| blob | 9e097ad624dd4b4691b3a6edcb81826b74a5b8bf |
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 {
2001 }
2003 /* If we have .sbss2 or .PPC.EMB.sbss0 output sections, we
2004 need to bump up the number of section headers. */
2006 static int
2009 {
2022 }
2024 /* Add extra PPC sections -- Note, for now, make .sbss2 and
2025 .PPC.EMB.sbss0 a normal section, and not a bss section so
2026 that the linker doesn't crater when trying to make more than
2027 2 sections. */
2030 {
2041 };
2043 /* This is what we want for new plt/got. */
2049 {
2052 /* See if this is one of the special sections. */
2059 {
2063 }
2066 }
2067 \f
2068 /* Very simple linked list structure for recording apuinfo values. */
2070 {
2073 }
2074 apuinfo_list;
2079 static void
2081 {
2084 }
2086 static void
2088 {
2092 {
2096 }
2105 }
2107 static unsigned
2109 {
2114 entry;
2119 }
2123 {
2129 ;
2132 }
2134 static void
2136 {
2140 {
2144 }
2147 }
2152 /* Scan the input BFDs and create a linked list of
2153 the APUinfo values that will need to be emitted. */
2155 static void
2157 {
2171 /* Read in the input sections contents. */
2173 {
2187 {
2194 }
2198 {
2201 }
2203 /* Verify the contents of the header. Note - we have to
2204 extract the values this way in order to allow for a
2205 host whose endian-ness is different from the target. */
2217 /* Get the number of bytes used for apuinfo entries. */
2222 /* Scan the apuinfo section, building a list of apuinfo numbers. */
2225 }
2230 {
2231 /* Compute the size of the output section. */
2234 /* Set the output section size, if it exists. */
2238 {
2241 }
2242 }
2244 fail:
2250 }
2252 /* Prevent the output section from accumulating the input sections'
2253 contents. We have already stored this in our linked list structure. */
2255 static bfd_boolean
2260 {
2262 }
2264 /* Finally we can generate the output section. */
2266 static void
2268 {
2273 bfd_size_type length;
2288 {
2292 }
2294 /* Create the apuinfo header. */
2303 {
2306 }
2317 }
2318 \f
2319 static bfd_boolean
2321 {
2331 }
2333 static bfd_boolean
2335 {
2340 }
2342 static long
2346 {
2351 bfd_vma stub_vma;
2375 /* Call common code to handle old-style executable PLTs. */
2380 /* If this object was prelinked, the prelinker stored the address
2381 of .glink at got[1]. If it wasn't prelinked, got[1] will be zero. */
2384 {
2398 {
2399 Elf_Internal_Dyn dyn;
2406 {
2414 }
2415 }
2417 }
2419 /* Otherwise we read the first plt entry. */
2421 {
2424 }
2429 /* The .glink section usually does not survive the final
2430 link; search for the section (usually .text) where the
2431 glink stubs now reside. */
2436 /* Determine glink PLT resolver by reading the relative branch
2437 from the first glink stub. */
2440 {
2443 /* The first glink stub may either branch to the resolver ... */
2448 /* ... or fall through a bunch of NOPs. */
2455 {
2458 }
2459 }
2463 /* If the stubs are those for -shared/-pie then we might have
2464 multiple stubs for each plt entry. If that is the case then
2465 there is no way to associate stubs with their plt entries short
2466 of figuring out the GOT pointer value used in the stub. */
2478 {
2482 }
2496 {
2500 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL set. Since
2501 we are defining a symbol, ensure one of them is set. */
2513 {
2518 }
2523 }
2525 /* Add a symbol at the start of the glink branch table. */
2534 s++;
2535 count++;
2538 {
2539 /* Add a symbol for the glink PLT resolver. */
2548 s++;
2549 count++;
2550 }
2553 }
2554 \f
2555 /* The following functions are specific to the ELF linker, while
2556 functions above are used generally. They appear in this file more
2557 or less in the order in which they are called. eg.
2558 ppc_elf_check_relocs is called early in the link process,
2559 ppc_elf_finish_dynamic_sections is one of the last functions
2560 called. */
2562 /* The PPC linker needs to keep track of the number of relocs that it
2563 decides to copy as dynamic relocs in check_relocs for each symbol.
2564 This is so that it can later discard them if they are found to be
2565 unnecessary. We store the information in a field extending the
2566 regular ELF linker hash table. */
2568 struct ppc_elf_dyn_relocs
2569 {
2572 /* The input section of the reloc. */
2575 /* Total number of relocs copied for the input section. */
2576 bfd_size_type count;
2578 /* Number of pc-relative relocs copied for the input section. */
2579 bfd_size_type pc_count;
2580 };
2582 /* Track PLT entries needed for a given symbol. We might need more
2583 than one glink entry per symbol when generating a pic binary. */
2584 struct plt_entry
2585 {
2588 /* -fPIC uses multiple GOT sections, one per file, called ".got2".
2589 This field stores the offset into .got2 used to initialise the
2590 GOT pointer reg. It will always be at least 32768. (Current
2591 gcc always uses an offset of 32768, but ld -r will pack .got2
2592 sections together resulting in larger offsets). */
2593 bfd_vma addend;
2595 /* The .got2 section. */
2598 /* PLT refcount or offset. */
2599 union
2600 {
2601 bfd_signed_vma refcount;
2602 bfd_vma offset;
2605 /* .glink stub offset. */
2606 bfd_vma glink_offset;
2607 };
2609 /* Of those relocs that might be copied as dynamic relocs, this function
2610 selects those that must be copied when linking a shared library,
2611 even when the symbol is local. */
2613 static int
2616 {
2618 {
2635 }
2636 }
2638 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
2639 copying dynamic variables from a shared lib into an app's dynbss
2640 section, and instead use a dynamic relocation to point into the
2641 shared lib. */
2642 #define ELIMINATE_COPY_RELOCS 1
2644 /* PPC ELF linker hash entry. */
2646 struct ppc_elf_link_hash_entry
2647 {
2650 /* If this symbol is used in the linker created sections, the processor
2651 specific backend uses this field to map the field into the offset
2652 from the beginning of the section. */
2655 /* Track dynamic relocs copied for this symbol. */
2658 /* Contexts in which symbol is used in the GOT (or TOC).
2659 TLS_GD .. TLS_TLS bits are or'd into the mask as the
2660 corresponding relocs are encountered during check_relocs.
