| blob | e3638cd20c68dca4af259cab108758752f408dda |
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 {
2788 }
2791 }
2793 /* Create a PPC ELF linker hash table. */
2797 {
2805 ppc_elf_link_hash_newfunc,
2807 PPC32_ELF_DATA))
2808 {
2811 }
2831 }
2833 /* Create .got and the related sections. */
2835 static bfd_boolean
2837 {
2840 flagword flags;
2851 {
2855 }
2856 else
2857 {
2858 /* The powerpc .got has a blrl instruction in it. Mark it
2859 executable. */
2864 }
2871 }
2873 static bfd_boolean
2875 {
2878 flagword flags;
2903 }
2905 /* We have to create .dynsbss and .rela.sbss here so that they get mapped
2906 to output sections (just like _bfd_elf_create_dynamic_sections has
2907 to create .dynbss and .rela.bss). */
2909 static bfd_boolean
2911 {
2914 flagword flags;
2937 {
2946 }
2959 /* The VxWorks PLT is a loaded section with contents. */
2962 }
2964 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2966 static void
2970 {
2977 {
2979 {
2983 /* Add reloc counts against the indirect sym to the direct sym
2984 list. Merge any entries against the same section. */
2986 {
2991 {
2996 }
2999 }
3001 }
3005 }
3010 /* If called to transfer flags for a weakdef during processing
3011 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
3012 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
3024 /* If we were called to copy over info for a weak sym, that's all. */
3028 /* Copy over the GOT refcount entries that we may have already seen to
3029 the symbol which just became indirect. */
3033 /* And plt entries. */
3035 {
3037 {
3042 {
3047 {
3051 }
3054 }
3056 }
3060 }
3063 {
3071 }
3072 }
3074 /* Hook called by the linker routine which adds symbols from an object
3075 file. We use it to put .comm items in .sbss, and not .bss. */
3077 static bfd_boolean
3085 {
3090 {
3091 /* Common symbols less than or equal to -G nn bytes are automatically
3092 put into .sbss. */
3097 {
3105 flags);
3108 }
3112 }
3119 }
3120 \f
3121 static bfd_boolean
3123 {
3135 }
3137 /* Create a special linker section. */
3139 static bfd_boolean
3142 flagword flags,
3144 {
3151 /* Record the first bfd that needs the special sections. */
3157 flags);
3164 }
3166 /* Find a linker generated pointer with a given addend and type. */
3169 elf_find_pointer_linker_section
3171 bfd_vma addend,
3173 {
3179 }
3181 /* Allocate a pointer to live in a linker created section. */
3183 static bfd_boolean
3188 {
3192 bfd_size_type amt;
3196 /* Is this a global symbol? */
3198 {
3201 /* Has this symbol already been allocated? If so, our work is done. */
3205 lsect))
3209 }
3210 else
3211 {
3214 /* Allocation of a pointer to a local symbol. */
3217 /* Allocate a table to hold the local symbols if first time. */
3219 {
3230 }
3232 /* Has this symbol already been allocated? If so, our work is done. */
3235 lsect))
3239 }
3241 /* Allocate space for a pointer in the linker section, and allocate
3242 a new pointer record from internal memory. */
3258 #ifdef DEBUG
3263 #endif
3266 }
3273 {
3279 {
3289 }
3297 }
3299 static bfd_boolean
3302 {
3311 {
3321 }
3324 }
3328 {
3337 }
3339 static bfd_boolean
3341 {
3352 }
3354 static void
3356 {
3359 abfd,
3362 }
3364 /* Look through the relocs for a section during the first phase, and
3365 allocate space in the global offset table or procedure linkage
3366 table. */
3368 static bfd_boolean
3373 {
3385 /* Don't do anything special with non-loaded, non-alloced sections.
3386 In particular, any relocs in such sections should not affect GOT
3387 and PLT reference counting (ie. we don't allow them to create GOT
3388 or PLT entries), there's no possibility or desire to optimize TLS
3389 relocs, and there's not much point in propagating relocs to shared
3390 libs that the dynamic linker won't relocate. */
3394 #ifdef DEBUG
3397 #endif
3401 /* Initialize howto table if not already done. */
3407 {
3412 }
3422 {
3431 else
3432 {
3437 }
3439 /* If a relocation refers to _GLOBAL_OFFSET_TABLE_, create the .got.
3440 This shows up in particular in an R_PPC_ADDR32 in the eabi
3441 startup code. */
3445 {
3451 }
3456 {
3465 {
3467 bfd_vma addend;
3470 PLT_IFUNC);
3474 /* STT_GNU_IFUNC symbols must have a PLT entry;
3475 In a non-pie executable even when there are
3476 no plt calls. */
3479 {
3483 }
3486 }
3487 }
3493 {
3497 /* We have a new-style __tls_get_addr call with a marker
3498 reloc. */
3499 ;
3500 else
3501 /* Mark this section as having an old-style call. */
3503 }
3506 {
3509 /* These special tls relocs tie a call to __tls_get_addr with
3510 its parameter symbol. */
3541 dogottls:
3543 /* Fall thru */
3545 /* GOT16 relocations */
3550 /* This symbol requires a global offset table entry. */
3552 {
3557 }
3559 {
3562 }
3563 else
3564 /* This is a global offset table entry for a local symbol. */
3568 /* We may also need a plt entry if the symbol turns out to be
3569 an ifunc. */
3571 {
3574 }
3577 /* Indirect .sdata relocation. */
3580 {
3583 }
3592 {
3595 }
3598 /* Indirect .sdata2 relocation. */
3601 {
3604 }
3613 {
3616 }
3624 {
3627 }
3632 {
3635 }
3640 {
3643 }
3649 {
3652 }
3660 {
3663 }
3672 {
3675 }
3683 /* Fall through */
3689 #ifdef DEBUG
3691 #endif
3692 /* This symbol requires a procedure linkage table entry. We
3693 actually build the entry in finish_dynamic_symbol,
3694 because this might be a case of linking PIC code without
3695 linking in any dynamic objects, in which case we don't
3696 need to generate a procedure linkage table after all. */
3699 {
3700 /* It does not make sense to have a procedure linkage
3701 table entry for a local symbol. */
3704 abfd,
3705 sec,
3710 }
3711 else
3712 {
3716 {
3720 }
3724 }
3727 /* The following relocations don't need to propagate the
3728 relocation if linking a shared object since they are
3729 section relative. */
3748 /* These are just markers. */
3758 /* These should only appear in dynamic objects. */
3766 /* These aren't handled yet. We'll report an error later. */
3775 /* This refers only to functions defined in the shared library. */
3778 {
3781 }
3784 /* This relocation describes the C++ object vtable hierarchy.
3785 Reconstruct it for later use during GC. */
3791 /* This relocation describes which C++ vtable entries are actually
3792 used. Record for later use during GC. */
3800 /* We shouldn't really be seeing these. */
3810 /* Nor these. */
3821 {
3822 /* Old -fPIC gcc code has .long LCTOC1-LCFx just before
3823 the start of a function, which assembles to a REL32
3824 reference to .got2. If we detect one of these, then
3825 force the old PLT layout because the linker cannot
3826 reliably deduce the GOT pointer value needed for
3827 PLT call stubs. */
3838 {
3841 }
3842 }
3845 /* fall through */
3855 {
3856 /* We may need a plt entry if the symbol turns out to be
3857 a function defined in a dynamic object. */
3861 /* We may need a copy reloc too. */
3864 }
3874 {
3876 {
3879 }
3881 }
3882 /* fall through */
3889 {
3890 /* We may need a plt entry if the symbol turns out to be
3891 a function defined in a dynamic object. */
3896 }
3898 dodyn:
3899 /* If we are creating a shared library, and this is a reloc
3900 against a global symbol, or a non PC relative reloc
3901 against a local symbol, then we need to copy the reloc
3902 into the shared library. However, if we are linking with
3903 -Bsymbolic, we do not need to copy a reloc against a
3904 global symbol which is defined in an object we are
3905 including in the link (i.e., DEF_REGULAR is set). At
3906 this point we have not seen all the input files, so it is
3907 possible that DEF_REGULAR is not set now but will be set
3908 later (it is never cleared). In case of a weak definition,
3909 DEF_REGULAR may be cleared later by a strong definition in
3910 a shared library. We account for that possibility below by
3911 storing information in the dyn_relocs field of the hash
3912 table entry. A similar situation occurs when creating
3913 shared libraries and symbol visibility changes render the
3914 symbol local.
