| blob | d130f4ecf39fe300da7af014417de364cfe39209 |
1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
22 /*
23 * Copyright (c) 1988 AT&T
24 * All Rights Reserved
25 *
26 * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
27 */
28 /*
29 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
30 */
32 /*
33 * Publicly available flags are defined in ld(1). The following flags are
34 * private, and may be removed at any time.
35 *
36 * OPTION MEANING
37 *
38 * -z dtrace=symbol assigns symbol to PT_SUNWDTRACE segment,
39 * providing scratch area for dtrace processing.
40 *
41 * -z noreloc suppress relocation processing. This provides
42 * a mechanism for validating kernel module symbol
43 * resolution that would normally incur fatal
44 * relocation errors.
45 *
46 * -z rtldinfo=symbol assigns symbol to SUNW_RTLDINF dynamic tag,
47 * providing pre-initialization specific routines
48 * for TLS initialization.
49 *
50 * -z nointerp suppress the addition of an interpreter
51 * section. This is used to generate the kernel,
52 * but makes no sense to be used by anyone else.
53 *
54 * -z norelaxreloc suppress the automatic addition of relaxed
55 * relocations to GNU linkonce/COMDAT sections.
56 *
57 * -z nosighandler suppress the registration of the signal handler
58 * used to manage SIGBUS.
59 */
61 /*
62 * The following flags are committed, and will not be removed, but are
63 * not publically documented, either because they are obsolete, or because
64 * they exist to work around defects in other software and are not of
65 * sufficient interest otherwise.
66 *
67 * OPTION MEANING
68 *
69 * -Wl,... compiler drivers and configuration tools
70 * have been known to pass this compiler option
71 * to ld(1). Strip off the "-Wl," prefix and
72 * process the remainder (...) as a normal option.
73 */
75 #include <sys/link.h>
76 #include <stdio.h>
77 #include <fcntl.h>
78 #include <string.h>
79 #include <errno.h>
80 #include <elf.h>
81 #include <unistd.h>
82 #include <debug.h>
86 /*
87 * Define a set of local argument flags, the settings of these will be
88 * verified in check_flags() and lead to the appropriate output file flags
89 * being initialized.
90 */
117 /*
118 * ztflag's state is set by pointing it to the matching string:
119 * text | textoff | textwarn
120 */
123 /*
124 * Remember the guidance flags that result from the initial -z guidance
125 * option, so that they can be compared to any that follow. We only want
126 * to issue a warning when they differ.
127 */
133 /*
134 * Print usage message to stderr - 2 modes, summary message only,
135 * and full usage message.
136 */
137 static void
139 {
232 }
234 /*
235 * Rescan the archives seen on the command line in order
236 * to handle circularly dependent archives, stopping when
237 * no further member extraction occurs.
238 *
239 * entry:
240 * ofl - Output file descriptor
241 * isgrp - True if this is a an archive group search, False
242 * to search starting with argv[1] through end_arg_ndx
243 * end_arg_ndx - Index of final argv element to consider.
244 */
245 static uintptr_t
247 {
251 Aliste idx;
262 /* If not to starting index yet, skip it */
266 /*
267 * If this archive was processed with -z allextract,
268 * then all members have already been extracted.
269 */
273 /*
274 * Reestablish any archive specific command line flags.
275 */
279 /*
280 * Re-process the archive. Note that a file descriptor
281 * is unnecessary, as the file is already available in
282 * memory.
283 */
288 }
289 }
292 }
294 /*
295 * Checks the command line option flags for consistency.
296 */
297 static uintptr_t
299 {
300 /*
301 * If the user specified -zguidance=noall, then we can safely disable
302 * the entire feature. The purpose of -zguidance=noall is to allow
303 * the user to override guidance specified from a makefile via
304 * the LD_OPTIONS environment variable, and so, we want to behave
305 * in exactly the same manner we would have if no option were present.
306 */
318 /*
319 * Combining relocations when building a relocatable
320 * object isn't allowed. Warn the user, but proceed.
321 */
328 /*
329 * Translating object capabilities to symbol capabilities is
330 * only meaningful when creating a relocatable object.
331 */
337 /*
338 * If the user hasn't explicitly requested that relocations
339 * not be combined, combine them by default.
