| blob | 2ca139d807ffb328f679986a22eb110ce232a192 |
1 /* PowerPC64-specific support for 64-bit ELF.
2 Copyright 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
3 Written by Linus Nordberg, Swox AB <info@swox.com>,
4 based on elf32-ppc.c by Ian Lance Taylor.
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 Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
22 /* This file is based on the 64-bit PowerPC ELF ABI. It is also based
23 on the file elf32-ppc.c. */
33 static void ppc_howto_init
37 static void ppc64_elf_info_to_howto
39 static bfd_reloc_status_type ppc64_elf_ha_reloc
41 static bfd_reloc_status_type ppc64_elf_brtaken_reloc
43 static bfd_reloc_status_type ppc64_elf_sectoff_reloc
45 static bfd_reloc_status_type ppc64_elf_sectoff_ha_reloc
47 static bfd_reloc_status_type ppc64_elf_toc_reloc
49 static bfd_reloc_status_type ppc64_elf_toc_ha_reloc
51 static bfd_reloc_status_type ppc64_elf_toc64_reloc
53 static bfd_reloc_status_type ppc64_elf_unhandled_reloc
55 static bfd_boolean ppc64_elf_object_p
57 static bfd_boolean ppc64_elf_merge_private_bfd_data
59 static bfd_boolean ppc64_elf_new_section_hook
63 /* The name of the dynamic interpreter. This is put in the .interp
64 section. */
67 /* The size in bytes of an entry in the procedure linkage table. */
68 #define PLT_ENTRY_SIZE 24
70 /* The initial size of the plt reserved for the dynamic linker. */
71 #define PLT_INITIAL_ENTRY_SIZE PLT_ENTRY_SIZE
73 /* TOC base pointers offset from start of TOC. */
74 #define TOC_BASE_OFF (0x8000)
76 /* .plt call stub instructions. */
82 /* ld %r11,xxx+16@l(%r12) */
85 /* The normal stub is this size. */
86 #define PLT_CALL_STUB_SIZE (7*4)
88 /* But sometimes the .plt entry crosses a 64k boundary, and we need
89 to adjust the high word with this insn. */
92 /* The .glink fixup call stub is the same as the .plt call stub, but
93 the first instruction restores r2, and the std is omitted. */
96 /* Always allow this much space. */
97 #define GLINK_CALL_STUB_SIZE (8*4)
99 /* Pad with this. */
100 #define NOP 0x60000000
102 /* Some other nops. */
103 #define CROR_151515 0x4def7b82
104 #define CROR_313131 0x4ffffb82
106 /* .glink entries for the first 32k functions are two instructions. */
110 /* After that, we need two instructions to load the index, followed by
111 a branch. */
115 /* Instructions to save and restore floating point regs. */
120 /* Since .opd is an array of descriptors and each entry will end up
121 with identical R_PPC64_RELATIVE relocs, there is really no need to
122 propagate .opd relocs; The dynamic linker should be taught to
123 relocate .opd without reloc entries. */
124 #ifndef NO_OPD_RELOCS
125 #define NO_OPD_RELOCS 0
126 #endif
127 \f
128 #define ONES(n) (((bfd_vma) 1 << ((n) - 1) << 1) - 1)
130 /* Relocation HOWTO's. */
134 /* This reloc does nothing. */
149 /* A standard 32 bit relocation. */
164 /* An absolute 26 bit branch; the lower two bits must be zero.
165 FIXME: we don't check that, we just clear them. */
180 /* A standard 16 bit relocation. */
195 /* A 16 bit relocation without overflow. */
210 /* Bits 16-31 of an address. */
225 /* Bits 16-31 of an address, plus 1 if the contents of the low 16
226 bits, treated as a signed number, is negative. */
241 /* An absolute 16 bit branch; the lower two bits must be zero.
242 FIXME: we don't check that, we just clear them. */
257 /* An absolute 16 bit branch, for which bit 10 should be set to
258 indicate that the branch is expected to be taken. The lower two
259 bits must be zero. */
274 /* An absolute 16 bit branch, for which bit 10 should be set to
275 indicate that the branch is not expected to be taken. The lower
276 two bits must be zero. */
291 /* A relative 26 bit branch; the lower two bits must be zero. */
306 /* A relative 16 bit branch; the lower two bits must be zero. */
321 /* A relative 16 bit branch. Bit 10 should be set to indicate that
322 the branch is expected to be taken. The lower two bits must be
323 zero. */
338 /* A relative 16 bit branch. Bit 10 should be set to indicate that
339 the branch is not expected to be taken. The lower two bits must
340 be zero. */
355 /* Like R_PPC64_ADDR16, but referring to the GOT table entry for the
356 symbol. */
371 /* Like R_PPC64_ADDR16_LO, but referring to the GOT table entry for
372 the symbol. */
387 /* Like R_PPC64_ADDR16_HI, but referring to the GOT table entry for
388 the symbol. */
403 /* Like R_PPC64_ADDR16_HA, but referring to the GOT table entry for
404 the symbol. */
419 /* This is used only by the dynamic linker. The symbol should exist
420 both in the object being run and in some shared library. The
421 dynamic linker copies the data addressed by the symbol from the
422 shared library into the object, because the object being
423 run has to have the data at some particular address. */
438 /* Like R_PPC64_ADDR64, but used when setting global offset table
439 entries. */
454 /* Created by the link editor. Marks a procedure linkage table
455 entry for a symbol. */
470 /* Used only by the dynamic linker. When the object is run, this
471 doubleword64 is set to the load address of the object, plus the
472 addend. */
487 /* Like R_PPC64_ADDR32, but may be unaligned. */
502 /* Like R_PPC64_ADDR16, but may be unaligned. */
517 /* 32-bit PC relative. */
524 /* FIXME: Verify. Was complain_overflow_bitfield. */
533 /* 32-bit relocation to the symbol's procedure linkage table. */
548 /* 32-bit PC relative relocation to the symbol's procedure linkage table.
549 FIXME: R_PPC64_PLTREL32 not supported. */
564 /* Like R_PPC64_ADDR16_LO, but referring to the PLT table entry for
565 the symbol. */
580 /* Like R_PPC64_ADDR16_HI, but referring to the PLT table entry for
581 the symbol. */
596 /* Like R_PPC64_ADDR16_HA, but referring to the PLT table entry for
597 the symbol. */
612 /* 16-bit section relative relocation. */
627 /* Like R_PPC64_SECTOFF, but no overflow warning. */
642 /* 16-bit upper half section relative relocation. */
657 /* 16-bit upper half adjusted section relative relocation. */
672 /* Like R_PPC64_REL24 without touching the two least significant bits. */
687 /* Relocs in the 64-bit PowerPC ELF ABI, not in the 32-bit ABI. */
689 /* A standard 64-bit relocation. */
704 /* The bits 32-47 of an address. */
719 /* The bits 32-47 of an address, plus 1 if the contents of the low
720 16 bits, treated as a signed number, is negative. */
735 /* The bits 48-63 of an address. */
750 /* The bits 48-63 of an address, plus 1 if the contents of the low
751 16 bits, treated as a signed number, is negative. */
766 /* Like ADDR64, but may be unaligned. */
781 /* 64-bit relative relocation. */
796 /* 64-bit relocation to the symbol's procedure linkage table. */
811 /* 64-bit PC relative relocation to the symbol's procedure linkage
812 table. */
813 /* FIXME: R_PPC64_PLTREL64 not supported. */
828 /* 16 bit TOC-relative relocation. */
830 /* R_PPC64_TOC16 47 half16* S + A - .TOC. */
845 /* 16 bit TOC-relative relocation without overflow. */
847 /* R_PPC64_TOC16_LO 48 half16 #lo (S + A - .TOC.) */
862 /* 16 bit TOC-relative relocation, high 16 bits. */
864 /* R_PPC64_TOC16_HI 49 half16 #hi (S + A - .TOC.) */
879 /* 16 bit TOC-relative relocation, high 16 bits, plus 1 if the
880 contents of the low 16 bits, treated as a signed number, is
881 negative. */
883 /* R_PPC64_TOC16_HA 50 half16 #ha (S + A - .TOC.) */
898 /* 64-bit relocation; insert value of TOC base (.TOC.). */
900 /* R_PPC64_TOC 51 doubleword64 .TOC. */
915 /* Like R_PPC64_GOT16, but also informs the link editor that the
916 value to relocate may (!) refer to a PLT entry which the link
917 editor (a) may replace with the symbol value. If the link editor
918 is unable to fully resolve the symbol, it may (b) create a PLT
919 entry and store the address to the new PLT entry in the GOT.
