| blob | 36674130e93bd68c1a69e57b79b666fab257790a |
1 /* PowerPC-specific support for 32-bit ELF
2 Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
3 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 Written by Ian Lance Taylor, Cygnus Support.
6 This file is part of BFD, the Binary File Descriptor library.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the
20 Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
21 Boston, MA 02110-1301, USA. */
24 /* This file is based on a preliminary PowerPC ELF ABI. The
25 information may not match the final PowerPC ELF ABI. It includes
26 suggestions from the in-progress Embedded PowerPC ABI, and that
27 information may also not match. */
30 #include <stdarg.h>
39 /* RELA relocations are used here. */
41 static bfd_reloc_status_type ppc_elf_addr16_ha_reloc
43 static bfd_reloc_status_type ppc_elf_unhandled_reloc
46 /* Branch prediction bit for branch taken relocs. */
47 #define BRANCH_PREDICT_BIT 0x200000
48 /* Mask to set RA in memory instructions. */
49 #define RA_REGISTER_MASK 0x001f0000
50 /* Value to shift register by to insert RA. */
51 #define RA_REGISTER_SHIFT 16
53 /* The name of the dynamic interpreter. This is put in the .interp
54 section. */
57 /* For old-style PLT. */
58 /* The number of single-slot PLT entries (the rest use two slots). */
59 #define PLT_NUM_SINGLE_ENTRIES 8192
61 /* For new-style .glink and .plt. */
62 #define GLINK_PLTRESOLVE 16*4
63 #define GLINK_ENTRY_SIZE 4*4
64 #define TLS_GET_ADDR_GLINK_SIZE 12*4
66 /* VxWorks uses its own plt layout, filled in by the static linker. */
68 /* The standard VxWorks PLT entry. */
69 #define VXWORKS_PLT_ENTRY_SIZE 32
70 static const bfd_vma ppc_elf_vxworks_plt_entry
72 {
81 };
82 static const bfd_vma ppc_elf_vxworks_pic_plt_entry
84 {
93 };
95 /* The initial VxWorks PLT entry. */
96 #define VXWORKS_PLT_INITIAL_ENTRY_SIZE 32
97 static const bfd_vma ppc_elf_vxworks_plt0_entry
99 {
108 };
109 static const bfd_vma ppc_elf_vxworks_pic_plt0_entry
111 {
120 };
122 /* For executables, we have some additional relocations in
123 .rela.plt.unloaded, for the kernel loader. */
125 /* The number of non-JMP_SLOT relocations per PLT0 slot. */
126 #define VXWORKS_PLT_NON_JMP_SLOT_RELOCS 3
127 /* The number of relocations in the PLTResolve slot. */
128 #define VXWORKS_PLTRESOLVE_RELOCS 2
129 /* The number of relocations in the PLTResolve slot when when creating
130 a shared library. */
131 #define VXWORKS_PLTRESOLVE_RELOCS_SHLIB 0
133 /* Some instructions. */
134 #define ADDIS_11_11 0x3d6b0000
135 #define ADDIS_11_30 0x3d7e0000
136 #define ADDIS_12_12 0x3d8c0000
137 #define ADDI_11_11 0x396b0000
138 #define ADD_0_11_11 0x7c0b5a14
139 #define ADD_3_12_2 0x7c6c1214
140 #define ADD_11_0_11 0x7d605a14
141 #define B 0x48000000
142 #define BCL_20_31 0x429f0005
143 #define BCTR 0x4e800420
144 #define BEQLR 0x4d820020
145 #define CMPWI_11_0 0x2c0b0000
146 #define LIS_11 0x3d600000
147 #define LIS_12 0x3d800000
148 #define LWZU_0_12 0x840c0000
149 #define LWZ_0_12 0x800c0000
150 #define LWZ_11_3 0x81630000
151 #define LWZ_11_11 0x816b0000
152 #define LWZ_11_30 0x817e0000
153 #define LWZ_12_3 0x81830000
154 #define LWZ_12_12 0x818c0000
155 #define MR_0_3 0x7c601b78
156 #define MR_3_0 0x7c030378
157 #define MFLR_0 0x7c0802a6
158 #define MFLR_12 0x7d8802a6
159 #define MTCTR_0 0x7c0903a6
160 #define MTCTR_11 0x7d6903a6
161 #define MTLR_0 0x7c0803a6
162 #define NOP 0x60000000
163 #define SUB_11_11_12 0x7d6c5850
165 /* Offset of tp and dtp pointers from start of TLS block. */
166 #define TP_OFFSET 0x7000
167 #define DTP_OFFSET 0x8000
169 /* The value of a defined global symbol. */
170 #define SYM_VAL(SYM) \
171 ((SYM)->root.u.def.section->output_section->vma \
172 + (SYM)->root.u.def.section->output_offset \
173 + (SYM)->root.u.def.value)
174 \f
178 /* This reloc does nothing. */
193 /* A standard 32 bit relocation. */
208 /* An absolute 26 bit branch; the lower two bits must be zero.