340 */
343 }
383 /*
384 * Set -Bdynamic on by default, setting is rechecked as input
385 * files are processed.
386 */
405 }
407 /*
408 * If the use of default library searching has been suppressed
409 * but no runpaths have been provided we're going to have a hard
410 * job running this object.
411 */
416 /*
417 * By default, text relocation warnings are given when building
418 * an executable unless the -b flag is specified. This option
419 * implies that unclean text can be created, so no warnings are
420 * generated unless specifically asked for.
421 */
429 }
432 /*
433 * Create a dynamic object. -Bdirect indicates that all
434 * references should be bound directly. This also
435 * enables lazyloading. Individual symbols can be
436 * bound directly (or not) using mapfiles and the
437 * DIRECT (NODIRECT) qualifier. With this capability,
438 * each syminfo entry is tagged SYMINFO_FLG_DIRECTBIND.
439 * Prior to this per-symbol direct binding, runtime
440 * direct binding was controlled via the DF_1_DIRECT
441 * flag. This flag affected all references from the
442 * object. -Bdirect continues to set this flag, and
443 * thus provides a means of taking a newly built
444 * direct binding object back to older systems.
445 *
446 * NOTE, any use of per-symbol NODIRECT bindings, or
447 * -znodirect, will disable the creation of the
448 * DF_1_DIRECT flag. Older runtime linkers do not
449 * have the capability to do per-symbol direct bindings.
450 */
456 }
458 /*
459 * -Bnodirect disables directly binding to any symbols
460 * exported from the object being created. Individual
461 * references to external objects can still be affected
462 * by -zdirect or mapfile DIRECT directives.
463 */
468 }
469 }
472 /*
473 * Dynamically linked executable.
474 */
480 /*
481 * -z textwarn is the default for executables, and
482 * only an explicit -z text* option can change that,
483 * so there's no need to provide additional guidance.
484 */
496 /*
497 * Shared library.
498 */
501 /*
502 * By default, print text relocation warnings for
503 * executables but *not* for shared objects. However,
504 * if -z guidance is on, issue warnings for shared
505 * objects as well.
506 *
507 * If -z textwarn is explicitly specified, also issue
508 * guidance messages if -z guidance is on, but not
509 * for -z text or -z textoff.
510 */
517 }
520 /*
521 * -Bsymbolic, and -Bnodirect make no sense.
522 */
530 }
532 /*
533 * Dynamic relocatable object.
534 */
544 }
574 /*
575 * We can only strip the symbol table and string table
576 * if no output relocations will refer to them.
577 */
594 /*
595 * Static executable.
596 */
601 }
602 }
604 /*
605 * If the user didn't supply an output file name supply a default.
606 */
610 /*
611 * We set the entrance criteria after all input argument processing as
612 * it is only at this point we're sure what the output image will be
613 * (static or dynamic).
614 */
618 /*
619 * Does the host currently running the linker have the same
620 * byte order as the target for which the object is being produced?
621 * If not, set FLG_OF1_ENCDIFF so relocation code will know
622 * to check.
623 */
627 /*
628 * If the target has special executable section filling requirements,
629 * register the fill function with libelf
630 */
634 /*
635 * Initialize string tables. Symbol definitions within mapfiles can
636 * result in the creation of input sections.
637 */
641 /*
642 * Process mapfiles. Mapfile can redefine or add sections/segments,
643 * so this must come after the default entrance criteria are established
644 * (above).
645 */
648 Aliste idx;
656 }
658 /*
659 * If a mapfile has been used to define a single symbolic scope of
660 * interfaces, -Bsymbolic is established. This global setting goes
661 * beyond individual symbol protection, and ensures all relocations
662 * (even those that reference section symbols) are processed within
663 * the object being built.
664 */
670 }
672 /*
673 * If -zloadfltr is set, verify that filtering is in effect. Filters
674 * are either established from the command line, and affect the whole
675 * object, or are set on a per-symbol basis from a mapfile.
676 */
682 }
684 /*
685 * Check that we have something to work with. This check is carried out
686 * after mapfile processing as its possible a mapfile is being used to
687 * define symbols, in which case it would be sufficient to build the
688 * output file purely from the mapfile.