920 This permits lazy resolution of function symbols at run time.
921 The link editor may also skip all of this and just (c) emit a
922 R_PPC64_GLOB_DAT to tie the symbol to the GOT entry. */
923 /* FIXME: R_PPC64_PLTGOT16 not implemented. */
938 /* Like R_PPC64_PLTGOT16, but without overflow. */
939 /* FIXME: R_PPC64_PLTGOT16_LO not implemented. */
954 /* Like R_PPC64_PLT_GOT16, but using bits 16-31 of the address. */
955 /* FIXME: R_PPC64_PLTGOT16_HI not implemented. */
970 /* Like R_PPC64_PLT_GOT16, but using bits 16-31 of the address, plus
971 1 if the contents of the low 16 bits, treated as a signed number,
972 is negative. */
973 /* FIXME: R_PPC64_PLTGOT16_HA not implemented. */
988 /* Like R_PPC64_ADDR16, but for instructions with a DS field. */
1003 /* Like R_PPC64_ADDR16_LO, but for instructions with a DS field. */
1018 /* Like R_PPC64_GOT16, but for instructions with a DS field. */
1033 /* Like R_PPC64_GOT16_LO, but for instructions with a DS field. */
1048 /* Like R_PPC64_PLT16_LO, but for instructions with a DS field. */
1063 /* Like R_PPC64_SECTOFF, but for instructions with a DS field. */
1078 /* Like R_PPC64_SECTOFF_LO, but for instructions with a DS field. */
1093 /* Like R_PPC64_TOC16, but for instructions with a DS field. */
1108 /* Like R_PPC64_TOC16_LO, but for instructions with a DS field. */
1123 /* Like R_PPC64_PLTGOT16, but for instructions with a DS field. */
1124 /* FIXME: R_PPC64_PLTGOT16_DS not implemented. */
1139 /* Like R_PPC64_PLTGOT16_LO, but for instructions with a DS field. */
1140 /* FIXME: R_PPC64_PLTGOT16_LO not implemented. */
1155 /* GNU extension to record C++ vtable hierarchy. */
1170 /* GNU extension to record C++ vtable member usage. */
1184 };
1186 \f
1187 /* Initialize the ppc64_elf_howto_table, so that linear accesses can
1188 be done. */
1190 static void
1192 {
1197 i++)
1198 {
1203 }
1204 }
1209 bfd_reloc_code_real_type code;
1210 {
1214 /* Initialize howto table if needed. */
1218 {
1344 }
1347 };
1349 /* Set the howto pointer for a PowerPC ELF reloc. */
1351 static void
1356 {
1359 /* Initialize howto table if needed. */
1367 }
1369 /* Handle the R_PPC64_ADDR16_HA and similar relocs. */
1371 static bfd_reloc_status_type
1377 PTR data;
1381 {
1382 /* If this is a relocatable link (output_bfd test tells us), just
1383 call the generic function. Any adjustment will be done at final
1384 link time. */
1389 /* Adjust the addend for sign extension of the low 16 bits.
1390 We won't actually be using the low 16 bits, so trashing them
1391 doesn't matter. */
1394 }
1396 static bfd_reloc_status_type
1402 PTR data;
1406 {
1409 bfd_size_type octets;
1410 /* Disabled until we sort out how ld should choose 'y' vs 'at'. */
1413 /* If this is a relocatable link (output_bfd test tells us), just
1414 call the generic function. Any adjustment will be done at final
1415 link time. */
1429 {
1430 /* Set 'a' bit. This is 0b00010 in BO field for branch
1431 on CR(BI) insns (BO == 001at or 011at), and 0b01000
1432 for branch on CTR insns (BO == 1a00t or 1a01t). */
1437 else
1439 }
1440 else
1441 {
1443 bfd_vma from;
1455 /* Invert 'y' bit if not the default. */
1458 }
1461 }
1463 static bfd_reloc_status_type
1469 PTR data;
1473 {
1474 /* If this is a relocatable link (output_bfd test tells us), just
1475 call the generic function. Any adjustment will be done at final
1476 link time. */
1481 /* Subtract the symbol section base address. */
1484 }
1486 static bfd_reloc_status_type
1492 PTR data;
1496 {
1497 /* If this is a relocatable link (output_bfd test tells us), just
1498 call the generic function. Any adjustment will be done at final
1499 link time. */
1504 /* Subtract the symbol section base address. */
1507 /* Adjust the addend for sign extension of the low 16 bits. */
1510 }
1512 static bfd_reloc_status_type
1518 PTR data;
1522 {
1523 bfd_vma TOCstart;
1525 /* If this is a relocatable link (output_bfd test tells us), just
1526 call the generic function. Any adjustment will be done at final
1527 link time. */
1536 /* Subtract the TOC base address. */
1539 }
1541 static bfd_reloc_status_type
1547 PTR data;
1551 {
1552 bfd_vma TOCstart;
1554 /* If this is a relocatable link (output_bfd test tells us), just
1555 call the generic function. Any adjustment will be done at final
1556 link time. */
1565 /* Subtract the TOC base address. */
1568 /* Adjust the addend for sign extension of the low 16 bits. */
1571 }
1573 static bfd_reloc_status_type
1579 PTR data;
1583 {
1584 bfd_vma TOCstart;
1585 bfd_size_type octets;
1587 /* If this is a relocatable link (output_bfd test tells us), just
1588 call the generic function. Any adjustment will be done at final
1589 link time. */
1601 }
1603 static bfd_reloc_status_type
1609 PTR data;
1613 {
1614 /* If this is a relocatable link (output_bfd test tells us), just
1615 call the generic function. Any adjustment will be done at final
1616 link time. */
1622 {
1627 }
1629 }
1631 /* Fix bad default arch selected for a 64 bit input bfd when the
1632 default is 32 bit. */
1634 static bfd_boolean
1637 {
1639 {
1643 {
1644 /* Relies on arch after 32 bit default being 64 bit default. */
1647 }
1648 }
1650 }
1652 /* Merge backend specific data from an object file to the output
1653 object file when linking. */
1655 static bfd_boolean
1659 {
1660 /* Check if we have the same endianess. */
1664 {
1669 else
1676 }
1679 }
1681 struct _ppc64_elf_section_data
1682 {
1684 union
1685 {
1689 };
1691 #define ppc64_elf_section_data(sec) \
1692 ((struct _ppc64_elf_section_data *) (sec)->used_by_bfd)
1694 static bfd_boolean
1698 {
1708 }
1709 \f
1710 /* The following functions are specific to the ELF linker, while
1711 functions above are used generally. Those named ppc64_elf_* are
1712 called by the main ELF linker code. They appear in this file more
1713 or less in the order in which they are called. eg.
1714 ppc64_elf_check_relocs is called early in the link process,
1715 ppc64_elf_finish_dynamic_sections is one of the last functions
1716 called.
1718 PowerPC64-ELF uses a similar scheme to PowerPC64-XCOFF in that
1719 functions have both a function code symbol and a function descriptor
1720 symbol. A call to foo in a relocatable object file looks like:
1722 . .text
1723 . x:
1724 . bl .foo
1725 . nop
1727 The function definition in another object file might be:
1729 . .section .opd
1730 . foo: .quad .foo
1731 . .quad .TOC.@tocbase
1732 . .quad 0
1733 .
1734 . .text
1735 . .foo: blr
1737 When the linker resolves the call during a static link, the branch
1738 unsurprisingly just goes to .foo and the .opd information is unused.
1739 If the function definition is in a shared library, things are a little
1740 different: The call goes via a plt call stub, the opd information gets
1741 copied to the plt, and the linker patches the nop.
1743 . x:
1744 . bl .foo_stub
1745 . ld 2,40(1)
1746 .
1747 .
1748 . .foo_stub:
1749 . addis 12,2,Lfoo@toc@ha # in practice, the call stub
1750 . addi 12,12,Lfoo@toc@l # is slightly optimised, but
1751 . std 2,40(1) # this is the general idea
1752 . ld 11,0(12)
1753 . ld 2,8(12)
1754 . mtctr 11
1755 . ld 11,16(12)
1756 . bctr
1757 .
