| blob | 58e5907240e1bf767c7e8e6721358917b08d0deb |
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 */
116 OT_RELOC,
117 OT_SHARED,
118 OT_EXEC,
119 OT_PIE,
120 };
124 /*
125 * ztflag's state is set by pointing it to the matching string:
126 * text | textoff | textwarn
127 */
130 /*
131 * Remember the guidance flags that result from the initial -z guidance
132 * option, so that they can be compared to any that follow. We only want
133 * to issue a warning when they differ.
134 */
140 /*
141 * Print usage message to stderr - 2 modes, summary message only,
142 * and full usage message.
143 */
144 static void
146 {
240 }
242 /*
243 * Rescan the archives seen on the command line in order
244 * to handle circularly dependent archives, stopping when
245 * no further member extraction occurs.
246 *
247 * entry:
248 * ofl - Output file descriptor
249 * isgrp - True if this is a an archive group search, False
250 * to search starting with argv[1] through end_arg_ndx
251 * end_arg_ndx - Index of final argv element to consider.
252 */
253 static uintptr_t
255 {
259 Aliste idx;
270 /* If not to starting index yet, skip it */
274 /*
275 * If this archive was processed with -z allextract,
276 * then all members have already been extracted.
277 */
281 /*
282 * Reestablish any archive specific command line flags.
283 */
287 /*
288 * Re-process the archive. Note that a file descriptor
289 * is unnecessary, as the file is already available in
290 * memory.
291 */
296 }
297 }
300 }
302 /*
303 * Checks the command line option flags for consistency.
304 */
305 static uintptr_t
307 {
308 /*
309 * If the user specified -zguidance=noall, then we can safely disable
310 * the entire feature. The purpose of -zguidance=noall is to allow
311 * the user to override guidance specified from a makefile via
312 * the LD_OPTIONS environment variable, and so, we want to behave
313 * in exactly the same manner we would have if no option were present.
314 */
326 /*
327 * Combining relocations when building a relocatable
328 * object isn't allowed. Warn the user, but proceed.
329 */
336 /*
337 * Translating object capabilities to symbol capabilities is
338 * only meaningful when creating a relocatable object.
339 */
345 /*
346 * If the user hasn't explicitly requested that relocations
347 * not be combined, combine them by default.
348 */
351 }
391 /*
392 * Set -Bdynamic on by default, setting is rechecked as input
393 * files are processed.
394 */
413 }
415 /*
416 * If the use of default library searching has been suppressed
417 * but no runpaths have been provided we're going to have a hard
418 * job running this object.
419 */
424 /*
425 * By default, text relocation warnings are given when building
426 * an executable unless the -b flag is specified. This option
427 * implies that unclean text can be created, so no warnings are
428 * generated unless specifically asked for.
429 */
437 }
441 /*
442 * Create a dynamic object. -Bdirect indicates that all
443 * references should be bound directly. This also
444 * enables lazyloading. Individual symbols can be
445 * bound directly (or not) using mapfiles and the
446 * DIRECT (NODIRECT) qualifier. With this capability,
447 * each syminfo entry is tagged SYMINFO_FLG_DIRECTBIND.
448 * Prior to this per-symbol direct binding, runtime
449 * direct binding was controlled via the DF_1_DIRECT
450 * flag. This flag affected all references from the
451 * object. -Bdirect continues to set this flag, and
452 * thus provides a means of taking a newly built
453 * direct binding object back to older systems.
454 *
455 * NOTE, any use of per-symbol NODIRECT bindings, or
456 * -znodirect, will disable the creation of the
457 * DF_1_DIRECT flag. Older runtime linkers do not
458 * have the capability to do per-symbol direct bindings.
459 */
465 }
467 /*
468 * -Bnodirect disables directly binding to any symbols
469 * exported from the object being created. Individual
470 * references to external objects can still be affected
471 * by -zdirect or mapfile DIRECT directives.
472 */
477 }
478 }
481 /*
482 * Dynamically linked executable.
483 */
489 /*
490 * -z textwarn is the default for executables, and
491 * only an explicit -z text* option can change that,
492 * so there's no need to provide additional guidance.
493 */
505 /*
506 * Shared Object.
507 */
513 /*
514 * By default, print text relocation warnings
515 * for executables but *not* for shared
516 * objects. However, if -z guidance is on,
517 * issue warnings for shared objects as well.
518 *
519 * If -z textwarn is explicitly specified,
520 * also issue guidance messages if -z guidance
521 * is on, but not for -z text or -z textoff.
522 */
526 FLG_OF1_TEXTOFF;
530 }
531 }
534 /*
535 * -Bsymbolic, and -Bnodirect make no sense.
536 */
544 }
546 /*
547 * Dynamic relocatable object.