689 */
698 }
699 }
701 }
703 /*
704 * Decompose the string pointed by optarg into argv[][] so that argv[][] can be
705 * used as an argument to getopt().
706 *
707 * If the second argument 'usage' is not NULL, then this is called from the
708 * first pass. Else this is called from the second pass.
709 */
710 static uintptr_t
712 {
717 /*
718 * The argument being examined is either:
719 * ld32= or
720 * ld64=
721 */
722 #if defined(_LP64)
725 #else
728 #endif
732 /*
733 * Count the number of arguments.
734 */
736 /*
737 * Pointing at non-separator character.
738 */
740 argc++;
742 p0++;
744 }
746 /*
747 * Pointing at a separator character.
748 */
751 p0++;
753 }
754 }
759 /*
760 * Allocate argument vector.
761 */
770 /*
771 * Pointing at the beginning of non-separator character string.
772 */
776 p0++;
780 p0++;
781 }
783 }
785 /*
786 * Pointing at the beginining of separator character string.
787 */
790 p0++;
792 }
793 }
798 /*
799 * Dispatch to pass1 or pass2
800 */
803 else
808 }
810 /*
811 * Parse the items in a '-z guidance' value, and set the ofl_guideflags.
812 * A guidance option looks like this:
813 *
814 * -z guidance[=item1,item2,...]
815 *
816 * Where each item specifies categories of guidance messages to suppress,
817 * each starting with the prefix 'no'. We allow arbitrary whitespace between
818 * the items, allow multiple ',' delimiters without an intervening item, and
819 * quietly ignore any items we don't recognize.
820 *
821 * - Such items are likely to be known to newer versions of the linker,
822 * and we do not want an older version of the linker to
823 * complain about them.
824 *
825 * - Times and standards can change, and so we wish to reserve the
826 * right to make an old item that no longer makes sense go away.
827 * Quietly ignoring unrecognized items facilitates this.
828 *
829 * However, we always display unrecognized items in debug output.
830 *
831 * entry:
832 * ofl - Output descriptor
833 * optarg - option string to be processed. This will either be a NULL
834 * terminated 'guidance', or it will be 'guidance=' followed
835 * by the item tokens as described above.
836 *
837 * exit:
838 * Returns TRUE (1) on success, FALSE (0) on failure.
839 *
840 */
841 static Boolean
843 {
846 ofl_guideflag_t flag;
859 };
865 /*
866 * Skip the 'guidance' prefix. If NULL terminated, there are no
867 * item values to parse. Otherwise, skip the '=' and parse the items.
868 */
871 optarg++;
887 }
891 }
892 }
894 /*
895 * If -zguidance is used more than once, we take the first one. We
896 * do this quietly if they have identical options, and with a warning
897 * otherwise.
898 */
904 }
906 /*
907 * First time: Save the flags for comparison to any subsequent
908 * -z guidance that comes along, and OR the resulting flags into
909 * the flags kept in the output descriptor.
910 */
914 }
916 /*
917 * Parse the -z assert-deflib option. This option can appear in two different
918 * forms:
919 * -z assert-deflib
920 * -z assert-deflib=libfred.so
921 *
922 * Either form enables this option, the latter form marks libfred.so as an
923 * exempt library from the check. It is valid to have multiple invocations of
924 * the second form. We silently ignore mulitple occurrences of the first form
925 * and multiple invocations of the first form when the second form also occurs.
926 *
927 * We only return false when we have an internal error, such as the failure of
928 * aplist_append. Every other time we return true, but we have the appropriate
929 * fatal flags set beacuse of the ld_eprintf.
930 */
931 static int
933 {
938 /* Minimum size of assert-deflib=lib%s.so */
940 MSG_STR_SOEXT_SIZE;
946 }
955 }
960 }
963 }
966 /*
967 * Parsing options pass1 for process_flags().
968 */
969 static uintptr_t
971 {
974 /*
975 * The -32, -64 and -ztarget options are special, in that we validate
976 * them, but otherwise ignore them. libld.so (this code) is called
977 * from the ld front end program. ld has already examined the
978 * arguments to determine the output class and machine type of the
979 * output object, as reflected in the version (32/64) of ld_main()
980 * that was called and the value of the 'mach' argument passed.
