|
goto call_lose;
|
|
|
|
/* Process program headers again after load segments are mapped in
|
|
case processing requires accessing those segments. Scan program
|
|
headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY
|
|
exits. */
|
|
for (ph = &phdr[l->l_phnum]; ph != phdr; --ph)
|
|
switch (ph[-1].p_type)
|
|
{
|
|
case PT_NOTE:
|
|
_dl_process_pt_note (l, &ph[-1]);
|
|
break;
|
|
case PT_GNU_PROPERTY:
|
|
_dl_process_pt_gnu_property (l, &ph[-1]);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (l->l_ld == 0)
|
|
{
|
|
if (__glibc_unlikely (type == ET_DYN))
|
|
{
|
|
errstring = N_("object file has no dynamic section");
|
|
goto call_lose;
|
|
}
|
|
}
|
|
else
|
|
l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
|
|
|
|
elf_get_dynamic_info (l, NULL);
|
|
|
|
/* Make sure we are not dlopen'ing an object that has the
|
|
DF_1_NOOPEN flag set, or a PIE object. */
|
|
if ((__glibc_unlikely (l->l_flags_1 & DF_1_NOOPEN)
|
|
&& (mode & __RTLD_DLOPEN))
|
|
|| (__glibc_unlikely (l->l_flags_1 & DF_1_PIE)
|
|
&& __glibc_unlikely ((mode & __RTLD_OPENEXEC) == 0)))
|
|
{
|
|
/* We are not supposed to load this object. Free all resources. */
|
|
_dl_unmap_segments (l);
|
|
|
|
if (!l->l_libname->dont_free)
|
|
free (l->l_libname);
|
|
|
|
if (l->l_phdr_allocated)
|
|
free ((void *) l->l_phdr);
|
|
|
|
if (l->l_flags_1 & DF_1_PIE)
|
|
errstring
|
|
= N_("cannot dynamically load position-independent executable");
|
|
else
|
|
errstring = N_("shared object cannot be dlopen()ed");
|
|
goto call_lose;
|
|
}
|
|
|
|
if (l->l_phdr == NULL)
|
|
{
|
|
/* The program header is not contained in any of the segments.
|
|
We have to allocate memory ourself and copy it over from out
|
|
temporary place. */
|
|
ElfW(Phdr) *newp = (ElfW(Phdr) *) malloc (header->e_phnum
|
|
* sizeof (ElfW(Phdr)));
|
|
if (newp == NULL)
|
|
{
|
|
errstring = N_("cannot allocate memory for program header");
|
|
goto call_lose_errno;
|
|
}
|
|
|
|
l->l_phdr = memcpy (newp, phdr,
|
|
(header->e_phnum * sizeof (ElfW(Phdr))));
|
|
l->l_phdr_allocated = 1;
|
|
}
|
|
else
|
|
/* Adjust the PT_PHDR value by the runtime load address. */
|
|
l->l_phdr = (ElfW(Phdr) *) ((ElfW(Addr)) l->l_phdr + l->l_addr);
|
|
|
|
if (__glibc_unlikely ((stack_flags &~ GL(dl_stack_flags)) & PF_X))
|
|
{
|
|
/* The stack is presently not executable, but this module
|
|
requires that it be executable. We must change the
|
|
protection of the variable which contains the flags used in
|
|
the mprotect calls. */
|
|
#ifdef SHARED
|
|
if ((mode & (__RTLD_DLOPEN | __RTLD_AUDIT)) == __RTLD_DLOPEN)
|
|
{
|
|
const uintptr_t p = (uintptr_t) &__stack_prot & -GLRO(dl_pagesize);
|
|
const size_t s = (uintptr_t) (&__stack_prot + 1) - p;
|
|
|
|
struct link_map *const m = &GL(dl_rtld_map);
|
|
const uintptr_t relro_end = ((m->l_addr + m->l_relro_addr
|
|
+ m->l_relro_size)
|
|
& -GLRO(dl_pagesize));
|
|
if (__glibc_likely (p + s <= relro_end))
|
|
{
|
|
/* The variable lies in the region protected by RELRO. */
|
|
if (__mprotect ((void *) p, s, PROT_READ|PROT_WRITE) < 0)
|
|
{
|
|
errstring = N_("cannot change memory protections");
|
|
goto call_lose_errno;
|
|
}
|
|
__stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
|
|
__mprotect ((void *) p, s, PROT_READ);
|
|
}
|
|
else
|
|
__stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
|
|
}
|
|
else
|
|
#endif
|
|
__stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC;
|
|
|
|
#ifdef check_consistency
|
|
check_consistency ();
|
|
#endif
|
|
|
|
errval = (*GL(dl_make_stack_executable_hook)) (stack_endp);
|
|
if (errval)
|
|
{
|
|
errstring = N_("\
|
|
cannot enable executable stack as shared object requires");
|
|
goto call_lose;
|
|
}
|
|
}
|
|
|
|
/* Adjust the address of the TLS initialization image. */
|
|
if (l->l_tls_initimage != NULL)
|
|
l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
|
|
|
|
/* We are done mapping in the file. We no longer need the descriptor. */
|
|
if (__glibc_unlikely (__close_nocancel (fd) != 0))
|
|
{
|
|
errstring = N_("cannot close file descriptor");
|
|
goto call_lose_errno;
|
|
}
|
|
/* Signal that we closed the file. */
|
|
fd = -1;
|
|
|
|
/* If this is ET_EXEC, we should have loaded it as lt_executable. */
|
|
assert (type != ET_EXEC || l->l_type == lt_executable);
|
|
|
|
l->l_entry += l->l_addr;
|
|
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
|
|
_dl_debug_printf ("\
|
|
dynamic: 0x%0*lx base: 0x%0*lx size: 0x%0*Zx\n\
|
|
entry: 0x%0*lx phdr: 0x%0*lx phnum: %*u\n\n",
|
|
(int) sizeof (void *) * 2,
|
|
(unsigned long int) l->l_ld,
|
|
(int) sizeof (void *) * 2,
|
|
(unsigned long int) l->l_addr,
|
|
(int) sizeof (void *) * 2, maplength,
|
|
(int) sizeof (void *) * 2,
|
|
(unsigned long int) l->l_entry,
|
|
(int) sizeof (void *) * 2,
|
|
(unsigned long int) l->l_phdr,
|
|
(int) sizeof (void *) * 2, l->l_phnum);
|
|
|
|
/* Set up the symbol hash table. */
|
|
_dl_setup_hash (l);
|
|
|
|
/* If this object has DT_SYMBOLIC set modify now its scope. We don't
|
|
have to do this for the main map. */
|
|
if ((mode & RTLD_DEEPBIND) == 0
|
|
&& __glibc_unlikely (l->l_info[DT_SYMBOLIC] != NULL)
|
|
&& &l->l_searchlist != l->l_scope[0])
|
|
{
|
|
/* Create an appropriate searchlist. It contains only this map.
