| blob | f05ddb26674fa6ed53b5575f03f32e602aa6f585 |
1 /* PowerPC-specific support for 32-bit ELF
2 Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
3 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Written by Ian Lance Taylor, Cygnus Support.
7 This file is part of BFD, the Binary File Descriptor library.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the
21 Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
22 Boston, MA 02110-1301, USA. */
25 /* This file is based on a preliminary PowerPC ELF ABI. The
26 information may not match the final PowerPC ELF ABI. It includes
27 suggestions from the in-progress Embedded PowerPC ABI, and that
28 information may also not match. */
31 #include <stdarg.h>
40 /* RELA relocations are used here. */
42 static bfd_reloc_status_type ppc_elf_addr16_ha_reloc
44 static bfd_reloc_status_type ppc_elf_unhandled_reloc
47 /* Branch prediction bit for branch taken relocs. */
48 #define BRANCH_PREDICT_BIT 0x200000
49 /* Mask to set RA in memory instructions. */
50 #define RA_REGISTER_MASK 0x001f0000
51 /* Value to shift register by to insert RA. */
52 #define RA_REGISTER_SHIFT 16
54 /* The name of the dynamic interpreter. This is put in the .interp
55 section. */
58 /* For old-style PLT. */
59 /* The number of single-slot PLT entries (the rest use two slots). */
60 #define PLT_NUM_SINGLE_ENTRIES 8192
62 /* For new-style .glink and .plt. */
63 #define GLINK_PLTRESOLVE 16*4
64 #define GLINK_ENTRY_SIZE 4*4
65 #define TLS_GET_ADDR_GLINK_SIZE 12*4
67 /* VxWorks uses its own plt layout, filled in by the static linker. */
69 /* The standard VxWorks PLT entry. */
70 #define VXWORKS_PLT_ENTRY_SIZE 32
71 static const bfd_vma ppc_elf_vxworks_plt_entry
73 {
82 };
83 static const bfd_vma ppc_elf_vxworks_pic_plt_entry
85 {
94 };
96 /* The initial VxWorks PLT entry. */
97 #define VXWORKS_PLT_INITIAL_ENTRY_SIZE 32
98 static const bfd_vma ppc_elf_vxworks_plt0_entry
100 {
109 };
110 static const bfd_vma ppc_elf_vxworks_pic_plt0_entry
112 {
121 };
123 /* For executables, we have some additional relocations in
124 .rela.plt.unloaded, for the kernel loader. */
126 /* The number of non-JMP_SLOT relocations per PLT0 slot. */
127 #define VXWORKS_PLT_NON_JMP_SLOT_RELOCS 3
128 /* The number of relocations in the PLTResolve slot. */
129 #define VXWORKS_PLTRESOLVE_RELOCS 2
130 /* The number of relocations in the PLTResolve slot when when creating
131 a shared library. */
132 #define VXWORKS_PLTRESOLVE_RELOCS_SHLIB 0
134 /* Some instructions. */
135 #define ADDIS_11_11 0x3d6b0000
136 #define ADDIS_11_30 0x3d7e0000
137 #define ADDIS_12_12 0x3d8c0000
138 #define ADDI_11_11 0x396b0000
139 #define ADD_0_11_11 0x7c0b5a14
140 #define ADD_3_12_2 0x7c6c1214
141 #define ADD_11_0_11 0x7d605a14
142 #define B 0x48000000
143 #define BCL_20_31 0x429f0005
144 #define BCTR 0x4e800420
145 #define BEQLR 0x4d820020
146 #define CMPWI_11_0 0x2c0b0000
147 #define LIS_11 0x3d600000
148 #define LIS_12 0x3d800000
149 #define LWZU_0_12 0x840c0000
150 #define LWZ_0_12 0x800c0000
151 #define LWZ_11_3 0x81630000
152 #define LWZ_11_11 0x816b0000
153 #define LWZ_11_30 0x817e0000
154 #define LWZ_12_3 0x81830000
155 #define LWZ_12_12 0x818c0000
156 #define MR_0_3 0x7c601b78
157 #define MR_3_0 0x7c030378
158 #define MFLR_0 0x7c0802a6
159 #define MFLR_12 0x7d8802a6
160 #define MTCTR_0 0x7c0903a6
161 #define MTCTR_11 0x7d6903a6
162 #define MTLR_0 0x7c0803a6
163 #define NOP 0x60000000
164 #define SUB_11_11_12 0x7d6c5850
166 /* Offset of tp and dtp pointers from start of TLS block. */
167 #define TP_OFFSET 0x7000
168 #define DTP_OFFSET 0x8000
170 /* The value of a defined global symbol. */
171 #define SYM_VAL(SYM) \
172 ((SYM)->root.u.def.section->output_section->vma \
173 + (SYM)->root.u.def.section->output_offset \
174 + (SYM)->root.u.def.value)
175 \f
179 /* This reloc does nothing. */
194 /* A standard 32 bit relocation. */
209 /* An absolute 26 bit branch; the lower two bits must be zero.
210 FIXME: we don't check that, we just clear them. */
225 /* A standard 16 bit relocation. */
240 /* A 16 bit relocation without overflow. */
255 /* The high order 16 bits of an address. */
270 /* The high order 16 bits of an address, plus 1 if the contents of
271 the low 16 bits, treated as a signed number, is negative. */
286 /* An absolute 16 bit branch; the lower two bits must be zero.
287 FIXME: we don't check that, we just clear them. */
302 /* An absolute 16 bit branch, for which bit 10 should be set to
303 indicate that the branch is expected to be taken. The lower two
304 bits must be zero. */
319 /* An absolute 16 bit branch, for which bit 10 should be set to
320 indicate that the branch is not expected to be taken. The lower
321 two bits must be zero. */
336 /* A relative 26 bit branch; the lower two bits must be zero. */
351 /* A relative 16 bit branch; the lower two bits must be zero. */
366 /* A relative 16 bit branch. Bit 10 should be set to indicate that
367 the branch is expected to be taken. The lower two bits must be
368 zero. */
383 /* A relative 16 bit branch. Bit 10 should be set to indicate that
384 the branch is not expected to be taken. The lower two bits must
385 be zero. */
400 /* Like R_PPC_ADDR16, but referring to the GOT table entry for the
401 symbol. */
416 /* Like R_PPC_ADDR16_LO, but referring to the GOT table entry for
417 the symbol. */
432 /* Like R_PPC_ADDR16_HI, but referring to the GOT table entry for
433 the symbol. */
448 /* Like R_PPC_ADDR16_HA, but referring to the GOT table entry for
449 the symbol. */
464 /* Like R_PPC_REL24, but referring to the procedure linkage table
465 entry for the symbol. */
480 /* This is used only by the dynamic linker. The symbol should exist
481 both in the object being run and in some shared library. The
482 dynamic linker copies the data addressed by the symbol from the
483 shared library into the object, because the object being
484 run has to have the data at some particular address. */
499 /* Like R_PPC_ADDR32, but used when setting global offset table
500 entries. */
515 /* Marks a procedure linkage table entry for a symbol. */
530 /* Used only by the dynamic linker. When the object is run, this
531 longword is set to the load address of the object, plus the
532 addend. */
547 /* Like R_PPC_REL24, but uses the value of the symbol within the
548 object rather than the final value. Normally used for
549 _GLOBAL_OFFSET_TABLE_. */
564 /* Like R_PPC_ADDR32, but may be unaligned. */
579 /* Like R_PPC_ADDR16, but may be unaligned. */
594 /* 32-bit PC relative */
609 /* 32-bit relocation to the symbol's procedure linkage table.
610 FIXME: not supported. */
625 /* 32-bit PC relative relocation to the symbol's procedure linkage table.
626 FIXME: not supported. */
641 /* Like R_PPC_ADDR16_LO, but referring to the PLT table entry for
642 the symbol. */
657 /* Like R_PPC_ADDR16_HI, but referring to the PLT table entry for
658 the symbol. */
673 /* Like R_PPC_ADDR16_HA, but referring to the PLT table entry for
674 the symbol. */
689 /* A sign-extended 16 bit value relative to _SDA_BASE_, for use with
690 small data items. */
705 /* 16-bit section relative relocation. */
720 /* 16-bit lower half section relative relocation. */
735 /* 16-bit upper half section relative relocation. */
750 /* 16-bit upper half adjusted section relative relocation. */
765 /* Marker relocs for TLS. */
808 /* Computes the load module index of the load module that contains the
809 definition of its TLS sym. */
824 /* Computes a dtv-relative displacement, the difference between the value
825 of sym+add and the base address of the thread-local storage block that
826 contains the definition of sym, minus 0x8000. */
841 /* A 16 bit dtprel reloc. */
856 /* Like DTPREL16, but no overflow. */
871 /* Like DTPREL16_LO, but next higher group of 16 bits. */
886 /* Like DTPREL16_HI, but adjust for low 16 bits. */
901 /* Computes a tp-relative displacement, the difference between the value of
902 sym+add and the value of the thread pointer (r13). */
917 /* A 16 bit tprel reloc. */
932 /* Like TPREL16, but no overflow. */
947 /* Like TPREL16_LO, but next higher group of 16 bits. */
962 /* Like TPREL16_HI, but adjust for low 16 bits. */
977 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
978 with values (sym+add)@dtpmod and (sym+add)@dtprel, and computes the offset
979 to the first entry. */
994 /* Like GOT_TLSGD16, but no overflow. */
1009 /* Like GOT_TLSGD16_LO, but next higher group of 16 bits. */
1024 /* Like GOT_TLSGD16_HI, but adjust for low 16 bits. */
1039 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
1040 with values (sym+add)@dtpmod and zero, and computes the offset to the
1041 first entry. */
1056 /* Like GOT_TLSLD16, but no overflow. */
1071 /* Like GOT_TLSLD16_LO, but next higher group of 16 bits. */
1086 /* Like GOT_TLSLD16_HI, but adjust for low 16 bits. */
1101 /* Allocates an entry in the GOT with value (sym+add)@dtprel, and computes
1102 the offset to the entry. */
1117 /* Like GOT_DTPREL16, but no overflow. */
1132 /* Like GOT_DTPREL16_LO, but next higher group of 16 bits. */
1147 /* Like GOT_DTPREL16_HI, but adjust for low 16 bits. */
1162 /* Allocates an entry in the GOT with value (sym+add)@tprel, and computes the
1163 offset to the entry. */
1178 /* Like GOT_TPREL16, but no overflow. */
1193 /* Like GOT_TPREL16_LO, but next higher group of 16 bits. */
1208 /* Like GOT_TPREL16_HI, but adjust for low 16 bits. */
1223 /* The remaining relocs are from the Embedded ELF ABI, and are not
1224 in the SVR4 ELF ABI. */
1226 /* 32 bit value resulting from the addend minus the symbol. */
