| blob | 6b17b2b7c63b2d8d2fd553e5a9a22717d9d77a96 |
1 /* PowerPC64-specific support for 64-bit ELF.
2 Copyright 1999, 2000, 2001, 2002 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. */
36 static void ppc_howto_init
40 static void ppc64_elf_info_to_howto
42 static bfd_reloc_status_type ppc64_elf_ha_reloc
44 static bfd_reloc_status_type ppc64_elf_brtaken_reloc
46 static bfd_reloc_status_type ppc64_elf_sectoff_reloc
48 static bfd_reloc_status_type ppc64_elf_sectoff_ha_reloc
50 static bfd_reloc_status_type ppc64_elf_toc_reloc
52 static bfd_reloc_status_type ppc64_elf_toc_ha_reloc
54 static bfd_reloc_status_type ppc64_elf_toc64_reloc
56 static bfd_reloc_status_type ppc64_elf_unhandled_reloc
58 static void ppc64_elf_get_symbol_info
60 static boolean ppc64_elf_set_private_flags
62 static boolean ppc64_elf_merge_private_bfd_data
64 static boolean ppc64_elf_section_from_shdr
68 /* The name of the dynamic interpreter. This is put in the .interp
69 section. */
72 /* The size in bytes of an entry in the procedure linkage table. */
73 #define PLT_ENTRY_SIZE 24
75 /* The initial size of the plt reserved for the dynamic linker. */
76 #define PLT_INITIAL_ENTRY_SIZE PLT_ENTRY_SIZE
78 /* TOC base pointers offset from start of TOC. */
79 #define TOC_BASE_OFF (0x8000)
81 /* .plt call stub instructions. */
87 /* ld %r11,xxx+16@l(%r12) */
90 /* The normal stub is this size. */
91 #define PLT_CALL_STUB_SIZE (7*4)
93 /* But sometimes the .plt entry crosses a 64k boundary, and we need
94 to adjust the high word with this insn. */
97 /* The .glink fixup call stub is the same as the .plt call stub, but
98 the first instruction restores r2, and the std is omitted. */
101 /* Always allow this much space. */
102 #define GLINK_CALL_STUB_SIZE (8*4)
104 /* Pad with this. */
105 #define NOP 0x60000000
107 /* Some other nops. */
108 #define CROR_151515 0x4def7b82
109 #define CROR_313131 0x4ffffb82
111 /* .glink entries for the first 32k functions are two instructions. */
115 /* After that, we need two instructions to load the index, followed by
116 a branch. */
120 /* Instructions to save and restore floating point regs. */
125 /* Since .opd is an array of descriptors and each entry will end up
126 with identical R_PPC64_RELATIVE relocs, there is really no need to
127 propagate .opd relocs; The dynamic linker should be taught to
128 relocate .opd without reloc entries. FIXME: .opd should be trimmed
129 of unused values. */
130 #ifndef NO_OPD_RELOCS
131 #define NO_OPD_RELOCS 0
132 #endif
133 \f
134 /* Relocation HOWTO's. */
138 /* This reloc does nothing. */
153 /* A standard 32 bit relocation. */
168 /* An absolute 26 bit branch; the lower two bits must be zero.
169 FIXME: we don't check that, we just clear them. */
184 /* A standard 16 bit relocation. */
199 /* A 16 bit relocation without overflow. */
214 /* Bits 16-31 of an address. */
229 /* Bits 16-31 of an address, plus 1 if the contents of the low 16
230 bits, treated as a signed number, is negative. */
245 /* An absolute 16 bit branch; the lower two bits must be zero.
246 FIXME: we don't check that, we just clear them. */
261 /* An absolute 16 bit branch, for which bit 10 should be set to
262 indicate that the branch is expected to be taken. The lower two
263 bits must be zero. */
278 /* An absolute 16 bit branch, for which bit 10 should be set to
279 indicate that the branch is not expected to be taken. The lower
280 two bits must be zero. */
295 /* A relative 26 bit branch; the lower two bits must be zero. */
310 /* A relative 16 bit branch; the lower two bits must be zero. */
325 /* A relative 16 bit branch. Bit 10 should be set to indicate that
326 the branch is expected to be taken. The lower two bits must be
327 zero. */
342 /* A relative 16 bit branch. Bit 10 should be set to indicate that
343 the branch is not expected to be taken. The lower two bits must
344 be zero. */
359 /* Like R_PPC64_ADDR16, but referring to the GOT table entry for the
360 symbol. */
375 /* Like R_PPC64_ADDR16_LO, but referring to the GOT table entry for
376 the symbol. */
391 /* Like R_PPC64_ADDR16_HI, but referring to the GOT table entry for
392 the symbol. */
407 /* Like R_PPC64_ADDR16_HA, but referring to the GOT table entry for
408 the symbol. */
423 /* This is used only by the dynamic linker. The symbol should exist
424 both in the object being run and in some shared library. The
425 dynamic linker copies the data addressed by the symbol from the
426 shared library into the object, because the object being
427 run has to have the data at some particular address. */
442 /* Like R_PPC64_ADDR64, but used when setting global offset table
443 entries. */
458 /* Created by the link editor. Marks a procedure linkage table
459 entry for a symbol. */
474 /* Used only by the dynamic linker. When the object is run, this
475 doubleword64 is set to the load address of the object, plus the
476 addend. */
491 /* Like R_PPC64_ADDR32, but may be unaligned. */
506 /* Like R_PPC64_ADDR16, but may be unaligned. */
521 /* 32-bit PC relative. */
528 /* FIXME: Verify. Was complain_overflow_bitfield. */
537 /* 32-bit relocation to the symbol's procedure linkage table. */
552 /* 32-bit PC relative relocation to the symbol's procedure linkage table.
553 FIXME: R_PPC64_PLTREL32 not supported. */
568 /* Like R_PPC64_ADDR16_LO, but referring to the PLT table entry for
569 the symbol. */
584 /* Like R_PPC64_ADDR16_HI, but referring to the PLT table entry for
585 the symbol. */
600 /* Like R_PPC64_ADDR16_HA, but referring to the PLT table entry for
601 the symbol. */
616 /* 16-bit section relative relocation. */
631 /* Like R_PPC64_SECTOFF, but no overflow warning. */
646 /* 16-bit upper half section relative relocation. */
661 /* 16-bit upper half adjusted section relative relocation. */
676 /* Like R_PPC64_REL24 without touching the two least significant
677 bits. Should have been named R_PPC64_REL30! */
692 /* Relocs in the 64-bit PowerPC ELF ABI, not in the 32-bit ABI. */
694 /* A standard 64-bit relocation. */
709 /* The bits 32-47 of an address. */
724 /* The bits 32-47 of an address, plus 1 if the contents of the low
725 16 bits, treated as a signed number, is negative. */
740 /* The bits 48-63 of an address. */
755 /* The bits 48-63 of an address, plus 1 if the contents of the low
756 16 bits, treated as a signed number, is negative. */
771 /* Like ADDR64, but may be unaligned. */
786 /* 64-bit relative relocation. */
801 /* 64-bit relocation to the symbol's procedure linkage table. */
816 /* 64-bit PC relative relocation to the symbol's procedure linkage
817 table. */
818 /* FIXME: R_PPC64_PLTREL64 not supported. */
833 /* 16 bit TOC-relative relocation. */
835 /* R_PPC64_TOC16 47 half16* S + A - .TOC. */
850 /* 16 bit TOC-relative relocation without overflow. */
852 /* R_PPC64_TOC16_LO 48 half16 #lo (S + A - .TOC.) */
867 /* 16 bit TOC-relative relocation, high 16 bits. */
869 /* R_PPC64_TOC16_HI 49 half16 #hi (S + A - .TOC.) */
884 /* 16 bit TOC-relative relocation, high 16 bits, plus 1 if the
885 contents of the low 16 bits, treated as a signed number, is
886 negative. */
888 /* R_PPC64_TOC16_HA 50 half16 #ha (S + A - .TOC.) */
903 /* 64-bit relocation; insert value of TOC base (.TOC.). */
905 /* R_PPC64_TOC 51 doubleword64 .TOC. */
920 /* Like R_PPC64_GOT16, but also informs the link editor that the
921 value to relocate may (!) refer to a PLT entry which the link
922 editor (a) may replace with the symbol value. If the link editor
923 is unable to fully resolve the symbol, it may (b) create a PLT
924 entry and store the address to the new PLT entry in the GOT.