|
|
This is the definition of DT_SYMBOLIC in SysVr4. */
|
|
l->l_symbolic_searchlist.r_list[0] = l;
|
|
l->l_symbolic_searchlist.r_nlist = 1;
|
|
|
|
/* Now move the existing entries one back. */
|
|
memmove (&l->l_scope[1], &l->l_scope[0],
|
|
(l->l_scope_max - 1) * sizeof (l->l_scope[0]));
|
|
|
|
/* Now add the new entry. */
|
|
l->l_scope[0] = &l->l_symbolic_searchlist;
|
|
}
|
|
|
|
/* Remember whether this object must be initialized first. */
|
|
if (l->l_flags_1 & DF_1_INITFIRST)
|
|
GL(dl_initfirst) = l;
|
|
|
|
/* Finally the file information. */
|
|
l->l_file_id = id;
|
|
|
|
#ifdef SHARED
|
|
/* When auditing is used the recorded names might not include the
|
|
name by which the DSO is actually known. Add that as well. */
|
|
if (__glibc_unlikely (origname != NULL))
|
|
add_name_to_object (l, origname);
|
|
#else
|
|
/* Audit modules only exist when linking is dynamic so ORIGNAME
|
|
cannot be non-NULL. */
|
|
assert (origname == NULL);
|
|
#endif
|
|
|
|
/* When we profile the SONAME might be needed for something else but
|
|
loading. Add it right away. */
|
|
if (__glibc_unlikely (GLRO(dl_profile) != NULL)
|
|
&& l->l_info[DT_SONAME] != NULL)
|
|
add_name_to_object (l, ((const char *) D_PTR (l, l_info[DT_STRTAB])
|
|
+ l->l_info[DT_SONAME]->d_un.d_val));
|
|
|
|
/* If we have newly loaded libc.so, update the namespace
|
|
description. */
|
|
if (GL(dl_ns)[nsid].libc_map == NULL
|
|
&& l->l_info[DT_SONAME] != NULL
|
|
&& strcmp (((const char *) D_PTR (l, l_info[DT_STRTAB])
|
|
+ l->l_info[DT_SONAME]->d_un.d_val), LIBC_SO) == 0)
|
|
GL(dl_ns)[nsid].libc_map = l;
|
|
|
|
/* _dl_close can only eventually undo the module ID assignment (via
|
|
remove_slotinfo) if this function returns a pointer to a link
|
|
map. Therefore, delay this step until all possibilities for
|
|
failure have been excluded. */
|
|
if (l->l_tls_blocksize > 0
|
|
&& (__glibc_likely (l->l_type == lt_library)
|
|
/* If GL(dl_tls_dtv_slotinfo_list) == NULL, then rtld.c did
|
|
not set up TLS data structures, so don't use them now. */
|
|
|| __glibc_likely (GL(dl_tls_dtv_slotinfo_list) != NULL)))
|
|
/* Assign the next available module ID. */
|
|
l->l_tls_modid = _dl_next_tls_modid ();
|
|
|
|
#ifdef DL_AFTER_LOAD
|
|
DL_AFTER_LOAD (l);
|
|
#endif
|
|
|
|
/* Now that the object is fully initialized add it to the object list. */
|
|
_dl_add_to_namespace_list (l, nsid);
|
|
|
|
#ifdef SHARED
|
|
/* Auditing checkpoint: we have a new object. */
|
|
if (__glibc_unlikely (GLRO(dl_naudit) > 0)
|
|
&& !GL(dl_ns)[l->l_ns]._ns_loaded->l_auditing)
|
|
{
|
|
struct audit_ifaces *afct = GLRO(dl_audit);
|
|
for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
|
|
{
|
|
if (afct->objopen != NULL)
|
|
{
|
|
struct auditstate *state = link_map_audit_state (l, cnt);
|
|
state->bindflags = afct->objopen (l, nsid, &state->cookie);
|
|
l->l_audit_any_plt |= state->bindflags != 0;
|
|
}
|
|
|
|
afct = afct->next;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
return l;
|
|
}
|
|
|
|
/* Print search path. */
|
|
static void
|
|
print_search_path (struct r_search_path_elem **list,
|
|
const char *what, const char *name)
|
|
{
|
|
char buf[max_dirnamelen + max_capstrlen];
|
|
int first = 1;
|
|
|
|
_dl_debug_printf (" search path=");
|
|
|
|
while (*list != NULL && (*list)->what == what) /* Yes, ==. */
|
|
{
|
|
char *endp = __mempcpy (buf, (*list)->dirname, (*list)->dirnamelen);
|
|
size_t cnt;
|
|
|
|
for (cnt = 0; cnt < ncapstr; ++cnt)
|
|
if ((*list)->status[cnt] != nonexisting)
|
|
{
|
|
char *cp = __mempcpy (endp, capstr[cnt].str, capstr[cnt].len);
|
|
if (cp == buf || (cp == buf + 1 && buf[0] == '/'))
|
|
cp[0] = '\0';
|
|
else
|
|
cp[-1] = '\0';
|
|
|
|
_dl_debug_printf_c (first ? "%s" : ":%s", buf);
|
|
first = 0;
|
|
}
|
|
|
|
++list;
|
|
}
|
|
|
|
if (name != NULL)
|
|
_dl_debug_printf_c ("\t\t(%s from file %s)\n", what,
|
|
DSO_FILENAME (name));
|
|
else
|
|
_dl_debug_printf_c ("\t\t(%s)\n", what);
|
|
}
|
|
|
|
/* Open a file and verify it is an ELF file for this architecture. We
|
|
ignore only ELF files for other architectures. Non-ELF files and
|
|
ELF files with different header information cause fatal errors since
|
|
this could mean there is something wrong in the installation and the
|
|
user might want to know about this.
