| blob | 28274c40437bb031332426dc80123accc1ae51aa |
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 Free Software Foundation, Inc.
4 Written by Ian Lance Taylor, Cygnus Support.
6 This file is part of BFD, the Binary File Descriptor library.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the
20 Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
21 Boston, MA 02110-1301, USA. */
24 /* This file is based on a preliminary PowerPC ELF ABI. The
25 information may not match the final PowerPC ELF ABI. It includes
26 suggestions from the in-progress Embedded PowerPC ABI, and that
27 information may also not match. */
30 #include <stdarg.h>
39 /* RELA relocations are used here. */
41 static bfd_reloc_status_type ppc_elf_addr16_ha_reloc
43 static bfd_reloc_status_type ppc_elf_unhandled_reloc
46 /* Branch prediction bit for branch taken relocs. */
47 #define BRANCH_PREDICT_BIT 0x200000
48 /* Mask to set RA in memory instructions. */
49 #define RA_REGISTER_MASK 0x001f0000
50 /* Value to shift register by to insert RA. */
51 #define RA_REGISTER_SHIFT 16
53 /* The name of the dynamic interpreter. This is put in the .interp
54 section. */
57 /* For old-style PLT. */
58 /* The number of single-slot PLT entries (the rest use two slots). */
59 #define PLT_NUM_SINGLE_ENTRIES 8192
61 /* For new-style .glink and .plt. */
62 #define GLINK_PLTRESOLVE 16*4
63 #define GLINK_ENTRY_SIZE 4*4
64 #define TLS_GET_ADDR_GLINK_SIZE 12*4
66 /* VxWorks uses its own plt layout, filled in by the static linker. */
68 /* The standard VxWorks PLT entry. */
69 #define VXWORKS_PLT_ENTRY_SIZE 32
70 static const bfd_vma ppc_elf_vxworks_plt_entry
72 {
81 };
82 static const bfd_vma ppc_elf_vxworks_pic_plt_entry
84 {
93 };
95 /* The initial VxWorks PLT entry. */
96 #define VXWORKS_PLT_INITIAL_ENTRY_SIZE 32
97 static const bfd_vma ppc_elf_vxworks_plt0_entry
99 {
108 };
109 static const bfd_vma ppc_elf_vxworks_pic_plt0_entry
111 {
120 };
122 /* For executables, we have some additional relocations in
123 .rela.plt.unloaded, for the kernel loader. */
125 /* The number of non-JMP_SLOT relocations per PLT0 slot. */
126 #define VXWORKS_PLT_NON_JMP_SLOT_RELOCS 3
127 /* The number of relocations in the PLTResolve slot. */
128 #define VXWORKS_PLTRESOLVE_RELOCS 2
129 /* The number of relocations in the PLTResolve slot when when creating
130 a shared library. */
131 #define VXWORKS_PLTRESOLVE_RELOCS_SHLIB 0
133 /* Some instructions. */
134 #define ADDIS_11_11 0x3d6b0000
135 #define ADDIS_11_30 0x3d7e0000
136 #define ADDIS_12_12 0x3d8c0000
137 #define ADDI_11_11 0x396b0000
138 #define ADD_0_11_11 0x7c0b5a14
139 #define ADD_3_12_2 0x7c6c1214
140 #define ADD_11_0_11 0x7d605a14
141 #define B 0x48000000
142 #define BCL_20_31 0x429f0005
143 #define BCTR 0x4e800420
144 #define BEQLR 0x4d820020
145 #define CMPWI_11_0 0x2c0b0000
146 #define LIS_11 0x3d600000
147 #define LIS_12 0x3d800000
148 #define LWZU_0_12 0x840c0000
149 #define LWZ_0_12 0x800c0000
150 #define LWZ_11_3 0x81630000
151 #define LWZ_11_11 0x816b0000
152 #define LWZ_11_30 0x817e0000
153 #define LWZ_12_3 0x81830000
154 #define LWZ_12_12 0x818c0000
155 #define MR_0_3 0x7c601b78
156 #define MR_3_0 0x7c030378
157 #define MFLR_0 0x7c0802a6
158 #define MFLR_12 0x7d8802a6
159 #define MTCTR_0 0x7c0903a6
160 #define MTCTR_11 0x7d6903a6
161 #define MTLR_0 0x7c0803a6
162 #define NOP 0x60000000
163 #define SUB_11_11_12 0x7d6c5850
165 /* Offset of tp and dtp pointers from start of TLS block. */
166 #define TP_OFFSET 0x7000
167 #define DTP_OFFSET 0x8000
169 /* The value of a defined global symbol. */
170 #define SYM_VAL(SYM) \
171 ((SYM)->root.u.def.section->output_section->vma \
172 + (SYM)->root.u.def.section->output_offset \
173 + (SYM)->root.u.def.value)
174 \f
178 /* This reloc does nothing. */
193 /* A standard 32 bit relocation. */
208 /* An absolute 26 bit branch; the lower two bits must be zero.
209 FIXME: we don't check that, we just clear them. */
224 /* A standard 16 bit relocation. */
239 /* A 16 bit relocation without overflow. */
254 /* The high order 16 bits of an address. */
269 /* The high order 16 bits of an address, plus 1 if the contents of
270 the low 16 bits, treated as a signed number, is negative. */
285 /* An absolute 16 bit branch; the lower two bits must be zero.
286 FIXME: we don't check that, we just clear them. */
301 /* An absolute 16 bit branch, for which bit 10 should be set to
302 indicate that the branch is expected to be taken. The lower two
303 bits must be zero. */
318 /* An absolute 16 bit branch, for which bit 10 should be set to
319 indicate that the branch is not expected to be taken. The lower
320 two bits must be zero. */
335 /* A relative 26 bit branch; the lower two bits must be zero. */
350 /* A relative 16 bit branch; the lower two bits must be zero. */
365 /* A relative 16 bit branch. Bit 10 should be set to indicate that
366 the branch is expected to be taken. The lower two bits must be
367 zero. */
382 /* A relative 16 bit branch. Bit 10 should be set to indicate that
383 the branch is not expected to be taken. The lower two bits must
384 be zero. */
399 /* Like R_PPC_ADDR16, but referring to the GOT table entry for the
400 symbol. */
415 /* Like R_PPC_ADDR16_LO, but referring to the GOT table entry for
416 the symbol. */
431 /* Like R_PPC_ADDR16_HI, but referring to the GOT table entry for
432 the symbol. */
447 /* Like R_PPC_ADDR16_HA, but referring to the GOT table entry for
448 the symbol. */
463 /* Like R_PPC_REL24, but referring to the procedure linkage table
464 entry for the symbol. */
479 /* This is used only by the dynamic linker. The symbol should exist
480 both in the object being run and in some shared library. The
481 dynamic linker copies the data addressed by the symbol from the
482 shared library into the object, because the object being
483 run has to have the data at some particular address. */
498 /* Like R_PPC_ADDR32, but used when setting global offset table
499 entries. */
514 /* Marks a procedure linkage table entry for a symbol. */
529 /* Used only by the dynamic linker. When the object is run, this
530 longword is set to the load address of the object, plus the
531 addend. */
546 /* Like R_PPC_REL24, but uses the value of the symbol within the
547 object rather than the final value. Normally used for
548 _GLOBAL_OFFSET_TABLE_. */
563 /* Like R_PPC_ADDR32, but may be unaligned. */
578 /* Like R_PPC_ADDR16, but may be unaligned. */
593 /* 32-bit PC relative */
608 /* 32-bit relocation to the symbol's procedure linkage table.
609 FIXME: not supported. */
624 /* 32-bit PC relative relocation to the symbol's procedure linkage table.