925 This permits lazy resolution of function symbols at run time.
926 The link editor may also skip all of this and just (c) emit a
927 R_PPC64_GLOB_DAT to tie the symbol to the GOT entry. */
928 /* FIXME: R_PPC64_PLTGOT16 not implemented. */
943 /* Like R_PPC64_PLTGOT16, but without overflow. */
944 /* FIXME: R_PPC64_PLTGOT16_LO not implemented. */
959 /* Like R_PPC64_PLT_GOT16, but using bits 16-31 of the address. */
960 /* FIXME: R_PPC64_PLTGOT16_HI not implemented. */
975 /* Like R_PPC64_PLT_GOT16, but using bits 16-31 of the address, plus
976 1 if the contents of the low 16 bits, treated as a signed number,
977 is negative. */
978 /* FIXME: R_PPC64_PLTGOT16_HA not implemented. */
993 /* Like R_PPC64_ADDR16, but for instructions with a DS field. */
1008 /* Like R_PPC64_ADDR16_LO, but for instructions with a DS field. */
1023 /* Like R_PPC64_GOT16, but for instructions with a DS field. */
1038 /* Like R_PPC64_GOT16_LO, but for instructions with a DS field. */
1053 /* Like R_PPC64_PLT16_LO, but for instructions with a DS field. */
1068 /* Like R_PPC64_SECTOFF, but for instructions with a DS field. */
1083 /* Like R_PPC64_SECTOFF_LO, but for instructions with a DS field. */
1098 /* Like R_PPC64_TOC16, but for instructions with a DS field. */
1113 /* Like R_PPC64_TOC16_LO, but for instructions with a DS field. */
1128 /* Like R_PPC64_PLTGOT16, but for instructions with a DS field. */
1129 /* FIXME: R_PPC64_PLTGOT16_DS not implemented. */
1144 /* Like R_PPC64_PLTGOT16_LO, but for instructions with a DS field. */
1145 /* FIXME: R_PPC64_PLTGOT16_LO not implemented. */
1160 /* GNU extension to record C++ vtable hierarchy. */
1175 /* GNU extension to record C++ vtable member usage. */
1189 };
1191 \f
1192 /* Initialize the ppc64_elf_howto_table, so that linear accesses can
1193 be done. */
1195 static void
1197 {
1202 i++)
1203 {
1208 }
1209 }
1214 bfd_reloc_code_real_type code;
1215 {
1219 /* Initialize howto table if needed. */
1223 {
1349 }
1352 };
1354 /* Set the howto pointer for a PowerPC ELF reloc. */
1356 static void
1361 {
1364 /* Initialize howto table if needed. */
1372 }
1374 /* Handle the R_PPC_ADDR16_HA and similar relocs. */
1376 static bfd_reloc_status_type
1382 PTR data;
1386 {
1387 /* If this is a relocatable link (output_bfd test tells us), just
1388 call the generic function. Any adjustment will be done at final
1389 link time. */
1394 /* Adjust the addend for sign extension of the low 16 bits.
1395 We won't actually be using the low 16 bits, so trashing them
1396 doesn't matter. */
1399 }
1401 static bfd_reloc_status_type
1407 PTR data;
1411 {
1414 bfd_size_type octets;
1415 /* Disabled until we sort out how ld should choose 'y' vs 'at'. */
1418 /* If this is a relocatable link (output_bfd test tells us), just
1419 call the generic function. Any adjustment will be done at final
1420 link time. */
1434 {
1435 /* Set 'a' bit. This is 0b00010 in BO field for branch
1436 on CR(BI) insns (BO == 001at or 011at), and 0b01000
1437 for branch on CTR insns (BO == 1a00t or 1a01t). */
1442 else
1444 }
1445 else
1446 {
1448 bfd_vma from;
1460 /* Invert 'y' bit if not the default. */
1463 }
1466 }
1468 static bfd_reloc_status_type
1474 PTR data;
1478 {
1479 /* If this is a relocatable link (output_bfd test tells us), just
1480 call the generic function. Any adjustment will be done at final
1481 link time. */
1486 /* Subtract the symbol section base address. */
1489 }
1491 static bfd_reloc_status_type
1497 PTR data;
1501 {
1502 /* If this is a relocatable link (output_bfd test tells us), just
1503 call the generic function. Any adjustment will be done at final
1504 link time. */
1509 /* Subtract the symbol section base address. */
1512 /* Adjust the addend for sign extension of the low 16 bits. */
1515 }
1517 static bfd_reloc_status_type
1523 PTR data;
1527 {
1528 bfd_vma TOCstart;
1530 /* If this is a relocatable link (output_bfd test tells us), just
1531 call the generic function. Any adjustment will be done at final
1532 link time. */
1541 /* Subtract the TOC base address. */
1544 }
1546 static bfd_reloc_status_type
1552 PTR data;
1556 {
1557 bfd_vma TOCstart;
1559 /* If this is a relocatable link (output_bfd test tells us), just
1560 call the generic function. Any adjustment will be done at final
1561 link time. */
1570 /* Subtract the TOC base address. */
1573 /* Adjust the addend for sign extension of the low 16 bits. */
1576 }
1578 static bfd_reloc_status_type
1584 PTR data;
1588 {
1589 bfd_vma TOCstart;
1590 bfd_size_type octets;
1592 /* If this is a relocatable link (output_bfd test tells us), just
1593 call the generic function. Any adjustment will be done at final
1594 link time. */
1606 }
1608 static bfd_reloc_status_type
1614 PTR data;
1618 {
1619 /* If this is a relocatable link (output_bfd test tells us), just
1620 call the generic function. Any adjustment will be done at final
1621 link time. */
1627 {
1632 }
1634 }
1636 /* Return symbol info as per usual for ELF targets, except that
1637 symbols in .opd are given 'd' or 'D' for type. */
1639 static void
1644 {
1650 }
1652 /* Function to set whether a module needs the -mrelocatable bit set. */
1654 static boolean
1657 flagword flags;
1658 {
1665 }
1667 /* Merge backend specific data from an object file to the output
1668 object file when linking. */
1669 static boolean
1673 {
1674 flagword old_flags;
1675 flagword new_flags;
1676 boolean error;
1678 /* Check if we have the same endianess. */
1681 {
1686 else
1693 }
1702 {
1703 /* First call, no flags set. */
1706 }
1709 /* Compatible flags are ok. */
1710 ;
1712 else
1713 {
1714 /* Incompatible flags. Warn about -mrelocatable mismatch.