548 */
558 }
595 /*
596 * We can only strip the symbol table and string table
597 * if no output relocations will refer to them.
598 */
615 /*
616 * Static executable.
617 */
622 }
623 }
625 /*
626 * If the user didn't supply an output file name supply a default.
627 */
631 /*
632 * We set the entrance criteria after all input argument processing as
633 * it is only at this point we're sure what the output image will be
634 * (static or dynamic).
635 */
639 /*
640 * Does the host currently running the linker have the same
641 * byte order as the target for which the object is being produced?
642 * If not, set FLG_OF1_ENCDIFF so relocation code will know
643 * to check.
644 */
648 /*
649 * If the target has special executable section filling requirements,
650 * register the fill function with libelf
651 */
655 /*
656 * Initialize string tables. Symbol definitions within mapfiles can
657 * result in the creation of input sections.
658 */
662 /*
663 * Process mapfiles. Mapfile can redefine or add sections/segments,
664 * so this must come after the default entrance criteria are established
665 * (above).
666 */
669 Aliste idx;
677 }
679 /*
680 * If a mapfile has been used to define a single symbolic scope of
681 * interfaces, -Bsymbolic is established. This global setting goes
682 * beyond individual symbol protection, and ensures all relocations
683 * (even those that reference section symbols) are processed within
684 * the object being built.
685 */
691 }
693 /*
694 * If -zloadfltr is set, verify that filtering is in effect. Filters
695 * are either established from the command line, and affect the whole
696 * object, or are set on a per-symbol basis from a mapfile.
697 */
703 }
705 /*
706 * Check that we have something to work with. This check is carried out
707 * after mapfile processing as its possible a mapfile is being used to
708 * define symbols, in which case it would be sufficient to build the
709 * output file purely from the mapfile.
710 */
719 }
720 }
722 }
724 /*
725 * Decompose the string pointed by optarg into argv[][] so that argv[][] can be
726 * used as an argument to getopt().
727 *
728 * If the second argument 'usage' is not NULL, then this is called from the
729 * first pass. Else this is called from the second pass.
730 */
731 static uintptr_t
733 {
738 /*
739 * The argument being examined is either:
740 * ld32= or
741 * ld64=
742 */
743 #if defined(_LP64)
746 #else
749 #endif
753 /*
754 * Count the number of arguments.
755 */
757 /*
758 * Pointing at non-separator character.
759 */
761 argc++;
763 p0++;
765 }
767 /*
768 * Pointing at a separator character.
769 */
772 p0++;
774 }
775 }
780 /*
781 * Allocate argument vector.
782 */
791 /*
792 * Pointing at the beginning of non-separator character string.
793 */
797 p0++;
801 p0++;
802 }
804 }
806 /*
807 * Pointing at the beginining of separator character string.
808 */
811 p0++;
813 }
814 }
819 /*
820 * Dispatch to pass1 or pass2
821 */
824 else
829 }
831 /*
832 * Parse the items in a '-z guidance' value, and set the ofl_guideflags.
833 * A guidance option looks like this:
834 *
835 * -z guidance[=item1,item2,...]
836 *
837 * Where each item specifies categories of guidance messages to suppress,
838 * each starting with the prefix 'no'. We allow arbitrary whitespace between
839 * the items, allow multiple ',' delimiters without an intervening item, and
840 * quietly ignore any items we don't recognize.
841 *
842 * - Such items are likely to be known to newer versions of the linker,
843 * and we do not want an older version of the linker to
844 * complain about them.
845 *
846 * - Times and standards can change, and so we wish to reserve the
847 * right to make an old item that no longer makes sense go away.
848 * Quietly ignoring unrecognized items facilitates this.
849 *
850 * However, we always display unrecognized items in debug output.
851 *
852 * entry:
853 * ofl - Output descriptor
854 * optarg - option string to be processed. This will either be a NULL
855 * terminated 'guidance', or it will be 'guidance=' followed
856 * by the item tokens as described above.
857 *
858 * exit:
859 * Returns TRUE (1) on success, FALSE (0) on failure.
860 *
861 */
862 static Boolean
864 {
867 ofl_guideflag_t flag;
880 };
886 /*
887 * Skip the 'guidance' prefix. If NULL terminated, there are no
888 * item values to parse. Otherwise, skip the '=' and parse the items.
889 */
892 optarg++;
908 }
912 }
913 }
915 /*
916 * If -zguidance is used more than once, we take the first one. We
917 * do this quietly if they have identical options, and with a warning
918 * otherwise.
919 */
925 }
927 /*
928 * First time: Save the flags for comparison to any subsequent
929 * -z guidance that comes along, and OR the resulting flags into
930 * the flags kept in the output descriptor.