3916 If on the other hand, we are creating an executable, we
3917 may need to keep relocations for symbols satisfied by a
3918 dynamic library if we manage to avoid copy relocs for the
3919 symbol. */
3926 || (ELIMINATE_COPY_RELOCS
3931 {
3935 #ifdef DEBUG
3937 "ppc_elf_check_relocs needs to "
3941 #endif
3943 {
3947 sreloc = _bfd_elf_make_dynamic_reloc_section
3952 }
3954 /* If this is a global symbol, we count the number of
3955 relocations we need for this symbol. */
3957 {
3959 }
3960 else
3961 {
3962 /* Track dynamic relocs needed for local syms too.
3963 We really need local syms available to do this
3964 easily. Oh well. */
3980 }
3984 {
3993 }
3998 }
4001 }
4002 }
4005 }
4006 \f
4008 /* Merge object attributes from IBFD into OBFD. Raise an error if
4009 there are conflicting attributes. */
4010 static bfd_boolean
4012 {
4017 {
4018 /* This is the first object. Copy the attributes. */
4021 /* Use the Tag_null value to indicate the attributes have been
4022 initialized. */
4026 }
4031 /* Check for conflicting Tag_GNU_Power_ABI_FP attributes and merge
4032 non-conflicting ones. */
4036 {
4041 ;
4043 _bfd_error_handler
4046 _bfd_error_handler
4050 _bfd_error_handler
4054 _bfd_error_handler
4058 _bfd_error_handler
4061 _bfd_error_handler
4064 else
4065 _bfd_error_handler
4068 }
4070 /* Check for conflicting Tag_GNU_Power_ABI_Vector attributes and
4071 merge non-conflicting ones. */
4075 {
4079 {
4083 }
4086 {
4090 }
4096 ;
4097 /* For now, allow generic to transition to AltiVec or SPE
4098 without a warning. If GCC marked files with their stack
4099 alignment and used don't-care markings for files which are
4100 not affected by the vector ABI, we could warn about this
4101 case too. */
4105 ;
4107 _bfd_error_handler
4111 _bfd_error_handler
4114 else
4115 _bfd_error_handler
4118 }
4120 /* Check for conflicting Tag_GNU_Power_ABI_Struct_Return attributes
4121 and merge non-conflicting ones. */
4125 {
4130 ;
4132 _bfd_error_handler
4135 _bfd_error_handler
4138 _bfd_error_handler
4141 else
4142 _bfd_error_handler
4145 }
4147 /* Merge Tag_compatibility attributes and any common GNU ones. */
4151 }
4153 /* Merge backend specific data from an object file to the output
4154 object file when linking. */
4156 static bfd_boolean
4158 {
4159 flagword old_flags;
4160 flagword new_flags;
4161 bfd_boolean error;
4166 /* Check if we have the same endianess. */
4176 {
4177 /* First call, no flags set. */
4180 }
4182 /* Compatible flags are ok. */
4184 ;
4186 /* Incompatible flags. */
4187 else
4188 {
4189 /* Warn about -mrelocatable mismatch. Allow -mrelocatable-lib
4190 to be linked with either. */
4194 {
4199 }
4202 {
4207 }
4209 /* The output is -mrelocatable-lib iff both the input files are. */
4213 /* The output is -mrelocatable iff it can't be -mrelocatable-lib,
4214 but each input file is either -mrelocatable or -mrelocatable-lib. */
4220 /* Do not warn about eabi vs. V.4 mismatch, just or in the bit if
4221 any module uses it. */
4227 /* Warn about any other mismatches. */
4229 {
4235 }
4238 {
4241 }
4242 }
4245 }
4246 \f
4247 /* Choose which PLT scheme to use, and set .plt flags appropriately.
4248 Returns -1 on error, 0 for old PLT, 1 for new PLT. */
4249 int
4254 {
4256 flagword flags;
4263 {
4266 else
4267 {
4271 /* Look through the reloc flags left by ppc_elf_check_relocs.
4272 Use the old style bss plt if a file makes plt calls
4273 without using the new relocs, and if ld isn't given
4274 --secure-plt and we never see REL16 relocs. */
4279 {
4283 {
4287 }
4288 }
4290 }
4291 }
4298 {
4302 /* The new PLT is a loaded section. */
4307 /* The new GOT is not executable. */
4311 }
4312 else
4313 {
4314 /* Stop an unused .glink section from affecting .text alignment. */
4318 }
4320 }
4321 \f
4322 /* Return the section that should be marked against GC for a given
4323 relocation. */
4331 {
4334 {
4338 }
4341 }
4343 /* Update the got, plt and dynamic reloc reference counts for the
4344 section being removed. */
4346 static bfd_boolean
4351 {
4375 {
4382 {
4394 {
4395 /* Everything must go for SEC. */
4398 }
4399 }
4407 {
4413 {
4424 }
4425 }
4428 {
4450 {
4454 {
4460 }
4461 }
4463 {
4466 }
4476 /* Fall thru */
4499 {
4508 }
4513 }
4514 }
4516 }
4517 \f
4518 /* Set plt output section type, htab->tls_get_addr, and call the
4519 generic ELF tls_setup function. */
4521 asection *
4525 {
4532 {
4539 {
4540 /* If glibc supports an optimized __tls_get_addr call stub,
4541 signalled by the presence of __tls_get_addr_opt, and we'll
4542 be calling __tls_get_addr via a plt call stub, then
4543 make __tls_get_addr point to __tls_get_addr_opt. */
4552 {
4558 {
4563 {
4564 /* Use __tls_get_addr_opt in dynamic relocations. */
4570 }
4572 }
4573 }
4574 }
4575 else
4577 }
4582 {
4585 }
4588 }
4590 /* Return TRUE iff REL is a branch reloc with a global symbol matching
4591 HASH. */
4593 static bfd_boolean
4597 {
4603 {
4613 }
4615 }
4617 /* Run through all the TLS relocs looking for optimization
4618 opportunities. */
4620 bfd_boolean
4623 {
4633 /* Make two passes through the relocs. First time check that tls
4634 relocs involved in setting up a tls_get_addr call are indeed
4635 followed by such a call. If they are not, exclude them from
4636 the optimizations done on the second pass. */
4639 {
4646 {
4649 /* Read the relocations. */
4657 {
4663 bfd_boolean is_local;
4669 {
4677 }
4687 {
4691 /* Fall thru */
4695 /* These relocs should never be against a symbol
4696 defined in a shared lib. Leave them alone if
4697 that turns out to be the case. */
4701 /* LD -> LE */
4709 /* Fall thru */
4714 /* GD -> LE */
4716 else
4717 /* GD -> IE */
4727 {
4728 /* IE -> LE */
4732 }
4733 else
4745 }
4748 {
4759 /* Uh oh, we didn't find the expected call. We
4760 could just mark this symbol to exclude it
4761 from tls optimization but it's safer to skip
4762 the entire section. */
4765 }
4768 {
4782 }
4785 {
4788 }
4789 else
4790 {
4796 {
4803 {
4807 }
4808 }
4817 }
4820 {
4821 /* We managed to get rid of a got entry. */
4824 }
4828 }
4832 }
4836 {
4839 else
4841 }
4842 }
4844 }
4845 \f
4846 /* Return true if we have dynamic relocs that apply to read-only sections. */
4848 static bfd_boolean
4850 {
4854 {
4861 }
4863 }
4865 /* Adjust a symbol defined by a dynamic object and referenced by a
4866 regular object. The current definition is in some section of the
4867 dynamic object, but we're not including those sections. We have to
4868 change the definition to something the rest of the link can
4869 understand. */
4871 static bfd_boolean
4874 {
4878 #ifdef DEBUG
4881 #endif
4883 /* Make sure we know what is going on here. */
4893 /* Deal with function syms. */
4897 {
4898 /* Clear procedure linkage table information for any symbol that
4899 won't need a .plt entry. */
4909 {
4910 /* A PLT entry is not required/allowed when:
4912 1. We are not using ld.so; because then the PLT entry
4913 can't be set up, so we can't use one. In this case,
4914 ppc_elf_adjust_dynamic_symbol won't even be called.