981 * By time execution reaches this point, these options have already
982 * been seen and acted on.
983 */
990 /*
991 * -32 is processed by ld to determine the output class.
992 * Here we sanity check the option incase some other
993 * -3* option is mistakenly passed to us.
994 */
1004 /*
1005 * -64 is processed by ld to determine the output class.
1006 * Here we sanity check the option incase some other
1007 * -6* option is mistakenly passed to us.
1008 */
1024 /*
1025 * This is a hack, and may be undone later.
1026 * The -b option is only used to build the Unix
1027 * kernel and its related kernel-mode modules.
1028 * We do not want those files to get a .SUNW_ldynsym
1029 * section. At least for now, the kernel makes no
1030 * use of .SUNW_ldynsym, and we do not want to use
1031 * the space to hold it. Therefore, we overload
1032 * the use of -b to also imply -znoldynsym.
1033 */
1043 else
1059 else
1066 else
1072 }
1081 else
1099 }
1115 }
1124 else
1139 else
1145 /*
1146 * For now, count any library as a shared object. This
1147 * is used to size the internal symbol cache. This
1148 * value is recalculated later on actual file processing
1149 * to get an accurate shared object count.
1150 */
1165 else
1172 /*
1173 * Multiple instances of this option may occur. Each
1174 * additional instance is effectively concatenated to
1175 * the previous separated by a colon.
1176 */
1182 }
1188 /*
1189 * Multiple instances of this option may occur. Each
1190 * additional instance is effectively concatenated to
1191 * the previous separated by a colon.
1192 */
1198 }
1209 /*
1210 * Multiple instances of this option may occur. Each
1211 * additional instance is effectively concatenated to
1212 * the previous separated by a colon.
1213 */
1219 }
1239 /*
1240 * For specific help, print our usage message and exit
1241 * immediately to ensure a 0 return code.
1242 */
1247 }
1249 /*
1250 * For some options set a flag - further consistancy
1251 * checks will be carried out in check_flags().
1252 */
1266 else
1275 else
1285 ztflag);
1294 ztflag);
1303 ztflag);
1306 /*
1307 * For other options simply set the ofl flags directly.
1308 */
1399 /*
1400 * Check archive group usage
1401 * -z rescan-start ... -z rescan-end
1402 * to ensure they don't overlap and are well formed.
1403 */
1409 /* Another group is still open */
1413 /* Don't report cascading errors */
1415 }
1421 /* There was no matching begin */
1426 /* Don't report cascading errors */
1428 }
1430 /*
1431 * If -z wrap is seen, enter the symbol to be wrapped
1432 * into the wrap AVL tree.
1433 */
1445 p++;
1462 }
1468 }
1484 }
1491 else
1494 /*
1495 * Process everything related to -z assert-deflib. This
1496 * must be done in pass 1 because it gets used in pass
1497 * 2.
1498 */
1503 /*
1504 * The following options just need validation as they
1505 * are interpreted on the second pass through the
1506 * command line arguments.
1507 */
1510 MSG_ARG_INITARRAY_SIZE) &&
1512 MSG_ARG_FINIARRAY_SIZE) &&
1514 MSG_ARG_PREINITARRAY_SIZE) &&
1516 MSG_ARG_RTLDINFO_SIZE) &&
1518 MSG_ARG_DTRACE_SIZE) &&
1532 MSG_ARG_TARGET_SIZE) &&
1538 }
1543 /*
1544 * If we have not yet read any input files go ahead
1545 * and process any debugging options (this allows any
1546 * argument processing, entrance criteria and library
1547 * initialization to be displayed). Otherwise, if an
1548 * input file has been seen, skip interpretation until
1549 * process_files (this allows debugging to be turned
1550 * on and off around individual groups of files).
1551 */
1556 }
1558 /*
1559 * A diagnostic can only be provided after dbg_setup().
1560 * As this is the first diagnostic that can be produced
1561 * by ld(1), issue a title for timing and basic output.
1562 */
1564 optitle++;
1566 }
1581 }
1592 }
1616 }
1646 else
1653 else
1659 }
1684 else
1692 else
1700 else
1706 }
1711 /*
1712 * If the option character is '-', we're looking at a
1713 * long option which couldn't be translated, display a
1714 * more useful error.