1715 Allow -mrelocatable-lib to be linked with either. */
1719 {
1724 }
1727 {
1732 }
1734 /* The output is -mrelocatable-lib iff both the input files are. */
1738 /* The output is -mrelocatable iff it can't be -mrelocatable-lib,
1739 but each input file is either -mrelocatable or -mrelocatable-lib. */
1745 /* Do not warn about eabi vs. V.4 mismatch, just or in the bit
1746 if any module uses it. */
1752 /* Warn about any other mismatches. */
1754 {
1759 }
1762 {
1765 }
1766 }
1769 }
1771 /* Handle a PowerPC specific section when reading an object file. This
1772 is called when elfcode.h finds a section with an unknown type. */
1774 static boolean
1779 {
1781 flagword flags;
1796 }
1797 \f
1798 /* The following functions are specific to the ELF linker, while
1799 functions above are used generally. Those named ppc64_elf_* are
1800 called by the main ELF linker code. They appear in this file more
1801 or less in the order in which they are called. eg.
1802 ppc64_elf_check_relocs is called early in the link process,
1803 ppc64_elf_finish_dynamic_sections is one of the last functions
1804 called.
1806 PowerPC64-ELF uses a similar scheme to PowerPC64-XCOFF in that
1807 functions have both a function code symbol and a function descriptor
1808 symbol. A call to foo in a relocatable object file looks like:
1810 . .text
1811 . x:
1812 . bl .foo
1813 . nop
1815 The function definition in another object file might be:
1817 . .section .opd
1818 . foo: .quad .foo
1819 . .quad .TOC.@tocbase
1820 . .quad 0
1821 .
1822 . .text
1823 . .foo: blr
1825 When the linker resolves the call during a static link, the branch
1826 unsurprisingly just goes to .foo and the .opd information is unused.
1827 If the function definition is in a shared library, things are a little
1828 different: The call goes via a plt call stub, the opd information gets
1829 copied to the plt, and the linker patches the nop.
1831 . x:
1832 . bl .foo_stub
1833 . ld 2,40(1)
1834 .
1835 .
1836 . .foo_stub:
1837 . addis 12,2,Lfoo@toc@ha # in practice, the call stub
1838 . addi 12,12,Lfoo@toc@l # is slightly optimised, but
1839 . std 2,40(1) # this is the general idea
1840 . ld 11,0(12)
1841 . ld 2,8(12)
1842 . mtctr 11
1843 . ld 11,16(12)
1844 . bctr
1845 .
1846 . .section .plt
1847 . Lfoo: reloc (R_PPC64_JMP_SLOT, foo)
1849 The "reloc ()" notation is supposed to indicate that the linker emits
1850 an R_PPC64_JMP_SLOT reloc against foo. The dynamic linker does the opd
1851 copying.
1853 What are the difficulties here? Well, firstly, the relocations
1854 examined by the linker in check_relocs are against the function code
1855 sym .foo, while the dynamic relocation in the plt is emitted against
1856 the function descriptor symbol, foo. Somewhere along the line, we need
1857 to carefully copy dynamic link information from one symbol to the other.
1858 Secondly, the generic part of the elf linker will make .foo a dynamic
1859 symbol as is normal for most other backends. We need foo dynamic
1860 instead, at least for an application final link. However, when
1861 creating a shared library containing foo, we need to have both symbols
1862 dynamic so that references to .foo are satisfied during the early
1863 stages of linking. Otherwise the linker might decide to pull in a
1864 definition from some other object, eg. a static library. */
1866 /* The linker needs to keep track of the number of relocs that it
1867 decides to copy as dynamic relocs in check_relocs for each symbol.
1868 This is so that it can later discard them if they are found to be
1869 unnecessary. We store the information in a field extending the
1870 regular ELF linker hash table. */
1872 struct ppc_dyn_relocs
1873 {
1876 /* The input section of the reloc. */
1879 /* Total number of relocs copied for the input section. */
1880 bfd_size_type count;
1882 /* Number of pc-relative relocs copied for the input section. */
1883 bfd_size_type pc_count;
1884 };
1886 /* Of those relocs that might be copied as dynamic relocs, this macro
1887 selects between relative and absolute types. */
1889 #define IS_ABSOLUTE_RELOC(RTYPE) \
1890 ((RTYPE) != R_PPC64_REL32 \
1891 && (RTYPE) != R_PPC64_REL64 \
1892 && (RTYPE) != R_PPC64_ADDR30)
1894 /* Section name for stubs is the associated section name plus this
1895 string. */
1898 /* Linker stubs.
1899 ppc_stub_long_branch:
1900 Used when a 14 bit branch (or even a 24 bit branch) can't reach its
1901 destination, but a 24 bit branch in a stub section will reach.
1902 . b dest
1904 ppc_stub_plt_branch:
1905 Similar to the above, but a 24 bit branch in the stub section won't
1906 reach its destination.
1907 . addis %r12,%r2,xxx@ha
1908 . ld %r11,xxx@l(%r12)
1909 . mtctr %r11
1910 . bctr
1912 ppc_stub_plt_call:
1913 Used to call a function in a shared library.
1914 . addis %r12,%r2,xxx@ha
1915 . std %r2,40(%r1)
1916 . ld %r11,xxx+0@l(%r12)
1917 . ld %r2,xxx+8@l(%r12)
1918 . mtctr %r11
1919 . ld %r11,xxx+16@l(%r12)
1920 . bctr
1921 */
1924 ppc_stub_none,
1925 ppc_stub_long_branch,
1926 ppc_stub_plt_branch,
1927 ppc_stub_plt_call
1928 };
1932 /* Base hash table entry structure. */
1935 /* The stub section. */
1938 /* Offset within stub_sec of the beginning of this stub. */
1939 bfd_vma stub_offset;
1941 /* Given the symbol's value and its section we can determine its final
1942 value when building the stubs (so the stub knows where to jump. */
1943 bfd_vma target_value;
1948 /* The symbol table entry, if any, that this was derived from. */
1951 /* Where this stub is being called from, or, in the case of combined
1952 stub sections, the first input section in the group. */
1954 };
1958 /* Base hash table entry structure. */
1961 /* Offset within .branch_lt. */
1964 /* Generation marker. */
1966 };
1968 struct ppc_link_hash_entry
1969 {
1972 /* A pointer to the most recently used stub hash entry against this
1973 symbol. */
1976 /* Track dynamic relocs copied for this symbol. */
1979 /* Link between function code and descriptor symbols. */
1982 /* Flag function code and descriptor symbols. */
1985 };
1987 /* ppc64 ELF linker hash table. */
1989 struct ppc_link_hash_table
1990 {
1993 /* The stub hash table. */
1996 /* Another hash table for plt_branch stubs. */
1999 /* Linker stub bfd. */
2002 /* Linker call-backs. */
2006 /* Array to keep track of which stub sections have been created, and
2007 information on stub grouping. */
2009 /* This is the section to which stubs in the group will be attached. */
2011 /* The stub section. */
2015 /* Assorted information used by ppc64_elf_size_stubs. */
2021 /* Short-cuts to get to dynamic linker sections. */
2033 /* Set on error. */
2036 /* Flag set when small branches are detected. Used to
2037 select suitable defaults for the stub group size. */
2040 /* Set if we detect a reference undefined weak symbol. */
2043 /* Incremented every time we size stubs. */
2046 /* Small local sym to section mapping cache. */
2048 };
2058 static void ppc64_elf_link_hash_table_free
2068 static boolean create_linkage_sections
2070 static boolean create_got_section
2072 static boolean ppc64_elf_create_dynamic_sections
