| blob | a70255a3496ccc4641686ff2071a1643968f3226 |
1 /* PowerPC-specific support for 32-bit ELF
2 Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
3 2004, 2005 Free Software Foundation, Inc.
4 Written by Ian Lance Taylor, Cygnus Support.
6 This file is part of BFD, the Binary File Descriptor library.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the
20 Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
21 Boston, MA 02110-1301, USA. */
23 /* This file is based on a preliminary PowerPC ELF ABI. The
24 information may not match the final PowerPC ELF ABI. It includes
25 suggestions from the in-progress Embedded PowerPC ABI, and that
26 information may also not match. */
36 /* RELA relocations are used here. */
38 static bfd_reloc_status_type ppc_elf_addr16_ha_reloc
40 static bfd_reloc_status_type ppc_elf_unhandled_reloc
43 /* Branch prediction bit for branch taken relocs. */
44 #define BRANCH_PREDICT_BIT 0x200000
45 /* Mask to set RA in memory instructions. */
46 #define RA_REGISTER_MASK 0x001f0000
47 /* Value to shift register by to insert RA. */
48 #define RA_REGISTER_SHIFT 16
50 /* The name of the dynamic interpreter. This is put in the .interp
51 section. */
54 /* For old-style PLT. */
55 /* The size in bytes of an entry in the procedure linkage table. */
56 #define PLT_ENTRY_SIZE 12
57 /* The initial size of the plt reserved for the dynamic linker. */
58 #define PLT_INITIAL_ENTRY_SIZE 72
59 /* The size of the gap between entries in the PLT. */
60 #define PLT_SLOT_SIZE 8
61 /* The number of single-slot PLT entries (the rest use two slots). */
62 #define PLT_NUM_SINGLE_ENTRIES 8192
64 /* For new-style .glink and .plt. */
65 #define GLINK_PLTRESOLVE 16*4
66 #define GLINK_ENTRY_SIZE 4*4
68 /* Some instructions. */
69 #define ADDIS_11_11 0x3d6b0000
70 #define ADDIS_11_30 0x3d7e0000
71 #define ADDIS_12_12 0x3d8c0000
72 #define ADDI_11_11 0x396b0000
73 #define ADD_0_11_11 0x7c0b5a14
74 #define ADD_11_0_11 0x7d605a14
75 #define B 0x48000000
76 #define BCL_20_31 0x429f0005
77 #define BCTR 0x4e800420
78 #define LIS_11 0x3d600000
79 #define LIS_12 0x3d800000
80 #define LWZU_0_12 0x840c0000
81 #define LWZ_0_12 0x800c0000
82 #define LWZ_11_11 0x816b0000
83 #define LWZ_11_30 0x817e0000
84 #define LWZ_12_12 0x818c0000
85 #define MFLR_0 0x7c0802a6
86 #define MFLR_12 0x7d8802a6
87 #define MTCTR_0 0x7c0903a6
88 #define MTCTR_11 0x7d6903a6
89 #define MTLR_0 0x7c0803a6
90 #define NOP 0x60000000
91 #define SUB_11_11_12 0x7d6c5850
93 /* Offset of tp and dtp pointers from start of TLS block. */
94 #define TP_OFFSET 0x7000
95 #define DTP_OFFSET 0x8000
96 \f
100 /* This reloc does nothing. */
115 /* A standard 32 bit relocation. */
130 /* An absolute 26 bit branch; the lower two bits must be zero.
131 FIXME: we don't check that, we just clear them. */
146 /* A standard 16 bit relocation. */
161 /* A 16 bit relocation without overflow. */
176 /* The high order 16 bits of an address. */
191 /* The high order 16 bits of an address, plus 1 if the contents of
192 the low 16 bits, treated as a signed number, is negative. */
207 /* An absolute 16 bit branch; the lower two bits must be zero.
208 FIXME: we don't check that, we just clear them. */
223 /* An absolute 16 bit branch, for which bit 10 should be set to
224 indicate that the branch is expected to be taken. The lower two
225 bits must be zero. */
240 /* An absolute 16 bit branch, for which bit 10 should be set to
241 indicate that the branch is not expected to be taken. The lower
242 two bits must be zero. */
257 /* A relative 26 bit branch; the lower two bits must be zero. */
272 /* A relative 16 bit branch; the lower two bits must be zero. */
287 /* A relative 16 bit branch. Bit 10 should be set to indicate that
288 the branch is expected to be taken. The lower two bits must be
289 zero. */
304 /* A relative 16 bit branch. Bit 10 should be set to indicate that
305 the branch is not expected to be taken. The lower two bits must
306 be zero. */
321 /* Like R_PPC_ADDR16, but referring to the GOT table entry for the
322 symbol. */
337 /* Like R_PPC_ADDR16_LO, but referring to the GOT table entry for
338 the symbol. */
353 /* Like R_PPC_ADDR16_HI, but referring to the GOT table entry for
354 the symbol. */
369 /* Like R_PPC_ADDR16_HA, but referring to the GOT table entry for
370 the symbol. */
385 /* Like R_PPC_REL24, but referring to the procedure linkage table
386 entry for the symbol. */
401 /* This is used only by the dynamic linker. The symbol should exist
402 both in the object being run and in some shared library. The
403 dynamic linker copies the data addressed by the symbol from the
404 shared library into the object, because the object being
405 run has to have the data at some particular address. */
420 /* Like R_PPC_ADDR32, but used when setting global offset table
421 entries. */
436 /* Marks a procedure linkage table entry for a symbol. */
451 /* Used only by the dynamic linker. When the object is run, this
452 longword is set to the load address of the object, plus the
453 addend. */
468 /* Like R_PPC_REL24, but uses the value of the symbol within the
469 object rather than the final value. Normally used for
470 _GLOBAL_OFFSET_TABLE_. */
485 /* Like R_PPC_ADDR32, but may be unaligned. */
500 /* Like R_PPC_ADDR16, but may be unaligned. */
515 /* 32-bit PC relative */
530 /* 32-bit relocation to the symbol's procedure linkage table.
531 FIXME: not supported. */
546 /* 32-bit PC relative relocation to the symbol's procedure linkage table.