209 FIXME: we don't check that, we just clear them. */
224 /* A standard 16 bit relocation. */
239 /* A 16 bit relocation without overflow. */
254 /* The high order 16 bits of an address. */
269 /* The high order 16 bits of an address, plus 1 if the contents of
270 the low 16 bits, treated as a signed number, is negative. */
285 /* An absolute 16 bit branch; the lower two bits must be zero.
286 FIXME: we don't check that, we just clear them. */
301 /* An absolute 16 bit branch, for which bit 10 should be set to
302 indicate that the branch is expected to be taken. The lower two
303 bits must be zero. */
318 /* An absolute 16 bit branch, for which bit 10 should be set to
319 indicate that the branch is not expected to be taken. The lower
320 two bits must be zero. */
335 /* A relative 26 bit branch; the lower two bits must be zero. */
350 /* A relative 16 bit branch; the lower two bits must be zero. */
365 /* A relative 16 bit branch. Bit 10 should be set to indicate that
366 the branch is expected to be taken. The lower two bits must be
367 zero. */
382 /* A relative 16 bit branch. Bit 10 should be set to indicate that
383 the branch is not expected to be taken. The lower two bits must
384 be zero. */
399 /* Like R_PPC_ADDR16, but referring to the GOT table entry for the
400 symbol. */
415 /* Like R_PPC_ADDR16_LO, but referring to the GOT table entry for
416 the symbol. */
431 /* Like R_PPC_ADDR16_HI, but referring to the GOT table entry for
432 the symbol. */
447 /* Like R_PPC_ADDR16_HA, but referring to the GOT table entry for
448 the symbol. */
463 /* Like R_PPC_REL24, but referring to the procedure linkage table
464 entry for the symbol. */
479 /* This is used only by the dynamic linker. The symbol should exist
480 both in the object being run and in some shared library. The
481 dynamic linker copies the data addressed by the symbol from the
482 shared library into the object, because the object being
483 run has to have the data at some particular address. */
498 /* Like R_PPC_ADDR32, but used when setting global offset table
499 entries. */
514 /* Marks a procedure linkage table entry for a symbol. */
529 /* Used only by the dynamic linker. When the object is run, this
530 longword is set to the load address of the object, plus the
531 addend. */
546 /* Like R_PPC_REL24, but uses the value of the symbol within the
547 object rather than the final value. Normally used for
548 _GLOBAL_OFFSET_TABLE_. */
563 /* Like R_PPC_ADDR32, but may be unaligned. */
578 /* Like R_PPC_ADDR16, but may be unaligned. */
593 /* 32-bit PC relative */
608 /* 32-bit relocation to the symbol's procedure linkage table.
609 FIXME: not supported. */
624 /* 32-bit PC relative relocation to the symbol's procedure linkage table.