2074 static void ppc64_elf_copy_indirect_symbol
2076 static boolean ppc64_elf_check_relocs
2082 static boolean ppc64_elf_gc_sweep_hook
2085 static boolean func_desc_adjust
2087 static boolean ppc64_elf_func_desc_adjust
2089 static boolean ppc64_elf_adjust_dynamic_symbol
2091 static void ppc64_elf_hide_symbol
2093 static boolean allocate_dynrelocs
2095 static boolean readonly_dynrelocs
2097 static enum elf_reloc_type_class ppc64_elf_reloc_type_class
2099 static boolean ppc64_elf_size_dynamic_sections
2106 static boolean ppc_build_one_stub
2108 static boolean ppc_size_one_stub
2110 static void group_sections
2112 static boolean get_local_syms
2114 static boolean ppc64_elf_fake_sections
2116 static boolean ppc64_elf_relocate_section
2119 asection **));
2120 static boolean ppc64_elf_finish_dynamic_symbol
2122 Elf_Internal_Sym *));
2123 static boolean ppc64_elf_finish_dynamic_sections
2126 /* Get the ppc64 ELF linker hash table from a link_info structure. */
2128 #define ppc_hash_table(p) \
2129 ((struct ppc_link_hash_table *) ((p)->hash))
2131 #define ppc_stub_hash_lookup(table, string, create, copy) \
2132 ((struct ppc_stub_hash_entry *) \
2133 bfd_hash_lookup ((table), (string), (create), (copy)))
2135 #define ppc_branch_hash_lookup(table, string, create, copy) \
2136 ((struct ppc_branch_hash_entry *) \
2137 bfd_hash_lookup ((table), (string), (create), (copy)))
2139 /* Create an entry in the stub hash table. */
2146 {
2147 /* Allocate the structure if it has not already been allocated by a
2148 subclass. */
2150 {
2154 }
2156 /* Call the allocation method of the superclass. */
2159 {
2162 /* Initialize the local fields. */
2171 }
2174 }
2176 /* Create an entry in the branch hash table. */
2183 {
2184 /* Allocate the structure if it has not already been allocated by a
2185 subclass. */
2187 {
2191 }
2193 /* Call the allocation method of the superclass. */
2196 {
2199 /* Initialize the local fields. */
2203 }
2206 }
2208 /* Create an entry in a ppc64 ELF linker hash table. */
2215 {
2216 /* Allocate the structure if it has not already been allocated by a
2217 subclass. */
2219 {
2223 }
2225 /* Call the allocation method of the superclass. */
2228 {
2236 }
2239 }
2241 /* Create a ppc64 ELF linker hash table. */
2246 {
2255 {
2258 }
2260 /* Init the stub hash table too. */
2264 /* And the branch hash table. */
2289 }
2291 /* Free the derived linker hash table. */
2293 static void
2296 {
2302 }
2304 /* Build a name for an entry in the stub hash table. */
2312 {
2314 bfd_size_type len;
2316 /* rel->r_addend is actually 64 bit, but who uses more than +/- 2^31
2317 offsets from a sym as a branch target? In fact, we could
2318 probably assume the addend is always zero. */
2322 {
2326 {
2331 }
2332 }
2333 else
2334 {
2338 {
2344 }
2345 }
2347 }
2349 /* Look up an entry in the stub hash. Stub entries are cached because
2350 creating the stub name takes a bit of time. */
2359 {
2364 /* If this input section is part of a group of sections sharing one
2365 stub section, then use the id of the first section in the group.
2366 Stub names need to include a section id, as there may well be
2367 more than one stub used to reach say, printf, and we need to
2368 distinguish between them. */
2374 {
2376 }
2377 else
2378 {
2391 }
2394 }
2396 /* Add a new stub entry to the stub hash. Not all fields of the new
2397 stub entry are initialised. */
2404 {
2412 {
2415 {
2416 bfd_size_type len;
2430 }
2432 }
2434 /* Enter this entry into the linker stub hash table. */
2438 {
2441 stub_name);
2443 }
2449 }
2451 /* Create sections for linker generated code. */
2453 static boolean
2457 {
2459 flagword flags;
2463 /* Create .sfpr for code to save and restore fp regs. */
2472 /* Create .glink for lazy dynamic linking support. */
2479 /* Create .branch_lt for plt_branch stubs. */
2489 {
2497 }
2499 }
2501 /* Create .got and .rela.got sections in DYNOBJ, and set up
2502 shortcuts to them in our hash table. */
2504 static boolean
2508 {
2528 }
2530 /* Create the dynamic sections, and set up shortcuts. */
2532 static boolean
2536 {
2557 }
2559 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2561 static void
2564 {
2571 {
2573 {
2580 /* Add reloc counts against the weak sym to the strong sym
2581 list. Merge any entries against the same section. */
2583 {
2588 {
2593 }
2596 }
2598 }
2602 }
2608 }
2610 /* Look through the relocs for a section during the first phase, and
2611 calculate needed space in the global offset table, procedure
2612 linkage table, and dynamic reloc sections. */
2614 static boolean
2620 {
2627 boolean is_opd;
2636 sym_hashes_end = (sym_hashes
2652 {
2660 else
2665 {
2666 /* GOT16 relocations */
2674 /* This symbol requires a global offset table entry. */
2680 {
2682 }
2683 else
2684 {
2687 /* This is a global offset table entry for a local symbol. */
2690 {
2691 bfd_size_type size;
2700 }
2702 }
2710 /* This symbol requires a procedure linkage table entry. We
2711 actually build the entry in adjust_dynamic_symbol,
2712 because this might be a case of linking PIC code without
2713 linking in any dynamic objects, in which case we don't
2714 need to generate a procedure linkage table after all. */
2716 {
2717 /* It does not make sense to have a procedure linkage
2718 table entry for a local symbol. */
2721 }
2728 /* The following relocations don't need to propagate the
2729 relocation if linking a shared object since they are
2730 section relative. */
2745 /* This relocation describes the C++ object vtable hierarchy.
2746 Reconstruct it for later use during GC. */
2752 /* This relocation describes which C++ vtable entries are actually
2753 used. Record for later use during GC. */
2763 /* Fall through. */
2769 {
2770 /* We may need a .plt entry if the function this reloc
2771 refers to is in a shared lib. */
2775 }
2783 {
2789 {
2794 }
2795 }
2796 /* Fall through. */
2820 /* Don't propagate .opd relocs. */
2824 /* If we are creating a shared library, and this is a reloc
2825 against a global symbol, or a non PC relative reloc
2826 against a local symbol, then we need to copy the reloc
2827 into the shared library. However, if we are linking with
2828 -Bsymbolic, we do not need to copy a reloc against a
2829 global symbol which is defined in an object we are
2830 including in the link (i.e., DEF_REGULAR is set). At
2831 this point we have not seen all the input files, so it is
2832 possible that DEF_REGULAR is not set now but will be set
2833 later (it is never cleared). In case of a weak definition,
2834 DEF_REGULAR may be cleared later by a strong definition in
2835 a shared library. We account for that possibility below by
2836 storing information in the relocs_copied field of the hash
2837 table entry. A similar situation occurs when creating
2838 shared libraries and symbol visibility changes render the
2839 symbol local.
2841 If on the other hand, we are creating an executable, we
2842 may need to keep relocations for symbols satisfied by a
2843 dynamic library if we manage to avoid copy relocs for the
2844 symbol. */
2859 {
2863 /* We must copy these reloc types into the output file.