547 FIXME: not supported. */
562 /* Like R_PPC_ADDR16_LO, but referring to the PLT table entry for
563 the symbol. */
578 /* Like R_PPC_ADDR16_HI, but referring to the PLT table entry for
579 the symbol. */
594 /* Like R_PPC_ADDR16_HA, but referring to the PLT table entry for
595 the symbol. */
610 /* A sign-extended 16 bit value relative to _SDA_BASE_, for use with
611 small data items. */
626 /* 16-bit section relative relocation. */
641 /* 16-bit lower half section relative relocation. */
656 /* 16-bit upper half section relative relocation. */
671 /* 16-bit upper half adjusted section relative relocation. */
686 /* Marker reloc for TLS. */
701 /* Computes the load module index of the load module that contains the
702 definition of its TLS sym. */
717 /* Computes a dtv-relative displacement, the difference between the value
718 of sym+add and the base address of the thread-local storage block that
719 contains the definition of sym, minus 0x8000. */
734 /* A 16 bit dtprel reloc. */
749 /* Like DTPREL16, but no overflow. */
764 /* Like DTPREL16_LO, but next higher group of 16 bits. */
779 /* Like DTPREL16_HI, but adjust for low 16 bits. */
794 /* Computes a tp-relative displacement, the difference between the value of
795 sym+add and the value of the thread pointer (r13). */
810 /* A 16 bit tprel reloc. */
825 /* Like TPREL16, but no overflow. */
840 /* Like TPREL16_LO, but next higher group of 16 bits. */
855 /* Like TPREL16_HI, but adjust for low 16 bits. */
870 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
871 with values (sym+add)@dtpmod and (sym+add)@dtprel, and computes the offset
872 to the first entry. */
887 /* Like GOT_TLSGD16, but no overflow. */
902 /* Like GOT_TLSGD16_LO, but next higher group of 16 bits. */
917 /* Like GOT_TLSGD16_HI, but adjust for low 16 bits. */
932 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
933 with values (sym+add)@dtpmod and zero, and computes the offset to the
934 first entry. */
949 /* Like GOT_TLSLD16, but no overflow. */
964 /* Like GOT_TLSLD16_LO, but next higher group of 16 bits. */
979 /* Like GOT_TLSLD16_HI, but adjust for low 16 bits. */
994 /* Allocates an entry in the GOT with value (sym+add)@dtprel, and computes
995 the offset to the entry. */
1010 /* Like GOT_DTPREL16, but no overflow. */
1025 /* Like GOT_DTPREL16_LO, but next higher group of 16 bits. */
1040 /* Like GOT_DTPREL16_HI, but adjust for low 16 bits. */
1055 /* Allocates an entry in the GOT with value (sym+add)@tprel, and computes the
1056 offset to the entry. */
1071 /* Like GOT_TPREL16, but no overflow. */
1086 /* Like GOT_TPREL16_LO, but next higher group of 16 bits. */
1101 /* Like GOT_TPREL16_HI, but adjust for low 16 bits. */
1116 /* The remaining relocs are from the Embedded ELF ABI, and are not
1117 in the SVR4 ELF ABI. */
1119 /* 32 bit value resulting from the addend minus the symbol. */
1134 /* 16 bit value resulting from the addend minus the symbol. */
1149 /* 16 bit value resulting from the addend minus the symbol. */
1164 /* The high order 16 bits of the addend minus the symbol. */
1179 /* The high order 16 bits of the result of the addend minus the address,
1180 plus 1 if the contents of the low 16 bits, treated as a signed number,
1181 is negative. */
1196 /* 16 bit value resulting from allocating a 4 byte word to hold an
1197 address in the .sdata section, and returning the offset from
1198 _SDA_BASE_ for that relocation. */
1213 /* 16 bit value resulting from allocating a 4 byte word to hold an
1214 address in the .sdata2 section, and returning the offset from
1215 _SDA2_BASE_ for that relocation. */
1230 /* A sign-extended 16 bit value relative to _SDA2_BASE_, for use with
1231 small data items. */
1246 /* Relocate against either _SDA_BASE_ or _SDA2_BASE_, filling in the 16 bit
1247 signed offset from the appropriate base, and filling in the register
1248 field with the appropriate register (0, 2, or 13). */
1263 /* Relocation not handled: R_PPC_EMB_MRKREF */
1264 /* Relocation not handled: R_PPC_EMB_RELSEC16 */
1265 /* Relocation not handled: R_PPC_EMB_RELST_LO */
1266 /* Relocation not handled: R_PPC_EMB_RELST_HI */
1267 /* Relocation not handled: R_PPC_EMB_RELST_HA */
1268 /* Relocation not handled: R_PPC_EMB_BIT_FLD */
1270 /* PC relative relocation against either _SDA_BASE_ or _SDA2_BASE_, filling
1271 in the 16 bit signed offset from the appropriate base, and filling in the
1272 register field with the appropriate register (0, 2, or 13). */
1287 /* A 16 bit relative relocation. */
1302 /* A 16 bit relative relocation without overflow. */
1317 /* The high order 16 bits of a relative address. */
1332 /* The high order 16 bits of a relative address, plus 1 if the contents of
1333 the low 16 bits, treated as a signed number, is negative. */
1348 /* GNU extension to record C++ vtable hierarchy. */
1363 /* GNU extension to record C++ vtable member usage. */
1378 /* Phony reloc to handle AIX style TOC entries. */
1392 };
1393 \f
1394 /* Initialize the ppc_elf_howto_table, so that linear accesses can be done. */
1396 static void
1398 {
1403 i++)
1404 {
1410 }
1411 }
1415 bfd_reloc_code_real_type code)
1416 {
1419 /* Initialize howto table if not already done. */
1424 {
1513 }
1516 };
1518 /* Set the howto pointer for a PowerPC ELF reloc. */
1520 static void
1524 {
1525 /* Initialize howto table if not already done. */
1531 }
1533 /* Handle the R_PPC_ADDR16_HA and R_PPC_REL16_HA relocs. */
1535 static bfd_reloc_status_type
1543 {
1544 bfd_vma relocation;
1547 {
1550 }
1557 else
1569 }
1571 static bfd_reloc_status_type
1579 {
1580 /* If this is a relocatable link (output_bfd test tells us), just
1581 call the generic function. Any adjustment will be done at final
1582 link time. */
1588 {
1593 }
1595 }
1596 \f
1597 /* Sections created by the linker. */
1600 {
1601 /* Pointer to the bfd section. */
1603 /* Section name. */
1605 /* Associated bss section name. */
1607 /* Associated symbol name. */
1609 /* Value of symbol. */
1610 bfd_vma sym_val;
1613 /* Linked list of allocated pointer entries. This hangs off of the
1614 symbol lists, and provides allows us to return different pointers,
1615 based on different addend's. */
1618 {
1619 /* next allocated pointer for this symbol */
1621 /* offset of pointer from beginning of section */
1622 bfd_vma offset;
1623 /* addend used */
1624 bfd_vma addend;
1625 /* which linker section this is */
1629 struct ppc_elf_obj_tdata
1630 {
1633 /* A mapping from local symbols to offsets into the various linker
1634 sections added. This is index by the symbol index. */
1636 };
1638 #define ppc_elf_tdata(bfd) \
1639 ((struct ppc_elf_obj_tdata *) (bfd)->tdata.any)
1641 #define elf_local_ptr_offsets(bfd) \
1642 (ppc_elf_tdata (bfd)->linker_section_pointers)
1644 /* Override the generic function because we store some extras. */
1646 static bfd_boolean
1648 {
1654 }
1656 /* Fix bad default arch selected for a 32 bit input bfd when the
1657 default is 64 bit. */
1659 static bfd_boolean
1661 {
1663 {
1667 {
1668 /* Relies on arch after 64 bit default being 32 bit default. */
1671 }
1672 }
1674 }
1676 /* Function to set whether a module needs the -mrelocatable bit set. */
1678 static bfd_boolean
1680 {
1687 }
1689 /* Support for core dump NOTE sections. */
1691 static bfd_boolean
1693 {
1698 {
1703 /* pr_cursig */
1706 /* pr_pid */
1709 /* pr_reg */
1714 }
1716 /* Make a ".reg/999" section. */
1719 }
1721 static bfd_boolean
1723 {
1725 {
1734 }
1736 /* Note that for some reason, a spurious space is tacked
1737 onto the end of the args in some (at least one anyway)
1738 implementations, so strip it off if it exists. */
1740 {
1746 }
1749 }
1751 /* Return address for Ith PLT stub in section PLT, for relocation REL
1752 or (bfd_vma) -1 if it should not be included. */
1754 static bfd_vma
1758 {
1760 }
1762 /* Handle a PowerPC specific section when reading an object file. This
1763 is called when bfd_section_from_shdr finds a section with an unknown
1764 type. */
1766 static bfd_boolean
1771 {
1773 flagword flags;
1788 }
1790 /* Set up any other section flags and such that may be necessary. */
1792 static bfd_boolean
1796 {
1804 }
1806 /* If we have .sbss2 or .PPC.EMB.sbss0 output sections, we
1807 need to bump up the number of section headers. */
1809 static int
1811 {
1824 }
1826 /* Add extra PPC sections -- Note, for now, make .sbss2 and
1827 .PPC.EMB.sbss0 a normal section, and not a bss section so
1828 that the linker doesn't crater when trying to make more than
1829 2 sections. */
1832 ppc_special_sections_p[] =
1833 {
1836 };
1839 ppc_special_sections_s[] =
1840 {
1846 };
1849 ppc_special_sections_t[] =
1850 {
1853 };
1856 ppc_special_sections_other[]=
1857 {
1862 };
1866 {
1894 };
1895 \f
1896 /* Very simple linked list structure for recording apuinfo values. */
1898 {
1901 }
1902 apuinfo_list;
1907 static void
1909 {
1911 }
1913 static void
1915 {
1919 {
1923 }
1932 }
1934 static unsigned
1936 {
1941 entry;
1946 }
1950 {
1956 ;
1959 }
1961 static void
1963 {
1967 {
1971 }
1974 }
1979 /* Scan the input BFDs and create a linked list of
1980 the APUinfo values that will need to be emitted. */
1982 static void
1984 {
1989 bfd_size_type output_section_size;
1999 /* Scan the input bfds, looking for apuinfo sections. */
2004 {
2007 {
2010 }
2011 }
2013 /* We need at least one input sections
2014 in order to make merging worthwhile. */
2018 /* Just make sure that the output section exists as well. */
2023 /* Allocate a buffer for the contents of the input sections. */
2031 /* Read in the input sections contents. */
2033 {
2043 {
2046 }
2050 {
2053 }
2055 /* Process the contents of the section. */
2059 /* Verify the contents of the header. Note - we have to
2060 extract the values this way in order to allow for a
2061 host whose endian-ness is different from the target. */
2073 /* Get the number of bytes used for apuinfo entries. */
2078 /* Make sure that we do not run off the end of the section. */
2082 /* Scan the apuinfo section, building a list of apuinfo numbers. */
2086 /* Update the offset. */
2088 }
2092 /* Compute the size of the output section. */
2102 fail:
2107 }
2109 /* Prevent the output section from accumulating the input sections'
2110 contents. We have already stored this in our linked list structure. */
2112 static bfd_boolean
2116 {
2119 }
2121 /* Finally we can generate the output section. */
2123 static void
2125 {
2130 bfd_size_type length;
2145 {
2149 }
2151 /* Create the apuinfo header. */
2160 {
2163 }
2174 }
2175 \f
2176 /* The following functions are specific to the ELF linker, while
2177 functions above are used generally. They appear in this file more
2178 or less in the order in which they are called. eg.