2661 tls_optimize clears TLS_GD .. TLS_TPREL when optimizing to
2662 indicate the corresponding GOT entry type is not needed. */
2672 /* Nonzero if we have seen a small data relocation referring to this
2673 symbol. */
2675 };
2677 #define ppc_elf_hash_entry(ent) ((struct ppc_elf_link_hash_entry *) (ent))
2679 /* PPC ELF linker hash table. */
2681 struct ppc_elf_link_hash_table
2682 {
2685 /* Short-cuts to get to dynamic linker sections. */
2700 /* The (unloaded but important) .rela.plt.unloaded on VxWorks. */
2703 /* The .got.plt section (VxWorks only)*/
2706 /* Shortcut to __tls_get_addr. */
2709 /* The bfd that forced an old-style PLT. */
2712 /* TLS local dynamic got entry handling. */
2714 bfd_signed_vma refcount;
2715 bfd_vma offset;
2718 /* Offset of branch table to PltResolve function in glink. */
2719 bfd_vma glink_pltresolve;
2721 /* Size of reserved GOT entries. */
2723 /* Non-zero if allocating the header left a gap. */
2726 /* The type of PLT we have chosen to use. */
2729 /* Set if we should emit symbols for stubs. */
2732 /* Set if __tls_get_addr optimization should not be done. */
2735 /* True if the target system is VxWorks. */
2738 /* The size of PLT entries. */
2740 /* The distance between adjacent PLT slots. */
2742 /* The size of the first PLT entry. */
2745 /* Small local sym cache. */
2747 };
2749 /* Rename some of the generic section flags to better document how they
2750 are used here. */
2752 /* Nonzero if this section has TLS related relocations. */
2753 #define has_tls_reloc sec_flg0
2755 /* Nonzero if this section has a call to __tls_get_addr. */
2756 #define has_tls_get_addr_call sec_flg1
2758 /* Get the PPC ELF linker hash table from a link_info structure. */
2760 #define ppc_elf_hash_table(p) \
2761 (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \
2762 == PPC32_ELF_DATA ? ((struct ppc_elf_link_hash_table *) ((p)->hash)) : NULL)
2764 /* Create an entry in a PPC ELF linker hash table. */
2770 {
2771 /* Allocate the structure if it has not already been allocated by a
2772 subclass. */
2774 {
2779 }
2781 /* Call the allocation method of the superclass. */
2784 {
2789 }
2792 }
2794 /* Create a PPC ELF linker hash table. */
2798 {
2806 ppc_elf_link_hash_newfunc,
2808 PPC32_ELF_DATA))
2809 {
2812 }
2832 }
2834 /* Create .got and the related sections. */
2836 static bfd_boolean
2838 {
2841 flagword flags;
2852 {
2856 }
2857 else
2858 {
2859 /* The powerpc .got has a blrl instruction in it. Mark it
2860 executable. */
2865 }
2872 }
2874 static bfd_boolean
2876 {
2879 flagword flags;
2904 }
2906 /* We have to create .dynsbss and .rela.sbss here so that they get mapped
2907 to output sections (just like _bfd_elf_create_dynamic_sections has
2908 to create .dynbss and .rela.bss). */
2910 static bfd_boolean
2912 {
2915 flagword flags;
2938 {
2947 }
2960 /* The VxWorks PLT is a loaded section with contents. */
2963 }
2965 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2967 static void
2971 {
2978 {
2980 {
2984 /* Add reloc counts against the indirect sym to the direct sym
2985 list. Merge any entries against the same section. */
2987 {
2992 {
2997 }
3000 }
3002 }
3006 }
3011 /* If called to transfer flags for a weakdef during processing
3012 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
3013 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
3025 /* If we were called to copy over info for a weak sym, that's all. */
3029 /* Copy over the GOT refcount entries that we may have already seen to
3030 the symbol which just became indirect. */
3034 /* And plt entries. */
3036 {
3038 {
3043 {
3048 {
3052 }
3055 }
3057 }
3061 }
3064 {
3072 }
3073 }
3075 /* Hook called by the linker routine which adds symbols from an object
3076 file. We use it to put .comm items in .sbss, and not .bss. */
3078 static bfd_boolean
3086 {
3091 {
3092 /* Common symbols less than or equal to -G nn bytes are automatically
3093 put into .sbss. */
3098 {
3106 flags);
3109 }
3113 }
3120 }
3121 \f
3122 static bfd_boolean
3124 {
3136 }
3138 /* Create a special linker section. */
3140 static bfd_boolean
3143 flagword flags,
3145 {
3152 /* Record the first bfd that needs the special sections. */
3158 flags);
3165 }
3167 /* Find a linker generated pointer with a given addend and type. */
3170 elf_find_pointer_linker_section
3172 bfd_vma addend,
3174 {
3180 }
3182 /* Allocate a pointer to live in a linker created section. */
3184 static bfd_boolean
3189 {
3193 bfd_size_type amt;
3197 /* Is this a global symbol? */
3199 {
3202 /* Has this symbol already been allocated? If so, our work is done. */
3206 lsect))
3210 }
3211 else
3212 {
3215 /* Allocation of a pointer to a local symbol. */
3218 /* Allocate a table to hold the local symbols if first time. */
3220 {
3231 }
3233 /* Has this symbol already been allocated? If so, our work is done. */
3236 lsect))
3240 }
3242 /* Allocate space for a pointer in the linker section, and allocate
3243 a new pointer record from internal memory. */
3259 #ifdef DEBUG
3264 #endif
3267 }
3274 {
3280 {
3290 }
3298 }
3300 static bfd_boolean
3303 {
3312 {
3322 }
3325 }
3329 {
3338 }
3340 static bfd_boolean
3342 {
3353 }
3355 static void
3357 {
3360 abfd,
3363 }
3365 /* Look through the relocs for a section during the first phase, and
3366 allocate space in the global offset table or procedure linkage
3367 table. */
3369 static bfd_boolean
3374 {
3386 /* Don't do anything special with non-loaded, non-alloced sections.
3387 In particular, any relocs in such sections should not affect GOT
3388 and PLT reference counting (ie. we don't allow them to create GOT
3389 or PLT entries), there's no possibility or desire to optimize TLS
3390 relocs, and there's not much point in propagating relocs to shared
3391 libs that the dynamic linker won't relocate. */
3395 #ifdef DEBUG
3398 #endif
3402 /* Initialize howto table if not already done. */
3408 {
3413 }
3423 {
3432 else
3433 {
3438 }
3440 /* If a relocation refers to _GLOBAL_OFFSET_TABLE_, create the .got.
3441 This shows up in particular in an R_PPC_ADDR32 in the eabi
3442 startup code. */
3446 {
3452 }
3457 {
3466 {
3468 bfd_vma addend;
3471 PLT_IFUNC);
3475 /* STT_GNU_IFUNC symbols must have a PLT entry;
3476 In a non-pie executable even when there are
3477 no plt calls. */
3480 {
3484 }
3487 }
3488 }
3494 {
3498 /* We have a new-style __tls_get_addr call with a marker
3499 reloc. */
3500 ;
3501 else
3502 /* Mark this section as having an old-style call. */
3504 }
3507 {
3510 /* These special tls relocs tie a call to __tls_get_addr with
3511 its parameter symbol. */
3542 dogottls:
3544 /* Fall thru */
3546 /* GOT16 relocations */
3551 /* This symbol requires a global offset table entry. */
3553 {
3558 }
3560 {
3563 }
3564 else
3565 /* This is a global offset table entry for a local symbol. */
3569 /* We may also need a plt entry if the symbol turns out to be
3570 an ifunc. */
3572 {
3575 }
3578 /* Indirect .sdata relocation. */
3581 {
3584 }
3593 {
3596 }
3599 /* Indirect .sdata2 relocation. */
3602 {
3605 }
3614 {
3617 }
3625 {
3628 }
3633 {
3636 }
3641 {
3644 }
3650 {
3653 }
3661 {
3664 }
3673 {
3676 }
3684 /* Fall through */
3690 #ifdef DEBUG
3692 #endif
3693 /* This symbol requires a procedure linkage table entry. We
3694 actually build the entry in finish_dynamic_symbol,
3695 because this might be a case of linking PIC code without
3696 linking in any dynamic objects, in which case we don't
3697 need to generate a procedure linkage table after all. */
3700 {
3701 /* It does not make sense to have a procedure linkage
3702 table entry for a local symbol. */
3705 abfd,
3706 sec,
3711 }
3712 else
3713 {
3717 {
3721 }
3725 }
3728 /* The following relocations don't need to propagate the
3729 relocation if linking a shared object since they are
3730 section relative. */
3749 /* These are just markers. */
3759 /* These should only appear in dynamic objects. */
3767 /* These aren't handled yet. We'll report an error later. */
3776 /* This refers only to functions defined in the shared library. */
3779 {
3782 }
3785 /* This relocation describes the C++ object vtable hierarchy.
3786 Reconstruct it for later use during GC. */
3792 /* This relocation describes which C++ vtable entries are actually
3793 used. Record for later use during GC. */
3801 /* We shouldn't really be seeing these. */
3811 /* Nor these. */
3822 {
3823 /* Old -fPIC gcc code has .long LCTOC1-LCFx just before
3824 the start of a function, which assembles to a REL32
3825 reference to .got2. If we detect one of these, then
3826 force the old PLT layout because the linker cannot
3827 reliably deduce the GOT pointer value needed for
3828 PLT call stubs. */
3839 {
3842 }
3843 }
3846 /* fall through */
3856 {
3857 /* We may need a plt entry if the symbol turns out to be
3858 a function defined in a dynamic object. */
3862 /* We may need a copy reloc too. */
3865 }
3875 {
3877 {
3880 }
3882 }
3883 /* fall through */
3890 {
3891 /* We may need a plt entry if the symbol turns out to be
3892 a function defined in a dynamic object. */
3897 }
3899 dodyn:
3900 /* If we are creating a shared library, and this is a reloc
3901 against a global symbol, or a non PC relative reloc
3902 against a local symbol, then we need to copy the reloc
3903 into the shared library. However, if we are linking with
3904 -Bsymbolic, we do not need to copy a reloc against a
3905 global symbol which is defined in an object we are
3906 including in the link (i.e., DEF_REGULAR is set). At
3907 this point we have not seen all the input files, so it is
3908 possible that DEF_REGULAR is not set now but will be set
3909 later (it is never cleared). In case of a weak definition,
3910 DEF_REGULAR may be cleared later by a strong definition in
3911 a shared library. We account for that possibility below by
3912 storing information in the dyn_relocs field of the hash
3913 table entry. A similar situation occurs when creating
3914 shared libraries and symbol visibility changes render the
3915 symbol local.
3917 If on the other hand, we are creating an executable, we
3918 may need to keep relocations for symbols satisfied by a
3919 dynamic library if we manage to avoid copy relocs for the
3920 symbol. */
3927 || (ELIMINATE_COPY_RELOCS
3932 {
3936 #ifdef DEBUG
3938 "ppc_elf_check_relocs needs to "
3942 #endif
3944 {
3948 sreloc = _bfd_elf_make_dynamic_reloc_section
3953 }
3955 /* If this is a global symbol, we count the number of
3956 relocations we need for this symbol. */
3958 {
3960 }
3961 else
3962 {
3963 /* Track dynamic relocs needed for local syms too.