625 FIXME: not supported. */
640 /* Like R_PPC_ADDR16_LO, but referring to the PLT table entry for
641 the symbol. */
656 /* Like R_PPC_ADDR16_HI, but referring to the PLT table entry for
657 the symbol. */
672 /* Like R_PPC_ADDR16_HA, but referring to the PLT table entry for
673 the symbol. */
688 /* A sign-extended 16 bit value relative to _SDA_BASE_, for use with
689 small data items. */
704 /* 16-bit section relative relocation. */
719 /* 16-bit lower half section relative relocation. */
734 /* 16-bit upper half section relative relocation. */
749 /* 16-bit upper half adjusted section relative relocation. */
764 /* Marker relocs for TLS. */
807 /* Computes the load module index of the load module that contains the
808 definition of its TLS sym. */
823 /* Computes a dtv-relative displacement, the difference between the value
824 of sym+add and the base address of the thread-local storage block that
825 contains the definition of sym, minus 0x8000. */
840 /* A 16 bit dtprel reloc. */
855 /* Like DTPREL16, but no overflow. */
870 /* Like DTPREL16_LO, but next higher group of 16 bits. */
885 /* Like DTPREL16_HI, but adjust for low 16 bits. */
900 /* Computes a tp-relative displacement, the difference between the value of
901 sym+add and the value of the thread pointer (r13). */
916 /* A 16 bit tprel reloc. */
931 /* Like TPREL16, but no overflow. */
946 /* Like TPREL16_LO, but next higher group of 16 bits. */
961 /* Like TPREL16_HI, but adjust for low 16 bits. */
976 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
977 with values (sym+add)@dtpmod and (sym+add)@dtprel, and computes the offset
978 to the first entry. */
993 /* Like GOT_TLSGD16, but no overflow. */
1008 /* Like GOT_TLSGD16_LO, but next higher group of 16 bits. */
1023 /* Like GOT_TLSGD16_HI, but adjust for low 16 bits. */
1038 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
1039 with values (sym+add)@dtpmod and zero, and computes the offset to the
1040 first entry. */
1055 /* Like GOT_TLSLD16, but no overflow. */
1070 /* Like GOT_TLSLD16_LO, but next higher group of 16 bits. */
1085 /* Like GOT_TLSLD16_HI, but adjust for low 16 bits. */
1100 /* Allocates an entry in the GOT with value (sym+add)@dtprel, and computes
1101 the offset to the entry. */
1116 /* Like GOT_DTPREL16, but no overflow. */
1131 /* Like GOT_DTPREL16_LO, but next higher group of 16 bits. */
1146 /* Like GOT_DTPREL16_HI, but adjust for low 16 bits. */
1161 /* Allocates an entry in the GOT with value (sym+add)@tprel, and computes the
1162 offset to the entry. */
1177 /* Like GOT_TPREL16, but no overflow. */
1192 /* Like GOT_TPREL16_LO, but next higher group of 16 bits. */
1207 /* Like GOT_TPREL16_HI, but adjust for low 16 bits. */
1222 /* The remaining relocs are from the Embedded ELF ABI, and are not
1223 in the SVR4 ELF ABI. */
1225 /* 32 bit value resulting from the addend minus the symbol. */
1240 /* 16 bit value resulting from the addend minus the symbol. */
1255 /* 16 bit value resulting from the addend minus the symbol. */
1270 /* The high order 16 bits of the addend minus the symbol. */
1285 /* The high order 16 bits of the result of the addend minus the address,
1286 plus 1 if the contents of the low 16 bits, treated as a signed number,
1287 is negative. */
1302 /* 16 bit value resulting from allocating a 4 byte word to hold an
1303 address in the .sdata section, and returning the offset from
1304 _SDA_BASE_ for that relocation. */
1319 /* 16 bit value resulting from allocating a 4 byte word to hold an
1320 address in the .sdata2 section, and returning the offset from
1321 _SDA2_BASE_ for that relocation. */
1336 /* A sign-extended 16 bit value relative to _SDA2_BASE_, for use with
1337 small data items. */
1352 /* Relocate against either _SDA_BASE_ or _SDA2_BASE_, filling in the 16 bit
1353 signed offset from the appropriate base, and filling in the register
1354 field with the appropriate register (0, 2, or 13). */
1369 /* Relocation not handled: R_PPC_EMB_MRKREF */
1370 /* Relocation not handled: R_PPC_EMB_RELSEC16 */
1371 /* Relocation not handled: R_PPC_EMB_RELST_LO */
1372 /* Relocation not handled: R_PPC_EMB_RELST_HI */
1373 /* Relocation not handled: R_PPC_EMB_RELST_HA */
1374 /* Relocation not handled: R_PPC_EMB_BIT_FLD */
1376 /* PC relative relocation against either _SDA_BASE_ or _SDA2_BASE_, filling
1377 in the 16 bit signed offset from the appropriate base, and filling in the
1378 register field with the appropriate register (0, 2, or 13). */
1407 /* A 16 bit relative relocation. */
1422 /* A 16 bit relative relocation without overflow. */
1437 /* The high order 16 bits of a relative address. */
1452 /* The high order 16 bits of a relative address, plus 1 if the contents of
1453 the low 16 bits, treated as a signed number, is negative. */
1468 /* GNU extension to record C++ vtable hierarchy. */
1483 /* GNU extension to record C++ vtable member usage. */
1498 /* Phony reloc to handle AIX style TOC entries. */
1512 };
1513 \f
1514 /* Initialize the ppc_elf_howto_table, so that linear accesses can be done. */
1516 static void
1518 {
1523 i++)
1524 {
1530 }
1531 }
1535 bfd_reloc_code_real_type code)
1536 {
1539 /* Initialize howto table if not already done. */
1544 {
1635 }
1638 };
1643 {
1648 i++)
1654 }
1656 /* Set the howto pointer for a PowerPC ELF reloc. */
1658 static void
1662 {
1663 /* Initialize howto table if not already done. */
1670 /* Just because the above assert didn't trigger doesn't mean that
1671 ELF32_R_TYPE (dst->r_info) is necessarily a valid relocation. */
1673 {
1679 }
1680 }
1682 /* Handle the R_PPC_ADDR16_HA and R_PPC_REL16_HA relocs. */
1684 static bfd_reloc_status_type
1692 {
1693 bfd_vma relocation;
1696 {
1699 }
1706 else
1718 }
1720 static bfd_reloc_status_type
1728 {
1729 /* If this is a relocatable link (output_bfd test tells us), just
1730 call the generic function. Any adjustment will be done at final
1731 link time. */
1737 {
1742 }
1744 }
1745 \f
1746 /* Sections created by the linker. */
1749 {
1750 /* Pointer to the bfd section. */
1752 /* Section name. */
1754 /* Associated bss section name. */
1756 /* Associated symbol name. */
1758 /* Associated symbol. */
1762 /* Linked list of allocated pointer entries. This hangs off of the
1763 symbol lists, and provides allows us to return different pointers,
1764 based on different addend's. */
1767 {
1768 /* next allocated pointer for this symbol */
1770 /* offset of pointer from beginning of section */
1771 bfd_vma offset;
1772 /* addend used */
1773 bfd_vma addend;
1774 /* which linker section this is */
1778 struct ppc_elf_obj_tdata
1779 {
1782 /* A mapping from local symbols to offsets into the various linker
1783 sections added. This is index by the symbol index. */
1786 /* Flags used to auto-detect plt type. */
1789 };
1791 #define ppc_elf_tdata(bfd) \
1792 ((struct ppc_elf_obj_tdata *) (bfd)->tdata.any)
1794 #define elf_local_ptr_offsets(bfd) \
1795 (ppc_elf_tdata (bfd)->linker_section_pointers)
1797 #define is_ppc_elf(bfd) \
1798 (bfd_get_flavour (bfd) == bfd_target_elf_flavour \
1799 && elf_object_id (bfd) == PPC32_ELF_DATA)
1801 /* Override the generic function because we store some extras. */
1803 static bfd_boolean
1805 {
1807 PPC32_ELF_DATA);
1808 }
1810 /* Fix bad default arch selected for a 32 bit input bfd when the
1811 default is 64 bit. */
1813 static bfd_boolean
1815 {
1817 {
1821 {
1822 /* Relies on arch after 64 bit default being 32 bit default. */
1825 }
1826 }
1828 }
1830 /* Function to set whether a module needs the -mrelocatable bit set. */
1832 static bfd_boolean
1834 {
1841 }
1843 /* Support for core dump NOTE sections. */
1845 static bfd_boolean
1847 {
1852 {
1857 /* pr_cursig */
1860 /* pr_pid */
1863 /* pr_reg */
1868 }
1870 /* Make a ".reg/999" section. */
1873 }
1875 static bfd_boolean
1877 {
1879 {
1888 }
1890 /* Note that for some reason, a spurious space is tacked
1891 onto the end of the args in some (at least one anyway)
1892 implementations, so strip it off if it exists. */
1894 {
1900 }
1903 }
1907 {
1909 {
1914 {
1925 }
1928 {
1947 }
1948 }
1949 }
1951 /* Return address for Ith PLT stub in section PLT, for relocation REL
1952 or (bfd_vma) -1 if it should not be included. */
1954 static bfd_vma
1958 {
1960 }
1962 /* Handle a PowerPC specific section when reading an object file. This
1963 is called when bfd_section_from_shdr finds a section with an unknown
1964 type. */
1966 static bfd_boolean
1971 {
1973 flagword flags;
1988 }
1990 /* Set up any other section flags and such that may be necessary. */
1992 static bfd_boolean
1996 {
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 /* The PPC linker needs to keep track of the number of relocs that it
2566 decides to copy as dynamic relocs in check_relocs for each symbol.
2567 This is so that it can later discard them if they are found to be
2568 unnecessary. We store the information in a field extending the
2569 regular ELF linker hash table. */
2571 struct ppc_elf_dyn_relocs
2572 {
2575 /* The input section of the reloc. */
2578 /* Total number of relocs copied for the input section. */
2579 bfd_size_type count;
2581 /* Number of pc-relative relocs copied for the input section. */
2582 bfd_size_type pc_count;
2583 };
2585 /* Track PLT entries needed for a given symbol. We might need more
2586 than one glink entry per symbol when generating a pic binary. */
2587 struct plt_entry
2588 {
2591 /* -fPIC uses multiple GOT sections, one per file, called ".got2".
2592 This field stores the offset into .got2 used to initialise the
2593 GOT pointer reg. It will always be at least 32768. (Current
2594 gcc always uses an offset of 32768, but ld -r will pack .got2
2595 sections together resulting in larger offsets). */
2596 bfd_vma addend;
2598 /* The .got2 section. */
2601 /* PLT refcount or offset. */
2602 union
2603 {
2604 bfd_signed_vma refcount;
2605 bfd_vma offset;
2608 /* .glink stub offset. */
2609 bfd_vma glink_offset;
2610 };
2612 /* Of those relocs that might be copied as dynamic relocs, this function
2613 selects those that must be copied when linking a shared library,
2614 even when the symbol is local. */
2616 static int
2619 {
2621 {
2638 }
2639 }
2641 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
2642 copying dynamic variables from a shared lib into an app's dynbss
2643 section, and instead use a dynamic relocation to point into the
2644 shared lib. */
2645 #define ELIMINATE_COPY_RELOCS 1
2647 /* PPC ELF linker hash entry. */
2649 struct ppc_elf_link_hash_entry
2650 {
2653 /* If this symbol is used in the linker created sections, the processor
2654 specific backend uses this field to map the field into the offset
2655 from the beginning of the section. */
2658 /* Track dynamic relocs copied for this symbol. */
2661 /* Contexts in which symbol is used in the GOT (or TOC).
2662 TLS_GD .. TLS_TLS bits are or'd into the mask as the
2663 corresponding relocs are encountered during check_relocs.