2179 ppc_elf_check_relocs is called early in the link process,
2180 ppc_elf_finish_dynamic_sections is one of the last functions
2181 called. */
2183 /* The PPC linker needs to keep track of the number of relocs that it
2184 decides to copy as dynamic relocs in check_relocs for each symbol.
2185 This is so that it can later discard them if they are found to be
2186 unnecessary. We store the information in a field extending the
2187 regular ELF linker hash table. */
2189 struct ppc_elf_dyn_relocs
2190 {
2193 /* The input section of the reloc. */
2196 /* Total number of relocs copied for the input section. */
2197 bfd_size_type count;
2199 /* Number of pc-relative relocs copied for the input section. */
2200 bfd_size_type pc_count;
2201 };
2203 /* Track PLT entries needed for a given symbol. We might need more
2204 than one glink entry per symbol. */
2205 struct plt_entry
2206 {
2209 /* -fPIC uses multiple GOT sections, one per file, called ".got2".
2210 This field stores the offset into .got2 used to initialise the
2211 GOT pointer reg. It will always be at least 32768 (and for
2212 current gcc this is the only offset used). */
2213 bfd_vma addend;
2215 /* The .got2 section. */
2218 /* PLT refcount or offset. */
2219 union
2220 {
2221 bfd_signed_vma refcount;
2222 bfd_vma offset;
2225 /* .glink stub offset. */
2226 bfd_vma glink_offset;
2227 };
2229 /* Of those relocs that might be copied as dynamic relocs, this macro
2230 selects those that must be copied when linking a shared library,
2231 even when the symbol is local. */
2233 #define MUST_BE_DYN_RELOC(RTYPE) \
2234 ((RTYPE) != R_PPC_REL24 \
2235 && (RTYPE) != R_PPC_REL14 \
2236 && (RTYPE) != R_PPC_REL14_BRTAKEN \
2237 && (RTYPE) != R_PPC_REL14_BRNTAKEN \
2238 && (RTYPE) != R_PPC_REL32)
2240 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
2241 copying dynamic variables from a shared lib into an app's dynbss
2242 section, and instead use a dynamic relocation to point into the
2243 shared lib. */
2244 #define ELIMINATE_COPY_RELOCS 1
2246 /* PPC ELF linker hash entry. */
2248 struct ppc_elf_link_hash_entry
2249 {
2252 /* If this symbol is used in the linker created sections, the processor
2253 specific backend uses this field to map the field into the offset
2254 from the beginning of the section. */
2257 /* Track dynamic relocs copied for this symbol. */
2260 /* Contexts in which symbol is used in the GOT (or TOC).
2261 TLS_GD .. TLS_TLS bits are or'd into the mask as the
2262 corresponding relocs are encountered during check_relocs.
2263 tls_optimize clears TLS_GD .. TLS_TPREL when optimizing to
2264 indicate the corresponding GOT entry type is not needed. */
2272 };
2274 #define ppc_elf_hash_entry(ent) ((struct ppc_elf_link_hash_entry *) (ent))
2276 /* PPC ELF linker hash table. */
2278 struct ppc_elf_link_hash_table
2279 {
2282 /* Short-cuts to get to dynamic linker sections. */
2295 /* Shortcut to .__tls_get_addr. */
2298 /* TLS local dynamic got entry handling. */
2300 bfd_signed_vma refcount;
2301 bfd_vma offset;
2304 /* Offset of PltResolve function in glink. */
2305 bfd_vma glink_pltresolve;
2307 /* Size of reserved GOT entries. */
2309 /* Non-zero if allocating the header left a gap. */
2312 /* Whether to use new plt/got layout or not. */
2316 /* Small local sym to section mapping cache. */
2318 };
2320 /* Get the PPC ELF linker hash table from a link_info structure. */
2322 #define ppc_elf_hash_table(p) \
2323 ((struct ppc_elf_link_hash_table *) (p)->hash)
2325 /* Create an entry in a PPC ELF linker hash table. */
2331 {
2332 /* Allocate the structure if it has not already been allocated by a
2333 subclass. */
2335 {
2340 }
2342 /* Call the allocation method of the superclass. */
2345 {
2349 }
2352 }
2354 /* Create a PPC ELF linker hash table. */
2358 {
2366 ppc_elf_link_hash_newfunc))
2367 {
2370 }
2386 }
2388 /* The powerpc .got has a blrl instruction in it. Mark it executable. */
2390 static bfd_boolean
2392 {
2395 flagword flags;
2418 }
2420 /* We have to create .dynsbss and .rela.sbss here so that they get mapped
2421 to output sections (just like _bfd_elf_create_dynamic_sections has
2422 to create .dynbss and .rela.bss). */
2424 static bfd_boolean
2426 {
2429 flagword flags;
2457 {
2464 }
2473 }
2475 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2477 static void
2481 {
2483 bfd_signed_vma tmp;
2489 {
2491 {
2498 /* Add reloc counts against the weak sym to the strong sym
2499 list. Merge any entries against the same section. */
2501 {
2506 {
2511 }
2514 }
2516 }
2520 }
2524 /* If called to transfer flags for a weakdef during processing
2525 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
2526 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
2537 /* If we were called to copy over info for a weak sym, that's all. */
2541 /* Copy over the GOT refcount entries that we may have already seen to
2542 the symbol which just became indirect. */
2545 {
2548 }
2549 else
2552 /* And plt entries. */
2554 {
2556 {
2561 {
2566 {
2570 }
2573 }
2575 }
2579 }
2582 {
2587 }
2588 else
2590 }
2592 /* Return 1 if target is one of ours. */
2594 static bfd_boolean
2596 {
2601 }
2603 /* Hook called by the linker routine which adds symbols from an object
2604 file. We use it to put .comm items in .sbss, and not .bss. */
2606 static bfd_boolean
2614 {
2619 {
2620 /* Common symbols less than or equal to -G nn bytes are automatically
2621 put into .sbss. */
2626 {
2634 flags);
2637 }
2641 }
2644 }
2645 \f
2646 /* Create a special linker section. */
2648 static bfd_boolean
2651 flagword flags,
2653 {
2660 /* Record the first bfd that needs the special sections. */
2666 flags);
2673 }
2675 /* Find a linker generated pointer with a given addend and type. */
2678 elf_find_pointer_linker_section
2680 bfd_vma addend,
2682 {
2688 }
2690 /* Allocate a pointer to live in a linker created section. */
2692 static bfd_boolean
2697 {
2701 bfd_size_type amt;
2705 /* Is this a global symbol? */
2707 {
2710 /* Has this symbol already been allocated? If so, our work is done. */
2714 lsect))
2718 }
2719 else
2720 {
2721 /* Allocation of a pointer to a local symbol. */
2724 /* Allocate a table to hold the local symbols if first time. */
2726 {
2737 }
2739 /* Has this symbol already been allocated? If so, our work is done. */
2742 lsect))
2746 }
2748 /* Allocate space for a pointer in the linker section, and allocate
2749 a new pointer record from internal memory. */
2765 #ifdef DEBUG
2770 #endif
2773 }
2775 static bfd_boolean
2780 {
2785 {
2793 }
2799 }
2801 static bfd_boolean
2804 {
2813 {
2823 }
2826 }
2830 {
2839 }
2841 static void
2843 {
2846 abfd,
2849 }
2851 /* Look through the relocs for a section during the first phase, and
2852 allocate space in the global offset table or procedure linkage
2853 table. */
2855 static bfd_boolean
2860 {
2871 /* Don't do anything special with non-loaded, non-alloced sections.