1241 /* 16 bit value resulting from the addend minus the symbol. */
1256 /* 16 bit value resulting from the addend minus the symbol. */
1271 /* The high order 16 bits of the addend minus the symbol. */
1286 /* The high order 16 bits of the result of the addend minus the address,
1287 plus 1 if the contents of the low 16 bits, treated as a signed number,
1288 is negative. */
1303 /* 16 bit value resulting from allocating a 4 byte word to hold an
1304 address in the .sdata section, and returning the offset from
1305 _SDA_BASE_ for that relocation. */
1320 /* 16 bit value resulting from allocating a 4 byte word to hold an
1321 address in the .sdata2 section, and returning the offset from
1322 _SDA2_BASE_ for that relocation. */
1337 /* A sign-extended 16 bit value relative to _SDA2_BASE_, for use with
1338 small data items. */
1353 /* Relocate against either _SDA_BASE_ or _SDA2_BASE_, filling in the 16 bit
1354 signed offset from the appropriate base, and filling in the register
1355 field with the appropriate register (0, 2, or 13). */
1370 /* Relocation not handled: R_PPC_EMB_MRKREF */
1371 /* Relocation not handled: R_PPC_EMB_RELSEC16 */
1372 /* Relocation not handled: R_PPC_EMB_RELST_LO */
1373 /* Relocation not handled: R_PPC_EMB_RELST_HI */
1374 /* Relocation not handled: R_PPC_EMB_RELST_HA */
1375 /* Relocation not handled: R_PPC_EMB_BIT_FLD */
1377 /* PC relative relocation against either _SDA_BASE_ or _SDA2_BASE_, filling
1378 in the 16 bit signed offset from the appropriate base, and filling in the
1379 register field with the appropriate register (0, 2, or 13). */
1408 /* A 16 bit relative relocation. */
1423 /* A 16 bit relative relocation without overflow. */
1438 /* The high order 16 bits of a relative address. */
1453 /* The high order 16 bits of a relative address, plus 1 if the contents of
1454 the low 16 bits, treated as a signed number, is negative. */
1469 /* GNU extension to record C++ vtable hierarchy. */
1484 /* GNU extension to record C++ vtable member usage. */
1499 /* Phony reloc to handle AIX style TOC entries. */
1513 };
1514 \f
1515 /* Initialize the ppc_elf_howto_table, so that linear accesses can be done. */
1517 static void
1519 {
1524 i++)
1525 {
1531 }
1532 }
1536 bfd_reloc_code_real_type code)
1537 {
1540 /* Initialize howto table if not already done. */
1545 {
1636 }
1639 };
1644 {
1649 i++)
1655 }
1657 /* Set the howto pointer for a PowerPC ELF reloc. */
1659 static void
1663 {
1664 /* Initialize howto table if not already done. */
1671 /* Just because the above assert didn't trigger doesn't mean that
1672 ELF32_R_TYPE (dst->r_info) is necessarily a valid relocation. */
1674 {
1680 }
1681 }
1683 /* Handle the R_PPC_ADDR16_HA and R_PPC_REL16_HA relocs. */
1685 static bfd_reloc_status_type
1693 {
1694 bfd_vma relocation;
1697 {
1700 }
1707 else
1719 }
1721 static bfd_reloc_status_type
1729 {
1730 /* If this is a relocatable link (output_bfd test tells us), just
1731 call the generic function. Any adjustment will be done at final
1732 link time. */
1738 {
1743 }
1745 }
1746 \f
1747 /* Sections created by the linker. */
1750 {
1751 /* Pointer to the bfd section. */
1753 /* Section name. */
1755 /* Associated bss section name. */
1757 /* Associated symbol name. */
1759 /* Associated symbol. */
1763 /* Linked list of allocated pointer entries. This hangs off of the
1764 symbol lists, and provides allows us to return different pointers,
1765 based on different addend's. */
1768 {
1769 /* next allocated pointer for this symbol */
1771 /* offset of pointer from beginning of section */
1772 bfd_vma offset;
1773 /* addend used */
1774 bfd_vma addend;
1775 /* which linker section this is */
1779 struct ppc_elf_obj_tdata
1780 {
1783 /* A mapping from local symbols to offsets into the various linker
1784 sections added. This is index by the symbol index. */
1787 /* Flags used to auto-detect plt type. */
1790 };
1792 #define ppc_elf_tdata(bfd) \
1793 ((struct ppc_elf_obj_tdata *) (bfd)->tdata.any)
1795 #define elf_local_ptr_offsets(bfd) \
1796 (ppc_elf_tdata (bfd)->linker_section_pointers)
1798 #define is_ppc_elf(bfd) \
1799 (bfd_get_flavour (bfd) == bfd_target_elf_flavour \
1800 && elf_object_id (bfd) == PPC32_ELF_DATA)
1802 /* Override the generic function because we store some extras. */
1804 static bfd_boolean
1806 {
1808 PPC32_ELF_DATA);
1809 }
1811 /* Fix bad default arch selected for a 32 bit input bfd when the
1812 default is 64 bit. */
1814 static bfd_boolean
1816 {
1818 {
1822 {
1823 /* Relies on arch after 64 bit default being 32 bit default. */
1826 }
1827 }
1829 }
1831 /* Function to set whether a module needs the -mrelocatable bit set. */
1833 static bfd_boolean
1835 {
1842 }
1844 /* Support for core dump NOTE sections. */
1846 static bfd_boolean
1848 {
1853 {
1858 /* pr_cursig */
1861 /* pr_pid */
1864 /* pr_reg */
1869 }
1871 /* Make a ".reg/999" section. */
1874 }
1876 static bfd_boolean
1878 {
1880 {
1891 }
1893 /* Note that for some reason, a spurious space is tacked
1894 onto the end of the args in some (at least one anyway)
1895 implementations, so strip it off if it exists. */
1897 {
1903 }
1906 }
1910 {
1912 {
1917 {
1928 }
1931 {
1950 }
1951 }
1952 }
1954 /* Return address for Ith PLT stub in section PLT, for relocation REL
1955 or (bfd_vma) -1 if it should not be included. */
1957 static bfd_vma
1961 {
1963 }
1965 /* Handle a PowerPC specific section when reading an object file. This
1966 is called when bfd_section_from_shdr finds a section with an unknown
1967 type. */
1969 static bfd_boolean
1974 {
1976 flagword flags;
1991 }
1993 /* Set up any other section flags and such that may be necessary. */
1995 static bfd_boolean
1999 {
2004 }
2006 /* If we have .sbss2 or .PPC.EMB.sbss0 output sections, we
2007 need to bump up the number of section headers. */
2009 static int
2012 {
2025 }
2027 /* Add extra PPC sections -- Note, for now, make .sbss2 and
2028 .PPC.EMB.sbss0 a normal section, and not a bss section so
2029 that the linker doesn't crater when trying to make more than
2030 2 sections. */
2033 {
2044 };
2046 /* This is what we want for new plt/got. */
2052 {
2055 /* See if this is one of the special sections. */
2062 {
2066 }
2069 }
2070 \f
2071 /* Very simple linked list structure for recording apuinfo values. */
2073 {
2076 }
2077 apuinfo_list;
2082 static void
2084 {
2087 }
2089 static void
2091 {
2095 {
2099 }
2108 }
2110 static unsigned
2112 {
2117 entry;
2122 }
2126 {
2132 ;
2135 }
2137 static void
2139 {
2143 {
2147 }
2150 }
2155 /* Scan the input BFDs and create a linked list of
2156 the APUinfo values that will need to be emitted. */
2158 static void
2160 {
2174 /* Read in the input sections contents. */
2176 {
2190 {
2197 }
2201 {
2204 }
2206 /* Verify the contents of the header. Note - we have to
2207 extract the values this way in order to allow for a
2208 host whose endian-ness is different from the target. */
2220 /* Get the number of bytes used for apuinfo entries. */
2225 /* Scan the apuinfo section, building a list of apuinfo numbers. */
2228 }
2233 {
2234 /* Compute the size of the output section. */
2237 /* Set the output section size, if it exists. */
2241 {
2244 }
2245 }
2247 fail:
2253 }
2255 /* Prevent the output section from accumulating the input sections'
2256 contents. We have already stored this in our linked list structure. */
2258 static bfd_boolean
2263 {
2265 }
2267 /* Finally we can generate the output section. */
2269 static void
2271 {
2276 bfd_size_type length;
2291 {
2295 }
2297 /* Create the apuinfo header. */
2306 {
2309 }
2320 }
2321 \f
2322 static bfd_boolean
2324 {
2334 }
2336 static bfd_boolean
2338 {
2343 }
2345 static long
2349 {
2354 bfd_vma stub_vma;
2378 /* Call common code to handle old-style executable PLTs. */
2383 /* If this object was prelinked, the prelinker stored the address
2384 of .glink at got[1]. If it wasn't prelinked, got[1] will be zero. */
2387 {
2401 {
2402 Elf_Internal_Dyn dyn;
2409 {
2417 }
2418 }
2420 }
2422 /* Otherwise we read the first plt entry. */
2424 {
2427 }
2432 /* The .glink section usually does not survive the final
2433 link; search for the section (usually .text) where the
2434 glink stubs now reside. */
2439 /* Determine glink PLT resolver by reading the relative branch
2440 from the first glink stub. */
2443 {
2446 /* The first glink stub may either branch to the resolver ... */
2451 /* ... or fall through a bunch of NOPs. */
2458 {
2461 }
2462 }
2466 /* If the stubs are those for -shared/-pie then we might have
2467 multiple stubs for each plt entry. If that is the case then
2468 there is no way to associate stubs with their plt entries short
2469 of figuring out the GOT pointer value used in the stub. */
2481 {
2485 }
2499 {
2503 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL set. Since
2504 we are defining a symbol, ensure one of them is set. */
2516 {
2521 }
2526 }
2528 /* Add a symbol at the start of the glink branch table. */
2537 s++;
2538 count++;
2541 {
2542 /* Add a symbol for the glink PLT resolver. */
2551 s++;
2552 count++;
2553 }
2556 }
2557 \f
2558 /* The following functions are specific to the ELF linker, while
2559 functions above are used generally. They appear in this file more
2560 or less in the order in which they are called. eg.
2561 ppc_elf_check_relocs is called early in the link process,
2562 ppc_elf_finish_dynamic_sections is one of the last functions
2563 called. */
2565 /* Track PLT entries needed for a given symbol. We might need more
2566 than one glink entry per symbol when generating a pic binary. */
2567 struct plt_entry
2568 {
2571 /* -fPIC uses multiple GOT sections, one per file, called ".got2".