2864 Create a reloc section in dynobj and make room for
2865 this reloc. */
2867 {
2871 name = (bfd_elf_string_from_elf_section
2881 {
2886 }
2891 {
2892 flagword flags;
2903 }
2905 }
2907 /* If this is a global symbol, we count the number of
2908 relocations we need for this symbol. */
2910 {
2912 }
2913 else
2914 {
2915 /* Track dynamic relocs needed for local syms too.
2916 We really need local syms available to do this
2917 easily. Oh well. */
2927 }
2931 {
2942 }
2947 }
2952 }
2953 }
2956 }
2958 /* Return the section that should be marked against GC for a given
2959 relocation. */
2968 {
2970 {
2975 {
2982 {
2992 }
2993 }
2994 }
2995 else
2996 {
2998 }
3001 }
3003 /* Update the .got, .plt. and dynamic reloc reference counts for the
3004 section being removed. */
3006 static boolean
3012 {
3026 {
3034 {
3042 {
3046 }
3047 else
3048 {
3051 }
3060 {
3064 }
3072 {
3076 }
3082 {
3092 {
3098 }
3099 }
3124 {
3134 {
3139 }
3140 }
3145 }
3146 }
3148 }
3150 /* Called via elf_link_hash_traverse to transfer dynamic linking
3151 information on function code symbol entries to their corresponding
3152 function descriptor symbol entries. */
3153 static boolean
3156 PTR inf;
3157 {
3170 /* If this is a function code symbol, transfer dynamic linking
3171 information to the function descriptor symbol. */
3182 {
3184 boolean force_local;
3186 /* Find the corresponding function descriptor symbol. Create it
3187 as undefined if necessary. */
3197 {
3214 {
3216 }
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 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 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_PPC_COPY reloc to tell the dynamic linker to
3477 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 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 /* This is the condition under which ppc64_elf_finish_dynamic_symbol
3571 will be called from elflink.h. If elflink.h doesn't call our
3572 finish_dynamic_symbol routine, we'll need to do something about
3573 initializing any .plt and .got entries in ppc64_elf_relocate_section. */
3574 #define WILL_CALL_FINISH_DYNAMIC_SYMBOL(DYN, INFO, H) \
3575 ((DYN) \
3576 && ((INFO)->shared \
3577 || ((H)->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0) \
3578 && ((H)->dynindx != -1 \
3579 || ((H)->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0))
3581 /* Allocate space in .plt, .got and associated reloc sections for
3582 dynamic relocs. */
3584 static boolean
3587 PTR inf;
3588 {
3607 {
3611 {
3612 /* If this is the first .plt entry, make room for the special
3613 first entry. */
3620 /* Make room for this entry. */
3623 /* Make room for the .glink code. */
3627 /* We need bigger stubs past index 32767. */
3632 /* We also need to make an entry in the .rela.plt section. */
3635 }
3636 else
3637 {
3640 }
3641 }
3642 else
3643 {
3646 }
3649 {
3650 boolean dyn;
3652 /* Make sure this symbol is output as a dynamic symbol.
3653 Undefined weak syms won't yet be marked as dynamic. */
3656 {
3659 }
3667 }
3668 else
3675 /* In the shared -Bsymbolic case, discard space allocated for
3676 dynamic pc-relative relocs against symbols which turn out to be
3677 defined in regular objects. For the normal shared case, discard
3678 space for relocs that have become local due to symbol visibility
3679 changes. */
3682 {
3686 {
3690 {
3695 else
3697 }
3698 }
3699 }
3700 else
3701 {
3702 /* For the non-shared case, discard space for relocs against
3703 symbols which turn out to need copy relocs or are not
3704 dynamic. */
3712 {
3713 /* Make sure this symbol is output as a dynamic symbol.
3714 Undefined weak syms won't yet be marked as dynamic. */
3717 {
3720 }
3722 /* If that succeeded, we know we'll be keeping all the
3723 relocs. */
3726 }
3730 keep: ;
3731 }
3733 /* Finally, allocate space. */
3735 {
3738 }
3741 }
3743 /* Find any dynamic relocs that apply to read-only sections. */
3745 static boolean
3748 PTR inf;
3749 {
3758 {
3762 {
3767 /* Not an error, just cut short the traversal. */
3769 }
3770 }
3772 }
3774 /* Set the sizes of the dynamic sections. */
3776 static boolean
3780 {
3784 boolean relocs;
3793 {
3794 /* Set the contents of the .interp section to the interpreter. */
3796 {
3802 }
3803 }
3805 /* Set up .got offsets for local syms, and space for local dynamic
3806 relocs. */
3808 {
3811 bfd_size_type locsymcount;
3819 {
3826 {
3829 {
3830 /* Input section has been discarded, either because
3831 it is a copy of a linkonce section or due to
3832 linker script /DISCARD/, so we'll be discarding
3833 the relocs too. */
3834 }
3836 {
3841 }
3842 }
3843 }
3855 {
3857 {
3862 }
3863 else
3865 }
3866 }
3868 /* Allocate global sym .plt and .got entries, and space for global
3869 sym dynamic relocs. */
3872 /* We now have determined the sizes of the various dynamic sections.
3873 Allocate memory for them. */
3876 {
3881 /* These haven't been allocated yet; don't strip. */
3886 {
3887 /* Strip this section if we don't need it; see the
3888 comment below. */
3889 }
3891 {
3893 {
3894 /* If we don't need this section, strip it from the
3895 output file. This is mostly to handle .rela.bss and
3896 .rela.plt. We must create both sections in
3897 create_dynamic_sections, because they must be created
3898 before the linker maps input sections to output
3899 sections. The linker does that before
3900 adjust_dynamic_symbol is called, and it is that
3901 function which decides whether anything needs to go
3902 into these sections. */
3903 }
3904 else
3905 {
3909 /* We use the reloc_count field as a counter if we need
3910 to copy relocs into the output file. */
3912 }
3913 }
3914 else
3915 {
3916 /* It's not one of our sections, so don't allocate space. */
3918 }
3921 {
3924 }
3926 /* .plt is in the bss section. We don't initialise it. */
3930 /* Allocate memory for the section contents. We use bfd_zalloc
3931 here in case unused entries are not reclaimed before the
3932 section's contents are written out. This should not happen,
3933 but this way if it does, we get a R_PPC64_NONE reloc instead
3934 of garbage. */
3938 }
3941 {
3942 /* Add some entries to the .dynamic section. We fill in the
3943 values later, in ppc64_elf_finish_dynamic_sections, but we
3944 must add the entries now so that we get the correct size for
3945 the .dynamic section. The DT_DEBUG entry is filled in by the
3946 dynamic linker and used by the debugger. */
3947 #define add_dynamic_entry(TAG, VAL) \
3948 bfd_elf64_add_dynamic_entry (info, (bfd_vma) (TAG), (bfd_vma) (VAL))
3951 {
3954 }
3957 {
3964 }
3967 {
3971 }
3974 {
3980 /* If any dynamic relocs apply to a read-only section,
3981 then we need a DT_TEXTREL entry. */
3987 {
3990 }
3991 }
3992 }
3993 #undef add_dynamic_entry
3996 }
3998 /* Determine the type of stub needed, if any, for a call. */
4005 bfd_vma destination;
4006 {
4008 bfd_vma location;
4009 bfd_vma branch_offset;
4010 bfd_vma max_branch_offset;
4014 {
4018 {
4021 }
4026 }
4028 /* Determine where the call point is. */
4036 /* Determine if a long branch stub is needed. */
4042 /* We need a stub. Figure out whether a long_branch or plt_branch
4043 is needed later. */
4047 }
4049 /* Build a .plt call stub. */
4057 {
4058 #define PPC_LO(v) ((v) & 0xffff)
4059 #define PPC_HI(v) (((v) >> 16) & 0xffff)
4060 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
4079 }
4081 static boolean
4084 PTR in_arg;
4085 {
4095 bfd_vma off;
4098 /* Massage our args to the form they really have. */
4105 /* Make a note of the offset within the stubs for this entry. */
4112 {
4114 /* Branches are relative. This is where we are going to. */