1758 . .section .plt
1759 . Lfoo: reloc (R_PPC64_JMP_SLOT, foo)
1761 The "reloc ()" notation is supposed to indicate that the linker emits
1762 an R_PPC64_JMP_SLOT reloc against foo. The dynamic linker does the opd
1763 copying.
1765 What are the difficulties here? Well, firstly, the relocations
1766 examined by the linker in check_relocs are against the function code
1767 sym .foo, while the dynamic relocation in the plt is emitted against
1768 the function descriptor symbol, foo. Somewhere along the line, we need
1769 to carefully copy dynamic link information from one symbol to the other.
1770 Secondly, the generic part of the elf linker will make .foo a dynamic
1771 symbol as is normal for most other backends. We need foo dynamic
1772 instead, at least for an application final link. However, when
1773 creating a shared library containing foo, we need to have both symbols
1774 dynamic so that references to .foo are satisfied during the early
1775 stages of linking. Otherwise the linker might decide to pull in a
1776 definition from some other object, eg. a static library. */
1778 /* The linker needs to keep track of the number of relocs that it
1779 decides to copy as dynamic relocs in check_relocs for each symbol.
1780 This is so that it can later discard them if they are found to be
1781 unnecessary. We store the information in a field extending the
1782 regular ELF linker hash table. */
1784 struct ppc_dyn_relocs
1785 {
1788 /* The input section of the reloc. */
1791 /* Total number of relocs copied for the input section. */
1792 bfd_size_type count;
1794 /* Number of pc-relative relocs copied for the input section. */
1795 bfd_size_type pc_count;
1796 };
1798 /* Of those relocs that might be copied as dynamic relocs, this macro
1799 selects between relative and absolute types. */
1801 #define IS_ABSOLUTE_RELOC(RTYPE) \
1802 ((RTYPE) != R_PPC64_REL32 \
1803 && (RTYPE) != R_PPC64_REL64 \
1804 && (RTYPE) != R_PPC64_REL30)
1806 /* Section name for stubs is the associated section name plus this
1807 string. */
1810 /* Linker stubs.
1811 ppc_stub_long_branch:
1812 Used when a 14 bit branch (or even a 24 bit branch) can't reach its
1813 destination, but a 24 bit branch in a stub section will reach.
1814 . b dest
1816 ppc_stub_plt_branch:
1817 Similar to the above, but a 24 bit branch in the stub section won't
1818 reach its destination.
1819 . addis %r12,%r2,xxx@toc@ha
1820 . ld %r11,xxx@toc@l(%r12)
1821 . mtctr %r11
1822 . bctr
1824 ppc_stub_plt_call:
1825 Used to call a function in a shared library.
1826 . addis %r12,%r2,xxx@toc@ha
1827 . std %r2,40(%r1)
1828 . ld %r11,xxx+0@toc@l(%r12)
1829 . ld %r2,xxx+8@toc@l(%r12)
1830 . mtctr %r11
1831 . ld %r11,xxx+16@toc@l(%r12)
1832 . bctr
1833 */
1836 ppc_stub_none,
1837 ppc_stub_long_branch,
1838 ppc_stub_plt_branch,
1839 ppc_stub_plt_call
1840 };
1844 /* Base hash table entry structure. */
1847 /* The stub section. */
1850 /* Offset within stub_sec of the beginning of this stub. */
1851 bfd_vma stub_offset;
1853 /* Given the symbol's value and its section we can determine its final
1854 value when building the stubs (so the stub knows where to jump. */
1855 bfd_vma target_value;
1860 /* The symbol table entry, if any, that this was derived from. */
1863 /* Where this stub is being called from, or, in the case of combined
1864 stub sections, the first input section in the group. */
1866 };
1870 /* Base hash table entry structure. */
1873 /* Offset within .branch_lt. */
1876 /* Generation marker. */
1878 };
1880 struct ppc_link_hash_entry
1881 {
1884 /* A pointer to the most recently used stub hash entry against this
1885 symbol. */
1888 /* Track dynamic relocs copied for this symbol. */
1891 /* Link between function code and descriptor symbols. */
1894 /* Flag function code and descriptor symbols. */
1898 };
1900 /* ppc64 ELF linker hash table. */
1902 struct ppc_link_hash_table
1903 {
1906 /* The stub hash table. */
1909 /* Another hash table for plt_branch stubs. */
1912 /* Linker stub bfd. */
1915 /* Linker call-backs. */
1919 /* Array to keep track of which stub sections have been created, and
1920 information on stub grouping. */
1922 /* This is the section to which stubs in the group will be attached. */
1924 /* The stub section. */
1928 /* Assorted information used by ppc64_elf_size_stubs. */
1932 /* Short-cuts to get to dynamic linker sections. */
1944 /* Set on error. */
1947 /* Flag set when small branches are detected. Used to
1948 select suitable defaults for the stub group size. */
1951 /* Set if we detect a reference undefined weak symbol. */
1954 /* Incremented every time we size stubs. */
1957 /* Small local sym to section mapping cache. */
1959 };
1969 static void ppc64_elf_link_hash_table_free
1979 static bfd_boolean create_linkage_sections
1981 static bfd_boolean create_got_section
1983 static bfd_boolean ppc64_elf_create_dynamic_sections
1985 static void ppc64_elf_copy_indirect_symbol
1988 static bfd_boolean ppc64_elf_check_relocs
1994 static bfd_boolean ppc64_elf_gc_sweep_hook
1997 static bfd_boolean func_desc_adjust
1999 static bfd_boolean ppc64_elf_func_desc_adjust
2001 static bfd_boolean ppc64_elf_adjust_dynamic_symbol
2003 static void ppc64_elf_hide_symbol
2005 static bfd_boolean allocate_dynrelocs
2007 static bfd_boolean readonly_dynrelocs
2009 static enum elf_reloc_type_class ppc64_elf_reloc_type_class
2011 static bfd_boolean ppc64_elf_size_dynamic_sections
2018 static bfd_boolean ppc_build_one_stub
2020 static bfd_boolean ppc_size_one_stub
2022 static void group_sections
2024 static bfd_boolean ppc64_elf_relocate_section
2027 asection **));
2028 static bfd_boolean ppc64_elf_finish_dynamic_symbol
2030 Elf_Internal_Sym *));
2031 static bfd_boolean ppc64_elf_finish_dynamic_sections
2034 /* Get the ppc64 ELF linker hash table from a link_info structure. */
2036 #define ppc_hash_table(p) \
2037 ((struct ppc_link_hash_table *) ((p)->hash))
2039 #define ppc_stub_hash_lookup(table, string, create, copy) \
2040 ((struct ppc_stub_hash_entry *) \
2041 bfd_hash_lookup ((table), (string), (create), (copy)))
2043 #define ppc_branch_hash_lookup(table, string, create, copy) \
2044 ((struct ppc_branch_hash_entry *) \
2045 bfd_hash_lookup ((table), (string), (create), (copy)))
2047 /* Create an entry in the stub hash table. */
2054 {
2055 /* Allocate the structure if it has not already been allocated by a
2056 subclass. */
2058 {
2062 }
2064 /* Call the allocation method of the superclass. */
2067 {
2070 /* Initialize the local fields. */
2079 }
2082 }
2084 /* Create an entry in the branch hash table. */
2091 {
2092 /* Allocate the structure if it has not already been allocated by a
2093 subclass. */
2095 {
2099 }
2101 /* Call the allocation method of the superclass. */
2104 {
2107 /* Initialize the local fields. */
2111 }
2114 }
2116 /* Create an entry in a ppc64 ELF linker hash table. */
2123 {
2124 /* Allocate the structure if it has not already been allocated by a
2125 subclass. */
2127 {
2131 }
2133 /* Call the allocation method of the superclass. */
2136 {
2145 }
2148 }
2150 /* Create a ppc64 ELF linker hash table. */
2155 {
2164 {
2167 }
2169 /* Init the stub hash table too. */
2173 /* And the branch hash table. */
2198 }
2200 /* Free the derived linker hash table. */
2202 static void
2205 {
2211 }
2213 /* Build a name for an entry in the stub hash table. */
2221 {
2223 bfd_size_type len;
2225 /* rel->r_addend is actually 64 bit, but who uses more than +/- 2^31
2226 offsets from a sym as a branch target? In fact, we could
2227 probably assume the addend is always zero. */
2231 {
2235 {
2240 }
2241 }
2242 else
2243 {
2247 {
2253 }
2254 }
2256 }
2258 /* Look up an entry in the stub hash. Stub entries are cached because
2259 creating the stub name takes a bit of time. */
2268 {
2273 /* If this input section is part of a group of sections sharing one
2274 stub section, then use the id of the first section in the group.