2572 This field stores the offset into .got2 used to initialise the
2573 GOT pointer reg. It will always be at least 32768. (Current
2574 gcc always uses an offset of 32768, but ld -r will pack .got2
2575 sections together resulting in larger offsets). */
2576 bfd_vma addend;
2578 /* The .got2 section. */
2581 /* PLT refcount or offset. */
2582 union
2583 {
2584 bfd_signed_vma refcount;
2585 bfd_vma offset;
2588 /* .glink stub offset. */
2589 bfd_vma glink_offset;
2590 };
2592 /* Of those relocs that might be copied as dynamic relocs, this function
2593 selects those that must be copied when linking a shared library,
2594 even when the symbol is local. */
2596 static int
2599 {
2601 {
2618 }
2619 }
2621 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
2622 copying dynamic variables from a shared lib into an app's dynbss
2623 section, and instead use a dynamic relocation to point into the
2624 shared lib. */
2625 #define ELIMINATE_COPY_RELOCS 1
2627 /* PPC ELF linker hash entry. */
2629 struct ppc_elf_link_hash_entry
2630 {
2633 /* If this symbol is used in the linker created sections, the processor
2634 specific backend uses this field to map the field into the offset
2635 from the beginning of the section. */
2638 /* Track dynamic relocs copied for this symbol. */
2641 /* Contexts in which symbol is used in the GOT (or TOC).
2642 TLS_GD .. TLS_TLS bits are or'd into the mask as the
2643 corresponding relocs are encountered during check_relocs.
2644 tls_optimize clears TLS_GD .. TLS_TPREL when optimizing to
2645 indicate the corresponding GOT entry type is not needed. */
2655 /* Nonzero if we have seen a small data relocation referring to this
2656 symbol. */
2658 };
2660 #define ppc_elf_hash_entry(ent) ((struct ppc_elf_link_hash_entry *) (ent))
2662 /* PPC ELF linker hash table. */
2664 struct ppc_elf_link_hash_table
2665 {
2668 /* Short-cuts to get to dynamic linker sections. */
2683 /* The (unloaded but important) .rela.plt.unloaded on VxWorks. */
2686 /* The .got.plt section (VxWorks only)*/
2689 /* Shortcut to __tls_get_addr. */
2692 /* The bfd that forced an old-style PLT. */
2695 /* TLS local dynamic got entry handling. */
2697 bfd_signed_vma refcount;
2698 bfd_vma offset;
2701 /* Offset of branch table to PltResolve function in glink. */
2702 bfd_vma glink_pltresolve;
2704 /* Size of reserved GOT entries. */
2706 /* Non-zero if allocating the header left a gap. */
2709 /* The type of PLT we have chosen to use. */
2712 /* Set if we should emit symbols for stubs. */
2715 /* Set if __tls_get_addr optimization should not be done. */
2718 /* True if the target system is VxWorks. */
2721 /* The size of PLT entries. */
2723 /* The distance between adjacent PLT slots. */
2725 /* The size of the first PLT entry. */
2728 /* Small local sym cache. */
2730 };
2732 /* Rename some of the generic section flags to better document how they
2733 are used here. */
2735 /* Nonzero if this section has TLS related relocations. */
2736 #define has_tls_reloc sec_flg0
2738 /* Nonzero if this section has a call to __tls_get_addr. */
2739 #define has_tls_get_addr_call sec_flg1
2741 /* Get the PPC ELF linker hash table from a link_info structure. */
2743 #define ppc_elf_hash_table(p) \
2744 (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \
2745 == PPC32_ELF_DATA ? ((struct ppc_elf_link_hash_table *) ((p)->hash)) : NULL)
2747 /* Create an entry in a PPC ELF linker hash table. */
2753 {
2754 /* Allocate the structure if it has not already been allocated by a
2755 subclass. */
2757 {
2762 }
2764 /* Call the allocation method of the superclass. */
2767 {
2772 }
2775 }
2777 /* Create a PPC ELF linker hash table. */
2781 {
2789 ppc_elf_link_hash_newfunc,
2791 PPC32_ELF_DATA))
2792 {
2795 }
2815 }
2817 /* Create .got and the related sections. */
2819 static bfd_boolean
2821 {
2824 flagword flags;
2835 {
2839 }
2840 else
2841 {
2842 /* The powerpc .got has a blrl instruction in it. Mark it
2843 executable. */
2848 }
2855 }
2857 static bfd_boolean
2859 {
2862 flagword flags;
2887 }
2889 /* We have to create .dynsbss and .rela.sbss here so that they get mapped
2890 to output sections (just like _bfd_elf_create_dynamic_sections has
2891 to create .dynbss and .rela.bss). */
2893 static bfd_boolean
2895 {
2898 flagword flags;
2921 {
2930 }
2943 /* The VxWorks PLT is a loaded section with contents. */
2946 }
2948 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2950 static void
2954 {
2961 {
2963 {
2967 /* Add reloc counts against the indirect sym to the direct sym
2968 list. Merge any entries against the same section. */
2970 {
2975 {
2980 }
2983 }
2985 }
2989 }
2994 /* If called to transfer flags for a weakdef during processing
2995 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
2996 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
3008 /* If we were called to copy over info for a weak sym, that's all. */
3012 /* Copy over the GOT refcount entries that we may have already seen to
3013 the symbol which just became indirect. */
3017 /* And plt entries. */
3019 {
3021 {
3026 {
3031 {
3035 }
3038 }
3040 }
3044 }
3047 {
3055 }
3056 }
3058 /* Hook called by the linker routine which adds symbols from an object
3059 file. We use it to put .comm items in .sbss, and not .bss. */
3061 static bfd_boolean
3069 {
3074 {
3075 /* Common symbols less than or equal to -G nn bytes are automatically
3076 put into .sbss. */
3081 {
3089 flags);
3092 }
3096 }
3104 }
3105 \f
3106 static bfd_boolean
3108 {
3120 }
3122 /* Create a special linker section. */
3124 static bfd_boolean
3127 flagword flags,
3129 {
3136 /* Record the first bfd that needs the special sections. */
3142 flags);
3149 }
3151 /* Find a linker generated pointer with a given addend and type. */
3154 elf_find_pointer_linker_section
3156 bfd_vma addend,
3158 {
3164 }
3166 /* Allocate a pointer to live in a linker created section. */
3168 static bfd_boolean
3173 {
3177 bfd_size_type amt;
3181 /* Is this a global symbol? */
3183 {
3186 /* Has this symbol already been allocated? If so, our work is done. */
3190 lsect))
3194 }
3195 else
3196 {
3199 /* Allocation of a pointer to a local symbol. */
3202 /* Allocate a table to hold the local symbols if first time. */
3204 {
3215 }
3217 /* Has this symbol already been allocated? If so, our work is done. */
3220 lsect))
3224 }
3226 /* Allocate space for a pointer in the linker section, and allocate
3227 a new pointer record from internal memory. */
3243 #ifdef DEBUG
3248 #endif
3251 }
3258 {
3264 {
3274 }
3282 }
3284 static bfd_boolean
3287 {
3296 {
3306 }
3309 }
3313 {
3322 }
3324 static bfd_boolean
3326 {
3337 }
3339 static void
3341 {
3344 abfd,
3347 }
3349 /* Look through the relocs for a section during the first phase, and
3350 allocate space in the global offset table or procedure linkage
3351 table. */
3353 static bfd_boolean
3358 {
3370 /* Don't do anything special with non-loaded, non-alloced sections.
3371 In particular, any relocs in such sections should not affect GOT
3372 and PLT reference counting (ie. we don't allow them to create GOT
3373 or PLT entries), there's no possibility or desire to optimize TLS
3374 relocs, and there's not much point in propagating relocs to shared
3375 libs that the dynamic linker won't relocate. */
3379 #ifdef DEBUG
3382 #endif
3386 /* Initialize howto table if not already done. */
3392 {
3397 }
3407 {
3416 else
3417 {
3422 }
3424 /* If a relocation refers to _GLOBAL_OFFSET_TABLE_, create the .got.
3425 This shows up in particular in an R_PPC_ADDR32 in the eabi
3426 startup code. */
3430 {
3436 }
3441 {
3450 {
3452 bfd_vma addend;
3455 PLT_IFUNC);
3459 /* STT_GNU_IFUNC symbols must have a PLT entry;
3460 In a non-pie executable even when there are
3461 no plt calls. */
3464 {
3468 }
3471 }
3472 }
3478 {
3482 /* We have a new-style __tls_get_addr call with a marker
3483 reloc. */
3484 ;
3485 else
3486 /* Mark this section as having an old-style call. */
3488 }
3491 {
3494 /* These special tls relocs tie a call to __tls_get_addr with
3495 its parameter symbol. */
3526 dogottls:
3528 /* Fall thru */
3530 /* GOT16 relocations */
3535 /* This symbol requires a global offset table entry. */
3537 {
3542 }
3544 {
3547 }
3548 else
3549 /* This is a global offset table entry for a local symbol. */
3553 /* We may also need a plt entry if the symbol turns out to be
3554 an ifunc. */
3556 {
3559 }
3562 /* Indirect .sdata relocation. */
3565 {
3568 }
3577 {
3580 }
3583 /* Indirect .sdata2 relocation. */
3586 {
3589 }
3598 {
3601 }
3609 {
3612 }
3617 {
3620 }
3625 {
3628 }
3634 {
3637 }
3645 {
3648 }
3657 {
3660 }
3668 /* Fall through */
3674 #ifdef DEBUG
3676 #endif
3677 /* This symbol requires a procedure linkage table entry. We
3678 actually build the entry in finish_dynamic_symbol,
3679 because this might be a case of linking PIC code without
3680 linking in any dynamic objects, in which case we don't
3681 need to generate a procedure linkage table after all. */
3684 {
3685 /* It does not make sense to have a procedure linkage
3686 table entry for a local symbol. */
3692 }
3693 else
3694 {
3698 {
3702 }
3706 }
3709 /* The following relocations don't need to propagate the
3710 relocation if linking a shared object since they are
3711 section relative. */
3730 /* These are just markers. */
3740 /* These should only appear in dynamic objects. */
3748 /* These aren't handled yet. We'll report an error later. */
3757 /* This refers only to functions defined in the shared library. */
3760 {
3763 }
3766 /* This relocation describes the C++ object vtable hierarchy.
3767 Reconstruct it for later use during GC. */
3773 /* This relocation describes which C++ vtable entries are actually
3774 used. Record for later use during GC. */
3782 /* We shouldn't really be seeing these. */
3792 /* Nor these. */
3803 {
3804 /* Old -fPIC gcc code has .long LCTOC1-LCFx just before
3805 the start of a function, which assembles to a REL32
3806 reference to .got2. If we detect one of these, then
3807 force the old PLT layout because the linker cannot
3808 reliably deduce the GOT pointer value needed for
3809 PLT call stubs. */
3820 {
3823 }
3824 }
3827 /* fall through */
3837 {
3838 /* We may need a plt entry if the symbol turns out to be
3839 a function defined in a dynamic object. */
3843 /* We may need a copy reloc too. */
3846 }
3856 {
3858 {
3861 }
3863 }
3864 /* fall through */
3871 {
3872 /* We may need a plt entry if the symbol turns out to be
3873 a function defined in a dynamic object. */
3878 }
3880 dodyn:
3881 /* If we are creating a shared library, and this is a reloc
3882 against a global symbol, or a non PC relative reloc
3883 against a local symbol, then we need to copy the reloc
3884 into the shared library. However, if we are linking with
3885 -Bsymbolic, we do not need to copy a reloc against a
3886 global symbol which is defined in an object we are
3887 including in the link (i.e., DEF_REGULAR is set). At
3888 this point we have not seen all the input files, so it is
3889 possible that DEF_REGULAR is not set now but will be set
3890 later (it is never cleared). In case of a weak definition,
3891 DEF_REGULAR may be cleared later by a strong definition in
3892 a shared library. We account for that possibility below by
3893 storing information in the dyn_relocs field of the hash
3894 table entry. A similar situation occurs when creating
3895 shared libraries and symbol visibility changes render the
3896 symbol local.