4119 /* And this is where we are coming from. */
4135 {
4140 }
4150 {
4151 /* Create a reloc for the branch lookup table entry. */
4152 Elf_Internal_Rela rela;
4164 }
4173 {
4180 }
4191 /* Build the .glink lazy link call stub. */
4195 {
4198 }
4199 else
4200 {
4205 }
4212 /* Do the best we can for shared libraries built without
4213 exporting ".foo" for each "foo". This can happen when symbol
4214 versioning scripts strip all bar a subset of symbols. */
4217 {
4218 /* Point the symbol at the stub. There may be multiple stubs,
4219 we don't really care; The main thing is to make this sym
4220 defined somewhere. */
4224 }
4226 /* Now build the stub. */
4238 {
4245 }
4254 }
4258 }
4260 /* As above, but don't actually build the stub. Just bump offset so
4261 we know stub section sizes, and select plt_branch stubs where
4262 long_branch stubs won't do. */
4264 static boolean
4267 PTR in_arg;
4268 {
4271 bfd_vma off;
4274 /* Massage our args to the form they really have. */
4279 {
4289 }
4290 else
4291 {
4292 /* ppc_stub_long_branch or ppc_stub_plt_branch. */
4304 {
4311 {
4316 }
4319 {
4323 }
4326 }
4327 }
4331 }
4333 /* Set up various things so that we can make a list of input sections
4334 for each output section included in the link. Returns -1 on error,
4335 0 when no stubs will be needed, and 1 on success. */
4337 int
4341 {
4347 bfd_size_type amt;
4354 /* Count the number of input BFDs and find the top input section id. */
4358 {
4363 {
4366 }
4367 }
4375 /* We can't use output_bfd->section_count here to find the top output
4376 section index as some sections may have been removed, and
4377 _bfd_strip_section_from_output doesn't renumber the indices. */
4381 {
4384 }
4393 /* For sections we aren't interested in, mark their entries with a
4394 value we can check later. */
4396 do
4403 {
4406 }
4409 }
4411 /* The linker repeatedly calls this function for each input section,
4412 in the order that input sections are linked into output sections.
4413 Build lists of input sections to determine groupings between which
4414 we may insert linker stubs. */
4416 void
4420 {
4424 {
4427 {
4428 /* Steal the link_sec pointer for our list. */
4429 #define PREV_SEC(sec) (htab->stub_group[(sec)->id].link_sec)
4430 /* This happens to make the list in reverse order,
4431 which is what we want. */
4434 }
4435 }
4436 }
4438 /* See whether we can group stub sections together. Grouping stub
4439 sections may result in fewer stubs. More importantly, we need to
4440 put all .init* and .fini* stubs at the beginning of the .init or
4441 .fini output sections respectively, because glibc splits the
4442 _init and _fini functions into multiple parts. Putting a stub in
4443 the middle of a function is not a good idea. */
4445 static void
4448 bfd_size_type stub_group_size;
4449 boolean stubs_always_before_branch;
4450 {
4452 do
4453 {
4458 {
4461 bfd_size_type total;
4466 else
4473 /* OK, the size from the start of CURR to the end is less
4474 than stub_group_size and thus can be handled by one stub
4475 section. (or the tail section is itself larger than
4476 stub_group_size, in which case we may be toast.) We
4477 should really be keeping track of the total size of stubs
4478 added here, as stubs contribute to the final output
4479 section size. That's a little tricky, and this way will
4480 only break if stubs added make the total size more than
4481 2^25, ie. for the default stub_group_size, if stubs total
4482 more than 2834432 bytes, or over 100000 plt call stubs. */
4483 do
4484 {
4486 /* Set up this stub group. */
4488 }
4491 /* But wait, there's more! Input sections up to stub_group_size
4492 bytes before the stub section can be handled by it too. */
4494 {
4499 {
4503 }
4504 }
4506 }
4507 }
4510 #undef PREV_SEC
4511 }
4513 /* Read in all local syms for all input bfds. */
4515 static boolean
4519 {
4523 /* We want to read in symbol extension records only once. To do this
4524 we need to read in the local symbols in parallel and save them for
4525 later use; so hold pointers to the local symbols in an array. */
4532 /* Walk over all the input BFDs, swapping in local symbols.
4533 If we are creating a shared library, create hash entries for the
4534 export stubs. */
4538 {
4544 bfd_size_type sec_size;
4546 /* We'll need the symbol table in a second. */
4551 /* We need an array of the local symbols attached to the input bfd.
4552 Unfortunately, we're going to have to read & swap them in. */
4568 {
4569 error_ret_free_ext_syms:
4572 }
4577 {
4586 {
4589 }
4590 }
4592 /* Swap the local symbols in. */
4599 /* Now we can free the external symbols. */
4602 }
4605 }
4607 /* Determine and set the size of the stub section for a final link.
4609 The basic idea here is to examine all the relocations looking for
4610 PC-relative calls to a target that is unreachable with a "bl"
4611 instruction. */
4613 boolean
4619 bfd_signed_vma group_size;
4622 {
4623 bfd_size_type stub_group_size;
4624 boolean stubs_always_before_branch;
4628 /* Stash our params away. */
4635 else
4638 {
4639 /* Default values. */
4643 }
4648 {
4652 }
4655 {
4659 boolean stub_changed;
4667 {
4672 /* We'll need the symbol table in a second. */
4679 /* Walk over each section attached to the input bfd. */
4683 {
4687 bfd_size_type amt;
4689 /* If there aren't any relocs, then there's nothing more
4690 to do. */
4695 /* If this section is a link-once section that will be
4696 discarded, then don't create any stubs. */
4701 /* Allocate space for the external relocations. */
4706 {
4708 }
4710 /* Likewise for the internal relocations. */
4715 {
4718 }
4720 /* Read in the external relocs. */
4726 {
4728 error_ret_free_internal:
4731 }
4733 /* Swap in the relocs. */
4740 /* We're done with the external relocs, free them. */
4743 /* Now examine each relocation. */
4747 {
4752 bfd_vma sym_value;
4753 bfd_vma destination;
4762 {
4765 }
4767 /* Only look for stubs on branch instructions. */
4774 /* Now determine the call target, its name, value,
4775 section. */
4781 {
4782 /* It's a local symbol. */
4794 }
4795 else
4796 {
4797 /* It's an external symbol. */
4811 {
4818 }
4820 ;
4822 ;
4823 else
4824 {
4827 }
4828 }
4830 /* Determine what (if any) linker stub is needed. */
4832 destination);
4836 /* Support for grouping stub sections. */
4839 /* Get the name of this stub. */
4847 {
4848 /* The proper stub has already been created. */
4851 }
4855 {
4858 }
4865 }
4867 /* We're done with the internal relocs, free them. */
4869 }
4870 }
4875 /* OK, we've added some stubs. Find out the new size of the
4876 stub sections. */
4880 {
4883 }
4889 /* Ask the linker to do its stuff. */
4891 }
4893 /* It would be nice to strip .branch_lt from the output if the
4894 section is empty, but it's too late. If we strip sections here,
4895 the dynamic symbol table is corrupted since the section symbol
4896 for the stripped section isn't written. */
4900 error_ret_free_local:
4907 }
4909 /* Called after we have determined section placement. If sections
4910 move, we'll be called again. Provide a value for TOCstart. */
4912 bfd_vma
4915 {
4917 bfd_vma TOCstart;
4919 /* The TOC consists of sections .got, .toc, .tocbss, .plt in that
4920 order. The TOC starts where the first of these sections starts. */
4929 {
4930 /* This may happen for
4931 o references to TOC base (SYM@toc / TOC[tc0]) without a
4932 .toc directive
4933 o bad linker script
4934 o --gc-sections and empty TOC sections
4936 FIXME: Warn user? */
4938 /* Look for a likely section. We probably won't even be
4939 using TOCstart. */
4957 }
4964 }
4966 /* Build all the stubs associated with the current output file.