2664 tls_optimize clears TLS_GD .. TLS_TPREL when optimizing to
2665 indicate the corresponding GOT entry type is not needed. */
2675 /* Nonzero if we have seen a small data relocation referring to this
2676 symbol. */
2678 };
2680 #define ppc_elf_hash_entry(ent) ((struct ppc_elf_link_hash_entry *) (ent))
2682 /* PPC ELF linker hash table. */
2684 struct ppc_elf_link_hash_table
2685 {
2688 /* Short-cuts to get to dynamic linker sections. */
2703 /* The (unloaded but important) .rela.plt.unloaded on VxWorks. */
2706 /* The .got.plt section (VxWorks only)*/
2709 /* Shortcut to __tls_get_addr. */
2712 /* The bfd that forced an old-style PLT. */
2715 /* TLS local dynamic got entry handling. */
2717 bfd_signed_vma refcount;
2718 bfd_vma offset;
2721 /* Offset of branch table to PltResolve function in glink. */
2722 bfd_vma glink_pltresolve;
2724 /* Size of reserved GOT entries. */
2726 /* Non-zero if allocating the header left a gap. */
2729 /* The type of PLT we have chosen to use. */
2732 /* Set if we should emit symbols for stubs. */
2735 /* Set if __tls_get_addr optimization should not be done. */
2738 /* True if the target system is VxWorks. */
2741 /* The size of PLT entries. */
2743 /* The distance between adjacent PLT slots. */
2745 /* The size of the first PLT entry. */
2748 /* Small local sym cache. */
2750 };
2752 /* Rename some of the generic section flags to better document how they
2753 are used here. */
2755 /* Nonzero if this section has TLS related relocations. */
2756 #define has_tls_reloc sec_flg0
2758 /* Nonzero if this section has a call to __tls_get_addr. */
2759 #define has_tls_get_addr_call sec_flg1
2761 /* Get the PPC ELF linker hash table from a link_info structure. */
2763 #define ppc_elf_hash_table(p) \
2764 (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \
2765 == PPC32_ELF_DATA ? ((struct ppc_elf_link_hash_table *) ((p)->hash)) : NULL)
2767 /* Create an entry in a PPC ELF linker hash table. */
2773 {
2774 /* Allocate the structure if it has not already been allocated by a
2775 subclass. */
2777 {
2782 }
2784 /* Call the allocation method of the superclass. */
2787 {
2791 }
2794 }
2796 /* Create a PPC ELF linker hash table. */
2800 {
2808 ppc_elf_link_hash_newfunc,
2810 PPC32_ELF_DATA))
2811 {
2814 }
2834 }
2836 /* Create .got and the related sections. */
2838 static bfd_boolean
2840 {
2843 flagword flags;
2854 {
2858 }
2859 else
2860 {
2861 /* The powerpc .got has a blrl instruction in it. Mark it
2862 executable. */
2867 }
2874 }
2876 static bfd_boolean
2878 {
2881 flagword flags;
2906 }
2908 /* We have to create .dynsbss and .rela.sbss here so that they get mapped
2909 to output sections (just like _bfd_elf_create_dynamic_sections has
2910 to create .dynbss and .rela.bss). */
2912 static bfd_boolean
2914 {
2917 flagword flags;
2940 {
2949 }
2962 /* The VxWorks PLT is a loaded section with contents. */
2965 }
2967 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2969 static void
2973 {
2980 {
2982 {
2986 /* Add reloc counts against the indirect sym to the direct sym
2987 list. Merge any entries against the same section. */
2989 {
2994 {
2999 }
3002 }
3004 }
3008 }
3013 /* If called to transfer flags for a weakdef during processing
3014 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
3015 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
3027 /* If we were called to copy over info for a weak sym, that's all. */
3031 /* Copy over the GOT refcount entries that we may have already seen to
3032 the symbol which just became indirect. */
3036 /* And plt entries. */
3038 {
3040 {
3045 {
3050 {
3054 }
3057 }
3059 }
3063 }
3066 {
3074 }
3075 }
3077 /* Hook called by the linker routine which adds symbols from an object
3078 file. We use it to put .comm items in .sbss, and not .bss. */
3080 static bfd_boolean
3088 {
3093 {
3094 /* Common symbols less than or equal to -G nn bytes are automatically
3095 put into .sbss. */
3100 {
3108 flags);
3111 }
3115 }
3122 }
3123 \f
3124 static bfd_boolean
3126 {
3138 }
3140 /* Create a special linker section. */
3142 static bfd_boolean
3145 flagword flags,
3147 {
3154 /* Record the first bfd that needs the special sections. */
3160 flags);
3167 }
3169 /* Find a linker generated pointer with a given addend and type. */
3172 elf_find_pointer_linker_section
3174 bfd_vma addend,
3176 {
3182 }
3184 /* Allocate a pointer to live in a linker created section. */
3186 static bfd_boolean
3191 {
3195 bfd_size_type amt;
3199 /* Is this a global symbol? */
3201 {
3204 /* Has this symbol already been allocated? If so, our work is done. */
3208 lsect))
3212 }
3213 else
3214 {
3217 /* Allocation of a pointer to a local symbol. */
3220 /* Allocate a table to hold the local symbols if first time. */
3222 {
3233 }
3235 /* Has this symbol already been allocated? If so, our work is done. */
3238 lsect))
3242 }
3244 /* Allocate space for a pointer in the linker section, and allocate
3245 a new pointer record from internal memory. */
3261 #ifdef DEBUG
3266 #endif
3269 }
3276 {
3282 {
3292 }
3300 }
3302 static bfd_boolean
3305 {
3314 {
3324 }
3327 }
3331 {
3340 }
3342 static bfd_boolean
3344 {
3355 }
3357 static void
3359 {
3362 abfd,
3365 }
3367 /* Look through the relocs for a section during the first phase, and
3368 allocate space in the global offset table or procedure linkage
3369 table. */
3371 static bfd_boolean
3376 {
3388 /* Don't do anything special with non-loaded, non-alloced sections.
3389 In particular, any relocs in such sections should not affect GOT
3390 and PLT reference counting (ie. we don't allow them to create GOT
3391 or PLT entries), there's no possibility or desire to optimize TLS
3392 relocs, and there's not much point in propagating relocs to shared
3393 libs that the dynamic linker won't relocate. */
3397 #ifdef DEBUG
3400 #endif
3404 /* Initialize howto table if not already done. */
3410 {
3415 }
3425 {
3434 else
3435 {
3440 }
3442 /* If a relocation refers to _GLOBAL_OFFSET_TABLE_, create the .got.
3443 This shows up in particular in an R_PPC_ADDR32 in the eabi
3444 startup code. */
3448 {
3454 }
3459 {
3468 {
3470 bfd_vma addend;
3473 PLT_IFUNC);
3477 /* STT_GNU_IFUNC symbols must have a PLT entry;
3478 In a non-pie executable even when there are
3479 no plt calls. */
3482 {
3486 }
3489 }
3490 }
3496 {
3500 /* We have a new-style __tls_get_addr call with a marker
3501 reloc. */
3502 ;
3503 else
3504 /* Mark this section as having an old-style call. */
3506 }
3509 {
3512 /* These special tls relocs tie a call to __tls_get_addr with
3513 its parameter symbol. */
3544 dogottls:
3546 /* Fall thru */
3548 /* GOT16 relocations */
3553 /* This symbol requires a global offset table entry. */
3555 {
3560 }
3562 {
3565 }
3566 else
3567 /* This is a global offset table entry for a local symbol. */
3571 /* We may also need a plt entry if the symbol turns out to be
3572 an ifunc. */
3574 {
3577 }
3580 /* Indirect .sdata relocation. */
3583 {
3586 }
3595 {
3598 }
3601 /* Indirect .sdata2 relocation. */
3604 {
3607 }
3616 {
3619 }
3627 {
3630 }
3635 {
3638 }
3643 {
3646 }
3652 {
3655 }
3663 {
3666 }
3675 {
3678 }
3686 /* Fall through */
3692 #ifdef DEBUG
3694 #endif
3695 /* This symbol requires a procedure linkage table entry. We
3696 actually build the entry in finish_dynamic_symbol,
3697 because this might be a case of linking PIC code without
3698 linking in any dynamic objects, in which case we don't
3699 need to generate a procedure linkage table after all. */
3702 {
3703 /* It does not make sense to have a procedure linkage
3704 table entry for a local symbol. */
3707 abfd,
3708 sec,
3713 }
3714 else
3715 {
3719 {
3723 }
3727 }
3730 /* The following relocations don't need to propagate the
3731 relocation if linking a shared object since they are
3732 section relative. */
3751 /* These are just markers. */
3761 /* These should only appear in dynamic objects. */
3769 /* These aren't handled yet. We'll report an error later. */
3778 /* This refers only to functions defined in the shared library. */
3781 {
3784 }
3787 /* This relocation describes the C++ object vtable hierarchy.
3788 Reconstruct it for later use during GC. */
3794 /* This relocation describes which C++ vtable entries are actually
3795 used. Record for later use during GC. */
3803 /* We shouldn't really be seeing these. */
3813 /* Nor these. */
3824 {
3825 /* Old -fPIC gcc code has .long LCTOC1-LCFx just before
3826 the start of a function, which assembles to a REL32
3827 reference to .got2. If we detect one of these, then
3828 force the old PLT layout because the linker cannot
3829 reliably deduce the GOT pointer value needed for
3830 PLT call stubs. */
3841 {
3844 }
3845 }
3848 /* fall through */
3858 {
3859 /* We may need a plt entry if the symbol turns out to be
3860 a function defined in a dynamic object. */
3864 /* We may need a copy reloc too. */
3867 }
3877 {
3879 {
3882 }
3884 }
3885 /* fall through */
3892 {
3893 /* We may need a plt entry if the symbol turns out to be
3894 a function defined in a dynamic object. */
3899 }
3901 dodyn:
3902 /* If we are creating a shared library, and this is a reloc
3903 against a global symbol, or a non PC relative reloc
3904 against a local symbol, then we need to copy the reloc
3905 into the shared library. However, if we are linking with
3906 -Bsymbolic, we do not need to copy a reloc against a
3907 global symbol which is defined in an object we are
3908 including in the link (i.e., DEF_REGULAR is set). At
3909 this point we have not seen all the input files, so it is
3910 possible that DEF_REGULAR is not set now but will be set
3911 later (it is never cleared). In case of a weak definition,
3912 DEF_REGULAR may be cleared later by a strong definition in
3913 a shared library. We account for that possibility below by
3914 storing information in the dyn_relocs field of the hash
3915 table entry. A similar situation occurs when creating
3916 shared libraries and symbol visibility changes render the
3917 symbol local.
3919 If on the other hand, we are creating an executable, we
3920 may need to keep relocations for symbols satisfied by a
3921 dynamic library if we manage to avoid copy relocs for the
3922 symbol. */
3929 || (ELIMINATE_COPY_RELOCS
3934 {
3938 #ifdef DEBUG
3940 "ppc_elf_check_relocs needs to "
3944 #endif
3946 {
3950 sreloc = _bfd_elf_make_dynamic_reloc_section
3955 }
3957 /* If this is a global symbol, we count the number of
3958 relocations we need for this symbol. */
3960 {
3962 }
3963 else
3964 {
3965 /* Track dynamic relocs needed for local syms too.