|
|
|
|
If FD is not -1, then the file is already open and FD refers to it.
|
|
In that case, FD is consumed for both successful and error returns. */
|
|
static int
|
|
open_verify (const char *name, int fd,
|
|
struct filebuf *fbp, struct link_map *loader,
|
|
int whatcode, int mode, bool *found_other_class, bool free_name)
|
|
{
|
|
/* This is the expected ELF header. */
|
|
#define ELF32_CLASS ELFCLASS32
|
|
#define ELF64_CLASS ELFCLASS64
|
|
#ifndef VALID_ELF_HEADER
|
|
# define VALID_ELF_HEADER(hdr,exp,size) (memcmp (hdr, exp, size) == 0)
|
|
# define VALID_ELF_OSABI(osabi) (osabi == ELFOSABI_SYSV)
|
|
# define VALID_ELF_ABIVERSION(osabi,ver) (ver == 0)
|
|
#elif defined MORE_ELF_HEADER_DATA
|
|
MORE_ELF_HEADER_DATA;
|
|
#endif
|
|
static const unsigned char expected[EI_NIDENT] =
|
|
{
|
|
[EI_MAG0] = ELFMAG0,
|
|
[EI_MAG1] = ELFMAG1,
|
|
[EI_MAG2] = ELFMAG2,
|
|
[EI_MAG3] = ELFMAG3,
|
|
[EI_CLASS] = ELFW(CLASS),
|
|
[EI_DATA] = byteorder,
|
|
[EI_VERSION] = EV_CURRENT,
|
|
[EI_OSABI] = ELFOSABI_SYSV,
|
|
[EI_ABIVERSION] = 0
|
|
};
|
|
static const struct
|
|
{
|
|
ElfW(Word) vendorlen;
|
|
ElfW(Word) datalen;
|
|
ElfW(Word) type;
|
|
char vendor[4];
|
|
} expected_note = { 4, 16, 1, "GNU" };
|
|
/* Initialize it to make the compiler happy. */
|
|
const char *errstring = NULL;
|
|
int errval = 0;
|
|
|
|
#ifdef SHARED
|
|
/* Give the auditing libraries a chance. */
|
|
if (__glibc_unlikely (GLRO(dl_naudit) > 0) && whatcode != 0
|
|
&& loader->l_auditing == 0)
|
|
{
|
|
const char *original_name = name;
|
|
struct audit_ifaces *afct = GLRO(dl_audit);
|
|
for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
|
|
{
|
|
if (afct->objsearch != NULL)
|
|
{
|
|
struct auditstate *state = link_map_audit_state (loader, cnt);
|
|
name = afct->objsearch (name, &state->cookie, whatcode);
|
|
if (name == NULL)
|
|
/* Ignore the path. */
|
|
return -1;
|
|
}
|
|
|
|
afct = afct->next;
|
|
}
|
|
|
|
if (fd != -1 && name != original_name && strcmp (name, original_name))
|
|
{
|
|
/* An audit library changed what we're supposed to open,
|
|
so FD no longer matches it. */
|
|
__close_nocancel (fd);
|
|
fd = -1;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (fd == -1)
|
|
/* Open the file. We always open files read-only. */
|
|
fd = __open64_nocancel (name, O_RDONLY | O_CLOEXEC);
|
|
|
|
if (fd != -1)
|
|
{
|
|
ElfW(Ehdr) *ehdr;
|
|
ElfW(Phdr) *phdr, *ph;
|
|
ElfW(Word) *abi_note;
|
|
ElfW(Word) *abi_note_malloced = NULL;
|
|
unsigned int osversion;
|
|
size_t maplength;
|
|
|
|
/* We successfully opened the file. Now verify it is a file
|
|
we can use. */
|
|
__set_errno (0);
|
|
fbp->len = 0;
|
|
assert (sizeof (fbp->buf) > sizeof (ElfW(Ehdr)));
|
|
/* Read in the header. */
|
|
do
|
|
{
|
|
ssize_t retlen = __read_nocancel (fd, fbp->buf + fbp->len,
|
|
sizeof (fbp->buf) - fbp->len);
|
|
if (retlen <= 0)
|
|
break;
|
|
fbp->len += retlen;
|
|
}
|
|
while (__glibc_unlikely (fbp->len < sizeof (ElfW(Ehdr))));
|
|
|
|
/* This is where the ELF header is loaded. */
|
|
ehdr = (ElfW(Ehdr) *) fbp->buf;
|
|
|
|
/* Now run the tests. */
|
|
if (__glibc_unlikely (fbp->len < (ssize_t) sizeof (ElfW(Ehdr))))
|
|
{
|
|
errval = errno;
|
|
errstring = (errval == 0
|
|
? N_("file too short") : N_("cannot read file data"));
|
|
call_lose:
|
|
if (free_name)
|
|
{
|
|
char *realname = (char *) name;
|
|
name = strdupa (realname);
|
|
free (realname);
|
|
}
|
|
lose (errval, fd, name, NULL, NULL, errstring, NULL, 0);
|
|
}
|
|
|
|
/* See whether the ELF header is what we expect. */
|
|
if (__glibc_unlikely (! VALID_ELF_HEADER (ehdr->e_ident, expected,
|
|
EI_ABIVERSION)
|
|
|| !VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
|
|
ehdr->e_ident[EI_ABIVERSION])
|
|
|| memcmp (&ehdr->e_ident[EI_PAD],
|
|
&expected[EI_PAD],
|
|
EI_NIDENT - EI_PAD) != 0))
|
|
{
|
|
/* Something is wrong. */
|
|
const Elf32_Word *magp = (const void *) ehdr->e_ident;
|
|
if (*magp !=
|
|
#if BYTE_ORDER == LITTLE_ENDIAN
|
|
((ELFMAG0 << (EI_MAG0 * 8))
|
|
| (ELFMAG1 << (EI_MAG1 * 8))
|
|
| (ELFMAG2 << (EI_MAG2 * 8))
|
|
| (ELFMAG3 << (EI_MAG3 * 8)))
|
|
#else
|
|
((ELFMAG0 << (EI_MAG3 * 8))
|
|
| (ELFMAG1 << (EI_MAG2 * 8))
|
|
| (ELFMAG2 << (EI_MAG1 * 8))
|
|
| (ELFMAG3 << (EI_MAG0 * 8)))
|
|
#endif
|
|
)
|
|
errstring = N_("invalid ELF header");
|
|
else if (ehdr->e_ident[EI_CLASS] != ELFW(CLASS))
|