3964 We really need local syms available to do this
3965 easily. Oh well. */
3981 }
3985 {
3994 }
3999 }
4002 }
4003 }
4006 }
4007 \f
4009 /* Merge object attributes from IBFD into OBFD. Raise an error if
4010 there are conflicting attributes. */
4011 static bfd_boolean
4013 {
4018 {
4019 /* This is the first object. Copy the attributes. */
4022 /* Use the Tag_null value to indicate the attributes have been
4023 initialized. */
4027 }
4032 /* Check for conflicting Tag_GNU_Power_ABI_FP attributes and merge
4033 non-conflicting ones. */
4037 {
4042 ;
4044 _bfd_error_handler
4047 _bfd_error_handler
4051 _bfd_error_handler
4055 _bfd_error_handler
4059 _bfd_error_handler
4062 _bfd_error_handler
4065 else
4066 _bfd_error_handler
4069 }
4071 /* Check for conflicting Tag_GNU_Power_ABI_Vector attributes and
4072 merge non-conflicting ones. */
4076 {
4080 {
4084 }
4087 {
4091 }
4097 ;
4098 /* For now, allow generic to transition to AltiVec or SPE
4099 without a warning. If GCC marked files with their stack
4100 alignment and used don't-care markings for files which are
4101 not affected by the vector ABI, we could warn about this
4102 case too. */
4106 ;
4108 _bfd_error_handler
4112 _bfd_error_handler
4115 else
4116 _bfd_error_handler
4119 }
4121 /* Check for conflicting Tag_GNU_Power_ABI_Struct_Return attributes
4122 and merge non-conflicting ones. */
4126 {
4131 ;
4133 _bfd_error_handler
4136 _bfd_error_handler
4139 _bfd_error_handler
4142 else
4143 _bfd_error_handler
4146 }
4148 /* Merge Tag_compatibility attributes and any common GNU ones. */
4152 }
4154 /* Merge backend specific data from an object file to the output
4155 object file when linking. */
4157 static bfd_boolean
4159 {
4160 flagword old_flags;
4161 flagword new_flags;
4162 bfd_boolean error;
4167 /* Check if we have the same endianess. */
4177 {
4178 /* First call, no flags set. */
4181 }
4183 /* Compatible flags are ok. */
4185 ;
4187 /* Incompatible flags. */
4188 else
4189 {
4190 /* Warn about -mrelocatable mismatch. Allow -mrelocatable-lib
4191 to be linked with either. */
4195 {
4200 }
4203 {
4208 }
4210 /* The output is -mrelocatable-lib iff both the input files are. */
4214 /* The output is -mrelocatable iff it can't be -mrelocatable-lib,
4215 but each input file is either -mrelocatable or -mrelocatable-lib. */
4221 /* Do not warn about eabi vs. V.4 mismatch, just or in the bit if
4222 any module uses it. */
4228 /* Warn about any other mismatches. */
4230 {
4236 }
4239 {
4242 }
4243 }
4246 }
4247 \f
4248 /* Choose which PLT scheme to use, and set .plt flags appropriately.
4249 Returns -1 on error, 0 for old PLT, 1 for new PLT. */
4250 int
4255 {
4257 flagword flags;
4264 {
4267 else
4268 {
4272 /* Look through the reloc flags left by ppc_elf_check_relocs.
4273 Use the old style bss plt if a file makes plt calls
4274 without using the new relocs, and if ld isn't given
4275 --secure-plt and we never see REL16 relocs. */
4280 {
4284 {
4288 }
4289 }
4291 }
4292 }
4299 {
4303 /* The new PLT is a loaded section. */
4308 /* The new GOT is not executable. */
4312 }
4313 else
4314 {
4315 /* Stop an unused .glink section from affecting .text alignment. */
4319 }
4321 }
4322 \f
4323 /* Return the section that should be marked against GC for a given
4324 relocation. */
4332 {
4335 {
4339 }
4342 }
4344 /* Update the got, plt and dynamic reloc reference counts for the
4345 section being removed. */
4347 static bfd_boolean
4352 {
4376 {
4383 {
4395 {
4396 /* Everything must go for SEC. */
4399 }
4400 }
4408 {
4414 {
4425 }
4426 }
4429 {
4451 {
4455 {
4461 }
4462 }
4464 {
4467 }
4477 /* Fall thru */
4500 {
4509 }
4514 }
4515 }
4517 }
4518 \f
4519 /* Set plt output section type, htab->tls_get_addr, and call the
4520 generic ELF tls_setup function. */
4522 asection *
4526 {
4533 {
4540 {
4541 /* If glibc supports an optimized __tls_get_addr call stub,
4542 signalled by the presence of __tls_get_addr_opt, and we'll
4543 be calling __tls_get_addr via a plt call stub, then
4544 make __tls_get_addr point to __tls_get_addr_opt. */
4553 {
4559 {
4564 {
4565 /* Use __tls_get_addr_opt in dynamic relocations. */
4571 }
4573 }
4574 }
4575 }
4576 else
4578 }
4583 {
4586 }
4589 }
4591 /* Return TRUE iff REL is a branch reloc with a global symbol matching
4592 HASH. */
4594 static bfd_boolean
4598 {
4604 {
4614 }
4616 }
4618 /* Run through all the TLS relocs looking for optimization
4619 opportunities. */
4621 bfd_boolean
4624 {
4637 /* Make two passes through the relocs. First time check that tls
4638 relocs involved in setting up a tls_get_addr call are indeed
4639 followed by such a call. If they are not, don't do any tls
4640 optimization. On the second pass twiddle tls_mask flags to
4641 notify relocate_section that optimization can be done, and
4642 adjust got and plt refcounts. */
4645 {
4652 {
4656 /* Read the relocations. */
4664 {
4670 bfd_boolean is_local;
4675 {
4683 }
4691 /* If this section has old-style __tls_get_addr calls
4692 without marker relocs, then check that each
4693 __tls_get_addr call reloc is preceded by a reloc
4694 that conceivably belongs to the __tls_get_addr arg
4695 setup insn. If we don't find matching arg setup
4696 relocs, don't do any tls optimization. */
4701 && !expecting_tls_get_addr
4703 {
4710 }
4714 {
4718 /* Fall thru */
4722 /* These relocs should never be against a symbol
4723 defined in a shared lib. Leave them alone if
4724 that turns out to be the case. */
4728 /* LD -> LE */
4736 /* Fall thru */
4741 /* GD -> LE */
4743 else
4744 /* GD -> IE */
4754 {
4755 /* IE -> LE */
4759 }
4760 else
4772 }
4775 {
4786 /* Uh oh, we didn't find the expected call. We
4787 could just mark this symbol to exclude it
4788 from tls optimization but it's safer to skip
4789 the entire optimization. */
4796 }
4799 {
4813 }
4816 {
4819 }
4820 else
4821 {
4827 {
4834 {
4838 }
4839 }
4848 }
4851 {
4852 /* We managed to get rid of a got entry. */
4855 }
4859 }
4863 }
4867 {
4870 else
4872 }
4873 }
4875 }
4876 \f
4877 /* Return true if we have dynamic relocs that apply to read-only sections. */
4879 static bfd_boolean
4881 {
4885 {
4892 }
4894 }
4896 /* Adjust a symbol defined by a dynamic object and referenced by a
4897 regular object. The current definition is in some section of the
4898 dynamic object, but we're not including those sections. We have to
4899 change the definition to something the rest of the link can
4900 understand. */
4902 static bfd_boolean
4905 {
4909 #ifdef DEBUG
4912 #endif
4914 /* Make sure we know what is going on here. */
4924 /* Deal with function syms. */
4928 {
4929 /* Clear procedure linkage table information for any symbol that
4930 won't need a .plt entry. */
4940 {
4941 /* A PLT entry is not required/allowed when:
4943 1. We are not using ld.so; because then the PLT entry
4944 can't be set up, so we can't use one. In this case,
4945 ppc_elf_adjust_dynamic_symbol won't even be called.
4947 2. GC has rendered the entry unused.
4949 3. We know for certain that a call to this symbol
4950 will go to this object, or will remain undefined. */
4953 }
4954 else
4955 {
4956 /* After adjust_dynamic_symbol, non_got_ref set in the
4957 non-shared case means that we have allocated space in
4958 .dynbss for the symbol and thus dyn_relocs for this
4959 symbol should be discarded.
4960 If we get here we know we are making a PLT entry for this
4961 symbol, and in an executable we'd normally resolve
4962 relocations against this symbol to the PLT entry. Allow
4963 dynamic relocs if the reference is weak, and the dynamic
4964 relocs will not cause text relocation. */
4972 }
4974 }
4975 else
4978 /* If this is a weak symbol, and there is a real definition, the
4979 processor independent code will have arranged for us to see the
4980 real definition first, and we can just use the same value. */
4982 {
4990 }
4992 /* This is a reference to a symbol defined by a dynamic object which
4993 is not a function. */
4995 /* If we are creating a shared library, we must presume that the
4996 only references to the symbol are via the global offset table.
4997 For such cases we need not do anything here; the relocations will
4998 be handled correctly by relocate_section. */
5002 /* If there are no references to this symbol that do not use the
5003 GOT, we don't need to generate a copy reloc. */
5007 /* If we didn't find any dynamic relocs in read-only sections, then
5008 we'll be keeping the dynamic relocs and avoiding the copy reloc.