2872 In particular, any relocs in such sections should not affect GOT
2873 and PLT reference counting (ie. we don't allow them to create GOT
2874 or PLT entries), there's no possibility or desire to optimize TLS
2875 relocs, and there's not much point in propagating relocs to shared
2876 libs that the dynamic linker won't relocate. */
2880 #ifdef DEBUG
2883 #endif
2885 /* Initialize howto table if not already done. */
2897 {
2906 else
2909 /* If a relocation refers to _GLOBAL_OFFSET_TABLE_, create the .got.
2910 This shows up in particular in an R_PPC_ADDR32 in the eabi
2911 startup code. */
2915 {
2921 }
2925 {
2955 dogottls:
2957 /* Fall thru */
2959 /* GOT16 relocations */
2964 /* This symbol requires a global offset table entry. */
2966 {
2971 }
2973 {
2976 }
2977 else
2978 /* This is a global offset table entry for a local symbol. */
2983 /* Indirect .sdata relocation. */
2986 {
2989 }
2999 /* Indirect .sdata2 relocation. */
3002 {
3005 }
3025 {
3028 }
3037 #ifdef DEBUG
3039 #endif
3040 /* This symbol requires a procedure linkage table entry. We
3041 actually build the entry in finish_dynamic_symbol,
3042 because this might be a case of linking PIC code without
3043 linking in any dynamic objects, in which case we don't
3044 need to generate a procedure linkage table after all. */
3047 {
3048 /* It does not make sense to have a procedure linkage
3049 table entry for a local symbol. */
3052 abfd,
3053 sec,
3058 }
3059 else
3060 {
3066 }
3069 /* The following relocations don't need to propagate the
3070 relocation if linking a shared object since they are
3071 section relative. */
3090 /* These are just markers. */
3097 /* These should only appear in dynamic objects. */
3104 /* These aren't handled yet. We'll report an error later. */
3113 /* This refers only to functions defined in the shared library. */
3119 /* This relocation describes the C++ object vtable hierarchy.
3120 Reconstruct it for later use during GC. */
3126 /* This relocation describes which C++ vtable entries are actually
3127 used. Record for later use during GC. */
3133 /* We shouldn't really be seeing these. */
3139 /* Nor these. */
3152 /* When creating a shared object, we must copy these
3153 relocs into the output file. We create a reloc
3154 section in dynobj and make room for the reloc. */
3163 {
3166 }
3167 /* fall through */
3181 {
3182 /* We may need a plt entry if the symbol turns out to be
3183 a function defined in a dynamic object. */
3187 /* We may need a copy reloc too. */
3189 }
3191 dodyn:
3192 /* If we are creating a shared library, and this is a reloc
3193 against a global symbol, or a non PC relative reloc
3194 against a local symbol, then we need to copy the reloc
3195 into the shared library. However, if we are linking with
3196 -Bsymbolic, we do not need to copy a reloc against a
3197 global symbol which is defined in an object we are
3198 including in the link (i.e., DEF_REGULAR is set). At
3199 this point we have not seen all the input files, so it is
3200 possible that DEF_REGULAR is not set now but will be set
3201 later (it is never cleared). In case of a weak definition,
3202 DEF_REGULAR may be cleared later by a strong definition in
3203 a shared library. We account for that possibility below by
3204 storing information in the dyn_relocs field of the hash
3205 table entry. A similar situation occurs when creating
3206 shared libraries and symbol visibility changes render the
3207 symbol local.
3209 If on the other hand, we are creating an executable, we
3210 may need to keep relocations for symbols satisfied by a
3211 dynamic library if we manage to avoid copy relocs for the
3212 symbol. */
3219 || (ELIMINATE_COPY_RELOCS
3224 {
3228 #ifdef DEBUG
3230 "ppc_elf_check_relocs needs to "
3234 #endif
3236 {
3239 name = (bfd_elf_string_from_elf_section
3254 {
3255 flagword flags;
3261 name,
3262 flags);
3267 }
3269 }
3271 /* If this is a global symbol, we count the number of
3272 relocations we need for this symbol. */
3274 {
3276 }
3277 else
3278 {
3279 /* Track dynamic relocs needed for local syms too.
3280 We really need local syms available to do this
3281 easily. Oh well. */
3291 }
3295 {
3304 }
3309 }
3312 }
3313 }
3316 }
3317 \f
3318 /* Merge backend specific data from an object file to the output
3319 object file when linking. */
3321 static bfd_boolean
3323 {
3324 flagword old_flags;
3325 flagword new_flags;
3326 bfd_boolean error;
3332 /* Check if we have the same endianess. */
3339 {
3340 /* First call, no flags set. */
3343 }
3345 /* Compatible flags are ok. */
3347 ;
3349 /* Incompatible flags. */
3350 else
3351 {
3352 /* Warn about -mrelocatable mismatch. Allow -mrelocatable-lib
3353 to be linked with either. */
3357 {
3362 }
3365 {
3370 }
3372 /* The output is -mrelocatable-lib iff both the input files are. */
3376 /* The output is -mrelocatable iff it can't be -mrelocatable-lib,
3377 but each input file is either -mrelocatable or -mrelocatable-lib. */
3383 /* Do not warn about eabi vs. V.4 mismatch, just or in the bit if
3384 any module uses it. */
3390 /* Warn about any other mismatches. */
3392 {
3398 }
3401 {
3404 }
3405 }
3408 }
3409 \f
3410 /* Choose which PLT scheme to use, and set .plt flags appropriately.
3411 Returns -1 on error, 0 for old PLT, 1 for new PLT. */
3412 int
3416 {
3424 {
3428 /* The new PLT is a loaded section. */
3433 /* The new GOT is not executable. */
3437 }
3438 else
3439 {
3440 /* Stop an unused .glink section from affecting .text alignment. */
3444 }
3446 }
3447 \f
3448 /* Return the section that should be marked against GC for a given
3449 relocation. */
3457 {
3459 {
3461 {
3468 {
3478 }
3479 }
3480 }
3481 else
3485 }
3487 /* Update the got, plt and dynamic reloc reference counts for the
3488 section being removed. */
3490 static bfd_boolean
3495 {
3516 {
3523 {
3535 {
3536 /* Everything must go for SEC. */
3539 }
3540 }
3544 {
3550 /* Fall thru */
3569 {
3572 }
3574 {
3577 }
3587 /* Fall thru */
3606 {
3611 }
3616 }
3617 }
3619 }
3620 \f
3621 /* Set htab->tls_get_addr and call the generic ELF tls_setup function. */
3623 asection *
3625 {
3632 {
3635 }
3640 }
3642 /* Run through all the TLS relocs looking for optimization
3643 opportunities. */
3645 bfd_boolean
3648 {
3658 {
3664 {
3668 /* Read the relocations. */
3677 {
3683 bfd_boolean is_local;
3687 {
3695 }
3704 {
3709 /* These relocs should never be against a symbol
3710 defined in a shared lib. Leave them alone if
3711 that turns out to be the case. */
3717 /* LD -> LE */
3728 /* GD -> LE */
3730 else
3731 /* GD -> IE */
3743 {
3744 /* IE -> LE */
3748 }
3749 else
3759 {
3763 }
3770 }
3773 {
3775 {
3776 /* We managed to get rid of a got entry. */
3779 }
3781 }
3782 else
3783 {
3789 {
3796 {
3800 }
3801 }
3807 {
3808 /* We managed to get rid of a got entry. */
3811 }
3814 }
3818 }
3822 }
3826 {
3829 else
3831 }
3832 }
3834 }
3835 \f
3836 /* Adjust a symbol defined by a dynamic object and referenced by a
3837 regular object. The current definition is in some section of the
3838 dynamic object, but we're not including those sections. We have to
3839 change the definition to something the rest of the link can
3840 understand. */
3842 static bfd_boolean
3845 {
3850 #ifdef DEBUG
3853 #endif
3855 /* Make sure we know what is going on here. */
3864 /* Deal with function syms. */
3867 {
3868 /* Clear procedure linkage table information for any symbol that
3869 won't need a .plt entry. */
3878 {
3879 /* A PLT entry is not required/allowed when:
3881 1. We are not using ld.so; because then the PLT entry
3882 can't be set up, so we can't use one. In this case,
3883 ppc_elf_adjust_dynamic_symbol won't even be called.