|
{
|
|
/* This is not a fatal error. On architectures where
|
|
32-bit and 64-bit binaries can be run this might
|
|
happen. */
|
|
*found_other_class = true;
|
|
goto close_and_out;
|
|
}
|
|
else if (ehdr->e_ident[EI_DATA] != byteorder)
|
|
{
|
|
if (BYTE_ORDER == BIG_ENDIAN)
|
|
errstring = N_("ELF file data encoding not big-endian");
|
|
else
|
|
errstring = N_("ELF file data encoding not little-endian");
|
|
}
|
|
else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT)
|
|
errstring
|
|
= N_("ELF file version ident does not match current one");
|
|
/* XXX We should be able so set system specific versions which are
|
|
allowed here. */
|
|
else if (!VALID_ELF_OSABI (ehdr->e_ident[EI_OSABI]))
|
|
errstring = N_("ELF file OS ABI invalid");
|
|
else if (!VALID_ELF_ABIVERSION (ehdr->e_ident[EI_OSABI],
|
|
ehdr->e_ident[EI_ABIVERSION]))
|
|
errstring = N_("ELF file ABI version invalid");
|
|
else if (memcmp (&ehdr->e_ident[EI_PAD], &expected[EI_PAD],
|
|
EI_NIDENT - EI_PAD) != 0)
|
|
errstring = N_("nonzero padding in e_ident");
|
|
else
|
|
/* Otherwise we don't know what went wrong. */
|
|
errstring = N_("internal error");
|
|
|
|
goto call_lose;
|
|
}
|
|
|
|
if (__glibc_unlikely (ehdr->e_version != EV_CURRENT))
|
|
{
|
|
errstring = N_("ELF file version does not match current one");
|
|
goto call_lose;
|
|
}
|
|
if (! __glibc_likely (elf_machine_matches_host (ehdr)))
|
|
goto close_and_out;
|
|
else if (__glibc_unlikely (ehdr->e_type != ET_DYN
|
|
&& ehdr->e_type != ET_EXEC))
|
|
{
|
|
errstring = N_("only ET_DYN and ET_EXEC can be loaded");
|
|
goto call_lose;
|
|
}
|
|
else if (__glibc_unlikely (ehdr->e_phentsize != sizeof (ElfW(Phdr))))
|
|
{
|
|
errstring = N_("ELF file's phentsize not the expected size");
|
|
goto call_lose;
|
|
}
|
|
|
|
maplength = ehdr->e_phnum * sizeof (ElfW(Phdr));
|
|
if (ehdr->e_phoff + maplength <= (size_t) fbp->len)
|
|
phdr = (void *) (fbp->buf + ehdr->e_phoff);
|
|
else
|
|
{
|
|
phdr = alloca (maplength);
|
|
if ((size_t) __pread64_nocancel (fd, (void *) phdr, maplength,
|
|
ehdr->e_phoff) != maplength)
|
|
{
|
|
read_error:
|
|
errval = errno;
|
|
errstring = N_("cannot read file data");
|
|
goto call_lose;
|
|
}
|
|
}
|
|
|
|
if (__glibc_unlikely (elf_machine_reject_phdr_p
|
|
(phdr, ehdr->e_phnum, fbp->buf, fbp->len,
|
|
loader, fd)))
|
|
goto close_and_out;
|
|
|
|
/* Check .note.ABI-tag if present. */
|
|
for (ph = phdr; ph < &phdr[ehdr->e_phnum]; ++ph)
|
|
if (ph->p_type == PT_NOTE && ph->p_filesz >= 32
|
|
&& (ph->p_align == 4 || ph->p_align == 8))
|
|
{
|
|
ElfW(Addr) size = ph->p_filesz;
|
|
|
|
if (ph->p_offset + size <= (size_t) fbp->len)
|
|
abi_note = (void *) (fbp->buf + ph->p_offset);
|
|
else
|
|
{
|
|
/* Note: __libc_use_alloca is not usable here, because
|
|
thread info may not have been set up yet. */
|
|
if (size < __MAX_ALLOCA_CUTOFF)
|
|
abi_note = alloca (size);
|
|
else
|
|
{
|
|
/* There could be multiple PT_NOTEs. */
|
|
abi_note_malloced = realloc (abi_note_malloced, size);
|
|
if (abi_note_malloced == NULL)
|
|
goto read_error;
|
|
|
|
abi_note = abi_note_malloced;
|
|
}
|
|
if (__pread64_nocancel (fd, (void *) abi_note, size,
|
|
ph->p_offset) != size)
|
|
{
|
|
free (abi_note_malloced);
|
|
goto read_error;
|
|
}
|
|
}
|
|
|
|
while (memcmp (abi_note, &expected_note, sizeof (expected_note)))
|
|
{
|
|
ElfW(Addr) note_size
|
|
= ELF_NOTE_NEXT_OFFSET (abi_note[0], abi_note[1],
|
|
ph->p_align);
|
|
|
|
if (size - 32 < note_size)
|
|
{
|
|
size = 0;
|
|
break;
|
|
}
|
|
size -= note_size;
|
|
abi_note = (void *) abi_note + note_size;
|
|
}
|
|
|
|
if (size == 0)
|
|
continue;
|
|
|
|
osversion = (abi_note[5] & 0xff) * 65536
|
|
+ (abi_note[6] & 0xff) * 256
|
|
+ (abi_note[7] & 0xff);
|
|
if (abi_note[4] != __ABI_TAG_OS
|
|
|| (GLRO(dl_osversion) && GLRO(dl_osversion) < osversion))
|
|
{
|
|
close_and_out:
|
|
__close_nocancel (fd);
|
|
__set_errno (ENOENT);
|
|
fd = -1;
|
|
}
|
|
|
|
break;
|
|
}
|
|
free (abi_note_malloced);
|
|
}
|
|
|
|
return fd;
|
|
}
|
|
|
|
/* Try to open NAME in one of the directories in *DIRSP.
|
|
Return the fd, or -1. If successful, fill in *REALNAME
|
|
with the malloc'd full directory name. If it turns out
|
|
that none of the directories in *DIRSP exists, *DIRSP is
|
|
replaced with (void *) -1, and the old value is free()d
|
|
if MAY_FREE_DIRS is true. */
|
|
|