4967 The stubs are kept in a hash table attached to the main linker
4968 hash table. This function is called via gldelf64ppc_finish. */
4970 boolean
4973 {
4976 bfd_vma plt_r2;
4982 {
4983 bfd_size_type size;
4985 /* Allocate memory to hold the linker stubs. */
4988 {
4992 }
4994 }
4997 {
4998 /* Build the .glink plt call stub. */
5006 {
5009 }
5012 /* Use reloc_count to count entries. */
5014 }
5017 {
5022 }
5024 /* Build the stubs as directed by the stub hash table. */
5031 {
5034 }
5038 {
5041 }
5044 }
5046 /* Set up any other section flags and such that may be necessary. */
5048 static boolean
5053 {
5061 }
5063 /* The RELOCATE_SECTION function is called by the ELF backend linker
5064 to handle the relocations for a section.
5066 The relocs are always passed as Rela structures; if the section
5067 actually uses Rel structures, the r_addend field will always be
5068 zero.
5070 This function is responsible for adjust the section contents as
5071 necessary, and (if using Rela relocs and generating a
5072 relocateable output file) adjusting the reloc addend as
5073 necessary.
5075 This function does not have to worry about setting the reloc
5076 address or the reloc symbol index.
5078 LOCAL_SYMS is a pointer to the swapped in local symbols.
5080 LOCAL_SECTIONS is an array giving the section in the input file
5081 corresponding to the st_shndx field of each local symbol.
5083 The global hash table entry for the global symbols can be found
5084 via elf_sym_hashes (input_bfd).
5086 When generating relocateable output, this function must handle
5087 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
5088 going to be the section symbol corresponding to the output
5089 section, which means that the addend must be adjusted
5090 accordingly. */
5092 static boolean
5103 {
5110 bfd_vma TOCstart;
5112 boolean is_opd;
5113 /* Disabled until we sort out how ld should choose 'y' vs 'at'. */
5119 /* Initialize howto table if needed. */
5133 {
5135 bfd_vma offset;
5136 bfd_vma addend;
5137 bfd_reloc_status_type r;
5144 bfd_vma relocation;
5145 boolean unresolved_reloc;
5146 boolean warned;
5149 bfd_vma max_br_offset;
5150 bfd_vma from;
5165 {
5166 /* Relocation value is TOC base. Symbol is ignored. */
5168 }
5170 {
5171 /* It's a local symbol. */
5177 /* rel may have changed, update our copy of addend. */
5179 }
5180 else
5181 {
5182 /* It's a global symbol. */
5191 {
5194 /* Set a flag that will be cleared later if we find a
5195 relocation value for this symbol. output_section
5196 is typically NULL for symbols satisfied by a shared
5197 library. */
5199 else
5203 }
5205 ;
5210 ;
5211 else
5212 {
5220 }
5221 }
5223 /* First handle relocations that tweak non-addend part of insn. */
5226 {
5230 /* Branch taken prediction relocations. */
5234 /* Fall thru. */
5236 /* Branch not taken prediction relocations. */
5241 {
5242 /* Set 'a' bit. This is 0b00010 in BO field for branch
5243 on CR(BI) insns (BO == 001at or 011at), and 0b01000
5244 for branch on CTR insns (BO == 1a00t or 1a01t). */
5249 else
5251 }
5252 else
5253 {
5254 from = (offset
5258 /* Invert 'y' bit if not the default. */
5261 }
5267 /* A REL24 branching to a linkage function is followed by a
5268 nop. We replace the nop with a ld in order to restore
5269 the TOC base pointer. Only calls to shared objects need
5270 to alter the TOC base. These are recognized by their
5271 need for a PLT entry. */
5277 {
5281 {
5285 {
5289 }
5290 }
5293 {
5294 /* If this is a plain branch rather than a branch
5295 and link, don't require a nop. */
5299 }
5302 {
5308 }
5309 }
5315 {
5316 /* Tweak calls to undefined weak functions to point at a
5317 blr. We can thus call a weak function without first
5318 checking whether the function is defined. We have a
5319 blr at the end of .sfpr. */
5324 from = (offset
5328 /* But let's not be silly about it. If the blr isn't in
5329 reach, just go to the next instruction. */
5333 }
5335 }
5337 /* Set `addend'. */
5339 {
5354 /* GOT16 relocations. Like an ADDR16 using the symbol's
5355 address in the GOT as relocation value instead of the
5356 symbols value itself. Also, create a GOT entry for the
5357 symbol and put the symbol value there. */
5364 {
5365 /* Relocation is to the entry for this symbol in the global
5366 offset table. */
5367 bfd_vma off;
5373 {
5374 boolean dyn;
5386 {
5387 /* This is actually a static link, or it is a
5388 -Bsymbolic link and the symbol is defined
5389 locally, or the symbol was forced to be local
5390 because of a version file. We must initialize
5391 this entry in the global offset table. Since the
5392 offset must always be a multiple of 8, we use the
5393 least significant bit to record whether we have
5394 initialized it already.
5396 When doing a dynamic link, we create a .rel.got
5397 relocation entry to initialize the value. This
5398 is done in the finish_dynamic_symbol routine. */
5401 else
5402 {
5406 }
5407 }
5408 else
5410 }
5411 else
5412 {
5418 /* The offset must always be a multiple of 8. We use
5419 the least significant bit to record whether we have
5420 already processed this entry. */
5423 else
5424 {
5429 {
5430 Elf_Internal_Rela outrel;
5433 /* We need to generate a R_PPC64_RELATIVE reloc
5434 for the dynamic linker. */
5443 }
5446 }
5447 }
5454 /* TOC base (r2) is TOC start plus 0x8000. */
5456 }
5464 /* Relocation is to the entry for this symbol in the
5465 procedure linkage table. */
5467 /* Resolve a PLT reloc against a local symbol directly,
5468 without using the procedure linkage table. */
5474 {
5475 /* We didn't make a PLT entry for this symbol. This
5476 happens when statically linking PIC code, or when
5477 using -Bsymbolic. */
5479 }
5487 /* TOC16 relocs. We want the offset relative to the TOC base,
5488 which is the address of the start of the TOC plus 0x8000.