3885 2. GC has rendered the entry unused.
3887 3. We know for certain that a call to this symbol
3888 will go to this object, or will remain undefined. */
3891 }
3893 }
3894 else
3897 /* If this is a weak symbol, and there is a real definition, the
3898 processor independent code will have arranged for us to see the
3899 real definition first, and we can just use the same value. */
3901 {
3909 }
3911 /* This is a reference to a symbol defined by a dynamic object which
3912 is not a function. */
3914 /* If we are creating a shared library, we must presume that the
3915 only references to the symbol are via the global offset table.
3916 For such cases we need not do anything here; the relocations will
3917 be handled correctly by relocate_section. */
3921 /* If there are no references to this symbol that do not use the
3922 GOT, we don't need to generate a copy reloc. */
3927 {
3930 {
3934 }
3936 /* If we didn't find any dynamic relocs in read-only sections, then
3937 we'll be keeping the dynamic relocs and avoiding the copy reloc. */
3939 {
3942 }
3943 }
3945 /* We must allocate the symbol in our .dynbss section, which will
3946 become part of the .bss section of the executable. There will be
3947 an entry for this symbol in the .dynsym section. The dynamic
3948 object will contain position independent code, so all references
3949 from the dynamic object to this symbol will go through the global
3950 offset table. The dynamic linker will use the .dynsym entry to
3951 determine the address it must put in the global offset table, so
3952 both the dynamic object and the regular object will refer to the
3953 same memory location for the variable.
3955 Of course, if the symbol is sufficiently small, we must instead
3956 allocate it in .sbss. FIXME: It would be better to do this if and
3957 only if there were actually SDAREL relocs for that symbol. */
3961 else
3965 /* We must generate a R_PPC_COPY reloc to tell the dynamic linker to
3966 copy the initial value out of the dynamic object and into the
3967 runtime process image. We need to remember the offset into the
3968 .rela.bss section we are going to use. */
3970 {
3975 else
3980 }
3982 /* We need to figure out the alignment required for this symbol. I
3983 have no idea how ELF linkers handle this. */
3988 /* Apply the required alignment. */
3991 {
3994 }
3996 /* Define the symbol as being at this point in the section. */
4000 /* Increment the section size to make room for the symbol. */
4004 }
4005 \f
4006 /* Allocate NEED contiguous space in .got, and return the offset.
4007 Handles allocation of the got header when crossing 32k. */
4009 static bfd_vma
4011 {
4012 bfd_vma where;
4019 {
4022 }
4023 else
4024 {
4027 {
4030 }
4033 }
4035 }
4037 /* Allocate space in associated reloc sections for dynamic relocs. */
4039 static bfd_boolean
4041 {
4051 /* When warning symbols are created, they **replace** the "real"
4052 entry in the hash table, thus we never get to see the real
4053 symbol in a hash traversal. So look at it now. */
4058 {
4065 {
4066 /* Make sure this symbol is output as a dynamic symbol. */
4069 {
4072 }
4076 {
4080 {
4082 {
4085 }
4090 {
4093 }
4097 {
4100 }
4102 }
4103 else
4104 {
4106 {
4107 /* If this is the first .plt entry, make room
4108 for the special first entry. */
4112 /* The PowerPC PLT is actually composed of two
4113 parts, the first part is 2 words (for a load
4114 and a jump), and then there is a remaining
4115 word available at the end. */
4116 plt_offset = (PLT_INITIAL_ENTRY_SIZE
4117 + (PLT_SLOT_SIZE
4121 /* If this symbol is not defined in a regular
4122 file, and we are not generating a shared
4123 library, then set the symbol to this location
4124 in the .plt. This is required to make
4125 function pointers compare as equal between
4126 the normal executable and the shared library. */
4129 {
4132 }
4134 /* Make room for this entry. After the 8192nd
4135 entry, room for two entries is allocated. */
4140 }
4142 }
4144 /* We also need to make an entry in the .rela.plt section. */
4146 {
4149 }
4150 }
4151 else
4155 {
4158 }
4159 }
4160 }
4161 else
4162 {
4165 }
4169 {
4170 /* Make sure this symbol is output as a dynamic symbol. */
4173 {
4176 }
4180 /* If just an LD reloc, we'll just use htab->tlsld_got.offset. */
4182 else
4183 {
4184 bfd_boolean dyn;
4187 {
4196 }
4197 else
4205 {
4206 /* All the entries we allocated need relocs.
4207 Except LD only needs one. */
4211 }
4212 }
4213 }
4214 else
4220 /* In the shared -Bsymbolic case, discard space allocated for
4221 dynamic pc-relative relocs against symbols which turn out to be
4222 defined in regular objects. For the normal shared case, discard
4223 space for relocs that have become local due to symbol visibility
4224 changes. */
4227 {
4228 /* Relocs that use pc_count are those that appear on a call insn,
4229 or certain REL relocs (see MUST_BE_DYN_RELOC) that can be
4230 generated via assembly. We want calls to protected symbols to
4231 resolve directly to the function rather than going via the plt.
4232 If people want function pointer comparisons to work as expected
4233 then they should avoid writing weird assembly. */
4235 {
4239 {
4244 else
4246 }
4247 }
4249 /* Also discard relocs on undefined weak syms with non-default
4250 visibility. */
4255 /* Make sure undefined weak symbols are output as a dynamic symbol
4256 in PIEs. */
4262 {
4265 }
4266 }
4268 {
4269 /* For the non-shared case, discard space for relocs against
4270 symbols which turn out to need copy relocs or are not
4271 dynamic. */
4276 {
4277 /* Make sure this symbol is output as a dynamic symbol.
4278 Undefined weak syms won't yet be marked as dynamic. */
4281 {
4284 }
4286 /* If that succeeded, we know we'll be keeping all the
4287 relocs. */
4290 }
4294 keep: ;
4295 }
4297 /* Finally, allocate space. */
4299 {
4302 }
4305 }
4307 /* Find any dynamic relocs that apply to read-only sections. */
4309 static bfd_boolean
4311 {
4321 {
4327 {
4330 /* Not an error, just cut short the traversal. */
4332 }
4333 }
4335 }
4337 /* Set the sizes of the dynamic sections. */
4339 static bfd_boolean
4342 {
4345 bfd_boolean relocs;
4348 #ifdef DEBUG
4350 #endif
4356 {
4357 /* Set the contents of the .interp section to the interpreter. */
4359 {
4364 }
4365 }
4369 else
4372 /* Set up .got offsets for local syms, and space for local dynamic
4373 relocs. */
4375 {
4379 bfd_size_type locsymcount;
4386 {
4393 {
4396 {
4397 /* Input section has been discarded, either because
4398 it is a copy of a linkonce section or due to
4399 linker script /DISCARD/, so we'll be discarding
4400 the relocs too. */
4401 }
4403 {
4410 }
4411 }
4412 }
4424 {
4426 {
4427 /* If just an LD reloc, we'll just use
4428 htab->tlsld_got.offset. */
4431 }
4432 else
4433 {
4436 {
4443 }
4444 else
4450 }
4451 }
4452 else
4454 }
4457 {
4461 }
4462 else
4465 /* Allocate space for global sym dynamic relocs. */
4469 {
4472 /* If we haven't allocated the header, do so now. */
4474 {
4477 }
4482 }
4485 {
4487 /* Space for the branch table. */
4489 /* Pad out to align the start of PLTresolve. */
4492 }
4494 /* We've now determined the sizes of the various dynamic sections.