|
static int
|
|
open_path (const char *name, size_t namelen, int mode,
|
|
struct r_search_path_struct *sps, char **realname,
|
|
struct filebuf *fbp, struct link_map *loader, int whatcode,
|
|
bool *found_other_class)
|
|
{
|
|
struct r_search_path_elem **dirs = sps->dirs;
|
|
char *buf;
|
|
int fd = -1;
|
|
const char *current_what = NULL;
|
|
int any = 0;
|
|
|
|
if (__glibc_unlikely (dirs == NULL))
|
|
/* We're called before _dl_init_paths when loading the main executable
|
|
given on the command line when rtld is run directly. */
|
|
return -1;
|
|
|
|
buf = alloca (max_dirnamelen + max_capstrlen + namelen);
|
|
do
|
|
{
|
|
struct r_search_path_elem *this_dir = *dirs;
|
|
size_t buflen = 0;
|
|
size_t cnt;
|
|
char *edp;
|
|
int here_any = 0;
|
|
int err;
|
|
|
|
/* If we are debugging the search for libraries print the path
|
|
now if it hasn't happened now. */
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)
|
|
&& current_what != this_dir->what)
|
|
{
|
|
current_what = this_dir->what;
|
|
print_search_path (dirs, current_what, this_dir->where);
|
|
}
|
|
|
|
edp = (char *) __mempcpy (buf, this_dir->dirname, this_dir->dirnamelen);
|
|
for (cnt = 0; fd == -1 && cnt < ncapstr; ++cnt)
|
|
{
|
|
/* Skip this directory if we know it does not exist. */
|
|
if (this_dir->status[cnt] == nonexisting)
|
|
continue;
|
|
|
|
buflen =
|
|
((char *) __mempcpy (__mempcpy (edp, capstr[cnt].str,
|
|
capstr[cnt].len),
|
|
name, namelen)
|
|
- buf);
|
|
|
|
/* Print name we try if this is wanted. */
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
|
|
_dl_debug_printf (" trying file=%s\n", buf);
|
|
|
|
fd = open_verify (buf, -1, fbp, loader, whatcode, mode,
|
|
found_other_class, false);
|
|
if (this_dir->status[cnt] == unknown)
|
|
{
|
|
if (fd != -1)
|
|
this_dir->status[cnt] = existing;
|
|
/* Do not update the directory information when loading
|
|
auditing code. We must try to disturb the program as
|
|
little as possible. */
|
|
else if (loader == NULL
|
|
|| GL(dl_ns)[loader->l_ns]._ns_loaded->l_auditing == 0)
|
|
{
|
|
/* We failed to open machine dependent library. Let's
|
|
test whether there is any directory at all. */
|
|
struct stat64 st;
|
|
|
|
buf[buflen - namelen - 1] = '\0';
|
|
|
|
if (__xstat64 (_STAT_VER, buf, &st) != 0
|
|
|| ! S_ISDIR (st.st_mode))
|
|
/* The directory does not exist or it is no directory. */
|
|
this_dir->status[cnt] = nonexisting;
|
|
else
|
|
this_dir->status[cnt] = existing;
|
|
}
|
|
}
|
|
|
|
/* Remember whether we found any existing directory. */
|
|
here_any |= this_dir->status[cnt] != nonexisting;
|
|
|
|
if (fd != -1 && __glibc_unlikely (mode & __RTLD_SECURE)
|
|
&& __libc_enable_secure)
|
|
{
|
|
/* This is an extra security effort to make sure nobody can
|
|
preload broken shared objects which are in the trusted
|
|
directories and so exploit the bugs. */
|
|
struct stat64 st;
|
|
|
|
if (__fxstat64 (_STAT_VER, fd, &st) != 0
|
|
|| (st.st_mode & S_ISUID) == 0)
|
|
{
|
|
/* The shared object cannot be tested for being SUID
|
|
or this bit is not set. In this case we must not
|
|
use this object. */
|
|
__close_nocancel (fd);
|
|
fd = -1;
|
|
/* We simply ignore the file, signal this by setting
|
|
the error value which would have been set by `open'. */
|
|
errno = ENOENT;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (fd != -1)
|
|
{
|
|
*realname = (char *) malloc (buflen);
|
|
if (*realname != NULL)
|
|
{
|
|
memcpy (*realname, buf, buflen);
|
|
return fd;
|
|
}
|
|
else
|
|
{
|
|
/* No memory for the name, we certainly won't be able
|
|
to load and link it. */
|
|
__close_nocancel (fd);
|
|
return -1;
|
|
}
|
|
}
|
|
if (here_any && (err = errno) != ENOENT && err != EACCES)
|
|
/* The file exists and is readable, but something went wrong. */
|
|
return -1;
|
|
|
|
/* Remember whether we found anything. */
|
|
any |= here_any;
|
|
}
|
|
while (*++dirs != NULL);
|
|
|
|
/* Remove the whole path if none of the directories exists. */
|
|
if (__glibc_unlikely (! any))
|
|
{
|
|
/* Paths which were allocated using the minimal malloc() in ld.so
|
|
must not be freed using the general free() in libc. */
|
|
if (sps->malloced)
|
|
free (sps->dirs);
|
|
|
|
/* rtld_search_dirs and env_path_list are attribute_relro, therefore
|
|
avoid writing into it. */
|
|
if (sps != &rtld_search_dirs && sps != &env_path_list)