3898 If on the other hand, we are creating an executable, we
3899 may need to keep relocations for symbols satisfied by a
3900 dynamic library if we manage to avoid copy relocs for the
3901 symbol. */
3908 || (ELIMINATE_COPY_RELOCS
3913 {
3917 #ifdef DEBUG
3919 "ppc_elf_check_relocs needs to "
3923 #endif
3925 {
3929 sreloc = _bfd_elf_make_dynamic_reloc_section
3934 }
3936 /* If this is a global symbol, we count the number of
3937 relocations we need for this symbol. */
3939 {
3941 }
3942 else
3943 {
3944 /* Track dynamic relocs needed for local syms too.
3945 We really need local syms available to do this
3946 easily. Oh well. */
3962 }
3966 {
3975 }
3980 }
3983 }
3984 }
3987 }
3988 \f
3990 /* Merge object attributes from IBFD into OBFD. Raise an error if
3991 there are conflicting attributes. */
3992 static bfd_boolean
3994 {
3999 {
4000 /* This is the first object. Copy the attributes. */
4003 /* Use the Tag_null value to indicate the attributes have been
4004 initialized. */
4008 }
4013 /* Check for conflicting Tag_GNU_Power_ABI_FP attributes and merge
4014 non-conflicting ones. */
4018 {
4023 ;
4025 _bfd_error_handler
4028 _bfd_error_handler
4032 _bfd_error_handler
4036 _bfd_error_handler
4040 _bfd_error_handler
4043 _bfd_error_handler
4046 else
4047 _bfd_error_handler
4050 }
4052 /* Check for conflicting Tag_GNU_Power_ABI_Vector attributes and
4053 merge non-conflicting ones. */
4057 {
4061 {
4065 }
4068 {
4072 }
4078 ;
4079 /* For now, allow generic to transition to AltiVec or SPE
4080 without a warning. If GCC marked files with their stack
4081 alignment and used don't-care markings for files which are
4082 not affected by the vector ABI, we could warn about this
4083 case too. */
4087 ;
4089 _bfd_error_handler
4093 _bfd_error_handler
4096 else
4097 _bfd_error_handler
4100 }
4102 /* Check for conflicting Tag_GNU_Power_ABI_Struct_Return attributes
4103 and merge non-conflicting ones. */
4107 {
4112 ;
4114 _bfd_error_handler
4117 _bfd_error_handler
4120 _bfd_error_handler
4123 else
4124 _bfd_error_handler
4127 }
4129 /* Merge Tag_compatibility attributes and any common GNU ones. */
4133 }
4135 /* Merge backend specific data from an object file to the output
4136 object file when linking. */
4138 static bfd_boolean
4140 {
4141 flagword old_flags;
4142 flagword new_flags;
4143 bfd_boolean error;
4148 /* Check if we have the same endianness. */
4158 {
4159 /* First call, no flags set. */
4162 }
4164 /* Compatible flags are ok. */
4166 ;
4168 /* Incompatible flags. */
4169 else
4170 {
4171 /* Warn about -mrelocatable mismatch. Allow -mrelocatable-lib
4172 to be linked with either. */
4176 {
4181 }
4184 {
4189 }
4191 /* The output is -mrelocatable-lib iff both the input files are. */
4195 /* The output is -mrelocatable iff it can't be -mrelocatable-lib,
4196 but each input file is either -mrelocatable or -mrelocatable-lib. */
4202 /* Do not warn about eabi vs. V.4 mismatch, just or in the bit if
4203 any module uses it. */
4209 /* Warn about any other mismatches. */
4211 {
4217 }
4220 {
4223 }
4224 }
4227 }
4228 \f
4229 /* Choose which PLT scheme to use, and set .plt flags appropriately.
4230 Returns -1 on error, 0 for old PLT, 1 for new PLT. */
4231 int
4236 {
4238 flagword flags;
4245 {
4248 else
4249 {
4253 /* Look through the reloc flags left by ppc_elf_check_relocs.
4254 Use the old style bss plt if a file makes plt calls
4255 without using the new relocs, and if ld isn't given
4256 --secure-plt and we never see REL16 relocs. */
4261 {
4265 {
4269 }
4270 }
4272 }
4273 }
4280 {
4284 /* The new PLT is a loaded section. */
4289 /* The new GOT is not executable. */
4293 }
4294 else
4295 {
4296 /* Stop an unused .glink section from affecting .text alignment. */
4300 }
4302 }
4303 \f
4304 /* Return the section that should be marked against GC for a given
4305 relocation. */
4313 {
4316 {
4320 }
4323 }
4325 /* Update the got, plt and dynamic reloc reference counts for the
4326 section being removed. */
4328 static bfd_boolean
4333 {
4357 {
4364 {
4376 {
4377 /* Everything must go for SEC. */
4380 }
4381 }
4389 {
4395 {
4406 }
4407 }
4410 {
4432 {
4436 {
4442 }
4443 }
4445 {
4448 }
4458 /* Fall thru */
4481 {
4490 }
4495 }
4496 }
4498 }
4499 \f
4500 /* Set plt output section type, htab->tls_get_addr, and call the
4501 generic ELF tls_setup function. */
4503 asection *
4507 {
4514 {
4521 {
4522 /* If glibc supports an optimized __tls_get_addr call stub,
4523 signalled by the presence of __tls_get_addr_opt, and we'll
4524 be calling __tls_get_addr via a plt call stub, then
4525 make __tls_get_addr point to __tls_get_addr_opt. */
4534 {
4540 {
4545 {
4546 /* Use __tls_get_addr_opt in dynamic relocations. */
4552 }
4554 }
4555 }
4556 }
4557 else
4559 }
4564 {
4567 }
4570 }
4572 /* Return TRUE iff REL is a branch reloc with a global symbol matching
4573 HASH. */
4575 static bfd_boolean
4579 {
4585 {
4595 }
4597 }
4599 /* Run through all the TLS relocs looking for optimization
4600 opportunities. */
4602 bfd_boolean
4605 {
4618 /* Make two passes through the relocs. First time check that tls
4619 relocs involved in setting up a tls_get_addr call are indeed
4620 followed by such a call. If they are not, don't do any tls
4621 optimization. On the second pass twiddle tls_mask flags to
4622 notify relocate_section that optimization can be done, and
4623 adjust got and plt refcounts. */
4626 {
4633 {
4637 /* Read the relocations. */
4645 {
4651 bfd_boolean is_local;
4656 {
4664 }
4672 /* If this section has old-style __tls_get_addr calls
4673 without marker relocs, then check that each
4674 __tls_get_addr call reloc is preceded by a reloc
4675 that conceivably belongs to the __tls_get_addr arg
4676 setup insn. If we don't find matching arg setup
4677 relocs, don't do any tls optimization. */
4682 && !expecting_tls_get_addr
4684 {
4691 }
4695 {
4699 /* Fall thru */
4703 /* These relocs should never be against a symbol
4704 defined in a shared lib. Leave them alone if
4705 that turns out to be the case. */
4709 /* LD -> LE */
4717 /* Fall thru */
4722 /* GD -> LE */
4724 else
4725 /* GD -> IE */
4735 {
4736 /* IE -> LE */
4740 }
4741 else
4753 }
4756 {
4767 /* Uh oh, we didn't find the expected call. We
4768 could just mark this symbol to exclude it
4769 from tls optimization but it's safer to skip
4770 the entire optimization. */
4777 }
4780 {
4794 }
4797 {
4800 }
4801 else
4802 {
4808 {
4815 {
4819 }
4820 }
4829 }
4832 {
4833 /* We managed to get rid of a got entry. */
4836 }
4840 }
4844 }
4848 {
4851 else
4853 }
4854 }
4856 }
4857 \f
4858 /* Return true if we have dynamic relocs that apply to read-only sections. */
4860 static bfd_boolean
4862 {
4866 {
4873 }
4875 }
4877 /* Adjust a symbol defined by a dynamic object and referenced by a
4878 regular object. The current definition is in some section of the
4879 dynamic object, but we're not including those sections. We have to
4880 change the definition to something the rest of the link can
4881 understand. */
4883 static bfd_boolean
4886 {
4890 #ifdef DEBUG
4893 #endif
4895 /* Make sure we know what is going on here. */
4905 /* Deal with function syms. */
4909 {
4910 /* Clear procedure linkage table information for any symbol that
4911 won't need a .plt entry. */
4921 {
4922 /* A PLT entry is not required/allowed when:
4924 1. We are not using ld.so; because then the PLT entry
4925 can't be set up, so we can't use one. In this case,
4926 ppc_elf_adjust_dynamic_symbol won't even be called.
4928 2. GC has rendered the entry unused.
4930 3. We know for certain that a call to this symbol
4931 will go to this object, or will remain undefined. */
4934 }
4935 else
4936 {
4937 /* After adjust_dynamic_symbol, non_got_ref set in the
4938 non-shared case means that we have allocated space in
4939 .dynbss for the symbol and thus dyn_relocs for this
4940 symbol should be discarded.
4941 If we get here we know we are making a PLT entry for this
4942 symbol, and in an executable we'd normally resolve
4943 relocations against this symbol to the PLT entry. Allow
4944 dynamic relocs if the reference is weak, and the dynamic
4945 relocs will not cause text relocation. */
4953 }
4955 }
4956 else
4959 /* If this is a weak symbol, and there is a real definition, the
4960 processor independent code will have arranged for us to see the
4961 real definition first, and we can just use the same value. */
4963 {
4971 }
4973 /* This is a reference to a symbol defined by a dynamic object which
4974 is not a function. */
4976 /* If we are creating a shared library, we must presume that the
4977 only references to the symbol are via the global offset table.
4978 For such cases we need not do anything here; the relocations will
4979 be handled correctly by relocate_section. */
4983 /* If there are no references to this symbol that do not use the
4984 GOT, we don't need to generate a copy reloc. */
4988 /* If we didn't find any dynamic relocs in read-only sections, then
4989 we'll be keeping the dynamic relocs and avoiding the copy reloc.
4990 We can't do this if there are any small data relocations. This
4991 doesn't work on VxWorks, where we can not have dynamic
4992 relocations (other than copy and jump slot relocations) in an
4993 executable. */
4999 {
5002 }
5005 {
5009 }
5011 /* We must allocate the symbol in our .dynbss section, which will
5012 become part of the .bss section of the executable. There will be
5013 an entry for this symbol in the .dynsym section. The dynamic
5014 object will contain position independent code, so all references
5015 from the dynamic object to this symbol will go through the global
5016 offset table. The dynamic linker will use the .dynsym entry to
5017 determine the address it must put in the global offset table, so
5018 both the dynamic object and the regular object will refer to the
5019 same memory location for the variable.