3966 We really need local syms available to do this
3967 easily. Oh well. */
3983 }
3987 {
3996 }
4001 }
4004 }
4005 }
4008 }
4009 \f
4011 /* Merge object attributes from IBFD into OBFD. Raise an error if
4012 there are conflicting attributes. */
4013 static bfd_boolean
4015 {
4020 {
4021 /* This is the first object. Copy the attributes. */
4024 /* Use the Tag_null value to indicate the attributes have been
4025 initialized. */
4029 }
4034 /* Check for conflicting Tag_GNU_Power_ABI_FP attributes and merge
4035 non-conflicting ones. */
4039 {
4044 ;
4046 _bfd_error_handler
4049 _bfd_error_handler
4053 _bfd_error_handler
4057 _bfd_error_handler
4061 _bfd_error_handler
4064 _bfd_error_handler
4067 else
4068 _bfd_error_handler
4071 }
4073 /* Check for conflicting Tag_GNU_Power_ABI_Vector attributes and
4074 merge non-conflicting ones. */
4078 {
4082 {
4086 }
4089 {
4093 }
4099 ;
4100 /* For now, allow generic to transition to AltiVec or SPE
4101 without a warning. If GCC marked files with their stack
4102 alignment and used don't-care markings for files which are
4103 not affected by the vector ABI, we could warn about this
4104 case too. */
4108 ;
4110 _bfd_error_handler
4114 _bfd_error_handler
4117 else
4118 _bfd_error_handler
4121 }
4123 /* Check for conflicting Tag_GNU_Power_ABI_Struct_Return attributes
4124 and merge non-conflicting ones. */
4128 {
4133 ;
4135 _bfd_error_handler
4138 _bfd_error_handler
4141 _bfd_error_handler
4144 else
4145 _bfd_error_handler
4148 }
4150 /* Merge Tag_compatibility attributes and any common GNU ones. */
4154 }
4156 /* Merge backend specific data from an object file to the output
4157 object file when linking. */
4159 static bfd_boolean
4161 {
4162 flagword old_flags;
4163 flagword new_flags;
4164 bfd_boolean error;
4169 /* Check if we have the same endianess. */
4179 {
4180 /* First call, no flags set. */
4183 }
4185 /* Compatible flags are ok. */
4187 ;
4189 /* Incompatible flags. */
4190 else
4191 {
4192 /* Warn about -mrelocatable mismatch. Allow -mrelocatable-lib
4193 to be linked with either. */
4197 {
4202 }
4205 {
4210 }
4212 /* The output is -mrelocatable-lib iff both the input files are. */
4216 /* The output is -mrelocatable iff it can't be -mrelocatable-lib,
4217 but each input file is either -mrelocatable or -mrelocatable-lib. */
4223 /* Do not warn about eabi vs. V.4 mismatch, just or in the bit if
4224 any module uses it. */
4230 /* Warn about any other mismatches. */
4232 {
4238 }
4241 {
4244 }
4245 }
4248 }
4249 \f
4250 /* Choose which PLT scheme to use, and set .plt flags appropriately.
4251 Returns -1 on error, 0 for old PLT, 1 for new PLT. */
4252 int
4257 {
4259 flagword flags;
4266 {
4269 else
4270 {
4274 /* Look through the reloc flags left by ppc_elf_check_relocs.
4275 Use the old style bss plt if a file makes plt calls
4276 without using the new relocs, and if ld isn't given
4277 --secure-plt and we never see REL16 relocs. */
4282 {
4286 {
4290 }
4291 }
4293 }
4294 }
4301 {
4305 /* The new PLT is a loaded section. */
4310 /* The new GOT is not executable. */
4314 }
4315 else
4316 {
4317 /* Stop an unused .glink section from affecting .text alignment. */
4321 }
4323 }
4324 \f
4325 /* Return the section that should be marked against GC for a given
4326 relocation. */
4334 {
4337 {
4341 }
4344 }
4346 /* Update the got, plt and dynamic reloc reference counts for the
4347 section being removed. */
4349 static bfd_boolean
4354 {
4378 {
4385 {
4397 {
4398 /* Everything must go for SEC. */
4401 }
4402 }
4410 {
4416 {
4427 }
4428 }
4431 {
4453 {
4457 {
4463 }
4464 }
4466 {
4469 }
4479 /* Fall thru */
4502 {
4511 }
4516 }
4517 }
4519 }
4520 \f
4521 /* Set plt output section type, htab->tls_get_addr, and call the
4522 generic ELF tls_setup function. */
4524 asection *
4528 {
4535 {
4542 {
4543 /* If glibc supports an optimized __tls_get_addr call stub,
4544 signalled by the presence of __tls_get_addr_opt, and we'll
4545 be calling __tls_get_addr via a plt call stub, then
4546 make __tls_get_addr point to __tls_get_addr_opt. */
4555 {
4561 {
4566 {
4567 /* Use __tls_get_addr_opt in dynamic relocations. */
4573 }
4575 }
4576 }
4577 }
4578 else
4580 }
4585 {
4588 }
4591 }
4593 /* Return TRUE iff REL is a branch reloc with a global symbol matching
4594 HASH. */
4596 static bfd_boolean
4600 {
4606 {
4616 }
4618 }
4620 /* Run through all the TLS relocs looking for optimization
4621 opportunities. */
4623 bfd_boolean
4626 {
4636 /* Make two passes through the relocs. First time check that tls
4637 relocs involved in setting up a tls_get_addr call are indeed
4638 followed by such a call. If they are not, exclude them from
4639 the optimizations done on the second pass. */
4642 {
4649 {
4652 /* Read the relocations. */
4660 {
4666 bfd_boolean is_local;
4672 {
4680 }
4690 {
4694 /* Fall thru */
4698 /* These relocs should never be against a symbol
4699 defined in a shared lib. Leave them alone if
4700 that turns out to be the case. */
4704 /* LD -> LE */
4712 /* Fall thru */
4717 /* GD -> LE */
4719 else
4720 /* GD -> IE */
4730 {
4731 /* IE -> LE */
4735 }
4736 else
4748 }
4751 {
4762 /* Uh oh, we didn't find the expected call. We
4763 could just mark this symbol to exclude it
4764 from tls optimization but it's safer to skip
4765 the entire section. */
4768 }
4771 {
4785 }
4788 {
4791 }
4792 else
4793 {
4800 {
4807 {
4811 }
4812 }
4822 }
4825 {
4826 /* We managed to get rid of a got entry. */
4829 }
4833 }
4837 }
4841 {
4844 else
4846 }
4847 }
4849 }
4850 \f
4851 /* Return true if we have dynamic relocs that apply to read-only sections. */
4853 static bfd_boolean
4855 {
4859 {
4866 }
4868 }
4870 /* Adjust a symbol defined by a dynamic object and referenced by a
4871 regular object. The current definition is in some section of the
4872 dynamic object, but we're not including those sections. We have to
4873 change the definition to something the rest of the link can
4874 understand. */
4876 static bfd_boolean
4879 {
4883 #ifdef DEBUG
4886 #endif
4888 /* Make sure we know what is going on here. */
4898 /* Deal with function syms. */
4902 {
4903 /* Clear procedure linkage table information for any symbol that
4904 won't need a .plt entry. */
4914 {
4915 /* A PLT entry is not required/allowed when:
4917 1. We are not using ld.so; because then the PLT entry
4918 can't be set up, so we can't use one. In this case,
4919 ppc_elf_adjust_dynamic_symbol won't even be called.
4921 2. GC has rendered the entry unused.
4923 3. We know for certain that a call to this symbol
4924 will go to this object, or will remain undefined. */
4927 }
4928 else
4929 {
4930 /* After adjust_dynamic_symbol, non_got_ref set in the
4931 non-shared case means that we have allocated space in
4932 .dynbss for the symbol and thus dyn_relocs for this
4933 symbol should be discarded.
4934 If we get here we know we are making a PLT entry for this
4935 symbol, and in an executable we'd normally resolve
4936 relocations against this symbol to the PLT entry. Allow
4937 dynamic relocs if the reference is weak, and the dynamic
4938 relocs will not cause text relocation. */
4946 }
4948 }
4949 else
4952 /* If this is a weak symbol, and there is a real definition, the
4953 processor independent code will have arranged for us to see the
4954 real definition first, and we can just use the same value. */
4956 {
4964 }
4966 /* This is a reference to a symbol defined by a dynamic object which
4967 is not a function. */
4969 /* If we are creating a shared library, we must presume that the
4970 only references to the symbol are via the global offset table.
4971 For such cases we need not do anything here; the relocations will
4972 be handled correctly by relocate_section. */
4976 /* If there are no references to this symbol that do not use the
4977 GOT, we don't need to generate a copy reloc. */
4981 /* If we didn't find any dynamic relocs in read-only sections, then
4982 we'll be keeping the dynamic relocs and avoiding the copy reloc.
4983 We can't do this if there are any small data relocations. This
4984 doesn't work on VxWorks, where we can not have dynamic
4985 relocations (other than copy and jump slot relocations) in an
4986 executable. */
4992 {
4995 }
4998 {
5002 }
5004 /* We must allocate the symbol in our .dynbss section, which will
5005 become part of the .bss section of the executable. There will be
5006 an entry for this symbol in the .dynsym section. The dynamic
5007 object will contain position independent code, so all references
5008 from the dynamic object to this symbol will go through the global
5009 offset table. The dynamic linker will use the .dynsym entry to
5010 determine the address it must put in the global offset table, so
5011 both the dynamic object and the regular object will refer to the
5012 same memory location for the variable.
5014 Of course, if the symbol is referenced using SDAREL relocs, we
5015 must instead allocate it in .sbss. */
5019 else
5023 /* We must generate a R_PPC_COPY reloc to tell the dynamic linker to
5024 copy the initial value out of the dynamic object and into the
5025 runtime process image. We need to remember the offset into the
5026 .rela.bss section we are going to use. */
5028 {
5033 else
5038 }
5041 }
5042 \f
5043 /* Generate a symbol to mark plt call stubs. For non-PIC code the sym is
5044 xxxxxxxx.plt_call32.<callee> where xxxxxxxx is a hex number, usually 0,
5045 specifying the addend on the plt relocation. For -fpic code, the sym
5046 is xxxxxxxx.plt_pic32.<callee>, and for -fPIC
5047 xxxxxxxx.got2.plt_pic32.<callee>. */
5049 static bfd_boolean
5053 {
5062 else
5082 {
5091 }
5093 }
5095 /* Allocate NEED contiguous space in .got, and return the offset.