1715 */
1723 }
1729 }
1731 /*
1732 * Update the argument index for the next getopt() iteration.
1733 */
1735 }
1737 }
1739 /*
1740 * Parsing options pass2 for
1741 */
1742 static uintptr_t
1744 {
1754 optarg));
1760 optarg));
1765 FLG_OF_DYNLIBS;
1770 }
1777 optarg));
1783 optarg));
1784 /*
1785 * Record DT_NEEDED string
1786 */
1805 optarg));
1810 optarg));
1817 optarg));
1836 FLG_OF1_WEAKEXT);
1870 MSG_STR_COMMAND)) ==
1880 MSG_STR_COMMAND)) ==
1890 MSG_STR_COMMAND)) ==
1900 MSG_STR_COMMAND)) ==
1910 MSG_STR_COMMAND)) ==
1917 S_ERROR)
1926 S_ERROR)
1934 }
1937 }
1939 /*
1940 * Update the argument index for the next getopt() iteration.
1941 */
1943 }
1945 }
1947 /*
1948 *
1949 * Pass 1 -- process_flags: collects all options and sets flags
1950 */
1951 static uintptr_t
1953 {
1955 /*
1956 * If we detect some more options return to getopt().
1957 * Checking argv[optind][1] against null prevents a forever
1958 * loop if an unadorned `-' argument is passed to us.
1959 */
1967 }
1971 }
1973 /* Did an unterminated archive group run off the end? */
1979 }
1982 }
1984 uintptr_t
1986 {
1992 }
1994 /*
1995 * Option handling
1996 */
2002 /*
2003 * Having parsed everything, did we have any usage errors.
2004 */
2008 }
2011 }
2013 /*
2014 * Pass 2 -- process_files: skips the flags collected in pass 1 and processes
2015 * files.
2016 */
2017 static uintptr_t
2019 {
2026 /*
2027 * If we detect some more options return to getopt().
2028 * Checking argv[optind][1] against null prevents a forever
2029 * loop if an unadorned `-' argument is passed to us.
2030 */
2037 }
2048 }
2059 /*
2060 * Check for mismatched input.
2061 */
2063 Conv_reject_desc_buf_t rej_buf;
2072 }
2073 }
2075 }
2077 uintptr_t
2079 {
2082 /*
2083 * Process command line files (taking into account any applicable
2084 * preceding flags). Return if any fatal errors have occurred.
2085 */
2093 /*
2094 * Guidance: Use -B direct/nodirect or -z direct/nodirect.
2095 *
2096 * This is a backstop for the case where the link had no dependencies.
2097 * Otherwise, it will get caught by ld_process_ifl(). We need both,
2098 * because -z direct is positional, and its value at the time where
2099 * the first dependency is seen might be different than it is now.
2100 */
2105 }
2107 /*
2108 * Now that all command line files have been processed see if there are
2109 * any additional `needed' shared object dependencies.
2110 */
2115 /*
2116 * If rescanning archives is enabled, do so now to determine whether
2117 * there might still be members extracted to satisfy references from any
2118 * explicit objects. Continue until no new objects are extracted. Note
2119 * that this pass is carried out *after* processing any implicit objects
2120 * (above) as they may already have resolved any undefined references
2121 * from any explicit dependencies.
2122 */
2128 }
2130 /*
2131 * If debugging, provide statistics on each archives extraction, or flag
2132 * any archive that has provided no members. Note that this could be a
2133 * nice place to free up much of the archive infrastructure, as we've
2134 * extracted any members we need. However, as we presently don't free
2135 * anything under ld(1) there's not much point in proceeding further.
2136 */
2139 /*
2140 * If any version definitions have been established, either via input
2141 * from a mapfile or from the input relocatable objects, make sure any
2142 * version dependencies are satisfied, and version symbols created.
2143 */
2148 /*
2149 * If input section ordering was specified within some segment
2150 * using a mapfile, verify that the expected sections were seen.
2151 */
2156 }
2158 uintptr_t
2160 {
2161 uint_t stflags;
2165 else
2174 }