5021 Of course, if the symbol is referenced using SDAREL relocs, we
5022 must instead allocate it in .sbss. */
5026 else
5030 /* We must generate a R_PPC_COPY reloc to tell the dynamic linker to
5031 copy the initial value out of the dynamic object and into the
5032 runtime process image. We need to remember the offset into the
5033 .rela.bss section we are going to use. */
5035 {
5040 else
5045 }
5048 }
5049 \f
5050 /* Generate a symbol to mark plt call stubs. For non-PIC code the sym is
5051 xxxxxxxx.plt_call32.<callee> where xxxxxxxx is a hex number, usually 0,
5052 specifying the addend on the plt relocation. For -fpic code, the sym
5053 is xxxxxxxx.plt_pic32.<callee>, and for -fPIC
5054 xxxxxxxx.got2.plt_pic32.<callee>. */
5056 static bfd_boolean
5060 {
5069 else
5089 {
5098 }
5100 }
5102 /* Allocate NEED contiguous space in .got, and return the offset.
5103 Handles allocation of the got header when crossing 32k. */
5105 static bfd_vma
5107 {
5108 bfd_vma where;
5112 {
5115 }
5116 else
5117 {
5120 {
5123 }
5124 else
5125 {
5128 {
5131 }
5134 }
5135 }
5137 }
5139 /* Allocate space in associated reloc sections for dynamic relocs. */
5141 static bfd_boolean
5143 {
5155 {
5159 bfd_boolean dyn;
5163 {
5164 /* Make sure this symbol is output as a dynamic symbol. */
5169 {
5172 }
5178 {
5184 {
5186 {
5189 }
5194 {
5200 }
5205 {
5208 }
5214 }
5215 else
5216 {
5218 {
5219 /* If this is the first .plt entry, make room
5220 for the special first entry. */
5224 /* The PowerPC PLT is actually composed of two
5225 parts, the first part is 2 words (for a load
5226 and a jump), and then there is a remaining
5227 word available at the end. */
5234 /* If this symbol is not defined in a regular
5235 file, and we are not generating a shared
5236 library, then set the symbol to this location
5237 in the .plt. This is to avoid text
5238 relocations, and is required to make
5239 function pointers compare as equal between
5240 the normal executable and the shared library. */
5244 {
5247 }
5249 /* Make room for this entry. */
5251 /* After the 8192nd entry, room for two entries
5252 is allocated. */
5258 }
5260 }
5262 /* We also need to make an entry in the .rela.plt section. */
5264 {
5268 else
5269 {
5273 {
5274 /* Allocate space for the unloaded relocations. */
5277 {
5280 {
5284 }
5289 }
5291 /* Every PLT entry has an associated GOT entry in
5292 .got.plt. */
5294 }
5295 }
5297 }
5298 }
5299 else
5301 }
5302 else
5306 {
5309 }
5310 }
5311 else
5312 {
5315 }
5319 {
5320 bfd_boolean dyn;
5323 /* Make sure this symbol is output as a dynamic symbol. */
5328 {
5331 }
5335 {
5337 {
5339 /* We'll just use htab->tlsld_got.offset. This should
5340 always be the case. It's a little odd if we have
5341 a local dynamic reloc against a non-local symbol. */
5343 else
5345 }
5352 }
5353 else
5357 else
5358 {
5365 {
5367 /* All the entries we allocated need relocs.
5368 Except LD only needs one. */
5373 }
5374 }
5375 }
5376 else
5383 /* In the shared -Bsymbolic case, discard space allocated for
5384 dynamic pc-relative relocs against symbols which turn out to be
5385 defined in regular objects. For the normal shared case, discard
5386 space for relocs that have become local due to symbol visibility
5387 changes. */
5390 {
5391 /* Relocs that use pc_count are those that appear on a call insn,
5392 or certain REL relocs (see must_be_dyn_reloc) that can be
5393 generated via assembly. We want calls to protected symbols to
5394 resolve directly to the function rather than going via the plt.
5395 If people want function pointer comparisons to work as expected
5396 then they should avoid writing weird assembly. */
5398 {
5402 {
5407 else
5409 }
5410 }
5413 {
5417 {
5420 else
5422 }
5423 }
5425 /* Discard relocs on undefined symbols that must be local. */
5432 /* Also discard relocs on undefined weak syms with non-default
5433 visibility. */
5436 {
5440 /* Make sure undefined weak symbols are output as a dynamic
5441 symbol in PIEs. */
5445 {
5448 }
5449 }
5450 }
5452 {
5453 /* For the non-shared case, discard space for relocs against
5454 symbols which turn out to need copy relocs or are not
5455 dynamic. */
5459 {
5460 /* Make sure this symbol is output as a dynamic symbol.
5461 Undefined weak syms won't yet be marked as dynamic. */
5464 {
5467 }
5469 /* If that succeeded, we know we'll be keeping all the
5470 relocs. */
5473 }
5477 keep: ;
5478 }
5480 /* Finally, allocate space. */
5482 {
5487 }
5490 }
5492 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
5493 read-only sections. */
5495 static bfd_boolean
5497 {
5502 {
5505 /* Not an error, just cut short the traversal. */
5507 }
5509 }
5511 /* Set the sizes of the dynamic sections. */
5513 static bfd_boolean
5516 {
5519 bfd_boolean relocs;
5522 #ifdef DEBUG
5524 #endif
5530 {
5531 /* Set the contents of the .interp section to the interpreter. */
5533 {
5538 }
5539 }
5546 /* Set up .got offsets for local syms, and space for local dynamic
5547 relocs. */
5549 {
5555 bfd_size_type locsymcount;
5562 {
5569 {
5572 {
5573 /* Input section has been discarded, either because
5574 it is a copy of a linkonce section or due to
5575 linker script /DISCARD/, so we'll be discarding
5576 the relocs too. */
5577 }
5581 {
5582 /* Relocations in vxworks .tls_vars sections are
5583 handled specially by the loader. */
5584 }
5586 {
5595 }
5596 }
5597 }
5612 {
5615 {
5624 }
5625 else
5629 else
5630 {
5635 }
5636 }
5637 else
5643 /* Allocate space for calls to local STT_GNU_IFUNC syms in .iplt. */
5645 {
5652 {
5656 {
5659 }
5664 {
5667 }
5671 {
5674 }
5675 }
5676 else
5678 }
5679 }
5681 /* Allocate space for global sym dynamic relocs. */
5685 {
5689 }
5690 else
5694 {
5697 /* If we haven't allocated the header, do so now. When we get here,
5698 for old plt/got the got size will be 0 to 32764 (not allocated),
5699 or 32780 to 65536 (header allocated). For new plt/got, the
5700 corresponding ranges are 0 to 32768 and 32780 to 65536. */
5702 {
5707 }
5710 }
5712 {
5717 {
5721 }
5722 }
5727 {
5729 /* Space for the branch table. */
5731 /* Pad out to align the start of PLTresolve. */
5736 {
5743 {
5752 }
5758 {
5767 }
5768 }
5769 }
5771 /* We've now determined the sizes of the various dynamic sections.
5772 Allocate memory for them. */
5775 {
5783 {
5784 /* We'd like to strip these sections if they aren't needed, but if
5785 we've exported dynamic symbols from them we must leave them.
5786 It's too late to tell BFD to get rid of the symbols. */
5789 /* Strip this section if we don't need it; see the
5790 comment below. */
5791 }
5800 {
5801 /* Strip these too. */
5802 }
5804 {
5806 {
5807 /* Remember whether there are any relocation sections. */
5810 /* We use the reloc_count field as a counter if we need
5811 to copy relocs into the output file. */
5813 }
5814 }
5815 else
5816 {
5817 /* It's not one of our sections, so don't allocate space. */
5819 }
5822 {
5823 /* If we don't need this section, strip it from the
5824 output file. This is mostly to handle .rela.bss and
5825 .rela.plt. We must create both sections in
5826 create_dynamic_sections, because they must be created
5827 before the linker maps input sections to output
5828 sections. The linker does that before
5829 adjust_dynamic_symbol is called, and it is that
5830 function which decides whether anything needs to go
5831 into these sections. */
5834 }
5839 /* Allocate memory for the section contents. */
5843 }
5846 {
5847 /* Add some entries to the .dynamic section. We fill in the
5848 values later, in ppc_elf_finish_dynamic_sections, but we
5849 must add the entries now so that we get the correct size for
5850 the .dynamic section. The DT_DEBUG entry is filled in by the
5851 dynamic linker and used by the debugger. */
5852 #define add_dynamic_entry(TAG, VAL) \
5853 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
5856 {
5859 }
5862 {
5868 }
5871 {
5879 }
5882 {
5887 }
5889 /* If any dynamic relocs apply to a read-only section, then we
5890 need a DT_TEXTREL entry. */
5893 info);
5896 {
5899 }
5903 }
5904 #undef add_dynamic_entry
5907 }
5909 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
5911 static bfd_boolean
5913 {
5921 }
5922 \f
5923 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
5925 /* Relaxation trampolines. r12 is available for clobbering (r11, is
5926 used for some functions that are allowed to break the ABI). */
5928 {
5937 };
5940 {
5945 };
5947 static bfd_boolean
5952 {
5953 struct one_fixup
5954 {
5957 /* Final link, can use the symbol offset. For a
5958 relocatable link we use the symbol's index. */
5959 bfd_vma toff;
5960 bfd_vma trampoff;
5961 };
5971 bfd_size_type trampoff;
5973 bfd_boolean maybe_pasted;
5977 /* Nothing to do if there are no relocations, and no need to do
5978 anything with non-alloc or non-code sections. */
5985 /* We cannot represent the required PIC relocs in the output, so don't
5986 do anything. The linker doesn't support mixing -shared and -r
5987 anyway. */
5994 /* Space for a branch around any trampolines. */
6000 /* Get a copy of the native relocations. */
6011 {
6025 {
6040 }
6042 /* Get the value of the symbol referred to by the reloc. */
6045 {
6046 /* A local symbol. */
6049 /* Read this BFD's local symbols. */
6051 {
6059 }
6067 else
6072 }
6073 else
6074 {
6075 /* Global symbol handling. */
6087 {
6090 }
6093 {
6096 }
6097 else
6101 }
6103 /* The condition here under which we call find_plt_ent must
6104 match that in relocate_section. If we call find_plt_ent here
6105 but not in relocate_section, or vice versa, then the branch
6106 destination used here may be incorrect. */
6109 {
6110 /* We know is_branch_reloc (r_type) is true. */
6114 }
6117 {
6122 }
6124 {
6132 {
6137 {
6140 }
6141 else
6142 {
6145 }
6146 }
6147 }
6149 /* If the branch and target are in the same section, you have
6150 no hope of adding stubs. We'll error out later should the
6151 branch overflow. */
6155 /* There probably isn't any reason to handle symbols in
6156 SEC_MERGE sections; SEC_MERGE doesn't seem a likely
6157 attribute for a code section, and we are only looking at
6158 branches. However, implement it correctly here as a
6159 reference for other target relax_section functions. */
6161 {
6162 /* At this stage in linking, no SEC_MERGE symbol has been
6163 adjusted, so all references to such symbols need to be
6164 passed through _bfd_merged_section_offset. (Later, in
6165 relocate_section, all SEC_MERGE symbols *except* for
6166 section symbols have been adjusted.)