5096 Handles allocation of the got header when crossing 32k. */
5098 static bfd_vma
5100 {
5101 bfd_vma where;
5105 {
5108 }
5109 else
5110 {
5113 {
5116 }
5117 else
5118 {
5121 {
5124 }
5127 }
5128 }
5130 }
5132 /* Allocate space in associated reloc sections for dynamic relocs. */
5134 static bfd_boolean
5136 {
5146 /* When warning symbols are created, they **replace** the "real"
5147 entry in the hash table, thus we never get to see the real
5148 symbol in a hash traversal. So look at it now. */
5154 {
5158 bfd_boolean dyn;
5162 {
5163 /* Make sure this symbol is output as a dynamic symbol. */
5168 {
5171 }
5177 {
5183 {
5185 {
5188 }
5193 {
5199 }
5204 {
5207 }
5213 }
5214 else
5215 {
5217 {
5218 /* If this is the first .plt entry, make room
5219 for the special first entry. */
5223 /* The PowerPC PLT is actually composed of two
5224 parts, the first part is 2 words (for a load
5225 and a jump), and then there is a remaining
5226 word available at the end. */
5233 /* If this symbol is not defined in a regular
5234 file, and we are not generating a shared
5235 library, then set the symbol to this location
5236 in the .plt. This is to avoid text
5237 relocations, and is required to make
5238 function pointers compare as equal between
5239 the normal executable and the shared library. */
5243 {
5246 }
5248 /* Make room for this entry. */
5250 /* After the 8192nd entry, room for two entries
5251 is allocated. */
5257 }
5259 }
5261 /* We also need to make an entry in the .rela.plt section. */
5263 {
5267 else
5268 {
5272 {
5273 /* Allocate space for the unloaded relocations. */
5276 {
5279 {
5283 }
5288 }
5290 /* Every PLT entry has an associated GOT entry in
5291 .got.plt. */
5293 }
5294 }
5296 }
5297 }
5298 else
5300 }
5301 else
5305 {
5308 }
5309 }
5310 else
5311 {
5314 }
5318 {
5319 bfd_boolean dyn;
5322 /* Make sure this symbol is output as a dynamic symbol. */
5327 {
5330 }
5334 {
5336 {
5338 /* We'll just use htab->tlsld_got.offset. This should
5339 always be the case. It's a little odd if we have
5340 a local dynamic reloc against a non-local symbol. */
5342 else
5344 }
5351 }
5352 else
5356 else
5357 {
5364 {
5366 /* All the entries we allocated need relocs.
5367 Except LD only needs one. */
5372 }
5373 }
5374 }
5375 else
5382 /* In the shared -Bsymbolic case, discard space allocated for
5383 dynamic pc-relative relocs against symbols which turn out to be
5384 defined in regular objects. For the normal shared case, discard
5385 space for relocs that have become local due to symbol visibility
5386 changes. */
5389 {
5390 /* Relocs that use pc_count are those that appear on a call insn,
5391 or certain REL relocs (see must_be_dyn_reloc) that can be
5392 generated via assembly. We want calls to protected symbols to
5393 resolve directly to the function rather than going via the plt.
5394 If people want function pointer comparisons to work as expected
5395 then they should avoid writing weird assembly. */
5397 {
5401 {
5406 else
5408 }
5409 }
5412 {
5416 {
5419 else
5421 }
5422 }
5424 /* Discard relocs on undefined symbols that must be local. */
5431 /* Also discard relocs on undefined weak syms with non-default
5432 visibility. */
5435 {
5439 /* Make sure undefined weak symbols are output as a dynamic
5440 symbol in PIEs. */
5444 {
5447 }
5448 }
5449 }
5451 {
5452 /* For the non-shared case, discard space for relocs against
5453 symbols which turn out to need copy relocs or are not
5454 dynamic. */
5458 {
5459 /* Make sure this symbol is output as a dynamic symbol.
5460 Undefined weak syms won't yet be marked as dynamic. */
5463 {
5466 }
5468 /* If that succeeded, we know we'll be keeping all the
5469 relocs. */
5472 }
5476 keep: ;
5477 }
5479 /* Finally, allocate space. */
5481 {
5486 }
5489 }
5491 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
5492 read-only sections. */
5494 static bfd_boolean
5496 {
5504 {
5507 /* Not an error, just cut short the traversal. */
5509 }
5511 }
5513 /* Set the sizes of the dynamic sections. */
5515 static bfd_boolean
5518 {
5521 bfd_boolean relocs;
5524 #ifdef DEBUG
5526 #endif
5532 {
5533 /* Set the contents of the .interp section to the interpreter. */
5535 {
5540 }
5541 }
5548 /* Set up .got offsets for local syms, and space for local dynamic
5549 relocs. */
5551 {
5557 bfd_size_type locsymcount;
5564 {
5571 {
5574 {
5575 /* Input section has been discarded, either because
5576 it is a copy of a linkonce section or due to
5577 linker script /DISCARD/, so we'll be discarding
5578 the relocs too. */
5579 }
5583 {
5584 /* Relocations in vxworks .tls_vars sections are
5585 handled specially by the loader. */
5586 }
5588 {
5597 }
5598 }
5599 }
5614 {
5617 {
5626 }
5627 else
5631 else
5632 {
5637 }
5638 }
5639 else
5645 /* Allocate space for calls to local STT_GNU_IFUNC syms in .iplt. */
5647 {
5654 {
5658 {
5661 }
5666 {
5669 }
5673 {
5676 }
5677 }
5678 else
5680 }
5681 }
5683 /* Allocate space for global sym dynamic relocs. */
5687 {
5691 }
5692 else
5696 {
5699 /* If we haven't allocated the header, do so now. When we get here,
5700 for old plt/got the got size will be 0 to 32764 (not allocated),
5701 or 32780 to 65536 (header allocated). For new plt/got, the
5702 corresponding ranges are 0 to 32768 and 32780 to 65536. */
5704 {
5709 }
5712 }
5714 {
5719 {
5723 }
5724 }
5729 {
5731 /* Space for the branch table. */
5733 /* Pad out to align the start of PLTresolve. */
5738 {
5745 {
5754 }
5760 {
5769 }
5770 }
5771 }
5773 /* We've now determined the sizes of the various dynamic sections.
5774 Allocate memory for them. */
5777 {
5785 {
5786 /* We'd like to strip these sections if they aren't needed, but if
5787 we've exported dynamic symbols from them we must leave them.
5788 It's too late to tell BFD to get rid of the symbols. */
5791 /* Strip this section if we don't need it; see the
5792 comment below. */
5793 }
5802 {
5803 /* Strip these too. */
5804 }
5806 {
5808 {
5809 /* Remember whether there are any relocation sections. */
5812 /* We use the reloc_count field as a counter if we need
5813 to copy relocs into the output file. */
5815 }
5816 }
5817 else
5818 {
5819 /* It's not one of our sections, so don't allocate space. */
5821 }
5824 {
5825 /* If we don't need this section, strip it from the
5826 output file. This is mostly to handle .rela.bss and
5827 .rela.plt. We must create both sections in
5828 create_dynamic_sections, because they must be created
5829 before the linker maps input sections to output
5830 sections. The linker does that before
5831 adjust_dynamic_symbol is called, and it is that
5832 function which decides whether anything needs to go
5833 into these sections. */
5836 }
5841 /* Allocate memory for the section contents. */
5845 }
5848 {
5849 /* Add some entries to the .dynamic section. We fill in the
5850 values later, in ppc_elf_finish_dynamic_sections, but we
5851 must add the entries now so that we get the correct size for
5852 the .dynamic section. The DT_DEBUG entry is filled in by the
5853 dynamic linker and used by the debugger. */
5854 #define add_dynamic_entry(TAG, VAL) \
5855 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
5858 {
5861 }
5864 {
5870 }
5873 {
5881 }
5884 {
5889 }
5891 /* If any dynamic relocs apply to a read-only section, then we
5892 need a DT_TEXTREL entry. */
5895 info);
5898 {
5901 }
5905 }
5906 #undef add_dynamic_entry
5909 }
5911 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
5913 static bfd_boolean
5915 {
5923 }
5924 \f
5925 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
5927 /* Relaxation trampolines. r12 is available for clobbering (r11, is
5928 used for some functions that are allowed to break the ABI). */
5930 {
5939 };
5942 {
5947 };
5949 static bfd_boolean
5954 {
5955 struct one_fixup
5956 {
5959 /* Final link, can use the symbol offset. For a
5960 relocatable link we use the symbol's index. */
5961 bfd_vma toff;
5962 bfd_vma trampoff;
5963 };
5973 bfd_size_type trampoff;
5978 /* Nothing to do if there are no relocations, and no need to do
5979 anything with non-alloc or non-code sections. */
5986 /* We cannot represent the required PIC relocs in the output, so don't
5987 do anything. The linker doesn't support mixing -shared and -r
5988 anyway. */
5993 /* Space for a branch around any trampolines. */
5998 /* Get a copy of the native relocations. */
6009 {
6023 {
6038 }
6040 /* Get the value of the symbol referred to by the reloc. */
6043 {
6044 /* A local symbol. */
6047 /* Read this BFD's local symbols. */
6049 {
6057 }
6065 else
6070 }
6071 else
6072 {
6073 /* Global symbol handling. */
6085 {
6088 }
6091 {
6094 }
6095 else
6099 }
6101 /* The condition here under which we call find_plt_ent must
6102 match that in relocate_section. If we call find_plt_ent here
6103 but not in relocate_section, or vice versa, then the branch
6104 destination used here may be incorrect. */
6107 {
6108 /* We know is_branch_reloc (r_type) is true. */
6112 }
6115 {
6120 }
6122 {
6130 {
6135 {
6138 }
6139 else
6140 {
6143 }
6144 }
6145 }
6147 /* If the branch and target are in the same section, you have
6148 no hope of adding stubs. We'll error out later should the
6149 branch overflow. */
6153 /* There probably isn't any reason to handle symbols in
6154 SEC_MERGE sections; SEC_MERGE doesn't seem a likely
6155 attribute for a code section, and we are only looking at
6156 branches. However, implement it correctly here as a
6157 reference for other target relax_section functions. */
6159 {
6160 /* At this stage in linking, no SEC_MERGE symbol has been
6161 adjusted, so all references to such symbols need to be
6162 passed through _bfd_merged_section_offset. (Later, in
6163 relocate_section, all SEC_MERGE symbols *except* for
6164 section symbols have been adjusted.)