5009 We can't do this if there are any small data relocations. This
5010 doesn't work on VxWorks, where we can not have dynamic
5011 relocations (other than copy and jump slot relocations) in an
5012 executable. */
5018 {
5021 }
5024 {
5028 }
5030 /* We must allocate the symbol in our .dynbss section, which will
5031 become part of the .bss section of the executable. There will be
5032 an entry for this symbol in the .dynsym section. The dynamic
5033 object will contain position independent code, so all references
5034 from the dynamic object to this symbol will go through the global
5035 offset table. The dynamic linker will use the .dynsym entry to
5036 determine the address it must put in the global offset table, so
5037 both the dynamic object and the regular object will refer to the
5038 same memory location for the variable.
5040 Of course, if the symbol is referenced using SDAREL relocs, we
5041 must instead allocate it in .sbss. */
5045 else
5049 /* We must generate a R_PPC_COPY reloc to tell the dynamic linker to
5050 copy the initial value out of the dynamic object and into the
5051 runtime process image. We need to remember the offset into the
5052 .rela.bss section we are going to use. */
5054 {
5059 else
5064 }
5067 }
5068 \f
5069 /* Generate a symbol to mark plt call stubs. For non-PIC code the sym is
5070 xxxxxxxx.plt_call32.<callee> where xxxxxxxx is a hex number, usually 0,
5071 specifying the addend on the plt relocation. For -fpic code, the sym
5072 is xxxxxxxx.plt_pic32.<callee>, and for -fPIC
5073 xxxxxxxx.got2.plt_pic32.<callee>. */
5075 static bfd_boolean
5079 {
5088 else
5108 {
5117 }
5119 }
5121 /* Allocate NEED contiguous space in .got, and return the offset.
5122 Handles allocation of the got header when crossing 32k. */
5124 static bfd_vma
5126 {
5127 bfd_vma where;
5131 {
5134 }
5135 else
5136 {
5139 {
5142 }
5143 else
5144 {
5147 {
5150 }
5153 }
5154 }
5156 }
5158 /* Allocate space in associated reloc sections for dynamic relocs. */
5160 static bfd_boolean
5162 {
5172 /* When warning symbols are created, they **replace** the "real"
5173 entry in the hash table, thus we never get to see the real
5174 symbol in a hash traversal. So look at it now. */
5180 {
5184 bfd_boolean dyn;
5188 {
5189 /* Make sure this symbol is output as a dynamic symbol. */
5194 {
5197 }
5203 {
5209 {
5211 {
5214 }
5219 {
5225 }
5230 {
5233 }
5239 }
5240 else
5241 {
5243 {
5244 /* If this is the first .plt entry, make room
5245 for the special first entry. */
5249 /* The PowerPC PLT is actually composed of two
5250 parts, the first part is 2 words (for a load
5251 and a jump), and then there is a remaining
5252 word available at the end. */
5259 /* If this symbol is not defined in a regular
5260 file, and we are not generating a shared
5261 library, then set the symbol to this location
5262 in the .plt. This is to avoid text
5263 relocations, and is required to make
5264 function pointers compare as equal between
5265 the normal executable and the shared library. */
5269 {
5272 }
5274 /* Make room for this entry. */
5276 /* After the 8192nd entry, room for two entries
5277 is allocated. */
5283 }
5285 }
5287 /* We also need to make an entry in the .rela.plt section. */
5289 {
5293 else
5294 {
5298 {
5299 /* Allocate space for the unloaded relocations. */
5302 {
5305 {
5309 }
5314 }
5316 /* Every PLT entry has an associated GOT entry in
5317 .got.plt. */
5319 }
5320 }
5322 }
5323 }
5324 else
5326 }
5327 else
5331 {
5334 }
5335 }
5336 else
5337 {
5340 }
5344 {
5345 bfd_boolean dyn;
5348 /* Make sure this symbol is output as a dynamic symbol. */
5353 {
5356 }
5360 {
5362 {
5364 /* We'll just use htab->tlsld_got.offset. This should
5365 always be the case. It's a little odd if we have
5366 a local dynamic reloc against a non-local symbol. */
5368 else
5370 }
5377 }
5378 else
5382 else
5383 {
5390 {
5392 /* All the entries we allocated need relocs.
5393 Except LD only needs one. */
5398 }
5399 }
5400 }
5401 else
5408 /* In the shared -Bsymbolic case, discard space allocated for
5409 dynamic pc-relative relocs against symbols which turn out to be
5410 defined in regular objects. For the normal shared case, discard
5411 space for relocs that have become local due to symbol visibility
5412 changes. */
5415 {
5416 /* Relocs that use pc_count are those that appear on a call insn,
5417 or certain REL relocs (see must_be_dyn_reloc) that can be
5418 generated via assembly. We want calls to protected symbols to
5419 resolve directly to the function rather than going via the plt.
5420 If people want function pointer comparisons to work as expected
5421 then they should avoid writing weird assembly. */
5423 {
5427 {
5432 else
5434 }
5435 }
5438 {
5442 {
5445 else
5447 }
5448 }
5450 /* Discard relocs on undefined symbols that must be local. */
5457 /* Also discard relocs on undefined weak syms with non-default
5458 visibility. */
5461 {
5465 /* Make sure undefined weak symbols are output as a dynamic
5466 symbol in PIEs. */
5470 {
5473 }
5474 }
5475 }
5477 {
5478 /* For the non-shared case, discard space for relocs against
5479 symbols which turn out to need copy relocs or are not
5480 dynamic. */
5484 {
5485 /* Make sure this symbol is output as a dynamic symbol.
5486 Undefined weak syms won't yet be marked as dynamic. */
5489 {
5492 }
5494 /* If that succeeded, we know we'll be keeping all the
5495 relocs. */
5498 }
5502 keep: ;
5503 }
5505 /* Finally, allocate space. */
5507 {
5512 }
5515 }
5517 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
5518 read-only sections. */
5520 static bfd_boolean
5522 {
5530 {
5533 /* Not an error, just cut short the traversal. */
5535 }
5537 }
5539 /* Set the sizes of the dynamic sections. */
5541 static bfd_boolean
5544 {
5547 bfd_boolean relocs;
5550 #ifdef DEBUG
5552 #endif
5558 {
5559 /* Set the contents of the .interp section to the interpreter. */
5561 {
5566 }
5567 }
5574 /* Set up .got offsets for local syms, and space for local dynamic
5575 relocs. */
5577 {
5583 bfd_size_type locsymcount;
5590 {
5597 {
5600 {
5601 /* Input section has been discarded, either because
5602 it is a copy of a linkonce section or due to
5603 linker script /DISCARD/, so we'll be discarding
5604 the relocs too. */
5605 }
5609 {
5610 /* Relocations in vxworks .tls_vars sections are
5611 handled specially by the loader. */
5612 }
5614 {
5623 }
5624 }
5625 }
5640 {
5643 {
5652 }
5653 else
5657 else
5658 {
5663 }
5664 }
5665 else
5671 /* Allocate space for calls to local STT_GNU_IFUNC syms in .iplt. */
5673 {
5680 {
5684 {
5687 }
5692 {
5695 }
5699 {
5702 }
5703 }
5704 else
5706 }
5707 }
5709 /* Allocate space for global sym dynamic relocs. */
5713 {
5717 }
5718 else
5722 {
5725 /* If we haven't allocated the header, do so now. When we get here,
5726 for old plt/got the got size will be 0 to 32764 (not allocated),
5727 or 32780 to 65536 (header allocated). For new plt/got, the
5728 corresponding ranges are 0 to 32768 and 32780 to 65536. */
5730 {
5735 }
5738 }
5740 {
5745 {
5749 }
5750 }
5755 {
5757 /* Space for the branch table. */
5759 /* Pad out to align the start of PLTresolve. */
5764 {
5771 {
5780 }
5786 {
5795 }
5796 }
5797 }
5799 /* We've now determined the sizes of the various dynamic sections.
5800 Allocate memory for them. */
5803 {
5811 {
5812 /* We'd like to strip these sections if they aren't needed, but if
5813 we've exported dynamic symbols from them we must leave them.