6168 gas may reduce relocations against symbols in SEC_MERGE
6169 sections to a relocation against the section symbol when
6170 the original addend was zero. When the reloc is against
6171 a section symbol we should include the addend in the
6172 offset passed to _bfd_merged_section_offset, since the
6173 location of interest is the original symbol. On the
6174 other hand, an access to "sym+addend" where "sym" is not
6175 a section symbol should not include the addend; Such an
6176 access is presumed to be an offset from "sym"; The
6177 location of interest is just "sym". */
6183 toff);
6187 }
6188 /* PLTREL24 addends are special. */
6192 /* Attempted -shared link of non-pic code loses. */
6198 /* If the branch is in range, no need to do anything. */
6201 /* A relocatable link may have sections moved during
6202 final link, so do not presume they remain in range. */
6204 {
6211 }
6213 /* Look for an existing fixup to this address. */
6219 {
6225 /* Oh dear, we can't reach a trampoline. Don't try to add
6226 one. We'll report an error later. */
6230 {
6233 }
6234 else
6235 {
6238 }
6242 {
6246 }
6248 /* Hijack the old relocation. Since we need two
6249 relocations for this use a "composite" reloc. */
6251 stub_rtype);
6257 /* Record the fixup so we don't do it again this section. */
6266 changes++;
6267 }
6268 else
6269 {
6274 /* Nop out the reloc, since we're finalizing things here. */
6276 }
6278 /* Get the section contents. */
6280 {
6281 /* Get cached copy if it exists. */
6284 else
6285 {
6286 /* Go get them off disk. */
6289 }
6290 }
6292 /* Fix up the existing branch to hit the trampoline. */
6295 {
6313 }
6314 }
6316 /* Write out the trampolines. */
6318 {
6323 do
6324 {
6328 }
6337 /* Branch around the trampolines. */
6339 {
6343 }
6347 {
6350 }
6351 else
6352 {
6355 }
6359 {
6361 i++;
6365 }
6367 }
6371 {
6374 else
6375 {
6376 /* Cache the symbols for elf_link_input_bfd. */
6378 }
6379 }
6383 {
6386 else
6387 {
6388 /* Cache the section contents for elf_link_input_bfd. */
6390 }
6391 }
6394 {
6395 /* Append sufficient NOP relocs so we can write out relocation
6396 information for the trampolines. */
6407 {
6411 }
6418 }
6424 {
6425 /* Convert the internal relax relocs to external form. */
6428 {
6431 /* Rewrite the reloc and convert one of the trailing nop
6432 relocs to describe this relocation. */
6434 /* The relocs are at the bottom 2 bytes */
6440 irel++;
6441 }
6442 }
6446 error_return:
6456 }
6457 \f
6458 /* What to do when ld finds relocations against symbols defined in
6459 discarded sections. */
6461 static unsigned int
6463 {
6471 }
6472 \f
6473 /* Fill in the address for a pointer generated in a linker section. */
6475 static bfd_vma
6479 bfd_vma relocation,
6481 {
6487 {
6488 /* Handle global symbol. */
6494 }
6495 else
6496 {
6497 /* Handle local symbol. */
6503 }
6507 lsect);
6510 /* Offset will always be a multiple of four, so use the bottom bit
6511 as a "written" flag. */
6513 {
6518 }
6525 #ifdef DEBUG
6529 #endif
6532 }
6534 #define PPC_LO(v) ((v) & 0xffff)
6535 #define PPC_HI(v) (((v) >> 16) & 0xffff)
6536 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
6538 static void
6541 {
6544 bfd_vma plt;
6551 {
6564 {
6573 }
6574 else
6575 {
6584 }
6585 }
6586 else
6587 {
6596 }
6597 }
6599 /* Return true if symbol is defined statically. */
6601 static bfd_boolean
6603 {
6608 }
6610 /* If INSN is an opcode that may be used with an @tls operand, return
6611 the transformed insn for TLS optimisation, otherwise return 0. If
6612 REG is non-zero only match an insn with RB or RA equal to REG. */
6614 unsigned int
6616 {
6626 else
6630 /* add -> addi. */
6636 /* load and store indexed -> dform. */
6639 /* ldx, ldux, stdx, stdux -> ld, ldu, std, stdu. */
6642 /* lwax -> lwa. */
6644 else
6648 }
6650 /* If INSN is an opcode that may be used with an @tprel operand, return
6651 the transformed insn for an undefined weak symbol, ie. with the
6652 thread pointer REG operand removed. Otherwise return 0. */
6654 unsigned int
6656 {
6677 {
6679 }
6684 {
6689 }
6690 else
6693 }
6695 /* The RELOCATE_SECTION function is called by the ELF backend linker
6696 to handle the relocations for a section.
6698 The relocs are always passed as Rela structures; if the section
6699 actually uses Rel structures, the r_addend field will always be
6700 zero.
6702 This function is responsible for adjust the section contents as
6703 necessary, and (if using Rela relocs and generating a
6704 relocatable output file) adjusting the reloc addend as
6705 necessary.
6707 This function does not have to worry about setting the reloc
6708 address or the reloc symbol index.
6710 LOCAL_SYMS is a pointer to the swapped in local symbols.
6712 LOCAL_SECTIONS is an array giving the section in the input file
6713 corresponding to the st_shndx field of each local symbol.
6715 The global hash table entry for the global symbols can be found
6716 via elf_sym_hashes (input_bfd).
6718 When generating relocatable output, this function must handle
6719 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
6720 going to be the section symbol corresponding to the output
6721 section, which means that the addend must be adjusted
6722 accordingly. */
6724 static bfd_boolean
6733 {
6739 Elf_Internal_Rela outrel;
6744 bfd_boolean is_vxworks_tls;
6746 #ifdef DEBUG
6752 #endif
6756 /* Initialize howto table if not already done. */
6764 /* We have to handle relocations in vxworks .tls_vars sections
6765 specially, because the dynamic loader is 'weird'. */
6772 {
6774 bfd_vma addend;
6775 bfd_reloc_status_type r;
6782 bfd_vma relocation;
6784 bfd_boolean unresolved_reloc;
6785 bfd_boolean warned;
6798 {
6804 }
6805 else
6806 {
6813 }
6816 {
6817 /* For relocs against symbols from removed linkonce sections,
6818 or sections discarded by a linker script, we just want the
6819 section contents zeroed. Avoid any special processing. */
6825 }
6828 {
6832 {
6833 /* R_PPC_PLTREL24 is rather special. If non-zero, the
6834 addend specifies the GOT pointer offset within .got2. */
6836 }
6838 }
6840 /* TLS optimizations. Replace instruction sequences and relocs
6841 based on information we collected in tls_optimize. We edit
6842 RELOCS so that --emit-relocs will output something sensible
6843 for the final instruction stream. */
6849 {
6852 local_plt
6856 }
6858 /* Ensure reloc mapping code below stays sane. */
6869 {
6877 {
6878 bfd_vma insn;
6886 }
6892 {
6893 bfd_vma insn;
6903 /* Was PPC_TLS which sits on insn boundary, now
6904 PPC_TPREL16_LO which is at low-order half-word. */
6906 }
6919 {
6920 tls_gdld_hi:
6924 else
6925 {
6929 }
6931 }
6944 {
6946 bfd_vma offset;
6948 tls_ldgd_opt:
6950 /* If not using the newer R_PPC_TLSGD/LD to mark
6951 __tls_get_addr calls, we must trust that the call
6952 stays with its arg setup insns, ie. that the next
6953 reloc is the __tls_get_addr call associated with
6954 the current reloc. Edit both insns. */
6961 {
6962 /* IE */
6968 {
6972 }
6976 }
6977 else
6978 {
6979 /* LE */
6982 {
6983 /* Was an LD reloc. */
6986 r_symndx++)
6996 }
7000 {
7006 }
7007 }
7011 {
7012 /* We changed the symbol on an LD reloc. Start over
7013 in order to get h, sym, sec etc. right. */
7014 rel--;
7016 }
7017 }
7022 {
7027 {
7028 /* IE */
7031 }
7032 else
7033 {
7034 /* LE */
7038 }
7041 /* Zap the reloc on the _tls_get_addr call too. */
7044 }
7049 {
7054 r_symndx++)
7070 /* Zap the reloc on the _tls_get_addr call too. */
7073 rel--;
7075 }
7077 }
7079 /* Handle other relocations that tweak non-addend part of insn. */
7082 {
7086 /* Branch taken prediction relocations. */
7090 /* Fall thru */
7092 /* Branch not taken prediction relocations. */
7095 {
7096 bfd_vma insn;
7106 /* Invert 'y' bit if not the default. */
7112 }
7113 }
7117 {
7121 {
7124 }
7127 {
7133 }
7139 {
7144 }
7146 {
7148 {
7149 Elf_Internal_Rela rela;
7163 }
7165 {
7170 }
7179 else
7183 }
7184 }
7192 {
7211 /* GOT16 relocations. Like an ADDR16 using the symbol's
7212 address in the GOT as relocation value instead of the
7213 symbol's value itself. Also, create a GOT entry for the
7214 symbol and put the symbol value there. */
7248 dogot:
7249 {
7250 /* Relocation is to the entry for this symbol in the global
7251 offset table. */
7252 bfd_vma off;
7265 {
7266 bfd_boolean dyn;
7271 /* This is actually a static link, or it is a
7272 -Bsymbolic link and the symbol is defined
7273 locally, or the symbol was forced to be local
7274 because of a version file. */
7275 ;
7276 else
7277 {
7280 }
7282 }
7283 else
7284 {
7288 }
7290 /* The offset must always be a multiple of 4. We use the
7291 least significant bit to record whether we have already
7292 processed this entry. */
7296 else
7297 {
7308 /* We might have multiple got entries for this sym.
7309 Initialize them all. */
7310 do
7311 {
7315 {
7318 }
7320 {
7323 }
7325 {
7328 }
7330 {
7333 }
7335 /* Generate relocs for the dynamic linker. */
7341 {
7350 {
7353 {
7360 outrel.r_info
7362 }
7363 }
7372 else
7375 {
7379 }
7384 }
7386 /* Init the .got section contents if we're not
7387 emitting a reloc. */
7388 else
7389 {
7395 {
7401 {
7405 }
7406 }
7409 }
7414 }
7419 }
7425 {
7427 {
7433 {
7437 {
7440 }
7441 }
7442 }
7443 }
7447 + off
7450 /* Addends on got relocations don't make much sense.