6166 gas may reduce relocations against symbols in SEC_MERGE
6167 sections to a relocation against the section symbol when
6168 the original addend was zero. When the reloc is against
6169 a section symbol we should include the addend in the
6170 offset passed to _bfd_merged_section_offset, since the
6171 location of interest is the original symbol. On the
6172 other hand, an access to "sym+addend" where "sym" is not
6173 a section symbol should not include the addend; Such an
6174 access is presumed to be an offset from "sym"; The
6175 location of interest is just "sym". */
6181 toff);
6185 }
6186 /* PLTREL24 addends are special. */
6190 /* Attempted -shared link of non-pic code loses. */
6196 /* If the branch is in range, no need to do anything. */
6199 /* A relocatable link may have sections moved during
6200 final link, so do not presume they remain in range. */
6202 {
6209 }
6211 /* Look for an existing fixup to this address. */
6217 {
6223 /* Oh dear, we can't reach a trampoline. Don't try to add
6224 one. We'll report an error later. */
6228 {
6231 }
6232 else
6233 {
6236 }
6240 {
6244 }
6246 /* Hijack the old relocation. Since we need two
6247 relocations for this use a "composite" reloc. */
6249 stub_rtype);
6255 /* Record the fixup so we don't do it again this section. */
6264 changes++;
6265 }
6266 else
6267 {
6272 /* Nop out the reloc, since we're finalizing things here. */
6274 }
6276 /* Get the section contents. */
6278 {
6279 /* Get cached copy if it exists. */
6282 else
6283 {
6284 /* Go get them off disk. */
6287 }
6288 }
6290 /* Fix up the existing branch to hit the trampoline. */
6293 {
6311 }
6312 }
6314 /* Write out the trampolines. */
6316 {
6319 bfd_vma val;
6322 do
6323 {
6327 }
6335 /* Branch around the trampolines. */
6343 {
6346 }
6347 else
6348 {
6351 }
6355 {
6357 i++;
6361 }
6363 }
6367 {
6370 else
6371 {
6372 /* Cache the symbols for elf_link_input_bfd. */
6374 }
6375 }
6379 {
6382 else
6383 {
6384 /* Cache the section contents for elf_link_input_bfd. */
6386 }
6387 }
6390 {
6391 /* Append sufficient NOP relocs so we can write out relocation
6392 information for the trampolines. */
6402 {
6406 }
6413 }
6419 {
6420 /* Convert the internal relax relocs to external form. */
6423 {
6426 /* Rewrite the reloc and convert one of the trailing nop
6427 relocs to describe this relocation. */
6429 /* The relocs are at the bottom 2 bytes */
6435 irel++;
6436 }
6437 }
6441 error_return:
6451 }
6452 \f
6453 /* What to do when ld finds relocations against symbols defined in
6454 discarded sections. */
6456 static unsigned int
6458 {
6466 }
6467 \f
6468 /* Fill in the address for a pointer generated in a linker section. */
6470 static bfd_vma
6474 bfd_vma relocation,
6476 {
6482 {
6483 /* Handle global symbol. */
6489 }
6490 else
6491 {
6492 /* Handle local symbol. */
6498 }
6502 lsect);
6505 /* Offset will always be a multiple of four, so use the bottom bit
6506 as a "written" flag. */
6508 {
6513 }
6520 #ifdef DEBUG
6524 #endif
6527 }
6529 #define PPC_LO(v) ((v) & 0xffff)
6530 #define PPC_HI(v) (((v) >> 16) & 0xffff)
6531 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
6533 static void
6536 {
6539 bfd_vma plt;
6546 {
6559 {
6568 }
6569 else
6570 {
6579 }
6580 }
6581 else
6582 {
6591 }
6592 }
6594 /* Return true if symbol is defined statically. */
6596 static bfd_boolean
6598 {
6603 }
6605 /* If INSN is an opcode that may be used with an @tls operand, return
6606 the transformed insn for TLS optimisation, otherwise return 0. If
6607 REG is non-zero only match an insn with RB or RA equal to REG. */
6609 unsigned int
6611 {
6621 else
6625 /* add -> addi. */
6631 /* load and store indexed -> dform. */
6634 /* ldx, ldux, stdx, stdux -> ld, ldu, std, stdu. */
6637 /* lwax -> lwa. */
6639 else
6643 }
6645 /* If INSN is an opcode that may be used with an @tprel operand, return
6646 the transformed insn for an undefined weak symbol, ie. with the
6647 thread pointer REG operand removed. Otherwise return 0. */
6649 unsigned int
6651 {
6672 {
6674 }
6679 {
6684 }
6685 else
6688 }
6690 /* The RELOCATE_SECTION function is called by the ELF backend linker
6691 to handle the relocations for a section.
6693 The relocs are always passed as Rela structures; if the section
6694 actually uses Rel structures, the r_addend field will always be
6695 zero.
6697 This function is responsible for adjust the section contents as
6698 necessary, and (if using Rela relocs and generating a
6699 relocatable output file) adjusting the reloc addend as
6700 necessary.
6702 This function does not have to worry about setting the reloc
6703 address or the reloc symbol index.
6705 LOCAL_SYMS is a pointer to the swapped in local symbols.
6707 LOCAL_SECTIONS is an array giving the section in the input file
6708 corresponding to the st_shndx field of each local symbol.
6710 The global hash table entry for the global symbols can be found
6711 via elf_sym_hashes (input_bfd).
6713 When generating relocatable output, this function must handle
6714 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
6715 going to be the section symbol corresponding to the output
6716 section, which means that the addend must be adjusted
6717 accordingly. */
6719 static bfd_boolean
6728 {
6734 Elf_Internal_Rela outrel;
6739 bfd_boolean is_vxworks_tls;
6741 #ifdef DEBUG
6747 #endif
6751 /* Initialize howto table if not already done. */
6759 /* We have to handle relocations in vxworks .tls_vars sections
6760 specially, because the dynamic loader is 'weird'. */
6767 {
6769 bfd_vma addend;
6770 bfd_reloc_status_type r;
6777 bfd_vma relocation;
6779 bfd_boolean unresolved_reloc;
6780 bfd_boolean warned;
6793 {
6799 }
6800 else
6801 {
6808 }
6811 {
6812 /* For relocs against symbols from removed linkonce sections,
6813 or sections discarded by a linker script, we just want the
6814 section contents zeroed. Avoid any special processing. */
6822 }
6825 {
6829 {
6830 /* R_PPC_PLTREL24 is rather special. If non-zero, the
6831 addend specifies the GOT pointer offset within .got2. */
6833 }
6835 }
6837 /* TLS optimizations. Replace instruction sequences and relocs
6838 based on information we collected in tls_optimize. We edit
6839 RELOCS so that --emit-relocs will output something sensible
6840 for the final instruction stream. */
6846 {
6849 local_plt
6853 }
6855 /* Ensure reloc mapping code below stays sane. */
6866 {
6874 {
6875 bfd_vma insn;
6883 }
6889 {
6890 bfd_vma insn;
6900 /* Was PPC_TLS which sits on insn boundary, now
6901 PPC_TPREL16_LO which is at low-order half-word. */
6903 }
6916 {
6917 tls_gdld_hi:
6921 else
6922 {
6926 }
6928 }
6941 {
6943 bfd_vma offset;
6945 tls_ldgd_opt:
6947 /* If not using the newer R_PPC_TLSGD/LD to mark
6948 __tls_get_addr calls, we must trust that the call
6949 stays with its arg setup insns, ie. that the next
6950 reloc is the __tls_get_addr call associated with
6951 the current reloc. Edit both insns. */
6958 {
6959 /* IE */
6965 {
6969 }
6973 }
6974 else
6975 {
6976 /* LE */
6979 {
6980 /* Was an LD reloc. */
6983 r_symndx++)
6993 }
6997 {
7003 }
7004 }
7008 {
7009 /* We changed the symbol on an LD reloc. Start over
7010 in order to get h, sym, sec etc. right. */
7011 rel--;
7013 }
7014 }
7019 {
7024 {
7025 /* IE */
7028 }
7029 else
7030 {
7031 /* LE */
7035 }
7038 /* Zap the reloc on the _tls_get_addr call too. */
7041 }
7046 {
7051 r_symndx++)
7067 /* Zap the reloc on the _tls_get_addr call too. */
7070 rel--;
7072 }
7074 }
7076 /* Handle other relocations that tweak non-addend part of insn. */
7079 {
7083 /* Branch taken prediction relocations. */
7087 /* Fall thru */
7089 /* Branch not taken prediction relocations. */
7092 {
7093 bfd_vma insn;
7103 /* Invert 'y' bit if not the default. */
7109 }
7110 }
7114 {
7118 {
7121 }
7124 {
7130 }
7136 {
7141 }
7143 {
7145 {
7146 Elf_Internal_Rela rela;
7160 }
7162 {
7167 }
7176 else
7180 }
7181 }
7189 {
7208 /* GOT16 relocations. Like an ADDR16 using the symbol's
7209 address in the GOT as relocation value instead of the
7210 symbol's value itself. Also, create a GOT entry for the
7211 symbol and put the symbol value there. */
7245 dogot:
7246 {
7247 /* Relocation is to the entry for this symbol in the global
7248 offset table. */
7249 bfd_vma off;
7262 {
7263 bfd_boolean dyn;
7268 /* This is actually a static link, or it is a
7269 -Bsymbolic link and the symbol is defined
7270 locally, or the symbol was forced to be local
7271 because of a version file. */
7272 ;
7273 else
7274 {
7277 }
7279 }
7280 else
7281 {
7285 }
7287 /* The offset must always be a multiple of 4. We use the
7288 least significant bit to record whether we have already
7289 processed this entry. */
7293 else
7294 {
7305 /* We might have multiple got entries for this sym.
7306 Initialize them all. */
7307 do
7308 {
7312 {
7315 }
7317 {
7320 }
7322 {
7325 }
7327 {
7330 }
7332 /* Generate relocs for the dynamic linker. */
7338 {
7347 {
7350 {
7357 outrel.r_info
7359 }
7360 }
7369 else
7372 {
7376 }
7381 }
7383 /* Init the .got section contents if we're not
7384 emitting a reloc. */
7385 else
7386 {
7392 {
7398 {
7402 }
7403 }
7406 }
7411 }
7416 }
7422 {
7424 {
7430 {
7434 {
7437 }
7438 }
7439 }
7440 }
7444 + off
7447 /* Addends on got relocations don't make much sense.
7448 x+off@got is actually x@got+off, and since the got is
7449 generated by a hash table traversal, the value in the
7450 got at entry m+n bears little relation to the entry m. */
7454 input_bfd,
7455 input_section,
7458 sym_name);
7459 }
7462 /* Relocations that need no special processing. */
7464 /* It makes no sense to point a local relocation
7465 at a symbol not in this object. */
7467 {
7470 input_bfd,
7471 input_section,
7473 TRUE))
7476 }
7486 /* Relocations that may need to be propagated if this is a shared
7487 object. */
7495 {
7496 /* Make this relocation against an undefined weak symbol
7497 resolve to zero. This is really just a tweak, since
7498 code using weak externs ought to check that they are
7499 defined before using them. */
7506 }
7508 /* The TPREL16 relocs shouldn't really be used in shared
7509 libs as they will result in DT_TEXTREL being set, but
7510 support them anyway. */
7535 /* fall through */
7550 /* If these relocations are not to a named symbol, they can be
7551 handled right here, no need to bother the dynamic linker. */
7555 /* fall through */
7563 /* fall through */
7565 dodyn:
7579 || (ELIMINATE_COPY_RELOCS
7585 {
7588 #ifdef DEBUG
7593 #endif
7595 /* When generating a shared object, these relocations
7596 are copied into the output file to be resolved at run
7597 time. */
7599 {
7605 }
7623 {
7627 }
7628 else
7629 {
7633 {
7637 {
7638 /* If we get here when building a static
7639 executable, then the libc startup function
7640 responsible for applying indirect function
7641 relocations is going to complain about
7642 the reloc type.