|
|
sps->dirs = (void *) -1;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/* Map in the shared object file NAME. */
|
|
|
|
struct link_map *
|
|
_dl_map_object (struct link_map *loader, const char *name,
|
|
int type, int trace_mode, int mode, Lmid_t nsid)
|
|
{
|
|
int fd;
|
|
const char *origname = NULL;
|
|
char *realname;
|
|
char *name_copy;
|
|
struct link_map *l;
|
|
struct filebuf fb;
|
|
|
|
assert (nsid >= 0);
|
|
assert (nsid < GL(dl_nns));
|
|
|
|
/* Look for this name among those already loaded. */
|
|
for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
|
|
{
|
|
/* If the requested name matches the soname of a loaded object,
|
|
use that object. Elide this check for names that have not
|
|
yet been opened. */
|
|
if (__glibc_unlikely ((l->l_faked | l->l_removed) != 0))
|
|
continue;
|
|
if (!_dl_name_match_p (name, l))
|
|
{
|
|
const char *soname;
|
|
|
|
if (__glibc_likely (l->l_soname_added)
|
|
|| l->l_info[DT_SONAME] == NULL)
|
|
continue;
|
|
|
|
soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
|
|
+ l->l_info[DT_SONAME]->d_un.d_val);
|
|
if (strcmp (name, soname) != 0)
|
|
continue;
|
|
|
|
/* We have a match on a new name -- cache it. */
|
|
add_name_to_object (l, soname);
|
|
l->l_soname_added = 1;
|
|
}
|
|
|
|
/* We have a match. */
|
|
return l;
|
|
}
|
|
|
|
/* Display information if we are debugging. */
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
|
|
&& loader != NULL)
|
|
_dl_debug_printf ((mode & __RTLD_CALLMAP) == 0
|
|
? "\nfile=%s [%lu]; needed by %s [%lu]\n"
|
|
: "\nfile=%s [%lu]; dynamically loaded by %s [%lu]\n",
|
|
name, nsid, DSO_FILENAME (loader->l_name), loader->l_ns);
|
|
|
|
#ifdef SHARED
|
|
/* Give the auditing libraries a chance to change the name before we
|
|
try anything. */
|
|
if (__glibc_unlikely (GLRO(dl_naudit) > 0)
|
|
&& (loader == NULL || loader->l_auditing == 0))
|
|
{
|
|
struct audit_ifaces *afct = GLRO(dl_audit);
|
|
for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
|
|
{
|
|
if (afct->objsearch != NULL)
|
|
{
|
|
const char *before = name;
|
|
struct auditstate *state = link_map_audit_state (loader, cnt);
|
|
name = afct->objsearch (name, &state->cookie, LA_SER_ORIG);
|
|
if (name == NULL)
|
|
{
|
|
/* Do not try anything further. */
|
|
fd = -1;
|
|
goto no_file;
|
|
}
|
|
if (before != name && strcmp (before, name) != 0)
|
|
{
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
|
|
_dl_debug_printf ("audit changed filename %s -> %s\n",
|
|
before, name);
|
|
|
|
if (origname == NULL)
|
|
origname = before;
|
|
}
|
|
}
|
|
|
|
afct = afct->next;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* Will be true if we found a DSO which is of the other ELF class. */
|
|
bool found_other_class = false;
|
|
|
|
if (strchr (name, '/') == NULL)
|
|
{
|
|
/* Search for NAME in several places. */
|
|
|
|
size_t namelen = strlen (name) + 1;
|
|
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
|
|
_dl_debug_printf ("find library=%s [%lu]; searching\n", name, nsid);
|
|
|
|
fd = -1;
|
|
|
|
/* When the object has the RUNPATH information we don't use any
|
|
RPATHs. */
|
|
if (loader == NULL || loader->l_info[DT_RUNPATH] == NULL)
|
|
{
|
|
/* This is the executable's map (if there is one). Make sure that
|
|
we do not look at it twice. */
|
|
struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
|
|
bool did_main_map = false;
|
|
|
|
/* First try the DT_RPATH of the dependent object that caused NAME
|
|
to be loaded. Then that object's dependent, and on up. */
|
|
for (l = loader; l; l = l->l_loader)
|
|
if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
|
|
{
|
|
fd = open_path (name, namelen, mode,
|
|
&l->l_rpath_dirs,
|
|
&realname, &fb, loader, LA_SER_RUNPATH,
|
|
&found_other_class);
|
|
if (fd != -1)
|
|
break;
|
|
|
|
did_main_map |= l == main_map;
|
|
}
|
|
|
|
/* If dynamically linked, try the DT_RPATH of the executable
|
|
itself. NB: we do this for lookups in any namespace. */
|
|
if (fd == -1 && !did_main_map
|
|
&& main_map != NULL && main_map->l_type != lt_loaded
|
|
&& cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
|
|
"RPATH"))
|
|
fd = open_path (name, namelen, mode,
|
|
&main_map->l_rpath_dirs,
|
|
&realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
|
|
&found_other_class);
|
|
}
|
|
|
|
/* Try the LD_LIBRARY_PATH environment variable. */