5489 The TOC consists of sections .got, .toc, .tocbss, and .plt,
5490 in this order. */
5500 /* Relocate against the beginning of the section. */
5517 /* Relocations that may need to be propagated if this is a
5518 dynamic object. */
5541 /* r_symndx will be zero only for relocs against symbols
5542 from removed linkonce sections, or sections discarded by
5543 a linker script. */
5546 /* Fall thru. */
5572 {
5573 Elf_Internal_Rela outrel;
5578 /* When generating a dynamic object, these relocations
5579 are copied into the output file to be resolved at run
5580 time. */
5600 && !is_opd
5607 else
5608 {
5609 /* This symbol is local, or marked to become local,
5610 or this is an opd section reloc which must point
5611 at a local function. */
5615 {
5617 {
5618 /* Lie about opd entries. This case occurs
5619 when building shared libraries and we
5620 reference a function in another shared
5621 lib. In that case we won't use the opd
5622 entry in this lib; We ought to edit the
5623 opd section to remove unused entries. */
5625 }
5627 }
5628 else
5629 {
5633 ;
5635 {
5638 }
5639 else
5640 {
5646 /* We are turning this relocation into one
5647 against a section symbol, so subtract out
5648 the output section's address but not the
5649 offset of the input section in the output
5650 section. */
5652 }
5655 }
5656 }
5666 /* If this reloc is against an external symbol, it will
5667 be computed at runtime, so there's no need to do
5668 anything now. */
5671 }
5678 /* We shouldn't ever see these dynamic relocs in relocatable
5679 files. */
5680 /* Fall thru */
5690 /* These ones haven't been implemented yet. */
5700 }
5702 /* Do any further special processing. */
5704 {
5714 /* It's just possible that this symbol is a weak symbol
5715 that's not actually defined anywhere. In that case,
5716 'sec' would be NULL, and we should leave the symbol
5717 alone (it will be set to zero elsewhere in the link). */
5719 /* Add 0x10000 if sign bit in 0:15 is set. */
5735 {
5743 }
5755 branch_check:
5756 /* If the branch is out of reach, then redirect the
5757 call to the local stub for this function. */
5758 from = (offset
5764 {
5765 /* Munge up the value and addend so that we call the stub
5766 rather than the procedure directly. */
5771 }
5773 }
5775 /* FIXME: Why do we allow debugging sections to escape this error?
5776 More importantly, why do we not emit dynamic relocs above in
5777 debugging sections (which are ! SEC_ALLOC)? If we had
5778 emitted the dynamic reloc, we could remove the fudge here. */
5783 {
5791 }
5794 input_bfd,
5795 input_section,
5796 contents,
5797 offset,
5798 relocation,
5799 addend);
5802 {
5806 {
5809 {
5810 /* Assume this is a call protected by other code that
5811 detects the symbol is undefined. If this is the case,
5812 we can safely ignore the overflow. If not, the
5813 program is hosed anyway, and a little warning isn't
5814 going to help. */
5817 }
5820 }
5821 else
5822 {
5830 }
5833 {
5840 }
5841 else
5842 {
5849 }
5850 }
5851 }
5854 }
5856 /* Finish up dynamic symbol handling. We set the contents of various
5857 dynamic sections here. */
5859 static boolean
5865 {
5874 {
5875 Elf_Internal_Rela rela;
5878 /* This symbol has an entry in the procedure linkage table. Set
5879 it up. */
5886 /* Create a JMP_SLOT reloc to inform the dynamic linker to
5887 fill in the PLT entry. */
5898 }
5901 {
5902 Elf_Internal_Rela rela;
5905 /* This symbol has an entry in the global offset table. Set it
5906 up. */
5915 /* If this is a static link, or it is a -Bsymbolic link and the
5916 symbol is defined locally or was forced to be local because
5917 of a version file, we just want to emit a RELATIVE reloc.
5918 The entry in the global offset table will already have been
5919 initialized in the relocate_section function. */
5925 {
5931 }
5932 else
5933 {
5939 }
5944 }
5947 {
5948 Elf_Internal_Rela rela;
5951 /* This symbol needs a copy reloc. Set it up. */
5967 }
5969 /* Mark some specially defined symbols as absolute. */
5974 }
5976 /* Used to decide how to sort relocs in an optimal manner for the
5977 dynamic linker, before writing them out. */
5979 static enum elf_reloc_type_class
5982 {
5987 {
5996 }
5997 }
5999 /* Finish up the dynamic sections. */
6001 static boolean
6005 {
6015 {
6024 {
6025 Elf_Internal_Dyn dyn;
6031 {
6067 /* Don't count procedure linkage table relocs in the
6068 overall reloc count. */
6072 }
6075 }
6076 }
6079 {
6080 /* Fill in the first entry in the global offset table.
6081 We use it to hold the link-time TOCbase. */
6086 /* Set .got entry size. */
6088 }
6091 {
6092 /* Set .plt entry size. */
6095 }
6098 }
6100 #define TARGET_LITTLE_SYM bfd_elf64_powerpcle_vec
6102 #define TARGET_BIG_SYM bfd_elf64_powerpc_vec
6104 #define ELF_ARCH bfd_arch_powerpc
6105 #define ELF_MACHINE_CODE EM_PPC64
6106 #define ELF_MAXPAGESIZE 0x10000
6107 #define elf_info_to_howto ppc64_elf_info_to_howto
6109 #ifdef EM_CYGNUS_POWERPC
6110 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
6111 #endif
6113 #ifdef EM_PPC_OLD
6114 #define ELF_MACHINE_ALT2 EM_PPC_OLD
6115 #endif
6117 #define elf_backend_want_got_sym 0
6118 #define elf_backend_want_plt_sym 0
6119 #define elf_backend_plt_alignment 3
6120 #define elf_backend_plt_not_loaded 1
6121 #define elf_backend_got_symbol_offset 0
6122 #define elf_backend_got_header_size 8
6123 #define elf_backend_plt_header_size PLT_INITIAL_ENTRY_SIZE
6124 #define elf_backend_can_gc_sections 1
6125 #define elf_backend_can_refcount 1
6126 #define elf_backend_rela_normal 1
6128 #define bfd_elf64_bfd_reloc_type_lookup ppc64_elf_reloc_type_lookup
6129 #define bfd_elf64_bfd_set_private_flags ppc64_elf_set_private_flags
6130 #define bfd_elf64_bfd_merge_private_bfd_data ppc64_elf_merge_private_bfd_data
6131 #define bfd_elf64_bfd_link_hash_table_create ppc64_elf_link_hash_table_create
6132 #define bfd_elf64_bfd_link_hash_table_free ppc64_elf_link_hash_table_free
6133 #define bfd_elf64_get_symbol_info ppc64_elf_get_symbol_info
6135 #define elf_backend_section_from_shdr ppc64_elf_section_from_shdr
6136 #define elf_backend_create_dynamic_sections ppc64_elf_create_dynamic_sections
6137 #define elf_backend_copy_indirect_symbol ppc64_elf_copy_indirect_symbol
6138 #define elf_backend_check_relocs ppc64_elf_check_relocs
6139 #define elf_backend_gc_mark_hook ppc64_elf_gc_mark_hook
6140 #define elf_backend_gc_sweep_hook ppc64_elf_gc_sweep_hook
6141 #define elf_backend_adjust_dynamic_symbol ppc64_elf_adjust_dynamic_symbol
6142 #define elf_backend_hide_symbol ppc64_elf_hide_symbol
6143 #define elf_backend_always_size_sections ppc64_elf_func_desc_adjust
6144 #define elf_backend_size_dynamic_sections ppc64_elf_size_dynamic_sections
6145 #define elf_backend_fake_sections ppc64_elf_fake_sections
6146 #define elf_backend_relocate_section ppc64_elf_relocate_section
6147 #define elf_backend_finish_dynamic_symbol ppc64_elf_finish_dynamic_symbol
6148 #define elf_backend_reloc_type_class ppc64_elf_reloc_type_class
6149 #define elf_backend_finish_dynamic_sections ppc64_elf_finish_dynamic_sections