5814 It's too late to tell BFD to get rid of the symbols. */
5817 /* Strip this section if we don't need it; see the
5818 comment below. */
5819 }
5828 {
5829 /* Strip these too. */
5830 }
5832 {
5834 {
5835 /* Remember whether there are any relocation sections. */
5838 /* We use the reloc_count field as a counter if we need
5839 to copy relocs into the output file. */
5841 }
5842 }
5843 else
5844 {
5845 /* It's not one of our sections, so don't allocate space. */
5847 }
5850 {
5851 /* If we don't need this section, strip it from the
5852 output file. This is mostly to handle .rela.bss and
5853 .rela.plt. We must create both sections in
5854 create_dynamic_sections, because they must be created
5855 before the linker maps input sections to output
5856 sections. The linker does that before
5857 adjust_dynamic_symbol is called, and it is that
5858 function which decides whether anything needs to go
5859 into these sections. */
5862 }
5867 /* Allocate memory for the section contents. */
5871 }
5874 {
5875 /* Add some entries to the .dynamic section. We fill in the
5876 values later, in ppc_elf_finish_dynamic_sections, but we
5877 must add the entries now so that we get the correct size for
5878 the .dynamic section. The DT_DEBUG entry is filled in by the
5879 dynamic linker and used by the debugger. */
5880 #define add_dynamic_entry(TAG, VAL) \
5881 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
5884 {
5887 }
5890 {
5896 }
5899 {
5907 }
5910 {
5915 }
5917 /* If any dynamic relocs apply to a read-only section, then we
5918 need a DT_TEXTREL entry. */
5921 info);
5924 {
5927 }
5931 }
5932 #undef add_dynamic_entry
5935 }
5937 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
5939 static bfd_boolean
5941 {
5949 }
5950 \f
5951 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
5953 /* Relaxation trampolines. r12 is available for clobbering (r11, is
5954 used for some functions that are allowed to break the ABI). */
5956 {
5965 };
5968 {
5973 };
5975 static bfd_boolean
5980 {
5981 struct one_fixup
5982 {
5985 /* Final link, can use the symbol offset. For a
5986 relocatable link we use the symbol's index. */
5987 bfd_vma toff;
5988 bfd_vma trampoff;
5989 };
5999 bfd_size_type trampoff;
6001 bfd_boolean maybe_pasted;
6005 /* Nothing to do if there are no relocations, and no need to do
6006 anything with non-alloc or non-code sections. */
6013 /* We cannot represent the required PIC relocs in the output, so don't
6014 do anything. The linker doesn't support mixing -shared and -r
6015 anyway. */
6022 /* Space for a branch around any trampolines. */
6028 /* Get a copy of the native relocations. */
6039 {
6053 {
6068 }
6070 /* Get the value of the symbol referred to by the reloc. */
6073 {
6074 /* A local symbol. */
6077 /* Read this BFD's local symbols. */
6079 {
6087 }
6095 else
6100 }
6101 else
6102 {
6103 /* Global symbol handling. */
6115 {
6118 }
6121 {
6124 }
6125 else
6129 }
6131 /* The condition here under which we call find_plt_ent must
6132 match that in relocate_section. If we call find_plt_ent here
6133 but not in relocate_section, or vice versa, then the branch
6134 destination used here may be incorrect. */
6137 {
6138 /* We know is_branch_reloc (r_type) is true. */
6142 }
6145 {
6150 }
6152 {
6160 {
6165 {
6168 }
6169 else
6170 {
6173 }
6174 }
6175 }
6177 /* If the branch and target are in the same section, you have
6178 no hope of adding stubs. We'll error out later should the
6179 branch overflow. */
6183 /* There probably isn't any reason to handle symbols in
6184 SEC_MERGE sections; SEC_MERGE doesn't seem a likely
6185 attribute for a code section, and we are only looking at
6186 branches. However, implement it correctly here as a
6187 reference for other target relax_section functions. */
6189 {
6190 /* At this stage in linking, no SEC_MERGE symbol has been
6191 adjusted, so all references to such symbols need to be
6192 passed through _bfd_merged_section_offset. (Later, in
6193 relocate_section, all SEC_MERGE symbols *except* for
6194 section symbols have been adjusted.)
6196 gas may reduce relocations against symbols in SEC_MERGE
6197 sections to a relocation against the section symbol when
6198 the original addend was zero. When the reloc is against
6199 a section symbol we should include the addend in the
6200 offset passed to _bfd_merged_section_offset, since the
6201 location of interest is the original symbol. On the
6202 other hand, an access to "sym+addend" where "sym" is not
6203 a section symbol should not include the addend; Such an
6204 access is presumed to be an offset from "sym"; The
6205 location of interest is just "sym". */
6211 toff);
6215 }
6216 /* PLTREL24 addends are special. */
6220 /* Attempted -shared link of non-pic code loses. */
6226 /* If the branch is in range, no need to do anything. */
6229 /* A relocatable link may have sections moved during
6230 final link, so do not presume they remain in range. */
6232 {
6239 }
6241 /* Look for an existing fixup to this address. */
6247 {
6253 /* Oh dear, we can't reach a trampoline. Don't try to add
6254 one. We'll report an error later. */
6258 {
6261 }
6262 else
6263 {
6266 }
6270 {
6274 }
6276 /* Hijack the old relocation. Since we need two
6277 relocations for this use a "composite" reloc. */
6279 stub_rtype);
6285 /* Record the fixup so we don't do it again this section. */
6294 changes++;
6295 }
6296 else
6297 {
6302 /* Nop out the reloc, since we're finalizing things here. */
6304 }
6306 /* Get the section contents. */
6308 {
6309 /* Get cached copy if it exists. */
6312 else
6313 {
6314 /* Go get them off disk. */
6317 }
6318 }
6320 /* Fix up the existing branch to hit the trampoline. */
6323 {
6341 }
6342 }
6344 /* Write out the trampolines. */
6346 {
6351 do
6352 {
6356 }
6365 /* Branch around the trampolines. */
6367 {
6371 }
6375 {
6378 }
6379 else
6380 {
6383 }
6387 {
6389 i++;
6393 }
6395 }
6399 {
6402 else
6403 {
6404 /* Cache the symbols for elf_link_input_bfd. */
6406 }
6407 }
6411 {
6414 else
6415 {
6416 /* Cache the section contents for elf_link_input_bfd. */
6418 }
6419 }
6422 {
6423 /* Append sufficient NOP relocs so we can write out relocation
6424 information for the trampolines. */
6435 {
6439 }
6446 }
6452 {
6453 /* Convert the internal relax relocs to external form. */
6456 {
6459 /* Rewrite the reloc and convert one of the trailing nop
6460 relocs to describe this relocation. */
6462 /* The relocs are at the bottom 2 bytes */
6468 irel++;
6469 }
6470 }
6474 error_return:
6484 }
6485 \f
6486 /* What to do when ld finds relocations against symbols defined in
6487 discarded sections. */
6489 static unsigned int
6491 {
6499 }
6500 \f
6501 /* Fill in the address for a pointer generated in a linker section. */
6503 static bfd_vma
6507 bfd_vma relocation,
6509 {
6515 {
6516 /* Handle global symbol. */
6522 }
6523 else
6524 {
6525 /* Handle local symbol. */
6531 }
6535 lsect);
6538 /* Offset will always be a multiple of four, so use the bottom bit
6539 as a "written" flag. */
6541 {
6546 }
6553 #ifdef DEBUG
6557 #endif
6560 }
6562 #define PPC_LO(v) ((v) & 0xffff)
6563 #define PPC_HI(v) (((v) >> 16) & 0xffff)
6564 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
6566 static void
6569 {
6572 bfd_vma plt;
6579 {
6592 {
6601 }
6602 else
6603 {
6612 }
6613 }
6614 else
6615 {
6624 }
6625 }
6627 /* Return true if symbol is defined statically. */
6629 static bfd_boolean
6631 {
6636 }
6638 /* If INSN is an opcode that may be used with an @tls operand, return
6639 the transformed insn for TLS optimisation, otherwise return 0. If
6640 REG is non-zero only match an insn with RB or RA equal to REG. */
6642 unsigned int
6644 {
6654 else
6658 /* add -> addi. */
6664 /* load and store indexed -> dform. */
6667 /* ldx, ldux, stdx, stdux -> ld, ldu, std, stdu. */
6670 /* lwax -> lwa. */
6672 else
6676 }
6678 /* If INSN is an opcode that may be used with an @tprel operand, return
6679 the transformed insn for an undefined weak symbol, ie. with the
6680 thread pointer REG operand removed. Otherwise return 0. */
6682 unsigned int
6684 {
6705 {
6707 }
6712 {
6717 }
6718 else
6721 }
6723 /* The RELOCATE_SECTION function is called by the ELF backend linker
6724 to handle the relocations for a section.
6726 The relocs are always passed as Rela structures; if the section
6727 actually uses Rel structures, the r_addend field will always be
6728 zero.
6730 This function is responsible for adjust the section contents as
6731 necessary, and (if using Rela relocs and generating a
6732 relocatable output file) adjusting the reloc addend as
6733 necessary.
6735 This function does not have to worry about setting the reloc
6736 address or the reloc symbol index.
6738 LOCAL_SYMS is a pointer to the swapped in local symbols.
6740 LOCAL_SECTIONS is an array giving the section in the input file
6741 corresponding to the st_shndx field of each local symbol.
6743 The global hash table entry for the global symbols can be found
6744 via elf_sym_hashes (input_bfd).