2275 Stub names need to include a section id, as there may well be
2276 more than one stub used to reach say, printf, and we need to
2277 distinguish between them. */
2283 {
2285 }
2286 else
2287 {
2300 }
2303 }
2305 /* Add a new stub entry to the stub hash. Not all fields of the new
2306 stub entry are initialised. */
2313 {
2321 {
2324 {
2326 bfd_size_type len;
2341 }
2343 }
2345 /* Enter this entry into the linker stub hash table. */
2349 {
2352 stub_name);
2354 }
2360 }
2362 /* Create sections for linker generated code. */
2364 static bfd_boolean
2368 {
2370 flagword flags;
2374 /* Create .sfpr for code to save and restore fp regs. */
2383 /* Create .glink for lazy dynamic linking support. */
2390 /* Create .branch_lt for plt_branch stubs. */
2400 {
2408 }
2410 }
2412 /* Create .got and .rela.got sections in DYNOBJ, and set up
2413 shortcuts to them in our hash table. */
2415 static bfd_boolean
2419 {
2439 }
2441 /* Create the dynamic sections, and set up shortcuts. */
2443 static bfd_boolean
2447 {
2468 }
2470 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2472 static void
2476 {
2483 {
2485 {
2492 /* Add reloc counts against the weak sym to the strong sym
2493 list. Merge any entries against the same section. */
2495 {
2500 {
2505 }
2508 }
2510 }
2514 }
2521 }
2523 /* Set a flag, used by ppc64_elf_gc_mark_hook, on the entry symbol and
2524 symbols undefined on the command-line. */
2526 bfd_boolean
2529 {
2535 {
2541 }
2543 }
2545 /* Look through the relocs for a section during the first phase, and
2546 calculate needed space in the global offset table, procedure
2547 linkage table, and dynamic reloc sections. */
2549 static bfd_boolean
2555 {
2571 sym_hashes_end = (sym_hashes
2578 {
2579 /* Garbage collection needs some extra help with .opd sections.
2580 We don't want to necessarily keep everything referenced by
2581 relocs in .opd, as that would keep all functions. Instead,
2582 if we reference an .opd symbol (a function descriptor), we
2583 want to keep the function code symbol's section. This is
2584 easy for global symbols, but for local syms we need to keep
2585 information about the associated function section. Later, if
2586 edit_opd deletes entries, we'll use this array to adjust
2587 local syms in .opd. */
2591 };
2592 bfd_size_type amt;
2599 }
2609 {
2617 else
2622 {
2623 /* GOT16 relocations */
2631 /* This symbol requires a global offset table entry. */
2637 {
2639 }
2640 else
2641 {
2644 /* This is a global offset table entry for a local symbol. */
2647 {
2648 bfd_size_type size;
2657 }
2659 }
2667 /* This symbol requires a procedure linkage table entry. We
2668 actually build the entry in adjust_dynamic_symbol,
2669 because this might be a case of linking PIC code without
2670 linking in any dynamic objects, in which case we don't
2671 need to generate a procedure linkage table after all. */
2673 {
2674 /* It does not make sense to have a procedure linkage
2675 table entry for a local symbol. */
2678 }
2685 /* The following relocations don't need to propagate the
2686 relocation if linking a shared object since they are
2687 section relative. */
2702 /* This relocation describes the C++ object vtable hierarchy.
2703 Reconstruct it for later use during GC. */
2709 /* This relocation describes which C++ vtable entries are actually
2710 used. Record for later use during GC. */
2720 /* Fall through. */
2726 {
2727 /* We may need a .plt entry if the function this reloc
2728 refers to is in a shared lib. */
2732 }
2740 {
2746 {
2751 }
2752 }
2758 {
2762 r_symndx);
2767 }
2768 /* Fall through. */
2792 /* Don't propagate .opd relocs. */
2796 /* If we are creating a shared library, and this is a reloc
2797 against a global symbol, or a non PC relative reloc
2798 against a local symbol, then we need to copy the reloc
2799 into the shared library. However, if we are linking with
2800 -Bsymbolic, we do not need to copy a reloc against a
2801 global symbol which is defined in an object we are
2802 including in the link (i.e., DEF_REGULAR is set). At
2803 this point we have not seen all the input files, so it is
2804 possible that DEF_REGULAR is not set now but will be set
2805 later (it is never cleared). In case of a weak definition,
2806 DEF_REGULAR may be cleared later by a strong definition in
2807 a shared library. We account for that possibility below by
2808 storing information in the relocs_copied field of the hash
2809 table entry. A similar situation occurs when creating
2810 shared libraries and symbol visibility changes render the
2811 symbol local.
2813 If on the other hand, we are creating an executable, we
2814 may need to keep relocations for symbols satisfied by a
2815 dynamic library if we manage to avoid copy relocs for the
2816 symbol. */
2831 {
2835 /* We must copy these reloc types into the output file.
2836 Create a reloc section in dynobj and make room for
2837 this reloc. */
2839 {
2843 name = (bfd_elf_string_from_elf_section
2853 {
2858 }
2863 {
2864 flagword flags;
2875 }
2877 }
2879 /* If this is a global symbol, we count the number of
2880 relocations we need for this symbol. */
2882 {
2884 }
2885 else
2886 {
2887 /* Track dynamic relocs needed for local syms too.
2888 We really need local syms available to do this
2889 easily. Oh well. */
2899 }
2903 {
2914 }
2919 }
2924 }
2925 }
2928 }
2930 /* Return the section that should be marked against GC for a given
2931 relocation. */
2940 {
2944 {
2950 {
2957 {
2962 /* Function descriptor syms cause the associated
2963 function code sym section to be marked. */
2967 /* Function entry syms return NULL if they are in .opd
2968 and are not ._start (or others undefined on the ld
2969 command line). Thus we avoid marking all function
2970 sections, as all functions are referenced in .opd. */
2983 }
2984 }
2985 }
2986 else
2987 {
2996 }
2999 }
3001 /* Update the .got, .plt. and dynamic reloc reference counts for the
3002 section being removed. */
3004 static bfd_boolean
3010 {
3024 {
3032 {
3040 {
3044 }
3045 else
3046 {
3049 }
3058 {
3062 }
3070 {
3074 }
3081 {
3091 {
3097 }
3098 }
3122 {
3132 {
3137 }
3138 }
3143 }
3144 }
3146 }
3148 /* Called via elf_link_hash_traverse to transfer dynamic linking
3149 information on function code symbol entries to their corresponding
3150 function descriptor symbol entries. */
3151 static bfd_boolean
3154 PTR inf;
3155 {
3168 /* If this is a function code symbol, transfer dynamic linking
3169 information to the function descriptor symbol. */
3180 {
3182 bfd_boolean force_local;
3184 /* Find the corresponding function descriptor symbol. Create it
3185 as undefined if necessary. */
3195 {
3213 {
3215 }
3218 }
3225 {
3230 & (ELF_LINK_HASH_REF_REGULAR
3231 | ELF_LINK_HASH_REF_DYNAMIC
3232 | ELF_LINK_HASH_REF_REGULAR_NONWEAK
3235 {
3238 }
3242 }
3244 /* Now that the info is on the function descriptor, clear the
3245 function code sym info. Any function code syms for which we
3246 don't have a definition in a regular file, we force local.