931 */
935 }
937 /*
938 * Parse the -z assert-deflib option. This option can appear in two different
939 * forms:
940 * -z assert-deflib
941 * -z assert-deflib=libfred.so
942 *
943 * Either form enables this option, the latter form marks libfred.so as an
944 * exempt library from the check. It is valid to have multiple invocations of
945 * the second form. We silently ignore mulitple occurrences of the first form
946 * and multiple invocations of the first form when the second form also occurs.
947 *
948 * We only return false when we have an internal error, such as the failure of
949 * aplist_append. Every other time we return true, but we have the appropriate
950 * fatal flags set beacuse of the ld_eprintf.
951 */
952 static int
954 {
959 /* Minimum size of assert-deflib=lib%s.so */
961 MSG_STR_SOEXT_SIZE;
967 }
976 }
981 }
984 }
987 /*
988 * Parsing options pass1 for process_flags().
989 */
990 static uintptr_t
992 {
995 /*
996 * The -32, -64 and -ztarget options are special, in that we validate
997 * them, but otherwise ignore them. libld.so (this code) is called
998 * from the ld front end program. ld has already examined the
999 * arguments to determine the output class and machine type of the
1000 * output object, as reflected in the version (32/64) of ld_main()
1001 * that was called and the value of the 'mach' argument passed.
1002 * By time execution reaches this point, these options have already
1003 * been seen and acted on.
1004 */
1011 /*
1012 * -32 is processed by ld to determine the output class.
1013 * Here we sanity check the option incase some other
1014 * -3* option is mistakenly passed to us.
1015 */
1025 /*
1026 * -64 is processed by ld to determine the output class.
1027 * Here we sanity check the option incase some other
1028 * -6* option is mistakenly passed to us.
1029 */
1045 /*
1046 * This is a hack, and may be undone later.
1047 * The -b option is only used to build the Unix
1048 * kernel and its related kernel-mode modules.
1049 * We do not want those files to get a .SUNW_ldynsym
1050 * section. At least for now, the kernel makes no
1051 * use of .SUNW_ldynsym, and we do not want to use
1052 * the space to hold it. Therefore, we overload
1053 * the use of -b to also imply -znoldynsym.
1054 */
1064 else
1080 else
1087 else
1093 }
1102 else
1120 }
1136 }
1145 else
1160 else
1166 /*
1167 * For now, count any library as a shared object. This
1168 * is used to size the internal symbol cache. This
1169 * value is recalculated later on actual file processing
1170 * to get an accurate shared object count.
1171 */
1186 else
1193 /*
1194 * Multiple instances of this option may occur. Each
1195 * additional instance is effectively concatenated to
1196 * the previous separated by a colon.
1197 */
1203 }
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 }
1230 /*
1231 * Multiple instances of this option may occur. Each
1232 * additional instance is effectively concatenated to
1233 * the previous separated by a colon.
1234 */
1240 }
1260 /*
1261 * For specific help, print our usage message and exit
1262 * immediately to ensure a 0 return code.
1263 */
1268 }
1270 /*
1271 * For some options set a flag - further consistancy
1272 * checks will be carried out in check_flags().
1273 */
1287 else
1296 else
1306 ztflag);
1315 ztflag);
1324 ztflag);
1327 /*
1328 * For other options simply set the ofl flags directly.
1329 */
1420 /*
1421 * Check archive group usage
1422 * -z rescan-start ... -z rescan-end
1423 * to ensure they don't overlap and are well formed.
1424 */
1430 /* Another group is still open */
1434 /* Don't report cascading errors */
1436 }
1442 /* There was no matching begin */
1447 /* Don't report cascading errors */
1449 }
1451 /*
1452 * If -z wrap is seen, enter the symbol to be wrapped
1453 * into the wrap AVL tree.
1454 */
1466 p++;
1483 }
1489 }
1505 }
1512 else
1515 /*
1516 * Process everything related to -z assert-deflib. This
1517 * must be done in pass 1 because it gets used in pass
1518 * 2.
1519 */
1532 }
1534 p++;
1552 }
1553 /*
1554 * The following options just need validation as they
1555 * are interpreted on the second pass through the
1556 * command line arguments.
1557 */
1560 MSG_ARG_INITARRAY_SIZE) &&
1562 MSG_ARG_FINIARRAY_SIZE) &&
1564 MSG_ARG_PREINITARRAY_SIZE) &&
1566 MSG_ARG_RTLDINFO_SIZE) &&
1568 MSG_ARG_DTRACE_SIZE) &&
1582 MSG_ARG_TARGET_SIZE) &&
1588 }
1593 /*
1594 * If we have not yet read any input files go ahead
1595 * and process any debugging options (this allows any
1596 * argument processing, entrance criteria and library
1597 * initialization to be displayed). Otherwise, if an
1598 * input file has been seen, skip interpretation until
1599 * process_files (this allows debugging to be turned
1600 * on and off around individual groups of files).