6746 When generating relocatable output, this function must handle
6747 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
6748 going to be the section symbol corresponding to the output
6749 section, which means that the addend must be adjusted
6750 accordingly. */
6752 static bfd_boolean
6761 {
6767 Elf_Internal_Rela outrel;
6772 bfd_boolean is_vxworks_tls;
6774 #ifdef DEBUG
6780 #endif
6784 /* Initialize howto table if not already done. */
6792 /* We have to handle relocations in vxworks .tls_vars sections
6793 specially, because the dynamic loader is 'weird'. */
6800 {
6802 bfd_vma addend;
6803 bfd_reloc_status_type r;
6810 bfd_vma relocation;
6812 bfd_boolean unresolved_reloc;
6813 bfd_boolean warned;
6826 {
6832 }
6833 else
6834 {
6841 }
6844 {
6845 /* For relocs against symbols from removed linkonce sections,
6846 or sections discarded by a linker script, we just want the
6847 section contents zeroed. Avoid any special processing. */
6853 }
6856 {
6860 {
6861 /* R_PPC_PLTREL24 is rather special. If non-zero, the
6862 addend specifies the GOT pointer offset within .got2. */
6864 }
6866 }
6868 /* TLS optimizations. Replace instruction sequences and relocs
6869 based on information we collected in tls_optimize. We edit
6870 RELOCS so that --emit-relocs will output something sensible
6871 for the final instruction stream. */
6877 {
6880 local_plt
6884 }
6886 /* Ensure reloc mapping code below stays sane. */
6897 {
6905 {
6906 bfd_vma insn;
6914 }
6920 {
6921 bfd_vma insn;
6931 /* Was PPC_TLS which sits on insn boundary, now
6932 PPC_TPREL16_LO which is at low-order half-word. */
6934 }
6947 {
6948 tls_gdld_hi:
6952 else
6953 {
6957 }
6959 }
6972 {
6974 bfd_vma offset;
6976 tls_ldgd_opt:
6978 /* If not using the newer R_PPC_TLSGD/LD to mark
6979 __tls_get_addr calls, we must trust that the call
6980 stays with its arg setup insns, ie. that the next
6981 reloc is the __tls_get_addr call associated with
6982 the current reloc. Edit both insns. */
6989 {
6990 /* IE */
6996 {
7000 }
7004 }
7005 else
7006 {
7007 /* LE */
7010 {
7011 /* Was an LD reloc. */
7014 r_symndx++)
7024 }
7028 {
7034 }
7035 }
7039 {
7040 /* We changed the symbol on an LD reloc. Start over
7041 in order to get h, sym, sec etc. right. */
7042 rel--;
7044 }
7045 }
7050 {
7055 {
7056 /* IE */
7059 }
7060 else
7061 {
7062 /* LE */
7066 }
7069 /* Zap the reloc on the _tls_get_addr call too. */
7072 }
7077 {
7082 r_symndx++)
7098 /* Zap the reloc on the _tls_get_addr call too. */
7101 rel--;
7103 }
7105 }
7107 /* Handle other relocations that tweak non-addend part of insn. */
7110 {
7114 /* Branch taken prediction relocations. */
7118 /* Fall thru */
7120 /* Branch not taken prediction relocations. */
7123 {
7124 bfd_vma insn;
7134 /* Invert 'y' bit if not the default. */
7140 }
7141 }
7145 {
7149 {
7152 }
7155 {
7161 }
7167 {
7172 }
7174 {
7176 {
7177 Elf_Internal_Rela rela;
7191 }
7193 {
7198 }
7207 else
7211 }
7212 }
7220 {
7239 /* GOT16 relocations. Like an ADDR16 using the symbol's
7240 address in the GOT as relocation value instead of the
7241 symbol's value itself. Also, create a GOT entry for the
7242 symbol and put the symbol value there. */
7276 dogot:
7277 {
7278 /* Relocation is to the entry for this symbol in the global
7279 offset table. */
7280 bfd_vma off;
7293 {
7294 bfd_boolean dyn;
7299 /* This is actually a static link, or it is a
7300 -Bsymbolic link and the symbol is defined
7301 locally, or the symbol was forced to be local
7302 because of a version file. */
7303 ;
7304 else
7305 {
7308 }
7310 }
7311 else
7312 {
7316 }
7318 /* The offset must always be a multiple of 4. We use the
7319 least significant bit to record whether we have already
7320 processed this entry. */
7324 else
7325 {
7336 /* We might have multiple got entries for this sym.
7337 Initialize them all. */
7338 do
7339 {
7343 {
7346 }
7348 {
7351 }
7353 {
7356 }
7358 {
7361 }
7363 /* Generate relocs for the dynamic linker. */
7369 {
7378 {
7381 {
7388 outrel.r_info
7390 }
7391 }
7400 else
7403 {
7407 }
7412 }
7414 /* Init the .got section contents if we're not
7415 emitting a reloc. */
7416 else
7417 {
7423 {
7429 {
7433 }
7434 }
7437 }
7442 }
7447 }
7453 {
7455 {
7461 {
7465 {
7468 }
7469 }
7470 }
7471 }
7475 + off
7478 /* Addends on got relocations don't make much sense.
7479 x+off@got is actually x@got+off, and since the got is
7480 generated by a hash table traversal, the value in the
7481 got at entry m+n bears little relation to the entry m. */
7485 input_bfd,
7486 input_section,
7489 sym_name);
7490 }
7493 /* Relocations that need no special processing. */
7495 /* It makes no sense to point a local relocation
7496 at a symbol not in this object. */
7498 {
7501 input_bfd,
7502 input_section,
7504 TRUE))
7507 }
7517 /* Relocations that may need to be propagated if this is a shared
7518 object. */
7526 {
7527 /* Make this relocation against an undefined weak symbol
7528 resolve to zero. This is really just a tweak, since
7529 code using weak externs ought to check that they are
7530 defined before using them. */
7537 }
7539 /* The TPREL16 relocs shouldn't really be used in shared
7540 libs as they will result in DT_TEXTREL being set, but
7541 support them anyway. */
7566 /* fall through */
7581 /* If these relocations are not to a named symbol, they can be
7582 handled right here, no need to bother the dynamic linker. */
7586 /* fall through */
7594 /* fall through */
7596 dodyn:
7610 || (ELIMINATE_COPY_RELOCS
7616 {
7619 #ifdef DEBUG
7624 #endif
7626 /* When generating a shared object, these relocations
7627 are copied into the output file to be resolved at run
7628 time. */
7630 {
7636 }
7640 input_section,
7654 {
7658 }
7659 else
7660 {
7664 {
7668 {
7669 /* If we get here when building a static
7670 executable, then the libc startup function
7671 responsible for applying indirect function
7672 relocations is going to complain about
7673 the reloc type.
7674 If we get here when building a dynamic
7675 executable, it will be because we have
7676 a text relocation. The dynamic loader
7677 will set the text segment writable and
7678 non-executable to apply text relocations.
7679 So we'll segfault when trying to run the
7680 indirection function to resolve the reloc. */
7684 input_bfd,
7685 input_section,
7688 sym_name);
7690 }
7692 ;
7694 {
7697 }
7698 else
7699 {
7702 /* We are turning this relocation into one
7703 against a section symbol. It would be
7704 proper to subtract the symbol's value,
7705 osec->vma, from the emitted reloc addend,
7706 but ld.so expects buggy relocs.
7707 FIXME: Why not always use a zero index? */
7711 {
7714 }
7716 #ifdef DEBUG
7721 #endif
7722 }
7725 }
7728 else
7730 }
7739 /* This reloc will be computed at runtime. We clear the memory
7740 so that it contains predictable value. */
7744 {
7748 }
7749 }
7755 {
7760 {
7764 }
7770 else
7774 }
7775 /* Fall thru */
7783 {
7790 /* We're clearing the bits for R_PPC_ADDR16_HA
7791 and R_PPC_ADDR16_LO here. */
7795 /* t0 is HA, t1 is LO */
7803 /* Rewrite the reloc and convert one of the trailing nop
7804 relocs to describe this relocation. */
7806 /* The relocs are at the bottom 2 bytes */
7812 rel++;
7813 }
7816 /* Indirect .sdata relocation. */
7820 {
7823 }
7824 relocation
7830 /* Indirect .sdata2 relocation. */
7834 {
7837 }
7838 relocation
7844 /* Handle the TOC16 reloc. We want to use the offset within the .got
7845 section, not the actual VMA. This is appropriate when generating
7846 an embedded ELF object, for which the .got section acts like the
7847 AIX .toc section. */
7850 {
7853 }
7863 /* Relocation is to the entry for this symbol in the
7864 procedure linkage table. */
7865 {
7871 {
7872 /* We didn't make a PLT entry for this symbol. This
7873 happens when statically linking PIC code, or when
7874 using -Bsymbolic. */
7876 }
7883 else
7887 }
7890 /* Relocate against _SDA_BASE_. */
7892 {
7899 {
7902 }
7910 {
7914 input_bfd,
7915 sym_name,
7917 name);
7918 }
7919 }
7922 /* Relocate against _SDA2_BASE_. */
7924 {
7931 {
7934 }
7940 {
7944 input_bfd,
7945 sym_name,
7947 name);
7948 }
7949 }
7952 /* Relocate against either _SDA_BASE_, _SDA2_BASE_, or 0. */
7955 {
7961 {
7964 }
7971 {
7974 }
7977 {
7980 }
7983 {
7985 }
7986 else
7987 {
7991 input_bfd,
7992 sym_name,
7994 name);
7999 }
8002 {
8004 {
8007 }
8009 }
8012 {
8018 }
8019 }
8022 /* Relocate against the beginning of the section. */
8028 {
8031 }
8035 /* Negative relocations. */
8062 input_bfd,
8064 sym_name);
8069 }
8071 /* Do any further special processing. */
8073 {
8084 /* It's just possible that this symbol is a weak symbol
8085 that's not actually defined anywhere. In that case,
8086 'sec' would be NULL, and we should leave the symbol
8087 alone (it will be set to zero elsewhere in the link). */
8090 /* Fall thru */
8098 /* Add 0x10000 if sign bit in 0:15 is set.