4495 Allocate memory for them. */
4498 {
4506 {
4507 /* Strip this section if we don't need it; see the
4508 comment below. */
4509 }
4512 {
4513 /* Strip these too. */
4514 }
4516 {
4518 {
4519 /* If we don't need this section, strip it from the
4520 output file. This is mostly to handle .rela.bss and
4521 .rela.plt. We must create both sections in
4522 create_dynamic_sections, because they must be created
4523 before the linker maps input sections to output
4524 sections. The linker does that before
4525 adjust_dynamic_symbol is called, and it is that
4526 function which decides whether anything needs to go
4527 into these sections. */
4528 }
4529 else
4530 {
4531 /* Remember whether there are any relocation sections. */
4534 /* We use the reloc_count field as a counter if we need
4535 to copy relocs into the output file. */
4537 }
4538 }
4539 else
4540 {
4541 /* It's not one of our sections, so don't allocate space. */
4543 }
4546 {
4549 }
4554 /* Allocate memory for the section contents. */
4558 }
4561 {
4562 /* Add some entries to the .dynamic section. We fill in the
4563 values later, in ppc_elf_finish_dynamic_sections, but we
4564 must add the entries now so that we get the correct size for
4565 the .dynamic section. The DT_DEBUG entry is filled in by the
4566 dynamic linker and used by the debugger. */
4567 #define add_dynamic_entry(TAG, VAL) \
4568 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
4571 {
4574 }
4577 {
4583 }
4586 {
4589 }
4592 {
4597 }
4599 /* If any dynamic relocs apply to a read-only section, then we
4600 need a DT_TEXTREL entry. */
4603 info);
4606 {
4609 }
4610 }
4611 #undef add_dynamic_entry
4614 }
4615 \f
4616 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
4619 {
4628 };
4631 {
4636 };
4638 static bfd_boolean
4643 {
4644 struct one_fixup
4645 {
4648 bfd_vma toff;
4649 bfd_vma trampoff;
4650 };
4658 bfd_boolean changed;
4660 bfd_size_type trampoff;
4665 /* Nothing to do if there are no relocations, and no need to do
4666 anything with non-alloc sections. */
4673 /* Space for a branch around any trampolines. */
4678 /* Get a copy of the native relocations. */
4689 {
4701 {
4716 }
4718 /* Get the value of the symbol referred to by the reloc. */
4720 {
4721 /* A local symbol. */
4724 /* Read this BFD's local symbols. */
4726 {
4734 }
4742 else
4747 }
4748 else
4749 {
4750 /* Global symbol handling. */
4765 {
4769 {
4771 {
4774 }
4775 else
4776 {
4779 }
4780 }
4781 }
4783 ;
4786 {
4789 }
4790 else
4794 }
4796 /* If the branch and target are in the same section, you have
4797 no hope of adding stubs. We'll error out later should the
4798 branch overflow. */
4802 /* There probably isn't any reason to handle symbols in
4803 SEC_MERGE sections; SEC_MERGE doesn't seem a likely
4804 attribute for a code section, and we are only looking at
4805 branches. However, implement it correctly here as a
4806 reference for other target relax_section functions. */
4808 {
4809 /* At this stage in linking, no SEC_MERGE symbol has been
4810 adjusted, so all references to such symbols need to be
4811 passed through _bfd_merged_section_offset. (Later, in
4812 relocate_section, all SEC_MERGE symbols *except* for
4813 section symbols have been adjusted.)
4815 gas may reduce relocations against symbols in SEC_MERGE
4816 sections to a relocation against the section symbol when
4817 the original addend was zero. When the reloc is against
4818 a section symbol we should include the addend in the
4819 offset passed to _bfd_merged_section_offset, since the
4820 location of interest is the original symbol. On the
4821 other hand, an access to "sym+addend" where "sym" is not
4822 a section symbol should not include the addend; Such an
4823 access is presumed to be an offset from "sym"; The
4824 location of interest is just "sym". */
4830 toff);
4834 }
4835 /* PLTREL24 addends are special. */
4844 /* If the branch is in range, no need to do anything. */
4848 /* Look for an existing fixup to this address. */
4854 {
4860 /* Oh dear, we can't reach a trampoline. Don't try to add
4861 one. We'll report an error later. */
4865 {
4869 }
4870 else
4871 {
4875 }
4884 /* Hijack the old relocation. Since we need two
4885 relocations for this use a "composite" reloc. */
4887 stub_rtype);
4890 /* Record the fixup so we don't do it again this section. */
4899 }
4900 else
4901 {
4906 /* Nop out the reloc, since we're finalizing things here. */
4908 }
4910 /* Get the section contents. */
4912 {
4913 /* Get cached copy if it exists. */
4916 else
4917 {
4918 /* Go get them off disk. */
4921 }
4922 }
4924 /* Fix up the existing branch to hit the trampoline. */
4927 {
4945 }
4946 }
4948 /* Write out the trampolines. */
4951 {
4954 bfd_vma val;
4957 do
4958 {
4962 }
4970 /* Branch around the trampolines. */
4978 {
4981 }
4982 else
4983 {
4986 }
4990 {
4992 i++;
4996 }
4998 }
5002 {
5005 else
5006 {
5007 /* Cache the symbols for elf_link_input_bfd. */
5009 }
5010 }
5014 {
5017 else
5018 {
5019 /* Cache the section contents for elf_link_input_bfd. */
5021 }
5022 }
5025 {
5028 else
5030 }
5035 error_return:
5045 }
5046 \f
5047 /* Set _SDA_BASE_, _SDA2_BASE, and sbss start and end syms. They are
5048 set here rather than via PROVIDE in the default linker script,
5049 because using PROVIDE inside an output section statement results in
5050 unnecessary output sections. Using PROVIDE outside an output section
5051 statement runs the risk of section alignment affecting where the
5052 section starts. */
5054 bfd_boolean
5056 {
5060 bfd_vma val;
5065 {
5082 }
5095 }
5096 \f
5097 /* Fill in the address for a pointer generated in a linker section. */
5099 static bfd_vma
5103 bfd_vma relocation,
5105 {
5111 {
5112 /* Handle global symbol. */
5118 }
5119 else
5120 {
5121 /* Handle local symbol. */
5126 }
5130 lsect);
5133 /* Offset will always be a multiple of four, so use the bottom bit
5134 as a "written" flag. */
5136 {
5141 }
5147 #ifdef DEBUG
5151 #endif
5153 /* Subtract out the addend, because it will get added back in by the normal
5154 processing. */
5156 }
5158 /* The RELOCATE_SECTION function is called by the ELF backend linker
5159 to handle the relocations for a section.
5161 The relocs are always passed as Rela structures; if the section
5162 actually uses Rel structures, the r_addend field will always be
5163 zero.
5165 This function is responsible for adjust the section contents as
5166 necessary, and (if using Rela relocs and generating a
5167 relocatable output file) adjusting the reloc addend as
5168 necessary.
5170 This function does not have to worry about setting the reloc
5171 address or the reloc symbol index.
5173 LOCAL_SYMS is a pointer to the swapped in local symbols.
5175 LOCAL_SECTIONS is an array giving the section in the input file
5176 corresponding to the st_shndx field of each local symbol.
5178 The global hash table entry for the global symbols can be found
5179 via elf_sym_hashes (input_bfd).