7643 If we get here when building a dynamic
7644 executable, it will be because we have
7645 a text relocation. The dynamic loader
7646 will set the text segment writable and
7647 non-executable to apply text relocations.
7648 So we'll segfault when trying to run the
7649 indirection function to resolve the reloc. */
7653 input_bfd,
7654 input_section,
7657 sym_name);
7659 }
7661 ;
7663 {
7666 }
7667 else
7668 {
7671 /* We are turning this relocation into one
7672 against a section symbol. It would be
7673 proper to subtract the symbol's value,
7674 osec->vma, from the emitted reloc addend,
7675 but ld.so expects buggy relocs.
7676 FIXME: Why not always use a zero index? */
7680 {
7683 }
7685 #ifdef DEBUG
7690 #endif
7691 }
7694 }
7697 else
7699 }
7708 /* This reloc will be computed at runtime. We clear the memory
7709 so that it contains predictable value. */
7713 {
7717 }
7718 }
7724 {
7729 {
7733 }
7739 else
7743 }
7744 /* Fall thru */
7752 {
7759 /* We're clearing the bits for R_PPC_ADDR16_HA
7760 and R_PPC_ADDR16_LO here. */
7764 /* t0 is HA, t1 is LO */
7772 /* Rewrite the reloc and convert one of the trailing nop
7773 relocs to describe this relocation. */
7775 /* The relocs are at the bottom 2 bytes */
7781 rel++;
7782 }
7785 /* Indirect .sdata relocation. */
7789 {
7792 }
7793 relocation
7799 /* Indirect .sdata2 relocation. */
7803 {
7806 }
7807 relocation
7813 /* Handle the TOC16 reloc. We want to use the offset within the .got
7814 section, not the actual VMA. This is appropriate when generating
7815 an embedded ELF object, for which the .got section acts like the
7816 AIX .toc section. */
7819 {
7822 }
7832 /* Relocation is to the entry for this symbol in the
7833 procedure linkage table. */
7834 {
7840 {
7841 /* We didn't make a PLT entry for this symbol. This
7842 happens when statically linking PIC code, or when
7843 using -Bsymbolic. */
7845 }
7852 else
7856 }
7859 /* Relocate against _SDA_BASE_. */
7861 {
7868 {
7871 }
7879 {
7883 input_bfd,
7884 sym_name,
7886 name);
7887 }
7888 }
7891 /* Relocate against _SDA2_BASE_. */
7893 {
7900 {
7903 }
7909 {
7913 input_bfd,
7914 sym_name,
7916 name);
7917 }
7918 }
7921 /* Relocate against either _SDA_BASE_, _SDA2_BASE_, or 0. */
7924 {
7930 {
7933 }
7940 {
7943 }
7946 {
7949 }
7952 {
7954 }
7955 else
7956 {
7960 input_bfd,
7961 sym_name,
7963 name);
7968 }
7971 {
7973 {
7976 }
7978 }
7981 {
7987 }
7988 }
7991 /* Relocate against the beginning of the section. */
7997 {
8000 }
8004 /* Negative relocations. */
8031 input_bfd,
8033 sym_name);
8038 }
8040 /* Do any further special processing. */
8042 {
8053 /* It's just possible that this symbol is a weak symbol
8054 that's not actually defined anywhere. In that case,
8055 'sec' would be NULL, and we should leave the symbol
8056 alone (it will be set to zero elsewhere in the link). */
8059 /* Fall thru */
8067 /* Add 0x10000 if sign bit in 0:15 is set.
8068 Bits 0:15 are not used. */
8071 }
8073 #ifdef DEBUG
8078 sym_name,
8079 r_symndx,
8082 #endif
8087 {
8090 input_bfd,
8091 input_section,
8094 sym_name);
8096 }
8099 input_bfd,
8100 input_section,
8101 contents,
8103 relocation,
8104 addend);
8107 {
8109 {
8115 {
8116 /* Assume this is a call protected by other code that
8117 detect the symbol is undefined. If this is the case,
8118 we can safely ignore the overflow. If not, the
8119 program is hosed anyway, and a little warning isn't
8120 going to help. */
8123 }
8127 sym_name,
8130 input_bfd,
8131 input_section,
8134 }
8135 else
8136 {
8142 }
8143 }
8144 }
8146 #ifdef DEBUG
8148 #endif
8151 }
8152 \f
8153 /* Finish up dynamic symbol handling. We set the contents of various
8154 dynamic sections here. */
8156 static bfd_boolean
8161 {
8164 bfd_boolean doneone;
8166 #ifdef DEBUG
8169 #endif
8177 {
8179 {
8180 Elf_Internal_Rela rela;
8182 bfd_vma reloc_index;
8188 else
8189 {
8195 }
8197 /* This symbol has an entry in the procedure linkage table.
8198 Set it up. */
8202 {
8203 bfd_vma got_offset;
8206 /* The first three entries in .got.plt are reserved. */
8209 /* Use the right PLT. */
8213 /* Fill in the .plt on VxWorks. */
8215 {
8222 }
8223 else
8224 {
8233 }
8240 /* This instruction is an immediate load. The value loaded is
8241 the byte offset of the R_PPC_JMP_SLOT relocation from the
8242 start of the .rela.plt section. The value is stored in the
8243 low-order 16 bits of the load instruction. */
8244 /* NOTE: It appears that this is now an index rather than a
8245 prescaled offset. */
8249 /* This instruction is a PC-relative branch whose target is
8250 the start of the PLT section. The address of this branch
8251 instruction is 20 bytes beyond the start of this PLT entry.
8252 The address is encoded in bits 6-29, inclusive. The value
8253 stored is right-shifted by two bits, permitting a 26-bit
8254 offset. */
8264 /* Fill in the GOT entry corresponding to this PLT slot with
8265 the address immediately after the the "bctr" instruction
8266 in this PLT entry. */
8273 {
8274 /* Fill in a couple of entries in .rela.plt.unloaded. */
8280 /* Provide the @ha relocation for the first instruction. */
8285 R_PPC_ADDR16_HA);
8290 /* Provide the @l relocation for the second instruction. */
8295 R_PPC_ADDR16_LO);
8300 /* Provide a relocation for the GOT entry corresponding to this
8301 PLT slot. Point it at the middle of the .plt entry. */
8306 R_PPC_ADDR32);
8309 }
8311 /* VxWorks uses non-standard semantics for R_PPC_JMP_SLOT.
8312 In particular, the offset for the relocation is not the
8313 address of the PLT entry for this function, as specified
8314 by the ABI. Instead, the offset is set to the address of
8315 the GOT slot for this function. See EABI 4.4.4.1. */
8320 }
8321 else
8322 {
8334 {
8335 /* We don't need to fill in the .plt. The ppc dynamic
8336 linker will fill it in. */
8337 }
8338 else
8339 {
8345 }
8346 }
8348 /* Fill in the entry in the .rela.plt section. */
8352 {
8359 }
8360 else
8368 else
8374 {
8375 /* Mark the symbol as undefined, rather than as
8376 defined in the .plt section. Leave the value if
8377 there were any relocations where pointer equality
8378 matters (this is a clue for the dynamic linker, to
8379 make function pointer comparisons work between an
8380 application and shared library), otherwise set it
8381 to zero. */
8386 {
8387 /* This breaks function pointer comparisons, but
8388 that is better than breaking tests for a NULL
8389 function pointer. */
8391 }
8392 }
8395 {
8396 /* Set the value of ifunc symbols in a non-pie
8397 executable to the glink entry. This is to avoid
8398 text relocations. We can't do this for ifunc in
8399 allocate_dynrelocs, as we do for normal dynamic
8400 function symbols with plt entries, because we need
8401 to keep the original value around for the ifunc
8402 relocation. */
8408 }
8410 }
8415 {
8425 {
8442 }
8447 /* We only need one non-PIC glink stub. */
8449 }
8450 else
8452 }
8455 {
8457 Elf_Internal_Rela rela;
8460 /* This symbols needs a copy reloc. Set it up. */
8462 #ifdef DEBUG
8464 #endif
8470 else
8479 }
8481 #ifdef DEBUG
8483 #endif
8485 /* Mark some specially defined symbols as absolute. */
8494 }
8495 \f
8496 static enum elf_reloc_type_class
8498 {
8500 {
8511 }
8512 }
8513 \f
8514 /* Finish up the dynamic sections. */
8516 static bfd_boolean
8519 {
8523 bfd_vma got;
8527 #ifdef DEBUG
8529 #endif
8536 else
8544 {
8552 {
8553 Elf_Internal_Dyn dyn;
8559 {
8563 else
8583 {
8587 }
8595 }
8598 }
8599 }
8602 {
8605 {
8610 {
8611 /* Add a blrl instruction at _GLOBAL_OFFSET_TABLE_-4
8612 so that a function can easily find the address of
8613 _GLOBAL_OFFSET_TABLE_. */
8617 }
8620 {
8625 }
8626 }
8627 else
8628 {
8635 }
8638 }
8640 /* Fill in the first entry in the VxWorks procedure linkage table. */
8642 {
8643 /* Use the right PLT. */
8649 {
8656 }
8657 else
8658 {
8661 }
8670 {
8671 Elf_Internal_Rela rela;
8676 /* Output the @ha relocation for the first instruction. */
8685 /* Output the @l relocation for the second instruction. */
8694 /* Fix up the remaining relocations. They may have the wrong
8695 symbol index for _G_O_T_ or _P_L_T_ depending on the order
8696 in which symbols were output. */
8698 {
8699 Elf_Internal_Rela rel;
8715 }
8716 }
8717 }
8722 {
8725 bfd_vma res0;
8728 /*
8729 * PIC glink code is the following:
8730 *
8731 * # ith PLT code stub.