3247 This prevents a shared library from exporting syms that have
3248 been imported from another library. Function code syms that
3249 are really in the library we must leave global to prevent the
3250 linker dragging in a definition from a static library. */
3260 }
3263 }
3265 #define MIN_SAVE_FPR 14
3266 #define MAX_SAVE_FPR 31
3268 /* Called near the start of bfd_elf_size_dynamic_sections. We use
3269 this hook to a) provide some gcc support functions, and b) transfer
3270 dynamic linking information gathered so far on function code symbol
3271 entries, to their corresponding function descriptor symbol entries. */
3272 static bfd_boolean
3276 {
3288 /* We don't have any relocs. */
3291 /* First provide any missing ._savef* and ._restf* functions. */
3294 {
3300 {
3309 }
3310 }
3314 {
3320 {
3330 }
3331 }
3339 {
3341 {
3344 }
3347 }
3355 {
3360 }
3362 {
3365 }
3368 {
3373 }
3376 {
3378 }
3381 }
3383 /* Adjust a symbol defined by a dynamic object and referenced by a
3384 regular object. The current definition is in some section of the
3385 dynamic object, but we're not including those sections. We have to
3386 change the definition to something the rest of the link can
3387 understand. */
3389 static bfd_boolean
3393 {
3402 /* Deal with function syms. */
3405 {
3406 /* Clear procedure linkage table information for any symbol that
3407 won't need a .plt entry. */
3414 {
3417 }
3419 }
3420 else
3423 /* If this is a weak symbol, and there is a real definition, the
3424 processor independent code will have arranged for us to see the
3425 real definition first, and we can just use the same value. */
3427 {
3433 }
3435 /* This is a reference to a symbol defined by a dynamic object which
3436 is not a function. */
3438 /* If we are creating a shared library, we must presume that the
3439 only references to the symbol are via the global offset table.
3440 For such cases we need not do anything here; the relocations will
3441 be handled correctly by relocate_section. */
3445 /* If there are no references to this symbol that do not use the
3446 GOT, we don't need to generate a copy reloc. */
3452 {
3456 }
3458 /* If we didn't find any dynamic relocs in read-only sections, then
3459 we'll be keeping the dynamic relocs and avoiding the copy reloc. */
3461 {
3464 }
3466 /* We must allocate the symbol in our .dynbss section, which will
3467 become part of the .bss section of the executable. There will be
3468 an entry for this symbol in the .dynsym section. The dynamic
3469 object will contain position independent code, so all references
3470 from the dynamic object to this symbol will go through the global
3471 offset table. The dynamic linker will use the .dynsym entry to
3472 determine the address it must put in the global offset table, so
3473 both the dynamic object and the regular object will refer to the
3474 same memory location for the variable. */
3476 /* We must generate a R_PPC64_COPY reloc to tell the dynamic linker
3477 to copy the initial value out of the dynamic object and into the
3478 runtime process image. We need to remember the offset into the
3479 .rela.bss section we are going to use. */
3481 {
3484 }
3486 /* We need to figure out the alignment required for this symbol. I
3487 have no idea how ELF linkers handle this. */
3492 /* Apply the required alignment. */
3496 {
3499 }
3501 /* Define the symbol as being at this point in the section. */
3505 /* Increment the section size to make room for the symbol. */
3509 }
3511 /* If given a function descriptor symbol, hide both the function code
3512 sym and the descriptor. */
3513 static void
3517 bfd_boolean force_local;
3518 {
3522 {
3526 {
3531 /* We aren't supposed to use alloca in BFD because on
3532 systems which do not have alloca the version in libiberty
3533 calls xmalloc, which might cause the program to crash
3534 when it runs out of memory. This function doesn't have a
3535 return status, so there's no way to gracefully return an
3536 error. So cheat. We know that string[-1] can be safely
3537 dereferenced; It's either a string in an ELF string
3538 table, or allocated in an objalloc structure. */
3547 /* Unfortunately, if it so happens that the string we were
3548 looking for was allocated immediately before this string,
3549 then we overwrote the string terminator. That's the only
3550 reason the lookup should fail. */
3552 {
3558 }
3560 {
3563 }
3564 }
3567 }
3568 }
3570 bfd_boolean
3574 {
3581 {
3587 bfd_vma offset;
3588 bfd_size_type amt;
3590 bfd_boolean need_edit;
3599 {
3600 /* Must be a ld -r link. ie. check_relocs hasn't been
3601 called. */
3604 }
3610 /* Look through the section relocs. */
3618 /* Read the relocations. */
3625 /* First run through the relocs to check they are sane, and to
3626 determine whether we need to edit this opd section. */
3631 {
3638 /* .opd contains a regular array of 24 byte entries. We're
3639 only interested in the reloc pointing to a function entry
3640 point. */
3646 {
3652 }
3661 {
3662 /* If someone messes with .opd alignment then after a
3663 "ld -r" we might have padding in the middle of .opd.
3664 Also, there's nothing to prevent someone putting
3665 something silly in .opd with the assembler. No .opd
3666 optimization for them! */
3672 }
3679 {
3687 }
3688 else
3689 {
3691 {
3699 }
3705 }
3708 {
3715 }
3717 /* opd entries are always for functions defined in the
3718 current input bfd. If the symbol isn't defined in the
3719 input bfd, then we won't be using the function in this
3720 bfd; It must be defined in a linkonce section in another
3721 bfd, or is weak. It's also possible that we are
3722 discarding the function due to a linker script /DISCARD/,
3723 which we test for via the output_section. */
3729 }
3732 {
3735 bfd_boolean skip;
3737 /* This seems a waste of time as input .opd sections are all
3738 zeros as generated by gcc, but I suppose there's no reason
3739 this will always be so. We might start putting something in
3740 the third word of .opd entries. */
3742 {
3747 {
3751 error_free_rel:
3755 }
3758 }
3768 {
3770 {
3781 {
3789 }
3790 else
3791 {
3798 }
3803 {
3805 {
3806 /* Arrange for the function descriptor sym
3807 to be dropped. */
3814 {
3827 }
3831 }
3832 }
3833 else
3834 {
3835 /* We'll be keeping this opd entry. */
3838 {
3839 /* Redefine the function descriptor symbol
3840 to this location in the opd section.
3841 We've checked above that opd relocs are
3842 ordered. */
3849 {
3862 }
3865 }
3866 else
3867 {
3868 /* Local syms are a bit tricky. We could
3869 tweak them as they can be cached, but
3870 we'd need to look through the local syms
3871 for the function descriptor sym which we
3872 don't have at the moment. So keep an
3873 array of adjustments. */
3875 }
3880 }
3883 }
3885 /* We need to adjust any reloc offsets to point to the
3886 new opd entries. While we're at it, we may as well
3887 remove redundant relocs. */
3889 {
3894 }
3895 }
3899 /* Fudge the size too, as this is used later in
3900 elf_bfd_final_link if we are emitting relocs. */
3904 }
3910 {
3913 else
3915 }
3916 }
3919 }
3921 /* This is the condition under which ppc64_elf_finish_dynamic_symbol
3922 will be called from elflink.h. If elflink.h doesn't call our
3923 finish_dynamic_symbol routine, we'll need to do something about
3924 initializing any .plt and .got entries in ppc64_elf_relocate_section. */
3925 #define WILL_CALL_FINISH_DYNAMIC_SYMBOL(DYN, INFO, H) \
3926 ((DYN) \
3927 && ((INFO)->shared \
3928 || ((H)->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0) \
3929 && ((H)->dynindx != -1 \
3930 || ((H)->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0))
3932 /* Allocate space in .plt, .got and associated reloc sections for
3933 dynamic relocs. */
3935 static bfd_boolean
3938 PTR inf;
3939 {
3958 {
3962 {
3963 /* If this is the first .plt entry, make room for the special
3964 first entry. */
3971 /* Make room for this entry. */
3974 /* Make room for the .glink code. */
3978 /* We need bigger stubs past index 32767. */
3983 /* We also need to make an entry in the .rela.plt section. */
3986 }
3987 else
3988 {
3991 }
3992 }
3993 else
3994 {
3997 }
4000 {
4001 bfd_boolean dyn;
4003 /* Make sure this symbol is output as a dynamic symbol.
4004 Undefined weak syms won't yet be marked as dynamic. */
4007 {
4010 }
4018 }
4019 else
4026 /* In the shared -Bsymbolic case, discard space allocated for
4027 dynamic pc-relative relocs against symbols which turn out to be
4028 defined in regular objects. For the normal shared case, discard
4029 space for relocs that have become local due to symbol visibility
4030 changes. */
4033 {
4037 {
4041 {
4046 else
4048 }
4049 }
4050 }
4051 else
4052 {
4053 /* For the non-shared case, discard space for relocs against
4054 symbols which turn out to need copy relocs or are not
4055 dynamic. */
4063 {
4064 /* Make sure this symbol is output as a dynamic symbol.