4916 2. GC has rendered the entry unused.
4918 3. We know for certain that a call to this symbol
4919 will go to this object, or will remain undefined. */
4922 }
4923 else
4924 {
4925 /* After adjust_dynamic_symbol, non_got_ref set in the
4926 non-shared case means that we have allocated space in
4927 .dynbss for the symbol and thus dyn_relocs for this
4928 symbol should be discarded.
4929 If we get here we know we are making a PLT entry for this
4930 symbol, and in an executable we'd normally resolve
4931 relocations against this symbol to the PLT entry. Allow
4932 dynamic relocs if the reference is weak, and the dynamic
4933 relocs will not cause text relocation. */
4941 }
4943 }
4944 else
4947 /* If this is a weak symbol, and there is a real definition, the
4948 processor independent code will have arranged for us to see the
4949 real definition first, and we can just use the same value. */
4951 {
4959 }
4961 /* This is a reference to a symbol defined by a dynamic object which
4962 is not a function. */
4964 /* If we are creating a shared library, we must presume that the
4965 only references to the symbol are via the global offset table.
4966 For such cases we need not do anything here; the relocations will
4967 be handled correctly by relocate_section. */
4971 /* If there are no references to this symbol that do not use the
4972 GOT, we don't need to generate a copy reloc. */
4976 /* If we didn't find any dynamic relocs in read-only sections, then
4977 we'll be keeping the dynamic relocs and avoiding the copy reloc.
4978 We can't do this if there are any small data relocations. This
4979 doesn't work on VxWorks, where we can not have dynamic
4980 relocations (other than copy and jump slot relocations) in an
4981 executable. */
4987 {
4990 }
4993 {
4997 }
4999 /* We must allocate the symbol in our .dynbss section, which will
5000 become part of the .bss section of the executable. There will be
5001 an entry for this symbol in the .dynsym section. The dynamic
5002 object will contain position independent code, so all references
5003 from the dynamic object to this symbol will go through the global
5004 offset table. The dynamic linker will use the .dynsym entry to
5005 determine the address it must put in the global offset table, so
5006 both the dynamic object and the regular object will refer to the
5007 same memory location for the variable.
5009 Of course, if the symbol is referenced using SDAREL relocs, we
5010 must instead allocate it in .sbss. */
5014 else
5018 /* We must generate a R_PPC_COPY reloc to tell the dynamic linker to
5019 copy the initial value out of the dynamic object and into the
5020 runtime process image. We need to remember the offset into the
5021 .rela.bss section we are going to use. */
5023 {
5028 else
5033 }
5036 }
5037 \f
5038 /* Generate a symbol to mark plt call stubs. For non-PIC code the sym is
5039 xxxxxxxx.plt_call32.<callee> where xxxxxxxx is a hex number, usually 0,
5040 specifying the addend on the plt relocation. For -fpic code, the sym
5041 is xxxxxxxx.plt_pic32.<callee>, and for -fPIC
5042 xxxxxxxx.got2.plt_pic32.<callee>. */
5044 static bfd_boolean
5048 {
5057 else
5077 {
5086 }
5088 }
5090 /* Allocate NEED contiguous space in .got, and return the offset.
5091 Handles allocation of the got header when crossing 32k. */
5093 static bfd_vma
5095 {
5096 bfd_vma where;
5100 {
5103 }
5104 else
5105 {
5108 {
5111 }
5112 else
5113 {
5116 {
5119 }
5122 }
5123 }
5125 }
5127 /* Allocate space in associated reloc sections for dynamic relocs. */
5129 static bfd_boolean
5131 {
5141 /* When warning symbols are created, they **replace** the "real"
5142 entry in the hash table, thus we never get to see the real
5143 symbol in a hash traversal. So look at it now. */
5149 {
5153 bfd_boolean dyn;
5157 {
5158 /* Make sure this symbol is output as a dynamic symbol. */
5163 {
5166 }
5172 {
5178 {
5180 {
5183 }
5188 {
5194 }
5199 {
5202 }
5208 }
5209 else
5210 {
5212 {
5213 /* If this is the first .plt entry, make room
5214 for the special first entry. */
5218 /* The PowerPC PLT is actually composed of two
5219 parts, the first part is 2 words (for a load
5220 and a jump), and then there is a remaining
5221 word available at the end. */
5228 /* If this symbol is not defined in a regular
5229 file, and we are not generating a shared
5230 library, then set the symbol to this location
5231 in the .plt. This is to avoid text
5232 relocations, and is required to make
5233 function pointers compare as equal between
5234 the normal executable and the shared library. */
5238 {
5241 }
5243 /* Make room for this entry. */
5245 /* After the 8192nd entry, room for two entries
5246 is allocated. */
5252 }
5254 }
5256 /* We also need to make an entry in the .rela.plt section. */
5258 {
5262 else
5263 {
5267 {
5268 /* Allocate space for the unloaded relocations. */
5271 {
5274 {
5278 }
5283 }
5285 /* Every PLT entry has an associated GOT entry in
5286 .got.plt. */
5288 }
5289 }
5291 }
5292 }
5293 else
5295 }
5296 else
5300 {
5303 }
5304 }
5305 else
5306 {
5309 }
5313 {
5314 bfd_boolean dyn;
5317 /* Make sure this symbol is output as a dynamic symbol. */
5322 {
5325 }
5329 {
5331 {
5333 /* We'll just use htab->tlsld_got.offset. This should
5334 always be the case. It's a little odd if we have
5335 a local dynamic reloc against a non-local symbol. */
5337 else
5339 }
5346 }
5347 else
5351 else
5352 {
5359 {
5361 /* All the entries we allocated need relocs.
5362 Except LD only needs one. */
5367 }
5368 }
5369 }
5370 else
5377 /* In the shared -Bsymbolic case, discard space allocated for
5378 dynamic pc-relative relocs against symbols which turn out to be
5379 defined in regular objects. For the normal shared case, discard
5380 space for relocs that have become local due to symbol visibility
5381 changes. */
5384 {
5385 /* Relocs that use pc_count are those that appear on a call insn,
5386 or certain REL relocs (see must_be_dyn_reloc) that can be
5387 generated via assembly. We want calls to protected symbols to
5388 resolve directly to the function rather than going via the plt.
5389 If people want function pointer comparisons to work as expected
5390 then they should avoid writing weird assembly. */
5392 {
5396 {
5401 else
5403 }
5404 }
5407 {
5411 {
5414 else
5416 }
5417 }
5419 /* Discard relocs on undefined symbols that must be local. */
5426 /* Also discard relocs on undefined weak syms with non-default
5427 visibility. */
5430 {
5434 /* Make sure undefined weak symbols are output as a dynamic
5435 symbol in PIEs. */
5439 {
5442 }
5443 }
5444 }
5446 {
5447 /* For the non-shared case, discard space for relocs against
5448 symbols which turn out to need copy relocs or are not
5449 dynamic. */
5453 {
5454 /* Make sure this symbol is output as a dynamic symbol.