8099 Bits 0:15 are not used. */
8102 }
8104 #ifdef DEBUG
8109 sym_name,
8110 r_symndx,
8113 #endif
8118 {
8121 input_bfd,
8122 input_section,
8125 sym_name);
8127 }
8130 input_bfd,
8131 input_section,
8132 contents,
8134 relocation,
8135 addend);
8138 {
8140 {
8146 {
8147 /* Assume this is a call protected by other code that
8148 detect the symbol is undefined. If this is the case,
8149 we can safely ignore the overflow. If not, the
8150 program is hosed anyway, and a little warning isn't
8151 going to help. */
8154 }
8158 sym_name,
8161 input_bfd,
8162 input_section,
8165 }
8166 else
8167 {
8173 }
8174 }
8175 }
8177 #ifdef DEBUG
8179 #endif
8182 }
8183 \f
8184 /* Finish up dynamic symbol handling. We set the contents of various
8185 dynamic sections here. */
8187 static bfd_boolean
8192 {
8195 bfd_boolean doneone;
8197 #ifdef DEBUG
8200 #endif
8208 {
8210 {
8211 Elf_Internal_Rela rela;
8213 bfd_vma reloc_index;
8219 else
8220 {
8226 }
8228 /* This symbol has an entry in the procedure linkage table.
8229 Set it up. */
8233 {
8234 bfd_vma got_offset;
8237 /* The first three entries in .got.plt are reserved. */
8240 /* Use the right PLT. */
8244 /* Fill in the .plt on VxWorks. */
8246 {
8253 }
8254 else
8255 {
8264 }
8271 /* This instruction is an immediate load. The value loaded is
8272 the byte offset of the R_PPC_JMP_SLOT relocation from the
8273 start of the .rela.plt section. The value is stored in the
8274 low-order 16 bits of the load instruction. */
8275 /* NOTE: It appears that this is now an index rather than a
8276 prescaled offset. */
8280 /* This instruction is a PC-relative branch whose target is
8281 the start of the PLT section. The address of this branch
8282 instruction is 20 bytes beyond the start of this PLT entry.
8283 The address is encoded in bits 6-29, inclusive. The value
8284 stored is right-shifted by two bits, permitting a 26-bit
8285 offset. */
8295 /* Fill in the GOT entry corresponding to this PLT slot with
8296 the address immediately after the the "bctr" instruction
8297 in this PLT entry. */
8304 {
8305 /* Fill in a couple of entries in .rela.plt.unloaded. */
8311 /* Provide the @ha relocation for the first instruction. */
8316 R_PPC_ADDR16_HA);
8321 /* Provide the @l relocation for the second instruction. */
8326 R_PPC_ADDR16_LO);
8331 /* Provide a relocation for the GOT entry corresponding to this
8332 PLT slot. Point it at the middle of the .plt entry. */
8337 R_PPC_ADDR32);
8340 }
8342 /* VxWorks uses non-standard semantics for R_PPC_JMP_SLOT.
8343 In particular, the offset for the relocation is not the
8344 address of the PLT entry for this function, as specified
8345 by the ABI. Instead, the offset is set to the address of
8346 the GOT slot for this function. See EABI 4.4.4.1. */
8351 }
8352 else
8353 {
8365 {
8366 /* We don't need to fill in the .plt. The ppc dynamic
8367 linker will fill it in. */
8368 }
8369 else
8370 {
8376 }
8377 }
8379 /* Fill in the entry in the .rela.plt section. */
8383 {
8390 }
8391 else
8399 else
8405 {
8406 /* Mark the symbol as undefined, rather than as
8407 defined in the .plt section. Leave the value if
8408 there were any relocations where pointer equality
8409 matters (this is a clue for the dynamic linker, to
8410 make function pointer comparisons work between an
8411 application and shared library), otherwise set it
8412 to zero. */
8417 {
8418 /* This breaks function pointer comparisons, but
8419 that is better than breaking tests for a NULL
8420 function pointer. */
8422 }
8423 }
8426 {
8427 /* Set the value of ifunc symbols in a non-pie
8428 executable to the glink entry. This is to avoid
8429 text relocations. We can't do this for ifunc in
8430 allocate_dynrelocs, as we do for normal dynamic
8431 function symbols with plt entries, because we need
8432 to keep the original value around for the ifunc
8433 relocation. */
8439 }
8441 }
8446 {
8456 {
8473 }
8478 /* We only need one non-PIC glink stub. */
8480 }
8481 else
8483 }
8486 {
8488 Elf_Internal_Rela rela;
8491 /* This symbols needs a copy reloc. Set it up. */
8493 #ifdef DEBUG
8495 #endif
8501 else
8510 }
8512 #ifdef DEBUG
8514 #endif
8516 /* Mark some specially defined symbols as absolute. */
8525 }
8526 \f
8527 static enum elf_reloc_type_class
8529 {
8531 {
8542 }
8543 }
8544 \f
8545 /* Finish up the dynamic sections. */
8547 static bfd_boolean
8550 {
8554 bfd_vma got;
8558 #ifdef DEBUG
8560 #endif
8567 else
8575 {
8583 {
8584 Elf_Internal_Dyn dyn;
8590 {
8594 else
8614 {
8618 }
8626 }
8629 }
8630 }
8633 {
8636 {
8641 {
8642 /* Add a blrl instruction at _GLOBAL_OFFSET_TABLE_-4
8643 so that a function can easily find the address of
8644 _GLOBAL_OFFSET_TABLE_. */
8648 }
8651 {
8656 }
8657 }
8658 else
8659 {
8666 }
8669 }
8671 /* Fill in the first entry in the VxWorks procedure linkage table. */
8673 {
8674 /* Use the right PLT. */
8676 ? ppc_elf_vxworks_pic_plt0_entry
8680 {
8687 }
8688 else
8689 {
8692 }
8701 {
8702 Elf_Internal_Rela rela;
8707 /* Output the @ha relocation for the first instruction. */
8716 /* Output the @l relocation for the second instruction. */
8725 /* Fix up the remaining relocations. They may have the wrong
8726 symbol index for _G_O_T_ or _P_L_T_ depending on the order
8727 in which symbols were output. */
8729 {
8730 Elf_Internal_Rela rel;
8746 }
8747 }
8748 }
8753 {
8756 bfd_vma res0;
8759 /*
8760 * PIC glink code is the following:
8761 *
8762 * # ith PLT code stub.
8763 * addis 11,30,(plt+(i-1)*4-got)@ha
8764 * lwz 11,(plt+(i-1)*4-got)@l(11)
8765 * mtctr 11
8766 * bctr
8767 *
8768 * # A table of branches, one for each plt entry.
8769 * # The idea is that the plt call stub loads ctr and r11 with these
8770 * # addresses, so (r11 - res_0) gives the plt index * 4.
8771 * res_0: b PLTresolve
8772 * res_1: b PLTresolve
8773 * .
8774 * # Some number of entries towards the end can be nops
8775 * res_n_m3: nop
8776 * res_n_m2: nop
8777 * res_n_m1:
8778 *
8779 * PLTresolve:
8780 * addis 11,11,(1f-res_0)@ha
8781 * mflr 0
8782 * bcl 20,31,1f
8783 * 1: addi 11,11,(1b-res_0)@l
8784 * mflr 12
8785 * mtlr 0
8786 * sub 11,11,12 # r11 = index * 4
8787 * addis 12,12,(got+4-1b)@ha
8788 * lwz 0,(got+4-1b)@l(12) # got[1] address of dl_runtime_resolve
8789 * lwz 12,(got+8-1b)@l(12) # got[2] contains the map address
8790 * mtctr 0
8791 * add 0,11,11
8792 * add 11,0,11 # r11 = index * 12 = reloc offset.
8793 * bctr
8794 */
8796 {
8797 ADDIS_11_11,
8798 MFLR_0,
8799 BCL_20_31,
8800 ADDI_11_11,
8801 MFLR_12,
8802 MTLR_0,
8803 SUB_11_11_12,
8804 ADDIS_12_12,
8805 LWZ_0_12,
8806 LWZ_12_12,
8807 MTCTR_0,
8808 ADD_0_11_11,
8809 ADD_11_0_11,
8810 BCTR,
8811 NOP,
8812 NOP
8813 };
8815 /*
8816 * Non-PIC glink code is a little simpler.