4065 Undefined weak syms won't yet be marked as dynamic. */
4068 {
4071 }
4073 /* If that succeeded, we know we'll be keeping all the
4074 relocs. */
4077 }
4081 keep: ;
4082 }
4084 /* Finally, allocate space. */
4086 {
4089 }
4092 }
4094 /* Find any dynamic relocs that apply to read-only sections. */
4096 static bfd_boolean
4099 PTR inf;
4100 {
4109 {
4113 {
4118 /* Not an error, just cut short the traversal. */
4120 }
4121 }
4123 }
4125 /* Set the sizes of the dynamic sections. */
4127 static bfd_boolean
4131 {
4135 bfd_boolean relocs;
4144 {
4145 /* Set the contents of the .interp section to the interpreter. */
4147 {
4153 }
4154 }
4156 /* Set up .got offsets for local syms, and space for local dynamic
4157 relocs. */
4159 {
4162 bfd_size_type locsymcount;
4170 {
4177 {
4180 {
4181 /* Input section has been discarded, either because
4182 it is a copy of a linkonce section or due to
4183 linker script /DISCARD/, so we'll be discarding
4184 the relocs too. */
4185 }
4187 {
4192 }
4193 }
4194 }
4206 {
4208 {
4213 }
4214 else
4216 }
4217 }
4219 /* Allocate global sym .plt and .got entries, and space for global
4220 sym dynamic relocs. */
4223 /* We now have determined the sizes of the various dynamic sections.
4224 Allocate memory for them. */
4227 {
4232 /* These haven't been allocated yet; don't strip. */
4237 {
4238 /* Strip this section if we don't need it; see the
4239 comment below. */
4240 }
4242 {
4244 {
4245 /* If we don't need this section, strip it from the
4246 output file. This is mostly to handle .rela.bss and
4247 .rela.plt. We must create both sections in
4248 create_dynamic_sections, because they must be created
4249 before the linker maps input sections to output
4250 sections. The linker does that before
4251 adjust_dynamic_symbol is called, and it is that
4252 function which decides whether anything needs to go
4253 into these sections. */
4254 }
4255 else
4256 {
4260 /* We use the reloc_count field as a counter if we need
4261 to copy relocs into the output file. */
4263 }
4264 }
4265 else
4266 {
4267 /* It's not one of our sections, so don't allocate space. */
4269 }
4272 {
4275 }
4277 /* .plt is in the bss section. We don't initialise it. */
4281 /* Allocate memory for the section contents. We use bfd_zalloc
4282 here in case unused entries are not reclaimed before the
4283 section's contents are written out. This should not happen,
4284 but this way if it does, we get a R_PPC64_NONE reloc instead
4285 of garbage. */
4289 }
4292 {
4293 /* Add some entries to the .dynamic section. We fill in the
4294 values later, in ppc64_elf_finish_dynamic_sections, but we
4295 must add the entries now so that we get the correct size for
4296 the .dynamic section. The DT_DEBUG entry is filled in by the
4297 dynamic linker and used by the debugger. */
4298 #define add_dynamic_entry(TAG, VAL) \
4299 bfd_elf64_add_dynamic_entry (info, (bfd_vma) (TAG), (bfd_vma) (VAL))
4302 {
4305 }
4308 {
4315 }
4318 {
4322 }
4325 {
4331 /* If any dynamic relocs apply to a read-only section,
4332 then we need a DT_TEXTREL entry. */
4338 {
4341 }
4342 }
4343 }
4344 #undef add_dynamic_entry
4347 }
4349 /* Determine the type of stub needed, if any, for a call. */
4356 bfd_vma destination;
4357 {
4359 bfd_vma location;
4360 bfd_vma branch_offset;
4361 bfd_vma max_branch_offset;
4365 {
4369 {
4372 }
4377 }
4379 /* Determine where the call point is. */
4387 /* Determine if a long branch stub is needed. */
4393 /* We need a stub. Figure out whether a long_branch or plt_branch
4394 is needed later. */
4398 }
4400 /* Build a .plt call stub. */
4408 {
4409 #define PPC_LO(v) ((v) & 0xffff)
4410 #define PPC_HI(v) (((v) >> 16) & 0xffff)
4411 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
4430 }
4432 static bfd_boolean
4435 PTR in_arg;
4436 {
4446 bfd_vma off;
4449 /* Massage our args to the form they really have. */
4456 /* Make a note of the offset within the stubs for this entry. */
4463 {
4465 /* Branches are relative. This is where we are going to. */
4470 /* And this is where we are coming from. */
4486 {
4491 }
4501 {
4502 /* Create a reloc for the branch lookup table entry. */
4503 Elf_Internal_Rela rela;
4515 }
4524 {
4531 }
4542 /* Do the best we can for shared libraries built without
4543 exporting ".foo" for each "foo". This can happen when symbol
4544 versioning scripts strip all bar a subset of symbols. */
4547 {
4548 /* Point the symbol at the stub. There may be multiple stubs,
4549 we don't really care; The main thing is to make this sym
4550 defined somewhere. */
4554 }
4556 /* Now build the stub. */
4568 {
4575 }
4584 }
4588 }
4590 /* As above, but don't actually build the stub. Just bump offset so
4591 we know stub section sizes, and select plt_branch stubs where
4592 long_branch stubs won't do. */
4594 static bfd_boolean
4597 PTR in_arg;
4598 {
4601 bfd_vma off;
4604 /* Massage our args to the form they really have. */
4609 {
4619 }
4620 else
4621 {
4622 /* ppc_stub_long_branch or ppc_stub_plt_branch. */
4634 {
4641 {
4646 }
4649 {
4653 }
4656 }
4657 }
4661 }
4663 /* Set up various things so that we can make a list of input sections
4664 for each output section included in the link. Returns -1 on error,
4665 0 when no stubs will be needed, and 1 on success. */
4667 int
4671 {
4676 bfd_size_type amt;
4683 /* Find the top input section id. */
4687 {
4691 {
4694 }
4695 }
4702 /* We can't use output_bfd->section_count here to find the top output
4703 section index as some sections may have been removed, and
4704 _bfd_strip_section_from_output doesn't renumber the indices. */
4708 {
4711 }
4720 /* For sections we aren't interested in, mark their entries with a
4721 value we can check later. */
4723 do
4730 {
4733 }
4736 }
4738 /* The linker repeatedly calls this function for each input section,
4739 in the order that input sections are linked into output sections.
4740 Build lists of input sections to determine groupings between which
4741 we may insert linker stubs. */
4743 void
4747 {
4751 {
4754 {
4755 /* Steal the link_sec pointer for our list. */
4756 #define PREV_SEC(sec) (htab->stub_group[(sec)->id].link_sec)
4757 /* This happens to make the list in reverse order,
4758 which is what we want. */
4761 }
4762 }
4763 }
4765 /* See whether we can group stub sections together. Grouping stub
4766 sections may result in fewer stubs. More importantly, we need to
4767 put all .init* and .fini* stubs at the beginning of the .init or
4768 .fini output sections respectively, because glibc splits the
4769 _init and _fini functions into multiple parts. Putting a stub in
4770 the middle of a function is not a good idea. */
4772 static void
4775 bfd_size_type stub_group_size;
4776 bfd_boolean stubs_always_before_branch;
4777 {
4779 do
4780 {
4785 {
4788 bfd_size_type total;
4793 else
4800 /* OK, the size from the start of CURR to the end is less
4801 than stub_group_size and thus can be handled by one stub
4802 section. (or the tail section is itself larger than
4803 stub_group_size, in which case we may be toast.) We
4804 should really be keeping track of the total size of stubs
4805 added here, as stubs contribute to the final output
4806 section size. That's a little tricky, and this way will
4807 only break if stubs added make the total size more than
4808 2^25, ie. for the default stub_group_size, if stubs total
4809 more than 2834432 bytes, or over 100000 plt call stubs. */
4810 do
4811 {
4813 /* Set up this stub group. */
4815 }
4818 /* But wait, there's more! Input sections up to stub_group_size
4819 bytes before the stub section can be handled by it too. */
4821 {
4826 {
4830 }
4831 }
4833 }
4834 }
4837 #undef PREV_SEC
4838 }
4840 /* Determine and set the size of the stub section for a final link.