5455 Undefined weak syms won't yet be marked as dynamic. */
5458 {
5461 }
5463 /* If that succeeded, we know we'll be keeping all the
5464 relocs. */
5467 }
5471 keep: ;
5472 }
5474 /* Finally, allocate space. */
5476 {
5481 }
5484 }
5486 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
5487 read-only sections. */
5489 static bfd_boolean
5491 {
5499 {
5502 /* Not an error, just cut short the traversal. */
5504 }
5506 }
5508 /* Set the sizes of the dynamic sections. */
5510 static bfd_boolean
5513 {
5516 bfd_boolean relocs;
5519 #ifdef DEBUG
5521 #endif
5527 {
5528 /* Set the contents of the .interp section to the interpreter. */
5530 {
5535 }
5536 }
5543 /* Set up .got offsets for local syms, and space for local dynamic
5544 relocs. */
5546 {
5552 bfd_size_type locsymcount;
5559 {
5566 {
5569 {
5570 /* Input section has been discarded, either because
5571 it is a copy of a linkonce section or due to
5572 linker script /DISCARD/, so we'll be discarding
5573 the relocs too. */
5574 }
5578 {
5579 /* Relocations in vxworks .tls_vars sections are
5580 handled specially by the loader. */
5581 }
5583 {
5592 }
5593 }
5594 }
5609 {
5612 {
5621 }
5622 else
5626 else
5627 {
5632 }
5633 }
5634 else
5640 /* Allocate space for calls to local STT_GNU_IFUNC syms in .iplt. */
5642 {
5649 {
5653 {
5656 }
5661 {
5664 }
5668 {
5671 }
5672 }
5673 else
5675 }
5676 }
5678 /* Allocate space for global sym dynamic relocs. */
5682 {
5686 }
5687 else
5691 {
5694 /* If we haven't allocated the header, do so now. When we get here,
5695 for old plt/got the got size will be 0 to 32764 (not allocated),
5696 or 32780 to 65536 (header allocated). For new plt/got, the
5697 corresponding ranges are 0 to 32768 and 32780 to 65536. */
5699 {
5704 }
5707 }
5709 {
5714 {
5718 }
5719 }
5724 {
5726 /* Space for the branch table. */
5728 /* Pad out to align the start of PLTresolve. */
5733 {
5740 {
5749 }
5755 {
5764 }
5765 }
5766 }
5768 /* We've now determined the sizes of the various dynamic sections.
5769 Allocate memory for them. */
5772 {
5780 {
5781 /* We'd like to strip these sections if they aren't needed, but if
5782 we've exported dynamic symbols from them we must leave them.
5783 It's too late to tell BFD to get rid of the symbols. */
5786 /* Strip this section if we don't need it; see the
5787 comment below. */
5788 }
5797 {
5798 /* Strip these too. */
5799 }
5801 {
5803 {
5804 /* Remember whether there are any relocation sections. */
5807 /* We use the reloc_count field as a counter if we need
5808 to copy relocs into the output file. */
5810 }
5811 }
5812 else
5813 {
5814 /* It's not one of our sections, so don't allocate space. */
5816 }
5819 {
5820 /* If we don't need this section, strip it from the
5821 output file. This is mostly to handle .rela.bss and
5822 .rela.plt. We must create both sections in
5823 create_dynamic_sections, because they must be created
5824 before the linker maps input sections to output
5825 sections. The linker does that before
5826 adjust_dynamic_symbol is called, and it is that
5827 function which decides whether anything needs to go
5828 into these sections. */
5831 }
5836 /* Allocate memory for the section contents. */
5840 }
5843 {
5844 /* Add some entries to the .dynamic section. We fill in the
5845 values later, in ppc_elf_finish_dynamic_sections, but we
5846 must add the entries now so that we get the correct size for
5847 the .dynamic section. The DT_DEBUG entry is filled in by the
5848 dynamic linker and used by the debugger. */
5849 #define add_dynamic_entry(TAG, VAL) \
5850 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
5853 {
5856 }
5859 {
5865 }
5868 {
5876 }
5879 {
5884 }
5886 /* If any dynamic relocs apply to a read-only section, then we
5887 need a DT_TEXTREL entry. */
5890 info);
5893 {
5896 }
5900 }
5901 #undef add_dynamic_entry
5904 }
5906 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
5908 static bfd_boolean
5910 {
5918 }
5919 \f
5920 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
5922 /* Relaxation trampolines. r12 is available for clobbering (r11, is
5923 used for some functions that are allowed to break the ABI). */
5925 {
5934 };
5937 {
5942 };
5944 static bfd_boolean
5949 {
5950 struct one_fixup
5951 {
5954 /* Final link, can use the symbol offset. For a
5955 relocatable link we use the symbol's index. */
5956 bfd_vma toff;
5957 bfd_vma trampoff;
5958 };
5968 bfd_size_type trampoff;
5970 bfd_boolean maybe_pasted;
5974 /* Nothing to do if there are no relocations, and no need to do
5975 anything with non-alloc or non-code sections. */
5982 /* We cannot represent the required PIC relocs in the output, so don't
5983 do anything. The linker doesn't support mixing -shared and -r
5984 anyway. */
5991 /* Space for a branch around any trampolines. */
5997 /* Get a copy of the native relocations. */
6008 {
6022 {
6037 }
6039 /* Get the value of the symbol referred to by the reloc. */
6042 {
6043 /* A local symbol. */
6046 /* Read this BFD's local symbols. */
6048 {
6056 }
6064 else
6069 }
6070 else
6071 {
6072 /* Global symbol handling. */
6084 {
6087 }
6090 {
6093 }
6094 else
6098 }
6100 /* The condition here under which we call find_plt_ent must
6101 match that in relocate_section. If we call find_plt_ent here
6102 but not in relocate_section, or vice versa, then the branch
6103 destination used here may be incorrect. */
6106 {
6107 /* We know is_branch_reloc (r_type) is true. */
6111 }
6114 {
6119 }
6121 {
6129 {
6134 {
6137 }
6138 else
6139 {
6142 }
6143 }
6144 }
6146 /* If the branch and target are in the same section, you have
6147 no hope of adding stubs. We'll error out later should the
6148 branch overflow. */
6152 /* There probably isn't any reason to handle symbols in
6153 SEC_MERGE sections; SEC_MERGE doesn't seem a likely
6154 attribute for a code section, and we are only looking at
6155 branches. However, implement it correctly here as a
6156 reference for other target relax_section functions. */
6158 {
6159 /* At this stage in linking, no SEC_MERGE symbol has been
6160 adjusted, so all references to such symbols need to be
6161 passed through _bfd_merged_section_offset. (Later, in
6162 relocate_section, all SEC_MERGE symbols *except* for
6163 section symbols have been adjusted.)