5181 When generating relocatable output, this function must handle
5182 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
5183 going to be the section symbol corresponding to the output
5184 section, which means that the addend must be adjusted
5185 accordingly. */
5187 static bfd_boolean
5196 {
5202 Elf_Internal_Rela outrel;
5208 #ifdef DEBUG
5214 #endif
5219 {
5226 {
5232 {
5233 /* R_PPC_PLTREL24 is rather special. If non-zero, the
5234 addend specifies the GOT pointer offset within .got2. */
5236 }
5237 }
5239 }
5241 /* Initialize howto table if not already done. */
5252 {
5254 bfd_vma addend;
5255 bfd_reloc_status_type r;
5262 bfd_vma relocation;
5264 bfd_boolean unresolved_reloc;
5265 bfd_boolean warned;
5277 {
5283 }
5284 else
5285 {
5292 }
5294 /* TLS optimizations. Replace instruction sequences and relocs
5295 based on information we collected in tls_optimize. We edit
5296 RELOCS so that --emit-relocs will output something sensible
5297 for the final instruction stream. */
5301 {
5305 {
5309 }
5310 }
5312 /* Ensure reloc mapping code below stays sane. */
5323 {
5331 {
5332 bfd_vma insn;
5339 }
5345 {
5354 else
5357 /* add -> addi. */
5363 /* load and store indexed -> dform. */
5367 /* ldx, ldux, stdx, stdux -> ld, ldu, std, stdu. */
5372 /* lwax -> lwa. */
5374 else
5380 /* Was PPC_TLS which sits on insn boundary, now
5381 PPC_TPREL16_LO which is at insn+2. */
5383 }
5396 {
5397 tls_gdld_hi:
5401 else
5402 {
5406 }
5408 }
5421 {
5422 tls_get_addr_check:
5424 {
5429 bfd_vma offset;
5431 /* The next instruction should be a call to
5432 __tls_get_addr. Peek at the reloc to be sure. */
5450 /* OK, it checks out. Replace the call. */
5455 {
5456 /* IE */
5464 }
5465 else
5466 {
5467 /* LE */
5471 {
5472 /* Was an LD reloc. */
5476 }
5480 R_PPC_TPREL16_LO);
5482 }
5486 {
5487 /* We changed the symbol on an LD reloc. Start over
5488 in order to get h, sym, sec etc. right. */
5489 rel--;
5491 }
5492 }
5493 }
5495 }
5497 /* Handle other relocations that tweak non-addend part of insn. */
5500 {
5504 /* Branch taken prediction relocations. */
5508 /* Fall thru */
5510 /* Branch not taken prediction relocations. */
5521 /* Invert 'y' bit if not the default. */
5527 }
5535 {
5552 /* GOT16 relocations. Like an ADDR16 using the symbol's
5553 address in the GOT as relocation value instead of the
5554 symbol's value itself. Also, create a GOT entry for the
5555 symbol and put the symbol value there. */
5588 dogot:
5589 {
5590 /* Relocation is to the entry for this symbol in the global
5591 offset table. */
5592 bfd_vma off;
5605 {
5606 bfd_boolean dyn;
5611 /* This is actually a static link, or it is a
5612 -Bsymbolic link and the symbol is defined
5613 locally, or the symbol was forced to be local
5614 because of a version file. */
5615 ;
5616 else
5617 {
5620 }
5622 }
5623 else
5624 {
5628 }
5630 /* The offset must always be a multiple of 4. We use the
5631 least significant bit to record whether we have already
5632 processed this entry. */
5636 else
5637 {
5648 /* We might have multiple got entries for this sym.
5649 Initialize them all. */
5650 do
5651 {
5655 {
5658 }
5660 {
5663 }
5665 {
5668 }
5670 {
5673 }
5675 /* Generate relocs for the dynamic linker. */
5680 {
5686 {
5689 {
5696 outrel.r_info
5698 }
5699 }
5706 else
5709 {
5713 }
5718 }
5720 /* Init the .got section contents if we're not
5721 emitting a reloc. */
5722 else
5723 {
5729 {
5735 {
5739 }
5740 }
5743 }
5748 }
5753 }
5759 {
5761 {
5767 {
5771 {
5774 }
5775 }
5776 }
5777 }
5782 /* Addends on got relocations don't make much sense.
5783 x+off@got is actually x@got+off, and since the got is
5784 generated by a hash table traversal, the value in the
5785 got at entry m+n bears little relation to the entry m. */
5789 input_bfd,
5790 input_section,
5793 sym_name);
5794 }
5797 /* Relocations that need no special processing. */
5799 /* It makes no sense to point a local relocation
5800 at a symbol not in this object. */
5802 {
5805 input_bfd,
5806 input_section,
5808 TRUE))
5811 }
5821 /* Relocations that may need to be propagated if this is a shared
5822 object. */
5828 /* The TPREL16 relocs shouldn't really be used in shared
5829 libs as they will result in DT_TEXTREL being set, but
5830 support them anyway. */
5857 /* If these relocations are not to a named symbol, they can be
5858 handled right here, no need to bother the dynamic linker. */
5862 /* fall through */
5864 /* Relocations that always need to be propagated if this is a shared
5865 object. */
5877 /* r_symndx will be zero only for relocs against symbols
5878 from removed linkonce sections, or sections discarded by
5879 a linker script. */
5880 dodyn:
5883 /* Fall thru. */
5887 /* Fall thru. */
5895 || (ELIMINATE_COPY_RELOCS
5902 {
5905 #ifdef DEBUG
5910 #endif
5912 /* When generating a shared object, these relocations
5913 are copied into the output file to be resolved at run
5914 time. */
5916 {
5919 name = (bfd_elf_string_from_elf_section
5928 input_section),
5933 }
5949 {
5953 }
5954 else
5955 {
5960 else
5961 {
5967 {
5970 }
5971 else
5972 {
5975 /* We are turning this relocation into one
5976 against a section symbol. It would be
5977 proper to subtract the symbol's value,
5978 osec->vma, from the emitted reloc addend,
5979 but ld.so expects buggy relocs. */
5983 #ifdef DEBUG
5988 #endif
5989 }
5992 }
5993 }
6002 /* This reloc will be computed at runtime. We clear the memory
6003 so that it contains predictable value. */
6007 {
6011 }
6012 }
6017 {
6024 else
6029 }
6032 /* Fall thru */
6038 /* Fall thru */
6041 relax32:
6042 {
6049 /* We're clearing the bits for R_PPC_ADDR16_HA
6050 and R_PPC_ADDR16_LO here. */
6054 /* t0 is HA, t1 is LO */
6061 }
6064 /* Indirect .sdata relocation. */
6067 relocation
6072 /* Indirect .sdata2 relocation. */
6075 relocation
6080 /* Handle the TOC16 reloc. We want to use the offset within the .got
6081 section, not the actual VMA. This is appropriate when generating
6082 an embedded ELF object, for which the .got section acts like the
6083 AIX .toc section. */
6094 /* Relocation is to the entry for this symbol in the
6095 procedure linkage table. */
6096 {
6102 {
6103 /* We didn't make a PLT entry for this symbol. This
6104 happens when statically linking PIC code, or when
6105 using -Bsymbolic. */
6107 }
6114 else
6118 }
6121 /* Relocate against _SDA_BASE_. */
6123 {
6132 {
6136 input_bfd,
6137 sym_name,
6139 name);
6140 }
6142 }
6145 /* Relocate against _SDA2_BASE_. */
6147 {
6154 {
6158 input_bfd,
6159 sym_name,
6161 name);
6166 }
6168 }
6171 /* Relocate against either _SDA_BASE_, _SDA2_BASE_, or 0. */
6174 {
6184 {
6187 }
6191 {
6194 }
6198 {
6200 }
6202 else
6203 {
6207 input_bfd,
6208 sym_name,
6210 name);
6215 }
6222 }
6223 }
6226 /* Relocate against the beginning of the section. */
6235 /* Negative relocations. */
6261 input_bfd,
6263 sym_name);
6268 }
6270 /* Do any further special processing. */
6272 {
6289 /* It's just possible that this symbol is a weak symbol
6290 that's not actually defined anywhere. In that case,
6291 'sec' would be NULL, and we should leave the symbol
6292 alone (it will be set to zero elsewhere in the link). */
6294 /* Add 0x10000 if sign bit in 0:15 is set.
6295 Bits 0:15 are not used. */
6298 }
6300 #ifdef DEBUG
6305 sym_name,
6306 r_symndx,
6309 #endif
6314 {
6317 input_bfd,
6318 input_section,
6321 sym_name);
6323 }
6326 input_bfd,
6327 input_section,
6328 contents,
6330 relocation,
6331 addend);
6334 {
6336 {
6342 {
6343 /* Assume this is a call protected by other code that
6344 detect the symbol is undefined. If this is the case,
6345 we can safely ignore the overflow. If not, the
6346 program is hosed anyway, and a little warning isn't
6347 going to help. */
6350 }
6354 sym_name,
6357 input_bfd,
6358 input_section,
6361 }
6362 else
6363 {
6369 }
6370 }
6371 }
6373 #ifdef DEBUG
6375 #endif
6378 }
6379 \f
6380 #define PPC_LO(v) ((v) & 0xffff)
6381 #define PPC_HI(v) (((v) >> 16) & 0xffff)
6382 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
6384 /* Finish up dynamic symbol handling. We set the contents of various
6385 dynamic sections here. */
6387 static bfd_boolean
6392 {
6395 bfd_boolean doneone;
6397 #ifdef DEBUG
6400 #endif
6408 {
6410 {
6411 Elf_Internal_Rela rela;
6413 bfd_vma reloc_index;
6415 /* This symbol has an entry in the procedure linkage table.