4842 The basic idea here is to examine all the relocations looking for
4843 PC-relative calls to a target that is unreachable with a "bl"
4844 instruction. */
4846 bfd_boolean
4852 bfd_signed_vma group_size;
4855 {
4856 bfd_size_type stub_group_size;
4857 bfd_boolean stubs_always_before_branch;
4860 /* Stash our params away. */
4867 else
4870 {
4871 /* Default values. */
4875 }
4880 {
4884 bfd_boolean stub_changed;
4892 {
4897 /* We'll need the symbol table in a second. */
4902 /* Walk over each section attached to the input bfd. */
4906 {
4909 /* If there aren't any relocs, then there's nothing more
4910 to do. */
4915 /* If this section is a link-once section that will be
4916 discarded, then don't create any stubs. */
4921 /* Get the relocs. */
4922 internal_relocs
4929 /* Now examine each relocation. */
4933 {
4938 bfd_vma sym_value;
4939 bfd_vma destination;
4948 {
4951 }
4953 /* Only look for stubs on branch instructions. */
4960 /* Now determine the call target, its name, value,
4961 section. */
4967 {
4968 /* It's a local symbol. */
4973 {
4974 local_syms
4977 local_syms
4983 }
4992 }
4993 else
4994 {
4995 /* It's an external symbol. */
5009 {
5016 }
5018 ;
5020 ;
5021 else
5022 {
5025 }
5026 }
5028 /* Determine what (if any) linker stub is needed. */
5030 destination);
5034 /* Support for grouping stub sections. */
5037 /* Get the name of this stub. */
5045 {
5046 /* The proper stub has already been created. */
5049 }
5053 {
5055 error_ret_free_internal:
5058 error_ret_free_local:
5064 }
5071 }
5073 /* We're done with the internal relocs, free them. */
5076 }
5080 {
5083 else
5085 }
5086 }
5091 /* OK, we've added some stubs. Find out the new size of the
5092 stub sections. */
5096 {
5099 }
5105 /* Ask the linker to do its stuff. */
5107 }
5109 /* It would be nice to strip .branch_lt from the output if the
5110 section is empty, but it's too late. If we strip sections here,
5111 the dynamic symbol table is corrupted since the section symbol
5112 for the stripped section isn't written. */
5115 }
5117 /* Called after we have determined section placement. If sections
5118 move, we'll be called again. Provide a value for TOCstart. */
5120 bfd_vma
5123 {
5125 bfd_vma TOCstart;
5127 /* The TOC consists of sections .got, .toc, .tocbss, .plt in that
5128 order. The TOC starts where the first of these sections starts. */
5137 {
5138 /* This may happen for
5139 o references to TOC base (SYM@toc / TOC[tc0]) without a
5140 .toc directive
5141 o bad linker script
5142 o --gc-sections and empty TOC sections
5144 FIXME: Warn user? */
5146 /* Look for a likely section. We probably won't even be
5147 using TOCstart. */
5165 }
5172 }
5174 /* Build all the stubs associated with the current output file.
5175 The stubs are kept in a hash table attached to the main linker
5176 hash table. This function is called via gldelf64ppc_finish. */
5178 bfd_boolean
5181 {
5184 bfd_vma plt_r2;
5190 {
5191 bfd_size_type size;
5193 /* Allocate memory to hold the linker stubs. */
5196 {
5200 }
5202 }
5205 {
5208 /* Build the .glink plt call stub. */
5216 {
5219 }
5221 /* Build the .glink lazy link call stubs. */
5224 {
5226 {
5229 }
5230 else
5231 {
5236 }
5239 indx++;
5241 }
5243 }
5246 {
5251 }
5253 /* Build the stubs as directed by the stub hash table. */
5259 {
5262 }
5266 {
5269 }
5272 }
5274 /* The RELOCATE_SECTION function is called by the ELF backend linker
5275 to handle the relocations for a section.
5277 The relocs are always passed as Rela structures; if the section
5278 actually uses Rel structures, the r_addend field will always be
5279 zero.
5281 This function is responsible for adjust the section contents as
5282 necessary, and (if using Rela relocs and generating a
5283 relocateable output file) adjusting the reloc addend as
5284 necessary.
5286 This function does not have to worry about setting the reloc
5287 address or the reloc symbol index.
5289 LOCAL_SYMS is a pointer to the swapped in local symbols.
5291 LOCAL_SECTIONS is an array giving the section in the input file
5292 corresponding to the st_shndx field of each local symbol.
5294 The global hash table entry for the global symbols can be found
5295 via elf_sym_hashes (input_bfd).
5297 When generating relocateable output, this function must handle
5298 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
5299 going to be the section symbol corresponding to the output
5300 section, which means that the addend must be adjusted
5301 accordingly. */
5303 static bfd_boolean
5314 {
5321 bfd_vma TOCstart;
5323 bfd_boolean is_opd;
5324 /* Disabled until we sort out how ld should choose 'y' vs 'at'. */
5330 /* Initialize howto table if needed. */
5344 {
5346 bfd_vma offset;
5347 bfd_vma addend;
5348 bfd_reloc_status_type r;
5355 bfd_vma relocation;
5356 bfd_boolean unresolved_reloc;
5357 bfd_boolean warned;
5360 bfd_vma max_br_offset;
5361 bfd_vma from;
5376 {
5377 /* Relocation value is TOC base. Symbol is ignored. */
5379 }
5381 {
5382 /* It's a local symbol. */
5388 /* rel may have changed, update our copy of addend. */
5392 {
5398 }
5399 }
5400 else
5401 {
5402 /* It's a global symbol. */
5411 {
5414 /* Set a flag that will be cleared later if we find a
5415 relocation value for this symbol. output_section
5416 is typically NULL for symbols satisfied by a shared
5417 library. */
5419 else
5423 }
5425 ;
5430 ;
5431 else
5432 {
5440 }
5441 }
5443 /* First handle relocations that tweak non-addend part of insn. */
5446 {
5450 /* Branch taken prediction relocations. */
5454 /* Fall thru. */
5456 /* Branch not taken prediction relocations. */
5461 {
5462 /* Set 'a' bit. This is 0b00010 in BO field for branch
5463 on CR(BI) insns (BO == 001at or 011at), and 0b01000
5464 for branch on CTR insns (BO == 1a00t or 1a01t). */
5469 else
5471 }
5472 else
5473 {
5474 from = (offset
5478 /* Invert 'y' bit if not the default. */
5481 }
5487 /* A REL24 branching to a linkage function is followed by a
5488 nop. We replace the nop with a ld in order to restore
5489 the TOC base pointer. Only calls to shared objects need
5490 to alter the TOC base. These are recognized by their
5491 need for a PLT entry. */
5497 {
5501 {
5505 {
5509 }
5510 }
5513 {
5514 /* If this is a plain branch rather than a branch
5515 and link, don't require a nop. */
5519 }
5522 {
5528 }
5529 }
5535 {
5536 /* Tweak calls to undefined weak functions to point at a
5537 blr. We can thus call a weak function without first
5538 checking whether the function is defined. We have a
5539 blr at the end of .sfpr. */
5544 from = (offset
5548 /* But let's not be silly about it. If the blr isn't in
5549 reach, just go to the next instruction. */
5553 }
5555 }
5557 /* Set `addend'. */
5559 {
5574 /* GOT16 relocations. Like an ADDR16 using the symbol's
5575 address in the GOT as relocation value instead of the
5576 symbols value itself. Also, create a GOT entry for the
5577 symbol and put the symbol value there. */
5584 {
5585 /* Relocation is to the entry for this symbol in the global
5586 offset table. */
5587 bfd_vma off;
5593 {
5594 bfd_boolean dyn;
5606 {
5607 /* This is actually a static link, or it is a
5608 -Bsymbolic link and the symbol is defined
5609 locally, or the symbol was forced to be local
5610 because of a version file. We must initialize
5611 this entry in the global offset table. Since the
5612 offset must always be a multiple of 8, we use the
5613 least significant bit to record whether we have
5614 initialized it already.
5616 When doing a dynamic link, we create a .rel.got
5617 relocation entry to initialize the value. This
5618 is done in the finish_dynamic_symbol routine. */
5621 else
5622 {
5626 }
5627 }
5628 else
5630 }
5631 else
5632 {
5638 /* The offset must always be a multiple of 8. We use
5639 the least significant bit to record whether we have
5640 already processed this entry. */
5643 else
5644 {
5649 {
5650 Elf_Internal_Rela outrel;
5653 /* We need to generate a R_PPC64_RELATIVE reloc
5654 for the dynamic linker. */
5664 }
5667 }
5668 }
5675 /* TOC base (r2) is TOC start plus 0x8000. */
5677 }
5685 /* Relocation is to the entry for this symbol in the
5686 procedure linkage table. */
5688 /* Resolve a PLT reloc against a local symbol directly,
5689 without using the procedure linkage table. */
5695 {
5696 /* We didn't make a PLT entry for this symbol. This
5697 happens when statically linking PIC code, or when
5698 using -Bsymbolic. */
5700 }
5708 /* TOC16 relocs. We want the offset relative to the TOC base,
5709 which is the address of the start of the TOC plus 0x8000.