6165 gas may reduce relocations against symbols in SEC_MERGE
6166 sections to a relocation against the section symbol when
6167 the original addend was zero. When the reloc is against
6168 a section symbol we should include the addend in the
6169 offset passed to _bfd_merged_section_offset, since the
6170 location of interest is the original symbol. On the
6171 other hand, an access to "sym+addend" where "sym" is not
6172 a section symbol should not include the addend; Such an
6173 access is presumed to be an offset from "sym"; The
6174 location of interest is just "sym". */
6180 toff);
6184 }
6185 /* PLTREL24 addends are special. */
6189 /* Attempted -shared link of non-pic code loses. */
6195 /* If the branch is in range, no need to do anything. */
6198 /* A relocatable link may have sections moved during
6199 final link, so do not presume they remain in range. */
6201 {
6208 }
6210 /* Look for an existing fixup to this address. */
6216 {
6222 /* Oh dear, we can't reach a trampoline. Don't try to add
6223 one. We'll report an error later. */
6227 {
6230 }
6231 else
6232 {
6235 }
6239 {
6243 }
6245 /* Hijack the old relocation. Since we need two
6246 relocations for this use a "composite" reloc. */
6248 stub_rtype);
6254 /* Record the fixup so we don't do it again this section. */
6263 changes++;
6264 }
6265 else
6266 {
6271 /* Nop out the reloc, since we're finalizing things here. */
6273 }
6275 /* Get the section contents. */
6277 {
6278 /* Get cached copy if it exists. */
6281 else
6282 {
6283 /* Go get them off disk. */
6286 }
6287 }
6289 /* Fix up the existing branch to hit the trampoline. */
6292 {
6310 }
6311 }
6313 /* Write out the trampolines. */
6315 {
6320 do
6321 {
6325 }
6334 /* Branch around the trampolines. */
6336 {
6340 }
6344 {
6347 }
6348 else
6349 {
6352 }
6356 {
6358 i++;
6362 }
6364 }
6368 {
6371 else
6372 {
6373 /* Cache the symbols for elf_link_input_bfd. */
6375 }
6376 }
6380 {
6383 else
6384 {
6385 /* Cache the section contents for elf_link_input_bfd. */
6387 }
6388 }
6391 {
6392 /* Append sufficient NOP relocs so we can write out relocation
6393 information for the trampolines. */
6403 {
6407 }
6414 }
6420 {
6421 /* Convert the internal relax relocs to external form. */
6424 {
6427 /* Rewrite the reloc and convert one of the trailing nop
6428 relocs to describe this relocation. */
6430 /* The relocs are at the bottom 2 bytes */
6436 irel++;
6437 }
6438 }
6442 error_return:
6452 }
6453 \f
6454 /* What to do when ld finds relocations against symbols defined in
6455 discarded sections. */
6457 static unsigned int
6459 {
6467 }
6468 \f
6469 /* Fill in the address for a pointer generated in a linker section. */
6471 static bfd_vma
6475 bfd_vma relocation,
6477 {
6483 {
6484 /* Handle global symbol. */
6490 }
6491 else
6492 {
6493 /* Handle local symbol. */
6499 }
6503 lsect);
6506 /* Offset will always be a multiple of four, so use the bottom bit
6507 as a "written" flag. */
6509 {
6514 }
6521 #ifdef DEBUG
6525 #endif
6528 }
6530 #define PPC_LO(v) ((v) & 0xffff)
6531 #define PPC_HI(v) (((v) >> 16) & 0xffff)
6532 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
6534 static void
6537 {
6540 bfd_vma plt;
6547 {
6560 {
6569 }
6570 else
6571 {
6580 }
6581 }
6582 else
6583 {
6592 }
6593 }
6595 /* Return true if symbol is defined statically. */
6597 static bfd_boolean
6599 {
6604 }
6606 /* If INSN is an opcode that may be used with an @tls operand, return
6607 the transformed insn for TLS optimisation, otherwise return 0. If
6608 REG is non-zero only match an insn with RB or RA equal to REG. */
6610 unsigned int
6612 {
6622 else
6626 /* add -> addi. */
6632 /* load and store indexed -> dform. */
6635 /* ldx, ldux, stdx, stdux -> ld, ldu, std, stdu. */
6638 /* lwax -> lwa. */
6640 else
6644 }
6646 /* If INSN is an opcode that may be used with an @tprel operand, return
6647 the transformed insn for an undefined weak symbol, ie. with the
6648 thread pointer REG operand removed. Otherwise return 0. */
6650 unsigned int
6652 {
6673 {
6675 }
6680 {
6685 }
6686 else
6689 }
6691 /* The RELOCATE_SECTION function is called by the ELF backend linker
6692 to handle the relocations for a section.
6694 The relocs are always passed as Rela structures; if the section
6695 actually uses Rel structures, the r_addend field will always be
6696 zero.
6698 This function is responsible for adjust the section contents as
6699 necessary, and (if using Rela relocs and generating a
6700 relocatable output file) adjusting the reloc addend as
6701 necessary.
6703 This function does not have to worry about setting the reloc
6704 address or the reloc symbol index.
6706 LOCAL_SYMS is a pointer to the swapped in local symbols.
6708 LOCAL_SECTIONS is an array giving the section in the input file
6709 corresponding to the st_shndx field of each local symbol.
6711 The global hash table entry for the global symbols can be found
6712 via elf_sym_hashes (input_bfd).
6714 When generating relocatable output, this function must handle
6715 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
6716 going to be the section symbol corresponding to the output
6717 section, which means that the addend must be adjusted
6718 accordingly. */
6720 static bfd_boolean
6729 {
6735 Elf_Internal_Rela outrel;
6740 bfd_boolean is_vxworks_tls;
6742 #ifdef DEBUG
6748 #endif
6752 /* Initialize howto table if not already done. */
6760 /* We have to handle relocations in vxworks .tls_vars sections
6761 specially, because the dynamic loader is 'weird'. */
6768 {
6770 bfd_vma addend;
6771 bfd_reloc_status_type r;
6778 bfd_vma relocation;
6780 bfd_boolean unresolved_reloc;
6781 bfd_boolean warned;
6794 {
6800 }
6801 else
6802 {
6809 }
6812 {
6813 /* For relocs against symbols from removed linkonce sections,
6814 or sections discarded by a linker script, we just want the
6815 section contents zeroed. Avoid any special processing. */
6823 }
6826 {
6830 {
6831 /* R_PPC_PLTREL24 is rather special. If non-zero, the
6832 addend specifies the GOT pointer offset within .got2. */
6834 }
6836 }
6838 /* TLS optimizations. Replace instruction sequences and relocs
6839 based on information we collected in tls_optimize. We edit
6840 RELOCS so that --emit-relocs will output something sensible
6841 for the final instruction stream. */
6847 {
6850 local_plt
6854 }
6856 /* Ensure reloc mapping code below stays sane. */
6867 {
6875 {
6876 bfd_vma insn;
6884 }
6890 {
6891 bfd_vma insn;
6901 /* Was PPC_TLS which sits on insn boundary, now
6902 PPC_TPREL16_LO which is at low-order half-word. */
6904 }
6917 {
6918 tls_gdld_hi:
6922 else
6923 {
6927 }
6929 }
6942 {
6944 bfd_vma offset;
6946 tls_ldgd_opt:
6948 /* If not using the newer R_PPC_TLSGD/LD to mark
6949 __tls_get_addr calls, we must trust that the call
6950 stays with its arg setup insns, ie. that the next
6951 reloc is the __tls_get_addr call associated with
6952 the current reloc. Edit both insns. */
6959 {
6960 /* IE */
6966 {
6970 }
6974 }
6975 else
6976 {
6977 /* LE */
6980 {
6981 /* Was an LD reloc. */
6984 r_symndx++)
6994 }
6998 {
7004 }
7005 }
7009 {
7010 /* We changed the symbol on an LD reloc. Start over
7011 in order to get h, sym, sec etc. right. */
7012 rel--;
7014 }
7015 }
7020 {
7025 {
7026 /* IE */
7029 }
7030 else
7031 {
7032 /* LE */
7036 }
7039 /* Zap the reloc on the _tls_get_addr call too. */
7042 }
7047 {
7052 r_symndx++)
7068 /* Zap the reloc on the _tls_get_addr call too. */
7071 rel--;
7073 }
7075 }
7077 /* Handle other relocations that tweak non-addend part of insn. */
7080 {
7084 /* Branch taken prediction relocations. */
7088 /* Fall thru */
7090 /* Branch not taken prediction relocations. */
7093 {
7094 bfd_vma insn;
7104 /* Invert 'y' bit if not the default. */
7110 }
7111 }
7115 {
7119 {
7122 }
7125 {
7131 }
7137 {
7142 }
7144 {
7146 {
7147 Elf_Internal_Rela rela;
7161 }
7163 {
7168 }
7177 else
7181 }
7182 }
7190 {
7209 /* GOT16 relocations. Like an ADDR16 using the symbol's
7210 address in the GOT as relocation value instead of the
7211 symbol's value itself. Also, create a GOT entry for the
7212 symbol and put the symbol value there. */
7246 dogot:
7247 {
7248 /* Relocation is to the entry for this symbol in the global
7249 offset table. */
7250 bfd_vma off;
7263 {
7264 bfd_boolean dyn;
7269 /* This is actually a static link, or it is a
7270 -Bsymbolic link and the symbol is defined
7271 locally, or the symbol was forced to be local
7272 because of a version file. */
7273 ;
7274 else
7275 {
7278 }
7280 }
7281 else
7282 {
7286 }
7288 /* The offset must always be a multiple of 4. We use the
7289 least significant bit to record whether we have already
7290 processed this entry. */
7294 else
7295 {
7306 /* We might have multiple got entries for this sym.