|
|
if (fd == -1 && env_path_list.dirs != (void *) -1)
|
|
fd = open_path (name, namelen, mode, &env_path_list,
|
|
&realname, &fb,
|
|
loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
|
|
LA_SER_LIBPATH, &found_other_class);
|
|
|
|
/* Look at the RUNPATH information for this binary. */
|
|
if (fd == -1 && loader != NULL
|
|
&& cache_rpath (loader, &loader->l_runpath_dirs,
|
|
DT_RUNPATH, "RUNPATH"))
|
|
fd = open_path (name, namelen, mode,
|
|
&loader->l_runpath_dirs, &realname, &fb, loader,
|
|
LA_SER_RUNPATH, &found_other_class);
|
|
|
|
if (fd == -1)
|
|
{
|
|
realname = _dl_sysdep_open_object (name, namelen, &fd);
|
|
if (realname != NULL)
|
|
{
|
|
fd = open_verify (realname, fd,
|
|
&fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
|
|
LA_SER_CONFIG, mode, &found_other_class,
|
|
false);
|
|
if (fd == -1)
|
|
free (realname);
|
|
}
|
|
}
|
|
|
|
#ifdef USE_LDCONFIG
|
|
if (fd == -1
|
|
&& (__glibc_likely ((mode & __RTLD_SECURE) == 0)
|
|
|| ! __libc_enable_secure)
|
|
&& __glibc_likely (GLRO(dl_inhibit_cache) == 0))
|
|
{
|
|
/* Check the list of libraries in the file /etc/ld.so.cache,
|
|
for compatibility with Linux's ldconfig program. */
|
|
char *cached = _dl_load_cache_lookup (name);
|
|
|
|
if (cached != NULL)
|
|
{
|
|
// XXX Correct to unconditionally default to namespace 0?
|
|
l = (loader
|
|
?: GL(dl_ns)[LM_ID_BASE]._ns_loaded
|
|
# ifdef SHARED
|
|
?: &GL(dl_rtld_map)
|
|
# endif
|
|
);
|
|
|
|
/* If the loader has the DF_1_NODEFLIB flag set we must not
|
|
use a cache entry from any of these directories. */
|
|
if (__glibc_unlikely (l->l_flags_1 & DF_1_NODEFLIB))
|
|
{
|
|
const char *dirp = system_dirs;
|
|
unsigned int cnt = 0;
|
|
|
|
do
|
|
{
|
|
if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0)
|
|
{
|
|
/* The prefix matches. Don't use the entry. */
|
|
free (cached);
|
|
cached = NULL;
|
|
break;
|
|
}
|
|
|
|
dirp += system_dirs_len[cnt] + 1;
|
|
++cnt;
|
|
}
|
|
while (cnt < nsystem_dirs_len);
|
|
}
|
|
|
|
if (cached != NULL)
|
|
{
|
|
fd = open_verify (cached, -1,
|
|
&fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
|
|
LA_SER_CONFIG, mode, &found_other_class,
|
|
false);
|
|
if (__glibc_likely (fd != -1))
|
|
realname = cached;
|
|
else
|
|
free (cached);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* Finally, try the default path. */
|
|
if (fd == -1
|
|
&& ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
|
|
|| __glibc_likely (!(l->l_flags_1 & DF_1_NODEFLIB)))
|
|
&& rtld_search_dirs.dirs != (void *) -1)
|
|
fd = open_path (name, namelen, mode, &rtld_search_dirs,
|
|
&realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
|
|
|
|
/* Add another newline when we are tracing the library loading. */
|
|
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
|
|
_dl_debug_printf ("\n");
|
|
}
|
|
else
|
|
{
|
|
/* The path may contain dynamic string tokens. */
|
|
realname = (loader
|
|
? expand_dynamic_string_token (loader, name)
|
|
: __strdup (name));
|
|
if (realname == NULL)
|
|
fd = -1;
|
|
else
|
|
{
|
|
fd = open_verify (realname, -1, &fb,
|
|
loader ?: GL(dl_ns)[nsid]._ns_loaded, 0, mode,
|
|
&found_other_class, true);
|
|
if (__glibc_unlikely (fd == -1))
|
|
free (realname);
|
|
}
|
|
}
|
|
|
|
#ifdef SHARED
|
|
no_file:
|
|
#endif
|
|
/* In case the LOADER information has only been provided to get to
|
|
the appropriate RUNPATH/RPATH information we do not need it
|
|
anymore. */
|
|
if (mode & __RTLD_CALLMAP)
|
|
loader = NULL;
|
|
|
|
if (__glibc_unlikely (fd == -1))
|
|
{
|
|
if (trace_mode
|
|
&& __glibc_likely ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) == 0))
|
|
{
|
|
/* We haven't found an appropriate library. But since we
|
|
are only interested in the list of libraries this isn't
|
|
so severe. Fake an entry with all the information we
|
|
have. */
|
|
static const Elf_Symndx dummy_bucket = STN_UNDEF;
|
|
|
|
/* Allocate a new object map. */
|
|
if ((name_copy = __strdup (name)) == NULL
|
|
|| (l = _dl_new_object (name_copy, name, type, loader,
|
|
mode, nsid)) == NULL)
|
|
{
|
|
free (name_copy);
|
|
_dl_signal_error (ENOMEM, name, NULL,
|
|
N_("cannot create shared object descriptor"));
|
|
}
|
|
/* Signal that this is a faked entry. */
|
|
l->l_faked = 1;
|
|
/* Since the descriptor is initialized with zero we do not
|
|
have do this here.