6416 Set it up. */
6418 {
6419 /* We don't need to fill in the .plt. The ppc dynamic
6420 linker will fill it in. */
6421 }
6422 else
6423 {
6429 }
6431 /* Fill in the entry in the .rela.plt section. */
6440 else
6441 {
6446 }
6452 {
6453 /* Mark the symbol as undefined, rather than as defined in
6454 the .plt section. Leave the value alone. */
6456 /* If the symbol is weak, we do need to clear the value.
6457 Otherwise, the PLT entry would provide a definition for
6458 the symbol even if the symbol wasn't defined anywhere,
6459 and so the symbol would never be NULL. */
6462 }
6464 }
6467 {
6468 bfd_vma plt;
6477 {
6492 {
6501 }
6502 else
6503 {
6512 }
6513 }
6514 else
6515 {
6525 /* We only need one non-PIC glink stub. */
6527 }
6528 }
6529 else
6531 }
6534 {
6536 Elf_Internal_Rela rela;
6539 /* This symbols needs a copy reloc. Set it up. */
6541 #ifdef DEBUG
6543 #endif
6549 else
6560 }
6562 #ifdef DEBUG
6564 #endif
6566 /* Mark some specially defined symbols as absolute. */
6573 }
6574 \f
6575 static enum elf_reloc_type_class
6577 {
6579 {
6590 }
6591 }
6592 \f
6593 /* Finish up the dynamic sections. */
6595 static bfd_boolean
6598 {
6601 bfd_vma got;
6603 #ifdef DEBUG
6605 #endif
6617 {
6625 {
6626 Elf_Internal_Dyn dyn;
6632 {
6653 }
6656 }
6657 }
6659 /* Add a blrl instruction at _GLOBAL_OFFSET_TABLE_-4 so that a function can
6660 easily find the address of the _GLOBAL_OFFSET_TABLE_. */
6662 {
6664 bfd_vma val;
6676 }
6679 {
6682 bfd_vma res0;
6685 /*
6686 * PIC glink code is the following:
6687 *
6688 * # ith PLT code stub.
6689 * addis 11,30,(plt+(i-1)*4-got)@ha
6690 * lwz 11,(plt+(i-1)*4-got)@l(11)
6691 * mtctr 11
6692 * bctr
6693 *
6694 * # A table of branches, one for each plt entry.
6695 * # The idea is that the plt call stub loads ctr (and r11) with these
6696 * # addresses, so (r11 - res_0) gives the plt index * 4.
6697 * res_0: b PLTresolve
6698 * res_1: b PLTresolve
6699 * .
6700 * # Some number of entries towards the end can be nops
6701 * res_n_m3: nop
6702 * res_n_m2: nop
6703 * res_n_m1:
6704 *
6705 * PLTresolve:
6706 * addis 11,11,(1f-res_0)@ha
6707 * mflr 0
6708 * bcl 20,31,1f
6709 * 1: addi 11,11,(1b-res_0)@l
6710 * mflr 12
6711 * mtlr 0
6712 * sub 11,11,12 # r11 = index * 4
6713 * addis 12,12,(got+4-1b)@ha
6714 * lwz 0,(got+4-1b)@l(12) # got[1] address of dl_runtime_resolve
6715 * lwz 12,(got+8-1b)@l(12) # got[2] contains the map address
6716 * mtctr 0
6717 * add 0,11,11
6718 * add 11,0,11 # r11 = index * 12 = reloc offset.
6719 * bctr
6720 */
6722 {
6723 ADDIS_11_11,
6724 MFLR_0,
6725 BCL_20_31,
6726 ADDI_11_11,
6727 MFLR_12,
6728 MTLR_0,
6729 SUB_11_11_12,
6730 ADDIS_12_12,
6731 LWZ_0_12,
6732 LWZ_12_12,
6733 MTCTR_0,
6734 ADD_0_11_11,
6735 ADD_11_0_11,
6736 BCTR,
6737 NOP,
6738 NOP
6739 };
6742 {
6743 LIS_12,
6744 ADDIS_11_11,
6745 LWZ_0_12,
6746 ADDI_11_11,
6747 MTCTR_0,
6748 ADD_0_11_11,
6749 LWZ_12_12,
6750 ADD_11_0_11,
6751 BCTR,
6752 NOP,
6753 NOP,
6754 NOP,
6755 NOP,
6756 NOP,
6757 NOP,
6758 NOP
6759 };
6766 /* Build the branch table, one for each plt entry (less one),
6767 and perhaps some padding. */
6773 {
6776 }
6778 {
6781 }
6787 /* Last comes the PLTresolve stub. */
6789 {
6790 bfd_vma bcl;
6793 {
6796 }
6810 {
6815 }
6816 else
6817 {
6822 }
6823 }
6824 else
6825 {
6827 {
6830 }
6840 {
6845 }
6846 else
6847 {
6852 }
6853 }
6854 }
6857 }
6858 \f
6859 #define TARGET_LITTLE_SYM bfd_elf32_powerpcle_vec
6861 #define TARGET_BIG_SYM bfd_elf32_powerpc_vec
6863 #define ELF_ARCH bfd_arch_powerpc
6864 #define ELF_MACHINE_CODE EM_PPC
6865 #ifdef __QNXTARGET__
6866 #define ELF_MAXPAGESIZE 0x1000
6867 #else
6868 #define ELF_MAXPAGESIZE 0x10000
6869 #endif
6870 #define ELF_MINPAGESIZE 0x1000
6871 #define elf_info_to_howto ppc_elf_info_to_howto
6873 #ifdef EM_CYGNUS_POWERPC
6874 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
6875 #endif
6877 #ifdef EM_PPC_OLD
6878 #define ELF_MACHINE_ALT2 EM_PPC_OLD
6879 #endif
6881 #define elf_backend_plt_not_loaded 1
6882 #define elf_backend_can_gc_sections 1
6883 #define elf_backend_can_refcount 1
6884 #define elf_backend_rela_normal 1
6886 #define bfd_elf32_mkobject ppc_elf_mkobject
6887 #define bfd_elf32_bfd_merge_private_bfd_data ppc_elf_merge_private_bfd_data
6888 #define bfd_elf32_bfd_relax_section ppc_elf_relax_section
6889 #define bfd_elf32_bfd_reloc_type_lookup ppc_elf_reloc_type_lookup
6890 #define bfd_elf32_bfd_set_private_flags ppc_elf_set_private_flags
6891 #define bfd_elf32_bfd_link_hash_table_create ppc_elf_link_hash_table_create
6893 #define elf_backend_object_p ppc_elf_object_p
6894 #define elf_backend_gc_mark_hook ppc_elf_gc_mark_hook
6895 #define elf_backend_gc_sweep_hook ppc_elf_gc_sweep_hook
6896 #define elf_backend_section_from_shdr ppc_elf_section_from_shdr
6897 #define elf_backend_relocate_section ppc_elf_relocate_section
6898 #define elf_backend_create_dynamic_sections ppc_elf_create_dynamic_sections
6899 #define elf_backend_check_relocs ppc_elf_check_relocs
6900 #define elf_backend_copy_indirect_symbol ppc_elf_copy_indirect_symbol
6901 #define elf_backend_adjust_dynamic_symbol ppc_elf_adjust_dynamic_symbol
6902 #define elf_backend_add_symbol_hook ppc_elf_add_symbol_hook
6903 #define elf_backend_size_dynamic_sections ppc_elf_size_dynamic_sections
6904 #define elf_backend_finish_dynamic_symbol ppc_elf_finish_dynamic_symbol
6905 #define elf_backend_finish_dynamic_sections ppc_elf_finish_dynamic_sections
6906 #define elf_backend_fake_sections ppc_elf_fake_sections
6907 #define elf_backend_additional_program_headers ppc_elf_additional_program_headers
6908 #define elf_backend_grok_prstatus ppc_elf_grok_prstatus
6909 #define elf_backend_grok_psinfo ppc_elf_grok_psinfo
6910 #define elf_backend_reloc_type_class ppc_elf_reloc_type_class
6911 #define elf_backend_begin_write_processing ppc_elf_begin_write_processing
6912 #define elf_backend_final_write_processing ppc_elf_final_write_processing
6913 #define elf_backend_write_section ppc_elf_write_section
6914 #define elf_backend_special_sections ppc_elf_special_sections
6915 #define elf_backend_plt_sym_val ppc_elf_plt_sym_val