7307 Initialize them all. */
7308 do
7309 {
7313 {
7316 }
7318 {
7321 }
7323 {
7326 }
7328 {
7331 }
7333 /* Generate relocs for the dynamic linker. */
7339 {
7348 {
7351 {
7358 outrel.r_info
7360 }
7361 }
7370 else
7373 {
7377 }
7382 }
7384 /* Init the .got section contents if we're not
7385 emitting a reloc. */
7386 else
7387 {
7393 {
7399 {
7403 }
7404 }
7407 }
7412 }
7417 }
7423 {
7425 {
7431 {
7435 {
7438 }
7439 }
7440 }
7441 }
7445 + off
7448 /* Addends on got relocations don't make much sense.
7449 x+off@got is actually x@got+off, and since the got is
7450 generated by a hash table traversal, the value in the
7451 got at entry m+n bears little relation to the entry m. */
7455 input_bfd,
7456 input_section,
7459 sym_name);
7460 }
7463 /* Relocations that need no special processing. */
7465 /* It makes no sense to point a local relocation
7466 at a symbol not in this object. */
7468 {
7471 input_bfd,
7472 input_section,
7474 TRUE))
7477 }
7487 /* Relocations that may need to be propagated if this is a shared
7488 object. */
7496 {
7497 /* Make this relocation against an undefined weak symbol
7498 resolve to zero. This is really just a tweak, since
7499 code using weak externs ought to check that they are
7500 defined before using them. */
7507 }
7509 /* The TPREL16 relocs shouldn't really be used in shared
7510 libs as they will result in DT_TEXTREL being set, but
7511 support them anyway. */
7536 /* fall through */
7551 /* If these relocations are not to a named symbol, they can be
7552 handled right here, no need to bother the dynamic linker. */
7556 /* fall through */
7564 /* fall through */
7566 dodyn:
7580 || (ELIMINATE_COPY_RELOCS
7586 {
7589 #ifdef DEBUG
7594 #endif
7596 /* When generating a shared object, these relocations
7597 are copied into the output file to be resolved at run
7598 time. */
7600 {
7606 }
7610 input_section,
7624 {
7628 }
7629 else
7630 {
7634 {
7638 {
7639 /* If we get here when building a static
7640 executable, then the libc startup function
7641 responsible for applying indirect function
7642 relocations is going to complain about
7643 the reloc type.
7644 If we get here when building a dynamic
7645 executable, it will be because we have
7646 a text relocation. The dynamic loader
7647 will set the text segment writable and
7648 non-executable to apply text relocations.
7649 So we'll segfault when trying to run the
7650 indirection function to resolve the reloc. */
7654 input_bfd,
7655 input_section,
7658 sym_name);
7660 }
7662 ;
7664 {
7667 }
7668 else
7669 {
7672 /* We are turning this relocation into one
7673 against a section symbol. It would be
7674 proper to subtract the symbol's value,
7675 osec->vma, from the emitted reloc addend,
7676 but ld.so expects buggy relocs.
7677 FIXME: Why not always use a zero index? */
7681 {
7684 }
7686 #ifdef DEBUG
7691 #endif
7692 }
7695 }
7698 else
7700 }
7709 /* This reloc will be computed at runtime. We clear the memory
7710 so that it contains predictable value. */
7714 {
7718 }
7719 }
7725 {
7730 {
7734 }
7740 else
7744 }
7745 /* Fall thru */
7753 {
7760 /* We're clearing the bits for R_PPC_ADDR16_HA
7761 and R_PPC_ADDR16_LO here. */
7765 /* t0 is HA, t1 is LO */
7773 /* Rewrite the reloc and convert one of the trailing nop
7774 relocs to describe this relocation. */
7776 /* The relocs are at the bottom 2 bytes */
7782 rel++;
7783 }
7786 /* Indirect .sdata relocation. */
7790 {
7793 }
7794 relocation
7800 /* Indirect .sdata2 relocation. */
7804 {
7807 }
7808 relocation
7814 /* Handle the TOC16 reloc. We want to use the offset within the .got
7815 section, not the actual VMA. This is appropriate when generating
7816 an embedded ELF object, for which the .got section acts like the
7817 AIX .toc section. */
7820 {
7823 }
7833 /* Relocation is to the entry for this symbol in the
7834 procedure linkage table. */
7835 {
7841 {
7842 /* We didn't make a PLT entry for this symbol. This
7843 happens when statically linking PIC code, or when
7844 using -Bsymbolic. */
7846 }
7853 else
7857 }
7860 /* Relocate against _SDA_BASE_. */
7862 {
7869 {
7872 }
7880 {
7884 input_bfd,
7885 sym_name,
7887 name);
7888 }
7889 }
7892 /* Relocate against _SDA2_BASE_. */
7894 {
7901 {
7904 }
7910 {
7914 input_bfd,
7915 sym_name,
7917 name);
7918 }
7919 }
7922 /* Relocate against either _SDA_BASE_, _SDA2_BASE_, or 0. */
7925 {
7931 {
7934 }
7941 {
7944 }
7947 {
7950 }
7953 {
7955 }
7956 else
7957 {
7961 input_bfd,
7962 sym_name,
7964 name);
7969 }
7972 {
7974 {
7977 }
7979 }
7982 {
7988 }
7989 }
7992 /* Relocate against the beginning of the section. */
7998 {
8001 }
8005 /* Negative relocations. */
8032 input_bfd,
8034 sym_name);
8039 }
8041 /* Do any further special processing. */
8043 {
8054 /* It's just possible that this symbol is a weak symbol
8055 that's not actually defined anywhere. In that case,
8056 'sec' would be NULL, and we should leave the symbol
8057 alone (it will be set to zero elsewhere in the link). */
8060 /* Fall thru */
8068 /* Add 0x10000 if sign bit in 0:15 is set.
8069 Bits 0:15 are not used. */
8072 }
8074 #ifdef DEBUG
8079 sym_name,
8080 r_symndx,
8083 #endif
8088 {
8091 input_bfd,
8092 input_section,
8095 sym_name);
8097 }
8100 input_bfd,
8101 input_section,
8102 contents,
8104 relocation,
8105 addend);
8108 {
8110 {
8116 {
8117 /* Assume this is a call protected by other code that
8118 detect the symbol is undefined. If this is the case,
8119 we can safely ignore the overflow. If not, the
8120 program is hosed anyway, and a little warning isn't
8121 going to help. */
8124 }
8128 sym_name,
8131 input_bfd,
8132 input_section,
8135 }
8136 else
8137 {
8143 }
8144 }
8145 }
8147 #ifdef DEBUG
8149 #endif
8152 }
8153 \f
8154 /* Finish up dynamic symbol handling. We set the contents of various
8155 dynamic sections here. */
8157 static bfd_boolean
8162 {
8165 bfd_boolean doneone;
8167 #ifdef DEBUG
8170 #endif
8178 {
8180 {
8181 Elf_Internal_Rela rela;
8183 bfd_vma reloc_index;
8189 else
8190 {
8196 }
8198 /* This symbol has an entry in the procedure linkage table.