8817 *
8818 * # ith PLT code stub.
8819 * lis 11,(plt+(i-1)*4)@ha
8820 * lwz 11,(plt+(i-1)*4)@l(11)
8821 * mtctr 11
8822 * bctr
8823 *
8824 * The branch table is the same, then comes
8825 *
8826 * PLTresolve:
8827 * lis 12,(got+4)@ha
8828 * addis 11,11,(-res_0)@ha
8829 * lwz 0,(got+4)@l(12) # got[1] address of dl_runtime_resolve
8830 * addi 11,11,(-res_0)@l # r11 = index * 4
8831 * mtctr 0
8832 * add 0,11,11
8833 * lwz 12,(got+8)@l(12) # got[2] contains the map address
8834 * add 11,0,11 # r11 = index * 12 = reloc offset.
8835 * bctr
8836 */
8838 {
8839 LIS_12,
8840 ADDIS_11_11,
8841 LWZ_0_12,
8842 ADDI_11_11,
8843 MTCTR_0,
8844 ADD_0_11_11,
8845 LWZ_12_12,
8846 ADD_11_0_11,
8847 BCTR,
8848 NOP,
8849 NOP,
8850 NOP,
8851 NOP,
8852 NOP,
8853 NOP,
8854 NOP
8855 };
8862 /* Build the branch table, one for each plt entry (less one),
8863 and perhaps some padding. */
8869 {
8872 }
8874 {
8877 }
8883 /* Last comes the PLTresolve stub. */
8885 {
8886 bfd_vma bcl;
8889 {
8892 }
8906 {
8911 }
8912 else
8913 {
8918 }
8919 }
8920 else
8921 {
8923 {
8926 }
8936 {
8941 }
8942 else
8943 {
8948 }
8949 }
8950 }
8953 }
8954 \f
8955 #define TARGET_LITTLE_SYM bfd_elf32_powerpcle_vec
8957 #define TARGET_BIG_SYM bfd_elf32_powerpc_vec
8959 #define ELF_ARCH bfd_arch_powerpc
8960 #define ELF_TARGET_ID PPC32_ELF_DATA
8961 #define ELF_MACHINE_CODE EM_PPC
8962 #ifdef __QNXTARGET__
8963 #define ELF_MAXPAGESIZE 0x1000
8964 #else
8965 #define ELF_MAXPAGESIZE 0x10000
8966 #endif
8967 #define ELF_MINPAGESIZE 0x1000
8968 #define ELF_COMMONPAGESIZE 0x1000
8969 #define elf_info_to_howto ppc_elf_info_to_howto
8971 #ifdef EM_CYGNUS_POWERPC
8972 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
8973 #endif
8975 #ifdef EM_PPC_OLD
8976 #define ELF_MACHINE_ALT2 EM_PPC_OLD
8977 #endif
8979 #define elf_backend_plt_not_loaded 1
8980 #define elf_backend_can_gc_sections 1
8981 #define elf_backend_can_refcount 1
8982 #define elf_backend_rela_normal 1
8984 #define bfd_elf32_mkobject ppc_elf_mkobject
8985 #define bfd_elf32_bfd_merge_private_bfd_data ppc_elf_merge_private_bfd_data
8986 #define bfd_elf32_bfd_relax_section ppc_elf_relax_section
8987 #define bfd_elf32_bfd_reloc_type_lookup ppc_elf_reloc_type_lookup
8988 #define bfd_elf32_bfd_reloc_name_lookup ppc_elf_reloc_name_lookup
8989 #define bfd_elf32_bfd_set_private_flags ppc_elf_set_private_flags
8990 #define bfd_elf32_bfd_link_hash_table_create ppc_elf_link_hash_table_create
8991 #define bfd_elf32_get_synthetic_symtab ppc_elf_get_synthetic_symtab
8993 #define elf_backend_object_p ppc_elf_object_p
8994 #define elf_backend_gc_mark_hook ppc_elf_gc_mark_hook
8995 #define elf_backend_gc_sweep_hook ppc_elf_gc_sweep_hook
8996 #define elf_backend_section_from_shdr ppc_elf_section_from_shdr
8997 #define elf_backend_relocate_section ppc_elf_relocate_section
8998 #define elf_backend_create_dynamic_sections ppc_elf_create_dynamic_sections
8999 #define elf_backend_check_relocs ppc_elf_check_relocs
9000 #define elf_backend_copy_indirect_symbol ppc_elf_copy_indirect_symbol
9001 #define elf_backend_adjust_dynamic_symbol ppc_elf_adjust_dynamic_symbol
9002 #define elf_backend_add_symbol_hook ppc_elf_add_symbol_hook
9003 #define elf_backend_size_dynamic_sections ppc_elf_size_dynamic_sections
9004 #define elf_backend_hash_symbol ppc_elf_hash_symbol
9005 #define elf_backend_finish_dynamic_symbol ppc_elf_finish_dynamic_symbol
9006 #define elf_backend_finish_dynamic_sections ppc_elf_finish_dynamic_sections
9007 #define elf_backend_fake_sections ppc_elf_fake_sections
9008 #define elf_backend_additional_program_headers ppc_elf_additional_program_headers
9009 #define elf_backend_grok_prstatus ppc_elf_grok_prstatus
9010 #define elf_backend_grok_psinfo ppc_elf_grok_psinfo
9011 #define elf_backend_write_core_note ppc_elf_write_core_note
9012 #define elf_backend_reloc_type_class ppc_elf_reloc_type_class
9013 #define elf_backend_begin_write_processing ppc_elf_begin_write_processing
9014 #define elf_backend_final_write_processing ppc_elf_final_write_processing
9015 #define elf_backend_write_section ppc_elf_write_section
9016 #define elf_backend_get_sec_type_attr ppc_elf_get_sec_type_attr
9017 #define elf_backend_plt_sym_val ppc_elf_plt_sym_val
9018 #define elf_backend_action_discarded ppc_elf_action_discarded
9019 #define elf_backend_init_index_section _bfd_elf_init_1_index_section
9020 #define elf_backend_post_process_headers _bfd_elf_set_osabi
9024 /* VxWorks Target */
9026 #undef TARGET_LITTLE_SYM
9027 #undef TARGET_LITTLE_NAME
9029 #undef TARGET_BIG_SYM
9030 #define TARGET_BIG_SYM bfd_elf32_powerpc_vxworks_vec
9031 #undef TARGET_BIG_NAME
9034 /* VxWorks uses the elf default section flags for .plt. */
9037 {
9045 }
9047 /* Like ppc_elf_link_hash_table_create, but overrides
9048 appropriately for VxWorks. */
9051 {
9056 {
9064 }
9066 }
9068 /* Tweak magic VxWorks symbols as they are loaded. */
9069 static bfd_boolean
9077 {
9079 valp))
9083 }
9085 static void
9087 {
9090 }
9092 /* On VxWorks, we emit relocations against _PROCEDURE_LINKAGE_TABLE_, so
9093 define it. */
9094 #undef elf_backend_want_plt_sym
9095 #define elf_backend_want_plt_sym 1
9096 #undef elf_backend_want_got_plt
9097 #define elf_backend_want_got_plt 1
9098 #undef elf_backend_got_symbol_offset
9099 #define elf_backend_got_symbol_offset 0
9100 #undef elf_backend_plt_not_loaded
9101 #define elf_backend_plt_not_loaded 0
9102 #undef elf_backend_plt_readonly
9103 #define elf_backend_plt_readonly 1
9104 #undef elf_backend_got_header_size
9105 #define elf_backend_got_header_size 12
9107 #undef bfd_elf32_get_synthetic_symtab
9109 #undef bfd_elf32_bfd_link_hash_table_create
9110 #define bfd_elf32_bfd_link_hash_table_create \
9111 ppc_elf_vxworks_link_hash_table_create
9112 #undef elf_backend_add_symbol_hook
9113 #define elf_backend_add_symbol_hook \
9114 ppc_elf_vxworks_add_symbol_hook
9115 #undef elf_backend_link_output_symbol_hook
9116 #define elf_backend_link_output_symbol_hook \
9117 elf_vxworks_link_output_symbol_hook
9118 #undef elf_backend_final_write_processing
9119 #define elf_backend_final_write_processing \
9120 ppc_elf_vxworks_final_write_processing
9121 #undef elf_backend_get_sec_type_attr
9122 #define elf_backend_get_sec_type_attr \
9123 ppc_elf_vxworks_get_sec_type_attr
9124 #undef elf_backend_emit_relocs
9125 #define elf_backend_emit_relocs \
9126 elf_vxworks_emit_relocs
9128 #undef elf32_bed
9129 #define elf32_bed ppc_elf_vxworks_bed
9130 #undef elf_backend_post_process_headers