8732 * addis 11,30,(plt+(i-1)*4-got)@ha
8733 * lwz 11,(plt+(i-1)*4-got)@l(11)
8734 * mtctr 11
8735 * bctr
8736 *
8737 * # A table of branches, one for each plt entry.
8738 * # The idea is that the plt call stub loads ctr and r11 with these
8739 * # addresses, so (r11 - res_0) gives the plt index * 4.
8740 * res_0: b PLTresolve
8741 * res_1: b PLTresolve
8742 * .
8743 * # Some number of entries towards the end can be nops
8744 * res_n_m3: nop
8745 * res_n_m2: nop
8746 * res_n_m1:
8747 *
8748 * PLTresolve:
8749 * addis 11,11,(1f-res_0)@ha
8750 * mflr 0
8751 * bcl 20,31,1f
8752 * 1: addi 11,11,(1b-res_0)@l
8753 * mflr 12
8754 * mtlr 0
8755 * sub 11,11,12 # r11 = index * 4
8756 * addis 12,12,(got+4-1b)@ha
8757 * lwz 0,(got+4-1b)@l(12) # got[1] address of dl_runtime_resolve
8758 * lwz 12,(got+8-1b)@l(12) # got[2] contains the map address
8759 * mtctr 0
8760 * add 0,11,11
8761 * add 11,0,11 # r11 = index * 12 = reloc offset.
8762 * bctr
8763 */
8765 {
8766 ADDIS_11_11,
8767 MFLR_0,
8768 BCL_20_31,
8769 ADDI_11_11,
8770 MFLR_12,
8771 MTLR_0,
8772 SUB_11_11_12,
8773 ADDIS_12_12,
8774 LWZ_0_12,
8775 LWZ_12_12,
8776 MTCTR_0,
8777 ADD_0_11_11,
8778 ADD_11_0_11,
8779 BCTR,
8780 NOP,
8781 NOP
8782 };
8784 /*
8785 * Non-PIC glink code is a little simpler.
8786 *
8787 * # ith PLT code stub.
8788 * lis 11,(plt+(i-1)*4)@ha
8789 * lwz 11,(plt+(i-1)*4)@l(11)
8790 * mtctr 11
8791 * bctr
8792 *
8793 * The branch table is the same, then comes
8794 *
8795 * PLTresolve:
8796 * lis 12,(got+4)@ha
8797 * addis 11,11,(-res_0)@ha
8798 * lwz 0,(got+4)@l(12) # got[1] address of dl_runtime_resolve
8799 * addi 11,11,(-res_0)@l # r11 = index * 4
8800 * mtctr 0
8801 * add 0,11,11
8802 * lwz 12,(got+8)@l(12) # got[2] contains the map address
8803 * add 11,0,11 # r11 = index * 12 = reloc offset.
8804 * bctr
8805 */
8807 {
8808 LIS_12,
8809 ADDIS_11_11,
8810 LWZ_0_12,
8811 ADDI_11_11,
8812 MTCTR_0,
8813 ADD_0_11_11,
8814 LWZ_12_12,
8815 ADD_11_0_11,
8816 BCTR,
8817 NOP,
8818 NOP,
8819 NOP,
8820 NOP,
8821 NOP,
8822 NOP,
8823 NOP
8824 };
8831 /* Build the branch table, one for each plt entry (less one),
8832 and perhaps some padding. */
8838 {
8841 }
8843 {
8846 }
8852 /* Last comes the PLTresolve stub. */
8854 {
8855 bfd_vma bcl;
8858 {
8861 }
8875 {
8880 }
8881 else
8882 {
8887 }
8888 }
8889 else
8890 {
8892 {
8895 }
8905 {
8910 }
8911 else
8912 {
8917 }
8918 }
8919 }
8922 }
8923 \f
8924 #define TARGET_LITTLE_SYM bfd_elf32_powerpcle_vec
8926 #define TARGET_BIG_SYM bfd_elf32_powerpc_vec
8928 #define ELF_ARCH bfd_arch_powerpc
8929 #define ELF_MACHINE_CODE EM_PPC
8930 #ifdef __QNXTARGET__
8931 #define ELF_MAXPAGESIZE 0x1000
8932 #else
8933 #define ELF_MAXPAGESIZE 0x10000
8934 #endif
8935 #define ELF_MINPAGESIZE 0x1000
8936 #define ELF_COMMONPAGESIZE 0x1000
8937 #define elf_info_to_howto ppc_elf_info_to_howto
8939 #ifdef EM_CYGNUS_POWERPC
8940 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
8941 #endif
8943 #ifdef EM_PPC_OLD
8944 #define ELF_MACHINE_ALT2 EM_PPC_OLD
8945 #endif
8947 #define elf_backend_plt_not_loaded 1
8948 #define elf_backend_can_gc_sections 1
8949 #define elf_backend_can_refcount 1
8950 #define elf_backend_rela_normal 1
8952 #define bfd_elf32_mkobject ppc_elf_mkobject
8953 #define bfd_elf32_bfd_merge_private_bfd_data ppc_elf_merge_private_bfd_data
8954 #define bfd_elf32_bfd_relax_section ppc_elf_relax_section
8955 #define bfd_elf32_bfd_reloc_type_lookup ppc_elf_reloc_type_lookup
8956 #define bfd_elf32_bfd_reloc_name_lookup ppc_elf_reloc_name_lookup
8957 #define bfd_elf32_bfd_set_private_flags ppc_elf_set_private_flags
8958 #define bfd_elf32_bfd_link_hash_table_create ppc_elf_link_hash_table_create
8959 #define bfd_elf32_get_synthetic_symtab ppc_elf_get_synthetic_symtab
8961 #define elf_backend_object_p ppc_elf_object_p
8962 #define elf_backend_gc_mark_hook ppc_elf_gc_mark_hook
8963 #define elf_backend_gc_sweep_hook ppc_elf_gc_sweep_hook
8964 #define elf_backend_section_from_shdr ppc_elf_section_from_shdr
8965 #define elf_backend_relocate_section ppc_elf_relocate_section
8966 #define elf_backend_create_dynamic_sections ppc_elf_create_dynamic_sections
8967 #define elf_backend_check_relocs ppc_elf_check_relocs
8968 #define elf_backend_copy_indirect_symbol ppc_elf_copy_indirect_symbol
8969 #define elf_backend_adjust_dynamic_symbol ppc_elf_adjust_dynamic_symbol
8970 #define elf_backend_add_symbol_hook ppc_elf_add_symbol_hook
8971 #define elf_backend_size_dynamic_sections ppc_elf_size_dynamic_sections
8972 #define elf_backend_hash_symbol ppc_elf_hash_symbol
8973 #define elf_backend_finish_dynamic_symbol ppc_elf_finish_dynamic_symbol
8974 #define elf_backend_finish_dynamic_sections ppc_elf_finish_dynamic_sections
8975 #define elf_backend_fake_sections ppc_elf_fake_sections
8976 #define elf_backend_additional_program_headers ppc_elf_additional_program_headers
8977 #define elf_backend_grok_prstatus ppc_elf_grok_prstatus
8978 #define elf_backend_grok_psinfo ppc_elf_grok_psinfo
8979 #define elf_backend_write_core_note ppc_elf_write_core_note
8980 #define elf_backend_reloc_type_class ppc_elf_reloc_type_class
8981 #define elf_backend_begin_write_processing ppc_elf_begin_write_processing
8982 #define elf_backend_final_write_processing ppc_elf_final_write_processing
8983 #define elf_backend_write_section ppc_elf_write_section
8984 #define elf_backend_get_sec_type_attr ppc_elf_get_sec_type_attr
8985 #define elf_backend_plt_sym_val ppc_elf_plt_sym_val
8986 #define elf_backend_action_discarded ppc_elf_action_discarded
8987 #define elf_backend_init_index_section _bfd_elf_init_1_index_section
8988 #define elf_backend_post_process_headers _bfd_elf_set_osabi
8992 /* VxWorks Target */
8994 #undef TARGET_LITTLE_SYM
8995 #undef TARGET_LITTLE_NAME
8997 #undef TARGET_BIG_SYM
8998 #define TARGET_BIG_SYM bfd_elf32_powerpc_vxworks_vec
8999 #undef TARGET_BIG_NAME
9002 /* VxWorks uses the elf default section flags for .plt. */
9005 {
9013 }
9015 /* Like ppc_elf_link_hash_table_create, but overrides
9016 appropriately for VxWorks. */
9019 {
9024 {
9032 }
9034 }
9036 /* Tweak magic VxWorks symbols as they are loaded. */
9037 static bfd_boolean
9045 {
9047 valp))
9051 }
9053 static void
9055 {
9058 }
9060 /* On VxWorks, we emit relocations against _PROCEDURE_LINKAGE_TABLE_, so
9061 define it. */
9062 #undef elf_backend_want_plt_sym
9063 #define elf_backend_want_plt_sym 1
9064 #undef elf_backend_want_got_plt
9065 #define elf_backend_want_got_plt 1
9066 #undef elf_backend_got_symbol_offset
9067 #define elf_backend_got_symbol_offset 0
9068 #undef elf_backend_plt_not_loaded
9069 #define elf_backend_plt_not_loaded 0
9070 #undef elf_backend_plt_readonly
9071 #define elf_backend_plt_readonly 1
9072 #undef elf_backend_got_header_size
9073 #define elf_backend_got_header_size 12
9075 #undef bfd_elf32_get_synthetic_symtab
9077 #undef bfd_elf32_bfd_link_hash_table_create
9078 #define bfd_elf32_bfd_link_hash_table_create \
9079 ppc_elf_vxworks_link_hash_table_create
9080 #undef elf_backend_add_symbol_hook
9081 #define elf_backend_add_symbol_hook \
9082 ppc_elf_vxworks_add_symbol_hook
9083 #undef elf_backend_link_output_symbol_hook
9084 #define elf_backend_link_output_symbol_hook \
9085 elf_vxworks_link_output_symbol_hook
9086 #undef elf_backend_final_write_processing
9087 #define elf_backend_final_write_processing \
9088 ppc_elf_vxworks_final_write_processing
9089 #undef elf_backend_get_sec_type_attr
9090 #define elf_backend_get_sec_type_attr \
9091 ppc_elf_vxworks_get_sec_type_attr
9092 #undef elf_backend_emit_relocs
9093 #define elf_backend_emit_relocs \
9094 elf_vxworks_emit_relocs
9096 #undef elf32_bed
9097 #define elf32_bed ppc_elf_vxworks_bed
9098 #undef elf_backend_post_process_headers