8199 Set it up. */
8203 {
8204 bfd_vma got_offset;
8207 /* The first three entries in .got.plt are reserved. */
8210 /* Use the right PLT. */
8214 /* Fill in the .plt on VxWorks. */
8216 {
8223 }
8224 else
8225 {
8234 }
8241 /* This instruction is an immediate load. The value loaded is
8242 the byte offset of the R_PPC_JMP_SLOT relocation from the
8243 start of the .rela.plt section. The value is stored in the
8244 low-order 16 bits of the load instruction. */
8245 /* NOTE: It appears that this is now an index rather than a
8246 prescaled offset. */
8250 /* This instruction is a PC-relative branch whose target is
8251 the start of the PLT section. The address of this branch
8252 instruction is 20 bytes beyond the start of this PLT entry.
8253 The address is encoded in bits 6-29, inclusive. The value
8254 stored is right-shifted by two bits, permitting a 26-bit
8255 offset. */
8265 /* Fill in the GOT entry corresponding to this PLT slot with
8266 the address immediately after the the "bctr" instruction
8267 in this PLT entry. */
8274 {
8275 /* Fill in a couple of entries in .rela.plt.unloaded. */
8281 /* Provide the @ha relocation for the first instruction. */
8286 R_PPC_ADDR16_HA);
8291 /* Provide the @l relocation for the second instruction. */
8296 R_PPC_ADDR16_LO);
8301 /* Provide a relocation for the GOT entry corresponding to this
8302 PLT slot. Point it at the middle of the .plt entry. */
8307 R_PPC_ADDR32);
8310 }
8312 /* VxWorks uses non-standard semantics for R_PPC_JMP_SLOT.
8313 In particular, the offset for the relocation is not the
8314 address of the PLT entry for this function, as specified
8315 by the ABI. Instead, the offset is set to the address of
8316 the GOT slot for this function. See EABI 4.4.4.1. */
8321 }
8322 else
8323 {
8335 {
8336 /* We don't need to fill in the .plt. The ppc dynamic
8337 linker will fill it in. */
8338 }
8339 else
8340 {
8346 }
8347 }
8349 /* Fill in the entry in the .rela.plt section. */
8353 {
8360 }
8361 else
8369 else
8375 {
8376 /* Mark the symbol as undefined, rather than as
8377 defined in the .plt section. Leave the value if
8378 there were any relocations where pointer equality
8379 matters (this is a clue for the dynamic linker, to
8380 make function pointer comparisons work between an
8381 application and shared library), otherwise set it
8382 to zero. */
8387 {
8388 /* This breaks function pointer comparisons, but
8389 that is better than breaking tests for a NULL
8390 function pointer. */
8392 }
8393 }
8396 {
8397 /* Set the value of ifunc symbols in a non-pie
8398 executable to the glink entry. This is to avoid
8399 text relocations. We can't do this for ifunc in
8400 allocate_dynrelocs, as we do for normal dynamic
8401 function symbols with plt entries, because we need
8402 to keep the original value around for the ifunc
8403 relocation. */
8409 }
8411 }
8416 {
8426 {
8443 }
8448 /* We only need one non-PIC glink stub. */
8450 }
8451 else
8453 }
8456 {
8458 Elf_Internal_Rela rela;
8461 /* This symbols needs a copy reloc. Set it up. */
8463 #ifdef DEBUG
8465 #endif
8471 else
8480 }
8482 #ifdef DEBUG
8484 #endif
8486 /* Mark some specially defined symbols as absolute. */
8495 }
8496 \f
8497 static enum elf_reloc_type_class
8499 {
8501 {
8512 }
8513 }
8514 \f
8515 /* Finish up the dynamic sections. */
8517 static bfd_boolean
8520 {
8524 bfd_vma got;
8528 #ifdef DEBUG
8530 #endif
8537 else
8545 {
8553 {
8554 Elf_Internal_Dyn dyn;
8560 {
8564 else
8584 {
8588 }
8596 }
8599 }
8600 }
8603 {
8606 {
8611 {
8612 /* Add a blrl instruction at _GLOBAL_OFFSET_TABLE_-4
8613 so that a function can easily find the address of
8614 _GLOBAL_OFFSET_TABLE_. */
8618 }
8621 {
8626 }
8627 }
8628 else
8629 {
8636 }
8639 }
8641 /* Fill in the first entry in the VxWorks procedure linkage table. */
8643 {
8644 /* Use the right PLT. */
8646 ? ppc_elf_vxworks_pic_plt0_entry
8650 {
8657 }
8658 else
8659 {
8662 }
8671 {
8672 Elf_Internal_Rela rela;
8677 /* Output the @ha relocation for the first instruction. */
8686 /* Output the @l relocation for the second instruction. */
8695 /* Fix up the remaining relocations. They may have the wrong
8696 symbol index for _G_O_T_ or _P_L_T_ depending on the order
8697 in which symbols were output. */
8699 {
8700 Elf_Internal_Rela rel;
8716 }
8717 }
8718 }
8723 {
8726 bfd_vma res0;
8729 /*
8730 * PIC glink code is the following:
8731 *
8732 * # ith PLT code stub.
8733 * addis 11,30,(plt+(i-1)*4-got)@ha
8734 * lwz 11,(plt+(i-1)*4-got)@l(11)
8735 * mtctr 11
8736 * bctr
8737 *
8738 * # A table of branches, one for each plt entry.
8739 * # The idea is that the plt call stub loads ctr and r11 with these
8740 * # addresses, so (r11 - res_0) gives the plt index * 4.
8741 * res_0: b PLTresolve
8742 * res_1: b PLTresolve
8743 * .
8744 * # Some number of entries towards the end can be nops
8745 * res_n_m3: nop
8746 * res_n_m2: nop
8747 * res_n_m1:
8748 *
8749 * PLTresolve:
8750 * addis 11,11,(1f-res_0)@ha
8751 * mflr 0
8752 * bcl 20,31,1f
8753 * 1: addi 11,11,(1b-res_0)@l
8754 * mflr 12
8755 * mtlr 0
8756 * sub 11,11,12 # r11 = index * 4
8757 * addis 12,12,(got+4-1b)@ha
8758 * lwz 0,(got+4-1b)@l(12) # got[1] address of dl_runtime_resolve
8759 * lwz 12,(got+8-1b)@l(12) # got[2] contains the map address
8760 * mtctr 0
8761 * add 0,11,11
8762 * add 11,0,11 # r11 = index * 12 = reloc offset.
8763 * bctr
8764 */
8766 {
8767 ADDIS_11_11,
8768 MFLR_0,
8769 BCL_20_31,
8770 ADDI_11_11,
8771 MFLR_12,
8772 MTLR_0,
8773 SUB_11_11_12,
8774 ADDIS_12_12,
8775 LWZ_0_12,
8776 LWZ_12_12,
8777 MTCTR_0,
8778 ADD_0_11_11,
8779 ADD_11_0_11,
8780 BCTR,
8781 NOP,
8782 NOP
8783 };
8785 /*
8786 * Non-PIC glink code is a little simpler.
8787 *
8788 * # ith PLT code stub.
8789 * lis 11,(plt+(i-1)*4)@ha
8790 * lwz 11,(plt+(i-1)*4)@l(11)
8791 * mtctr 11
8792 * bctr
8793 *
8794 * The branch table is the same, then comes
8795 *
8796 * PLTresolve:
8797 * lis 12,(got+4)@ha
8798 * addis 11,11,(-res_0)@ha
8799 * lwz 0,(got+4)@l(12) # got[1] address of dl_runtime_resolve
8800 * addi 11,11,(-res_0)@l # r11 = index * 4
8801 * mtctr 0
8802 * add 0,11,11
8803 * lwz 12,(got+8)@l(12) # got[2] contains the map address
8804 * add 11,0,11 # r11 = index * 12 = reloc offset.