7451 x+off@got is actually x@got+off, and since the got is
7452 generated by a hash table traversal, the value in the
7453 got at entry m+n bears little relation to the entry m. */
7459 sym_name);
7460 }
7463 /* Relocations that need no special processing. */
7465 /* It makes no sense to point a local relocation
7466 at a symbol not in this object. */
7468 {
7471 input_bfd,
7472 input_section,
7474 TRUE))
7477 }
7487 /* Relocations that may need to be propagated if this is a shared
7488 object. */
7496 {
7497 /* Make this relocation against an undefined weak symbol
7498 resolve to zero. This is really just a tweak, since
7499 code using weak externs ought to check that they are
7500 defined before using them. */
7507 }
7509 /* The TPREL16 relocs shouldn't really be used in shared
7510 libs as they will result in DT_TEXTREL being set, but
7511 support them anyway. */
7536 /* fall through */
7551 /* If these relocations are not to a named symbol, they can be
7552 handled right here, no need to bother the dynamic linker. */
7556 /* fall through */
7564 /* fall through */
7566 dodyn:
7580 || (ELIMINATE_COPY_RELOCS
7586 {
7589 #ifdef DEBUG
7594 #endif
7596 /* When generating a shared object, these relocations
7597 are copied into the output file to be resolved at run
7598 time. */
7600 {
7606 }
7610 input_section,
7624 {
7628 }
7629 else
7630 {
7634 {
7638 {
7639 /* If we get here when building a static
7640 executable, then the libc startup function
7641 responsible for applying indirect function
7642 relocations is going to complain about
7643 the reloc type.
7644 If we get here when building a dynamic
7645 executable, it will be because we have
7646 a text relocation. The dynamic loader
7647 will set the text segment writable and
7648 non-executable to apply text relocations.
7649 So we'll segfault when trying to run the
7650 indirection function to resolve the reloc. */
7656 sym_name);
7658 }
7660 ;
7662 {
7665 }
7666 else
7667 {
7670 /* We are turning this relocation into one
7671 against a section symbol. It would be
7672 proper to subtract the symbol's value,
7673 osec->vma, from the emitted reloc addend,
7674 but ld.so expects buggy relocs.
7675 FIXME: Why not always use a zero index? */
7679 {
7682 }
7684 #ifdef DEBUG
7689 #endif
7690 }
7693 }
7696 else
7698 }
7707 /* This reloc will be computed at runtime. We clear the memory
7708 so that it contains predictable value. */
7712 {
7716 }
7717 }
7723 {
7728 {
7732 }
7738 else
7742 }
7743 /* Fall thru */
7751 {
7758 /* We're clearing the bits for R_PPC_ADDR16_HA
7759 and R_PPC_ADDR16_LO here. */
7763 /* t0 is HA, t1 is LO */
7771 /* Rewrite the reloc and convert one of the trailing nop
7772 relocs to describe this relocation. */
7774 /* The relocs are at the bottom 2 bytes */
7780 rel++;
7781 }
7784 /* Indirect .sdata relocation. */
7788 {
7791 }
7792 relocation
7798 /* Indirect .sdata2 relocation. */
7802 {
7805 }
7806 relocation
7812 /* Handle the TOC16 reloc. We want to use the offset within the .got
7813 section, not the actual VMA. This is appropriate when generating
7814 an embedded ELF object, for which the .got section acts like the
7815 AIX .toc section. */
7818 {
7821 }
7831 /* Relocation is to the entry for this symbol in the
7832 procedure linkage table. */
7833 {
7839 {
7840 /* We didn't make a PLT entry for this symbol. This
7841 happens when statically linking PIC code, or when
7842 using -Bsymbolic. */
7844 }
7851 else
7855 }
7858 /* Relocate against _SDA_BASE_. */
7860 {
7867 {
7870 }
7878 {
7882 input_bfd,
7883 sym_name,
7885 name);
7886 }
7887 }
7890 /* Relocate against _SDA2_BASE_. */
7892 {
7899 {
7902 }
7908 {
7912 input_bfd,
7913 sym_name,
7915 name);
7916 }
7917 }
7920 /* Relocate against either _SDA_BASE_, _SDA2_BASE_, or 0. */
7923 {
7929 {
7932 }
7939 {
7942 }
7945 {
7948 }
7951 {
7953 }
7954 else
7955 {
7959 input_bfd,
7960 sym_name,
7962 name);
7967 }
7970 {
7972 {
7975 }
7977 }
7980 {
7986 }
7987 }
7990 /* Relocate against the beginning of the section. */
7996 {
7999 }
8003 /* Negative relocations. */
8030 input_bfd,
8032 sym_name);
8037 }
8039 /* Do any further special processing. */
8041 {
8052 /* It's just possible that this symbol is a weak symbol
8053 that's not actually defined anywhere. In that case,
8054 'sec' would be NULL, and we should leave the symbol
8055 alone (it will be set to zero elsewhere in the link). */
8058 /* Fall thru */
8066 /* Add 0x10000 if sign bit in 0:15 is set.
8067 Bits 0:15 are not used. */
8070 }
8072 #ifdef DEBUG
8077 sym_name,
8078 r_symndx,
8081 #endif
8086 {
8091 sym_name);
8093 }
8096 input_bfd,
8097 input_section,
8098 contents,
8100 relocation,
8101 addend);
8104 {
8106 {
8112 {
8113 /* Assume this is a call protected by other code that
8114 detect the symbol is undefined. If this is the case,
8115 we can safely ignore the overflow. If not, the
8116 program is hosed anyway, and a little warning isn't
8117 going to help. */
8120 }
8124 sym_name,
8127 input_bfd,
8128 input_section,
8131 }
8132 else
8133 {
8139 }
8140 }
8141 }
8143 #ifdef DEBUG
8145 #endif
8148 }
8149 \f
8150 /* Finish up dynamic symbol handling. We set the contents of various
8151 dynamic sections here. */
8153 static bfd_boolean
8158 {
8161 bfd_boolean doneone;
8163 #ifdef DEBUG
8166 #endif
8174 {
8176 {
8177 Elf_Internal_Rela rela;
8179 bfd_vma reloc_index;
8185 else
8186 {
8192 }
8194 /* This symbol has an entry in the procedure linkage table.
8195 Set it up. */
8199 {
8200 bfd_vma got_offset;
8203 /* The first three entries in .got.plt are reserved. */
8206 /* Use the right PLT. */
8210 /* Fill in the .plt on VxWorks. */
8212 {
8219 }
8220 else
8221 {
8230 }
8237 /* This instruction is an immediate load. The value loaded is
8238 the byte offset of the R_PPC_JMP_SLOT relocation from the
8239 start of the .rela.plt section. The value is stored in the
8240 low-order 16 bits of the load instruction. */
8241 /* NOTE: It appears that this is now an index rather than a
8242 prescaled offset. */
8246 /* This instruction is a PC-relative branch whose target is
8247 the start of the PLT section. The address of this branch
8248 instruction is 20 bytes beyond the start of this PLT entry.
8249 The address is encoded in bits 6-29, inclusive. The value
8250 stored is right-shifted by two bits, permitting a 26-bit
8251 offset. */
8261 /* Fill in the GOT entry corresponding to this PLT slot with
8262 the address immediately after the the "bctr" instruction
8263 in this PLT entry. */
8270 {
8271 /* Fill in a couple of entries in .rela.plt.unloaded. */
8277 /* Provide the @ha relocation for the first instruction. */
8282 R_PPC_ADDR16_HA);
8287 /* Provide the @l relocation for the second instruction. */
8292 R_PPC_ADDR16_LO);
8297 /* Provide a relocation for the GOT entry corresponding to this
8298 PLT slot. Point it at the middle of the .plt entry. */
8303 R_PPC_ADDR32);
8306 }
8308 /* VxWorks uses non-standard semantics for R_PPC_JMP_SLOT.
8309 In particular, the offset for the relocation is not the
8310 address of the PLT entry for this function, as specified
8311 by the ABI. Instead, the offset is set to the address of
8312 the GOT slot for this function. See EABI 4.4.4.1. */
8317 }
8318 else
8319 {
8331 {
8332 /* We don't need to fill in the .plt. The ppc dynamic
8333 linker will fill it in. */
8334 }
8335 else
8336 {
8342 }
8343 }
8345 /* Fill in the entry in the .rela.plt section. */
8349 {
8356 }
8357 else
8365 else
8371 {
8372 /* Mark the symbol as undefined, rather than as
8373 defined in the .plt section. Leave the value if
8374 there were any relocations where pointer equality
8375 matters (this is a clue for the dynamic linker, to
8376 make function pointer comparisons work between an
8377 application and shared library), otherwise set it
8378 to zero. */
8383 {
8384 /* This breaks function pointer comparisons, but
8385 that is better than breaking tests for a NULL
8386 function pointer. */
8388 }
8389 }
8392 {
8393 /* Set the value of ifunc symbols in a non-pie
8394 executable to the glink entry. This is to avoid
8395 text relocations. We can't do this for ifunc in
8396 allocate_dynrelocs, as we do for normal dynamic
8397 function symbols with plt entries, because we need
8398 to keep the original value around for the ifunc
8399 relocation. */
8405 }
8407 }
8412 {
8422 {
8439 }
8444 /* We only need one non-PIC glink stub. */
8446 }
8447 else
8449 }
8452 {
8454 Elf_Internal_Rela rela;
8457 /* This symbols needs a copy reloc. Set it up. */
8459 #ifdef DEBUG
8461 #endif
8467 else
8476 }
8478 #ifdef DEBUG
8480 #endif
8482 /* Mark some specially defined symbols as absolute. */
8491 }
8492 \f
8493 static enum elf_reloc_type_class
8495 {
8497 {
8508 }
8509 }
8510 \f
8511 /* Finish up the dynamic sections. */
8513 static bfd_boolean
8516 {
8520 bfd_vma got;
8524 #ifdef DEBUG
8526 #endif
8533 else
8541 {
8549 {
8550 Elf_Internal_Dyn dyn;
8556 {
8560 else
8580 {
8584 }
8592 }
8595 }
8596 }
8599 {
8602 {
8607 {
8608 /* Add a blrl instruction at _GLOBAL_OFFSET_TABLE_-4
8609 so that a function can easily find the address of
8610 _GLOBAL_OFFSET_TABLE_. */
8614 }
8617 {
8622 }
8623 }
8624 else
8625 {
8632 }
8635 }
8637 /* Fill in the first entry in the VxWorks procedure linkage table. */
8639 {
8640 /* Use the right PLT. */
8642 ? ppc_elf_vxworks_pic_plt0_entry
8646 {
8653 }
8654 else
8655 {
8658 }
8667 {
8668 Elf_Internal_Rela rela;
8673 /* Output the @ha relocation for the first instruction. */
8682 /* Output the @l relocation for the second instruction. */
8691 /* Fix up the remaining relocations. They may have the wrong
8692 symbol index for _G_O_T_ or _P_L_T_ depending on the order
8693 in which symbols were output. */
8695 {
8696 Elf_Internal_Rela rel;
8712 }
8713 }
8714 }
8719 {
8722 bfd_vma res0;
8725 /*
8726 * PIC glink code is the following:
8727 *
8728 * # ith PLT code stub.