|
|
l->l_reserved = 0; */
|
|
l->l_buckets = &dummy_bucket;
|
|
l->l_nbuckets = 1;
|
|
l->l_relocated = 1;
|
|
|
|
/* Enter the object in the object list. */
|
|
_dl_add_to_namespace_list (l, nsid);
|
|
|
|
return l;
|
|
}
|
|
else if (found_other_class)
|
|
_dl_signal_error (0, name, NULL,
|
|
ELFW(CLASS) == ELFCLASS32
|
|
? N_("wrong ELF class: ELFCLASS64")
|
|
: N_("wrong ELF class: ELFCLASS32"));
|
|
else
|
|
_dl_signal_error (errno, name, NULL,
|
|
N_("cannot open shared object file"));
|
|
}
|
|
|
|
void *stack_end = __libc_stack_end;
|
|
return _dl_map_object_from_fd (name, origname, fd, &fb, realname, loader,
|
|
type, mode, &stack_end, nsid);
|
|
}
|
|
|
|
struct add_path_state
|
|
{
|
|
bool counting;
|
|
unsigned int idx;
|
|
Dl_serinfo *si;
|
|
char *allocptr;
|
|
};
|
|
|
|
static void
|
|
add_path (struct add_path_state *p, const struct r_search_path_struct *sps,
|
|
unsigned int flags)
|
|
{
|
|
if (sps->dirs != (void *) -1)
|
|
{
|
|
struct r_search_path_elem **dirs = sps->dirs;
|
|
do
|
|
{
|
|
const struct r_search_path_elem *const r = *dirs++;
|
|
if (p->counting)
|
|
{
|
|
p->si->dls_cnt++;
|
|
p->si->dls_size += MAX (2, r->dirnamelen);
|
|
}
|
|
else
|
|
{
|
|
Dl_serpath *const sp = &p->si->dls_serpath[p->idx++];
|
|
sp->dls_name = p->allocptr;
|
|
if (r->dirnamelen < 2)
|
|
*p->allocptr++ = r->dirnamelen ? '/' : '.';
|
|
else
|
|
p->allocptr = __mempcpy (p->allocptr,
|
|
r->dirname, r->dirnamelen - 1);
|
|
*p->allocptr++ = '\0';
|
|
sp->dls_flags = flags;
|
|
}
|
|
}
|
|
while (*dirs != NULL);
|
|
}
|
|
}
|
|
|
|
void
|
|
_dl_rtld_di_serinfo (struct link_map *loader, Dl_serinfo *si, bool counting)
|
|
{
|
|
if (counting)
|
|
{
|
|
si->dls_cnt = 0;
|
|
si->dls_size = 0;
|
|
}
|
|
|
|
struct add_path_state p =
|
|
{
|
|
.counting = counting,
|
|
.idx = 0,
|
|
.si = si,
|
|
.allocptr = (char *) &si->dls_serpath[si->dls_cnt]
|
|
};
|
|
|
|
# define add_path(p, sps, flags) add_path(p, sps, 0) /* XXX */
|
|
|
|
/* When the object has the RUNPATH information we don't use any RPATHs. */
|
|
if (loader->l_info[DT_RUNPATH] == NULL)
|
|
{
|
|
/* First try the DT_RPATH of the dependent object that caused NAME
|
|
to be loaded. Then that object's dependent, and on up. */
|
|
|
|
struct link_map *l = loader;
|
|
do
|
|
{
|
|
if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
|
|
add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
|
|
l = l->l_loader;
|
|
}
|
|
while (l != NULL);
|
|
|
|
/* If dynamically linked, try the DT_RPATH of the executable itself. */
|
|
if (loader->l_ns == LM_ID_BASE)
|
|
{
|
|
l = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
|
|
if (l != NULL && l->l_type != lt_loaded && l != loader)
|
|
if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
|
|
add_path (&p, &l->l_rpath_dirs, XXX_RPATH);
|
|
}
|
|
}
|
|
|
|
/* Try the LD_LIBRARY_PATH environment variable. */
|
|
add_path (&p, &env_path_list, XXX_ENV);
|
|
|
|
/* Look at the RUNPATH information for this binary. */
|
|
if (cache_rpath (loader, &loader->l_runpath_dirs, DT_RUNPATH, "RUNPATH"))
|
|
add_path (&p, &loader->l_runpath_dirs, XXX_RUNPATH);
|
|
|
|
/* XXX
|
|
Here is where ld.so.cache gets checked, but we don't have
|
|
a way to indicate that in the results for Dl_serinfo. */
|
|
|
|
/* Finally, try the default path. */
|
|
if (!(loader->l_flags_1 & DF_1_NODEFLIB))
|
|
add_path (&p, &rtld_search_dirs, XXX_default);
|
|
|
|
if (counting)
|
|
/* Count the struct size before the string area, which we didn't
|
|
know before we completed dls_cnt. */
|
|
si->dls_size += (char *) &si->dls_serpath[si->dls_cnt] - (char *) si;
|
|
}
|
|
|