1601 */
1606 }
1608 /*
1609 * A diagnostic can only be provided after dbg_setup().
1610 * As this is the first diagnostic that can be produced
1611 * by ld(1), issue a title for timing and basic output.
1612 */
1614 optitle++;
1616 }
1631 }
1642 }
1666 }
1696 else
1703 else
1709 }
1734 else
1742 else
1750 else
1756 }
1761 /*
1762 * If the option character is '-', we're looking at a
1763 * long option which couldn't be translated, display a
1764 * more useful error.
1765 */
1773 }
1779 }
1781 /*
1782 * Update the argument index for the next getopt() iteration.
1783 */
1785 }
1787 }
1789 /*
1790 * Parsing options pass2 for
1791 */
1792 static uintptr_t
1794 {
1804 optarg));
1810 optarg));
1815 FLG_OF_DYNLIBS;
1820 }
1827 optarg));
1833 optarg));
1834 /*
1835 * Record DT_NEEDED string
1836 */
1855 optarg));
1860 optarg));
1867 optarg));
1886 FLG_OF1_WEAKEXT);
1920 MSG_STR_COMMAND)) ==
1930 MSG_STR_COMMAND)) ==
1940 MSG_STR_COMMAND)) ==
1950 MSG_STR_COMMAND)) ==
1960 MSG_STR_COMMAND)) ==
1967 S_ERROR)
1976 S_ERROR)
1984 }
1987 }
1989 /*
1990 * Update the argument index for the next getopt() iteration.
1991 */
1993 }
1995 }
1997 /*
1998 *
1999 * Pass 1 -- process_flags: collects all options and sets flags
2000 */
2001 static uintptr_t
2003 {
2005 /*
2006 * If we detect some more options return to getopt().
2007 * Checking argv[optind][1] against null prevents a forever
2008 * loop if an unadorned `-' argument is passed to us.
2009 */
2017 }
2021 }
2023 /* Did an unterminated archive group run off the end? */
2029 }
2032 }
2034 uintptr_t
2036 {
2042 }
2044 /*
2045 * Option handling
2046 */
2052 /*
2053 * Having parsed everything, did we have any usage errors.
2054 */
2058 }
2061 }
2063 /*
2064 * Pass 2 -- process_files: skips the flags collected in pass 1 and processes
2065 * files.
2066 */
2067 static uintptr_t
2069 {
2076 /*
2077 * If we detect some more options return to getopt().
2078 * Checking argv[optind][1] against null prevents a forever
2079 * loop if an unadorned `-' argument is passed to us.
2080 */
2087 }
2098 }
2109 /*
2110 * Check for mismatched input.
2111 */
2113 Conv_reject_desc_buf_t rej_buf;
2122 }
2123 }
2125 }
2127 uintptr_t
2129 {
2132 /*
2133 * Process command line files (taking into account any applicable
2134 * preceding flags). Return if any fatal errors have occurred.
2135 */
2143 /*
2144 * Guidance: Use -B direct/nodirect or -z direct/nodirect.
2145 *
2146 * This is a backstop for the case where the link had no dependencies.
2147 * Otherwise, it will get caught by ld_process_ifl(). We need both,
2148 * because -z direct is positional, and its value at the time where
2149 * the first dependency is seen might be different than it is now.
2150 */
2155 }
2157 /*
2158 * Now that all command line files have been processed see if there are
2159 * any additional `needed' shared object dependencies.
2160 */
2165 /*
2166 * If rescanning archives is enabled, do so now to determine whether
2167 * there might still be members extracted to satisfy references from any
2168 * explicit objects. Continue until no new objects are extracted. Note
2169 * that this pass is carried out *after* processing any implicit objects
2170 * (above) as they may already have resolved any undefined references
2171 * from any explicit dependencies.
2172 */
2178 }
2180 /*
2181 * If debugging, provide statistics on each archives extraction, or flag
2182 * any archive that has provided no members. Note that this could be a
2183 * nice place to free up much of the archive infrastructure, as we've
2184 * extracted any members we need. However, as we presently don't free
2185 * anything under ld(1) there's not much point in proceeding further.
2186 */
2189 /*
2190 * If any version definitions have been established, either via input
2191 * from a mapfile or from the input relocatable objects, make sure any
2192 * version dependencies are satisfied, and version symbols created.
2193 */
2198 /*
2199 * If input section ordering was specified within some segment
2200 * using a mapfile, verify that the expected sections were seen.
2201 */
2206 }
2208 uintptr_t
2210 {
2211 uint_t stflags;
2215 else
2224 }