8805 * bctr
8806 */
8808 {
8809 LIS_12,
8810 ADDIS_11_11,
8811 LWZ_0_12,
8812 ADDI_11_11,
8813 MTCTR_0,
8814 ADD_0_11_11,
8815 LWZ_12_12,
8816 ADD_11_0_11,
8817 BCTR,
8818 NOP,
8819 NOP,
8820 NOP,
8821 NOP,
8822 NOP,
8823 NOP,
8824 NOP
8825 };
8832 /* Build the branch table, one for each plt entry (less one),
8833 and perhaps some padding. */
8839 {
8842 }
8844 {
8847 }
8853 /* Last comes the PLTresolve stub. */
8855 {
8856 bfd_vma bcl;
8859 {
8862 }
8876 {
8881 }
8882 else
8883 {
8888 }
8889 }
8890 else
8891 {
8893 {
8896 }
8906 {
8911 }
8912 else
8913 {
8918 }
8919 }
8920 }
8923 }
8924 \f
8925 #define TARGET_LITTLE_SYM bfd_elf32_powerpcle_vec
8927 #define TARGET_BIG_SYM bfd_elf32_powerpc_vec
8929 #define ELF_ARCH bfd_arch_powerpc
8930 #define ELF_MACHINE_CODE EM_PPC
8931 #ifdef __QNXTARGET__
8932 #define ELF_MAXPAGESIZE 0x1000
8933 #else
8934 #define ELF_MAXPAGESIZE 0x10000
8935 #endif
8936 #define ELF_MINPAGESIZE 0x1000
8937 #define ELF_COMMONPAGESIZE 0x1000
8938 #define elf_info_to_howto ppc_elf_info_to_howto
8940 #ifdef EM_CYGNUS_POWERPC
8941 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
8942 #endif
8944 #ifdef EM_PPC_OLD
8945 #define ELF_MACHINE_ALT2 EM_PPC_OLD
8946 #endif
8948 #define elf_backend_plt_not_loaded 1
8949 #define elf_backend_can_gc_sections 1
8950 #define elf_backend_can_refcount 1
8951 #define elf_backend_rela_normal 1
8953 #define bfd_elf32_mkobject ppc_elf_mkobject
8954 #define bfd_elf32_bfd_merge_private_bfd_data ppc_elf_merge_private_bfd_data
8955 #define bfd_elf32_bfd_relax_section ppc_elf_relax_section
8956 #define bfd_elf32_bfd_reloc_type_lookup ppc_elf_reloc_type_lookup
8957 #define bfd_elf32_bfd_reloc_name_lookup ppc_elf_reloc_name_lookup
8958 #define bfd_elf32_bfd_set_private_flags ppc_elf_set_private_flags
8959 #define bfd_elf32_bfd_link_hash_table_create ppc_elf_link_hash_table_create
8960 #define bfd_elf32_get_synthetic_symtab ppc_elf_get_synthetic_symtab
8962 #define elf_backend_object_p ppc_elf_object_p
8963 #define elf_backend_gc_mark_hook ppc_elf_gc_mark_hook
8964 #define elf_backend_gc_sweep_hook ppc_elf_gc_sweep_hook
8965 #define elf_backend_section_from_shdr ppc_elf_section_from_shdr
8966 #define elf_backend_relocate_section ppc_elf_relocate_section
8967 #define elf_backend_create_dynamic_sections ppc_elf_create_dynamic_sections
8968 #define elf_backend_check_relocs ppc_elf_check_relocs
8969 #define elf_backend_copy_indirect_symbol ppc_elf_copy_indirect_symbol
8970 #define elf_backend_adjust_dynamic_symbol ppc_elf_adjust_dynamic_symbol
8971 #define elf_backend_add_symbol_hook ppc_elf_add_symbol_hook
8972 #define elf_backend_size_dynamic_sections ppc_elf_size_dynamic_sections
8973 #define elf_backend_hash_symbol ppc_elf_hash_symbol
8974 #define elf_backend_finish_dynamic_symbol ppc_elf_finish_dynamic_symbol
8975 #define elf_backend_finish_dynamic_sections ppc_elf_finish_dynamic_sections
8976 #define elf_backend_fake_sections ppc_elf_fake_sections
8977 #define elf_backend_additional_program_headers ppc_elf_additional_program_headers
8978 #define elf_backend_grok_prstatus ppc_elf_grok_prstatus
8979 #define elf_backend_grok_psinfo ppc_elf_grok_psinfo
8980 #define elf_backend_write_core_note ppc_elf_write_core_note
8981 #define elf_backend_reloc_type_class ppc_elf_reloc_type_class
8982 #define elf_backend_begin_write_processing ppc_elf_begin_write_processing
8983 #define elf_backend_final_write_processing ppc_elf_final_write_processing
8984 #define elf_backend_write_section ppc_elf_write_section
8985 #define elf_backend_get_sec_type_attr ppc_elf_get_sec_type_attr
8986 #define elf_backend_plt_sym_val ppc_elf_plt_sym_val
8987 #define elf_backend_action_discarded ppc_elf_action_discarded
8988 #define elf_backend_init_index_section _bfd_elf_init_1_index_section
8989 #define elf_backend_post_process_headers _bfd_elf_set_osabi
8993 /* VxWorks Target */
8995 #undef TARGET_LITTLE_SYM
8996 #undef TARGET_LITTLE_NAME
8998 #undef TARGET_BIG_SYM
8999 #define TARGET_BIG_SYM bfd_elf32_powerpc_vxworks_vec
9000 #undef TARGET_BIG_NAME
9003 /* VxWorks uses the elf default section flags for .plt. */
9006 {
9014 }
9016 /* Like ppc_elf_link_hash_table_create, but overrides
9017 appropriately for VxWorks. */
9020 {
9025 {
9033 }
9035 }
9037 /* Tweak magic VxWorks symbols as they are loaded. */
9038 static bfd_boolean
9046 {
9048 valp))
9052 }
9054 static void
9056 {
9059 }
9061 /* On VxWorks, we emit relocations against _PROCEDURE_LINKAGE_TABLE_, so
9062 define it. */
9063 #undef elf_backend_want_plt_sym
9064 #define elf_backend_want_plt_sym 1
9065 #undef elf_backend_want_got_plt
9066 #define elf_backend_want_got_plt 1
9067 #undef elf_backend_got_symbol_offset
9068 #define elf_backend_got_symbol_offset 0
9069 #undef elf_backend_plt_not_loaded
9070 #define elf_backend_plt_not_loaded 0
9071 #undef elf_backend_plt_readonly
9072 #define elf_backend_plt_readonly 1
9073 #undef elf_backend_got_header_size
9074 #define elf_backend_got_header_size 12
9076 #undef bfd_elf32_get_synthetic_symtab
9078 #undef bfd_elf32_bfd_link_hash_table_create
9079 #define bfd_elf32_bfd_link_hash_table_create \
9080 ppc_elf_vxworks_link_hash_table_create
9081 #undef elf_backend_add_symbol_hook
9082 #define elf_backend_add_symbol_hook \
9083 ppc_elf_vxworks_add_symbol_hook
9084 #undef elf_backend_link_output_symbol_hook
9085 #define elf_backend_link_output_symbol_hook \
9086 elf_vxworks_link_output_symbol_hook
9087 #undef elf_backend_final_write_processing
9088 #define elf_backend_final_write_processing \
9089 ppc_elf_vxworks_final_write_processing
9090 #undef elf_backend_get_sec_type_attr
9091 #define elf_backend_get_sec_type_attr \
9092 ppc_elf_vxworks_get_sec_type_attr
9093 #undef elf_backend_emit_relocs
9094 #define elf_backend_emit_relocs \
9095 elf_vxworks_emit_relocs
9097 #undef elf32_bed
9098 #define elf32_bed ppc_elf_vxworks_bed
9099 #undef elf_backend_post_process_headers