8729 * addis 11,30,(plt+(i-1)*4-got)@ha
8730 * lwz 11,(plt+(i-1)*4-got)@l(11)
8731 * mtctr 11
8732 * bctr
8733 *
8734 * # A table of branches, one for each plt entry.
8735 * # The idea is that the plt call stub loads ctr and r11 with these
8736 * # addresses, so (r11 - res_0) gives the plt index * 4.
8737 * res_0: b PLTresolve
8738 * res_1: b PLTresolve
8739 * .
8740 * # Some number of entries towards the end can be nops
8741 * res_n_m3: nop
8742 * res_n_m2: nop
8743 * res_n_m1:
8744 *
8745 * PLTresolve:
8746 * addis 11,11,(1f-res_0)@ha
8747 * mflr 0
8748 * bcl 20,31,1f
8749 * 1: addi 11,11,(1b-res_0)@l
8750 * mflr 12
8751 * mtlr 0
8752 * sub 11,11,12 # r11 = index * 4
8753 * addis 12,12,(got+4-1b)@ha
8754 * lwz 0,(got+4-1b)@l(12) # got[1] address of dl_runtime_resolve
8755 * lwz 12,(got+8-1b)@l(12) # got[2] contains the map address
8756 * mtctr 0
8757 * add 0,11,11
8758 * add 11,0,11 # r11 = index * 12 = reloc offset.
8759 * bctr
8760 */
8762 {
8763 ADDIS_11_11,
8764 MFLR_0,
8765 BCL_20_31,
8766 ADDI_11_11,
8767 MFLR_12,
8768 MTLR_0,
8769 SUB_11_11_12,
8770 ADDIS_12_12,
8771 LWZ_0_12,
8772 LWZ_12_12,
8773 MTCTR_0,
8774 ADD_0_11_11,
8775 ADD_11_0_11,
8776 BCTR,
8777 NOP,
8778 NOP
8779 };
8781 /*
8782 * Non-PIC glink code is a little simpler.
8783 *
8784 * # ith PLT code stub.
8785 * lis 11,(plt+(i-1)*4)@ha
8786 * lwz 11,(plt+(i-1)*4)@l(11)
8787 * mtctr 11
8788 * bctr
8789 *
8790 * The branch table is the same, then comes
8791 *
8792 * PLTresolve:
8793 * lis 12,(got+4)@ha
8794 * addis 11,11,(-res_0)@ha
8795 * lwz 0,(got+4)@l(12) # got[1] address of dl_runtime_resolve
8796 * addi 11,11,(-res_0)@l # r11 = index * 4
8797 * mtctr 0
8798 * add 0,11,11
8799 * lwz 12,(got+8)@l(12) # got[2] contains the map address
8800 * add 11,0,11 # r11 = index * 12 = reloc offset.
8801 * bctr
8802 */
8804 {
8805 LIS_12,
8806 ADDIS_11_11,
8807 LWZ_0_12,
8808 ADDI_11_11,
8809 MTCTR_0,
8810 ADD_0_11_11,
8811 LWZ_12_12,
8812 ADD_11_0_11,
8813 BCTR,
8814 NOP,
8815 NOP,
8816 NOP,
8817 NOP,
8818 NOP,
8819 NOP,
8820 NOP
8821 };
8828 /* Build the branch table, one for each plt entry (less one),
8829 and perhaps some padding. */
8835 {
8838 }
8840 {
8843 }
8849 /* Last comes the PLTresolve stub. */
8851 {
8852 bfd_vma bcl;
8855 {
8858 }
8872 {
8877 }
8878 else
8879 {
8884 }
8885 }
8886 else
8887 {
8889 {
8892 }
8902 {
8907 }
8908 else
8909 {
8914 }
8915 }
8916 }
8919 }
8920 \f
8921 #define TARGET_LITTLE_SYM bfd_elf32_powerpcle_vec
8923 #define TARGET_BIG_SYM bfd_elf32_powerpc_vec
8925 #define ELF_ARCH bfd_arch_powerpc
8926 #define ELF_TARGET_ID PPC32_ELF_DATA
8927 #define ELF_MACHINE_CODE EM_PPC
8928 #ifdef __QNXTARGET__
8929 #define ELF_MAXPAGESIZE 0x1000
8930 #else
8931 #define ELF_MAXPAGESIZE 0x10000
8932 #endif
8933 #define ELF_MINPAGESIZE 0x1000
8934 #define ELF_COMMONPAGESIZE 0x1000
8935 #define elf_info_to_howto ppc_elf_info_to_howto
8937 #ifdef EM_CYGNUS_POWERPC
8938 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
8939 #endif
8941 #ifdef EM_PPC_OLD
8942 #define ELF_MACHINE_ALT2 EM_PPC_OLD
8943 #endif
8945 #define elf_backend_plt_not_loaded 1
8946 #define elf_backend_can_gc_sections 1
8947 #define elf_backend_can_refcount 1
8948 #define elf_backend_rela_normal 1
8950 #define bfd_elf32_mkobject ppc_elf_mkobject
8951 #define bfd_elf32_bfd_merge_private_bfd_data ppc_elf_merge_private_bfd_data
8952 #define bfd_elf32_bfd_relax_section ppc_elf_relax_section
8953 #define bfd_elf32_bfd_reloc_type_lookup ppc_elf_reloc_type_lookup
8954 #define bfd_elf32_bfd_reloc_name_lookup ppc_elf_reloc_name_lookup
8955 #define bfd_elf32_bfd_set_private_flags ppc_elf_set_private_flags
8956 #define bfd_elf32_bfd_link_hash_table_create ppc_elf_link_hash_table_create
8957 #define bfd_elf32_get_synthetic_symtab ppc_elf_get_synthetic_symtab
8959 #define elf_backend_object_p ppc_elf_object_p
8960 #define elf_backend_gc_mark_hook ppc_elf_gc_mark_hook
8961 #define elf_backend_gc_sweep_hook ppc_elf_gc_sweep_hook
8962 #define elf_backend_section_from_shdr ppc_elf_section_from_shdr
8963 #define elf_backend_relocate_section ppc_elf_relocate_section
8964 #define elf_backend_create_dynamic_sections ppc_elf_create_dynamic_sections
8965 #define elf_backend_check_relocs ppc_elf_check_relocs
8966 #define elf_backend_copy_indirect_symbol ppc_elf_copy_indirect_symbol
8967 #define elf_backend_adjust_dynamic_symbol ppc_elf_adjust_dynamic_symbol
8968 #define elf_backend_add_symbol_hook ppc_elf_add_symbol_hook
8969 #define elf_backend_size_dynamic_sections ppc_elf_size_dynamic_sections
8970 #define elf_backend_hash_symbol ppc_elf_hash_symbol
8971 #define elf_backend_finish_dynamic_symbol ppc_elf_finish_dynamic_symbol
8972 #define elf_backend_finish_dynamic_sections ppc_elf_finish_dynamic_sections
8973 #define elf_backend_fake_sections ppc_elf_fake_sections
8974 #define elf_backend_additional_program_headers ppc_elf_additional_program_headers
8975 #define elf_backend_grok_prstatus ppc_elf_grok_prstatus
8976 #define elf_backend_grok_psinfo ppc_elf_grok_psinfo
8977 #define elf_backend_write_core_note ppc_elf_write_core_note
8978 #define elf_backend_reloc_type_class ppc_elf_reloc_type_class
8979 #define elf_backend_begin_write_processing ppc_elf_begin_write_processing
8980 #define elf_backend_final_write_processing ppc_elf_final_write_processing
8981 #define elf_backend_write_section ppc_elf_write_section
8982 #define elf_backend_get_sec_type_attr ppc_elf_get_sec_type_attr
8983 #define elf_backend_plt_sym_val ppc_elf_plt_sym_val
8984 #define elf_backend_action_discarded ppc_elf_action_discarded
8985 #define elf_backend_init_index_section _bfd_elf_init_1_index_section
8986 #define elf_backend_post_process_headers _bfd_elf_set_osabi
8990 /* VxWorks Target */
8992 #undef TARGET_LITTLE_SYM
8993 #undef TARGET_LITTLE_NAME
8995 #undef TARGET_BIG_SYM
8996 #define TARGET_BIG_SYM bfd_elf32_powerpc_vxworks_vec
8997 #undef TARGET_BIG_NAME
9000 /* VxWorks uses the elf default section flags for .plt. */
9003 {
9011 }
9013 /* Like ppc_elf_link_hash_table_create, but overrides
9014 appropriately for VxWorks. */
9017 {
9022 {
9030 }
9032 }
9034 /* Tweak magic VxWorks symbols as they are loaded. */
9035 static bfd_boolean
9043 {
9045 valp))
9049 }
9051 static void
9053 {
9056 }
9058 /* On VxWorks, we emit relocations against _PROCEDURE_LINKAGE_TABLE_, so
9059 define it. */
9060 #undef elf_backend_want_plt_sym
9061 #define elf_backend_want_plt_sym 1
9062 #undef elf_backend_want_got_plt
9063 #define elf_backend_want_got_plt 1
9064 #undef elf_backend_got_symbol_offset
9065 #define elf_backend_got_symbol_offset 0
9066 #undef elf_backend_plt_not_loaded
9067 #define elf_backend_plt_not_loaded 0
9068 #undef elf_backend_plt_readonly
9069 #define elf_backend_plt_readonly 1
9070 #undef elf_backend_got_header_size
9071 #define elf_backend_got_header_size 12
9073 #undef bfd_elf32_get_synthetic_symtab
9075 #undef bfd_elf32_bfd_link_hash_table_create
9076 #define bfd_elf32_bfd_link_hash_table_create \
9077 ppc_elf_vxworks_link_hash_table_create
9078 #undef elf_backend_add_symbol_hook
9079 #define elf_backend_add_symbol_hook \
9080 ppc_elf_vxworks_add_symbol_hook
9081 #undef elf_backend_link_output_symbol_hook
9082 #define elf_backend_link_output_symbol_hook \
9083 elf_vxworks_link_output_symbol_hook
9084 #undef elf_backend_final_write_processing
9085 #define elf_backend_final_write_processing \
9086 ppc_elf_vxworks_final_write_processing
9087 #undef elf_backend_get_sec_type_attr
9088 #define elf_backend_get_sec_type_attr \
9089 ppc_elf_vxworks_get_sec_type_attr
9090 #undef elf_backend_emit_relocs
9091 #define elf_backend_emit_relocs \
9092 elf_vxworks_emit_relocs
9094 #undef elf32_bed
9095 #define elf32_bed ppc_elf_vxworks_bed
9096 #undef elf_backend_post_process_headers