5710 The TOC consists of sections .got, .toc, .tocbss, and .plt,
5711 in this order. */
5721 /* Relocate against the beginning of the section. */
5738 /* Relocations that may need to be propagated if this is a
5739 dynamic object. */
5762 /* r_symndx will be zero only for relocs against symbols
5763 from removed linkonce sections, or sections discarded by
5764 a linker script. */
5767 /* Fall thru. */
5793 {
5794 Elf_Internal_Rela outrel;
5799 /* When generating a dynamic object, these relocations
5800 are copied into the output file to be resolved at run
5801 time. */
5821 && !is_opd
5828 else
5829 {
5830 /* This symbol is local, or marked to become local,
5831 or this is an opd section reloc which must point
5832 at a local function. */
5836 {
5838 {
5839 /* Lie about opd entries. This case occurs
5840 when building shared libraries and we
5841 reference a function in another shared
5842 lib. The same thing happens for a weak
5843 definition in an application that's
5844 overridden by a strong definition in a
5845 shared lib. (I believe this is a generic
5846 bug in binutils handling of weak syms.)
5847 In these cases we won't use the opd
5848 entry in this lib. */
5850 }
5852 }
5853 else
5854 {
5858 ;
5860 {
5863 }
5864 else
5865 {
5871 /* We are turning this relocation into one
5872 against a section symbol, so subtract out
5873 the output section's address but not the
5874 offset of the input section in the output
5875 section. */
5877 }
5880 }
5881 }
5891 /* If this reloc is against an external symbol, it will
5892 be computed at runtime, so there's no need to do
5893 anything now. */
5896 }
5903 /* We shouldn't ever see these dynamic relocs in relocatable
5904 files. */
5905 /* Fall thru */
5915 /* These ones haven't been implemented yet. */
5925 }
5927 /* Do any further special processing. */
5929 {
5941 /* It's just possible that this symbol is a weak symbol
5942 that's not actually defined anywhere. In that case,
5943 'sec' would be NULL, and we should leave the symbol
5944 alone (it will be set to zero elsewhere in the link). */
5946 /* Add 0x10000 if sign bit in 0:15 is set. */
5962 {
5970 }
5982 branch_check:
5983 /* If the branch is out of reach, then redirect the
5984 call to the local stub for this function. */
5985 from = (offset
5991 {
5992 /* Munge up the value and addend so that we call the stub
5993 rather than the procedure directly. */
5998 }
6000 }
6002 /* Dynamic relocs are not propagated for SEC_DEBUGGING sections
6003 because such sections are not SEC_ALLOC and thus ld.so will
6004 not process them. */
6008 {
6016 }
6019 input_bfd,
6020 input_section,
6021 contents,
6022 offset,
6023 relocation,
6024 addend);
6027 {
6031 {
6034 {
6035 /* Assume this is a call protected by other code that
6036 detects the symbol is undefined. If this is the case,
6037 we can safely ignore the overflow. If not, the
6038 program is hosed anyway, and a little warning isn't
6039 going to help. */
6042 }
6045 }
6046 else
6047 {
6055 }
6058 {
6065 }
6066 else
6067 {
6074 }
6075 }
6076 }
6079 }
6081 /* Finish up dynamic symbol handling. We set the contents of various
6082 dynamic sections here. */
6084 static bfd_boolean
6090 {
6099 {
6100 Elf_Internal_Rela rela;
6103 /* This symbol has an entry in the procedure linkage table. Set
6104 it up. */
6111 /* Create a JMP_SLOT reloc to inform the dynamic linker to
6112 fill in the PLT entry. */
6124 }
6127 {
6128 Elf_Internal_Rela rela;
6131 /* This symbol has an entry in the global offset table. Set it
6132 up. */
6141 /* If this is a static link, or it is a -Bsymbolic link and the
6142 symbol is defined locally or was forced to be local because
6143 of a version file, we just want to emit a RELATIVE reloc.
6144 The entry in the global offset table will already have been
6145 initialized in the relocate_section function. */
6151 {
6157 }
6158 else
6159 {
6165 }
6170 }
6173 {
6174 Elf_Internal_Rela rela;
6177 /* This symbol needs a copy reloc. Set it up. */
6193 }
6195 /* Mark some specially defined symbols as absolute. */
6200 }
6202 /* Used to decide how to sort relocs in an optimal manner for the
6203 dynamic linker, before writing them out. */
6205 static enum elf_reloc_type_class
6208 {
6213 {
6222 }
6223 }
6225 /* Finish up the dynamic sections. */
6227 static bfd_boolean
6231 {
6241 {
6250 {
6251 Elf_Internal_Dyn dyn;
6257 {
6295 /* Don't count procedure linkage table relocs in the
6296 overall reloc count. */
6304 /* We may not be using the standard ELF linker script.
6305 If .rela.plt is the first .rela section, we adjust
6306 DT_RELA to not include it. */
6314 }
6317 }
6318 }
6321 {
6322 /* Fill in the first entry in the global offset table.
6323 We use it to hold the link-time TOCbase. */
6328 /* Set .got entry size. */
6330 }
6333 {
6334 /* Set .plt entry size. */
6337 }
6340 }
6342 #define TARGET_LITTLE_SYM bfd_elf64_powerpcle_vec
6344 #define TARGET_BIG_SYM bfd_elf64_powerpc_vec
6346 #define ELF_ARCH bfd_arch_powerpc
6347 #define ELF_MACHINE_CODE EM_PPC64
6348 #define ELF_MAXPAGESIZE 0x10000
6349 #define elf_info_to_howto ppc64_elf_info_to_howto
6351 #ifdef EM_CYGNUS_POWERPC
6352 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
6353 #endif
6355 #ifdef EM_PPC_OLD
6356 #define ELF_MACHINE_ALT2 EM_PPC_OLD
6357 #endif
6359 #define elf_backend_want_got_sym 0
6360 #define elf_backend_want_plt_sym 0
6361 #define elf_backend_plt_alignment 3
6362 #define elf_backend_plt_not_loaded 1
6363 #define elf_backend_got_symbol_offset 0
6364 #define elf_backend_got_header_size 8
6365 #define elf_backend_plt_header_size PLT_INITIAL_ENTRY_SIZE
6366 #define elf_backend_can_gc_sections 1
6367 #define elf_backend_can_refcount 1
6368 #define elf_backend_rela_normal 1
6370 #define bfd_elf64_bfd_reloc_type_lookup ppc64_elf_reloc_type_lookup
6371 #define bfd_elf64_bfd_merge_private_bfd_data ppc64_elf_merge_private_bfd_data
6372 #define bfd_elf64_new_section_hook ppc64_elf_new_section_hook
6373 #define bfd_elf64_bfd_link_hash_table_create ppc64_elf_link_hash_table_create
6374 #define bfd_elf64_bfd_link_hash_table_free ppc64_elf_link_hash_table_free
6376 #define elf_backend_object_p ppc64_elf_object_p
6377 #define elf_backend_create_dynamic_sections ppc64_elf_create_dynamic_sections
6378 #define elf_backend_copy_indirect_symbol ppc64_elf_copy_indirect_symbol
6379 #define elf_backend_check_relocs ppc64_elf_check_relocs
6380 #define elf_backend_gc_mark_hook ppc64_elf_gc_mark_hook
6381 #define elf_backend_gc_sweep_hook ppc64_elf_gc_sweep_hook
6382 #define elf_backend_adjust_dynamic_symbol ppc64_elf_adjust_dynamic_symbol
6383 #define elf_backend_hide_symbol ppc64_elf_hide_symbol
6384 #define elf_backend_always_size_sections ppc64_elf_func_desc_adjust
6385 #define elf_backend_size_dynamic_sections ppc64_elf_size_dynamic_sections
6386 #define elf_backend_relocate_section ppc64_elf_relocate_section
6387 #define elf_backend_finish_dynamic_symbol ppc64_elf_finish_dynamic_symbol
6388 #define elf_backend_reloc_type_class ppc64_elf_reloc_type_class
6389 #define elf_backend_finish_dynamic_sections ppc64_elf_finish_dynamic_sections