625 FIXME: not supported. */
640 /* Like R_PPC_ADDR16_LO, but referring to the PLT table entry for
641 the symbol. */
656 /* Like R_PPC_ADDR16_HI, but referring to the PLT table entry for
657 the symbol. */
672 /* Like R_PPC_ADDR16_HA, but referring to the PLT table entry for
673 the symbol. */
688 /* A sign-extended 16 bit value relative to _SDA_BASE_, for use with
689 small data items. */
704 /* 16-bit section relative relocation. */
719 /* 16-bit lower half section relative relocation. */
734 /* 16-bit upper half section relative relocation. */
749 /* 16-bit upper half adjusted section relative relocation. */
764 /* Marker relocs for TLS. */
807 /* Computes the load module index of the load module that contains the
808 definition of its TLS sym. */
823 /* Computes a dtv-relative displacement, the difference between the value
824 of sym+add and the base address of the thread-local storage block that
825 contains the definition of sym, minus 0x8000. */
840 /* A 16 bit dtprel reloc. */
855 /* Like DTPREL16, but no overflow. */
870 /* Like DTPREL16_LO, but next higher group of 16 bits. */
885 /* Like DTPREL16_HI, but adjust for low 16 bits. */
900 /* Computes a tp-relative displacement, the difference between the value of
901 sym+add and the value of the thread pointer (r13). */
916 /* A 16 bit tprel reloc. */
931 /* Like TPREL16, but no overflow. */
946 /* Like TPREL16_LO, but next higher group of 16 bits. */
961 /* Like TPREL16_HI, but adjust for low 16 bits. */
976 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
977 with values (sym+add)@dtpmod and (sym+add)@dtprel, and computes the offset
978 to the first entry. */
993 /* Like GOT_TLSGD16, but no overflow. */
1008 /* Like GOT_TLSGD16_LO, but next higher group of 16 bits. */
1023 /* Like GOT_TLSGD16_HI, but adjust for low 16 bits. */
1038 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
1039 with values (sym+add)@dtpmod and zero, and computes the offset to the
1040 first entry. */
1055 /* Like GOT_TLSLD16, but no overflow. */
1070 /* Like GOT_TLSLD16_LO, but next higher group of 16 bits. */
1085 /* Like GOT_TLSLD16_HI, but adjust for low 16 bits. */
1100 /* Allocates an entry in the GOT with value (sym+add)@dtprel, and computes
1101 the offset to the entry. */
1116 /* Like GOT_DTPREL16, but no overflow. */
1131 /* Like GOT_DTPREL16_LO, but next higher group of 16 bits. */
1146 /* Like GOT_DTPREL16_HI, but adjust for low 16 bits. */
1161 /* Allocates an entry in the GOT with value (sym+add)@tprel, and computes the
1162 offset to the entry. */
1177 /* Like GOT_TPREL16, but no overflow. */
1192 /* Like GOT_TPREL16_LO, but next higher group of 16 bits. */
1207 /* Like GOT_TPREL16_HI, but adjust for low 16 bits. */
1222 /* The remaining relocs are from the Embedded ELF ABI, and are not
1223 in the SVR4 ELF ABI. */
1225 /* 32 bit value resulting from the addend minus the symbol. */
1240 /* 16 bit value resulting from the addend minus the symbol. */
1255 /* 16 bit value resulting from the addend minus the symbol. */
1270 /* The high order 16 bits of the addend minus the symbol. */
1285 /* The high order 16 bits of the result of the addend minus the address,
1286 plus 1 if the contents of the low 16 bits, treated as a signed number,
1287 is negative. */
1302 /* 16 bit value resulting from allocating a 4 byte word to hold an
1303 address in the .sdata section, and returning the offset from
1304 _SDA_BASE_ for that relocation. */
1319 /* 16 bit value resulting from allocating a 4 byte word to hold an
1320 address in the .sdata2 section, and returning the offset from
1321 _SDA2_BASE_ for that relocation. */
1336 /* A sign-extended 16 bit value relative to _SDA2_BASE_, for use with
1337 small data items. */
1352 /* Relocate against either _SDA_BASE_ or _SDA2_BASE_, filling in the 16 bit
1353 signed offset from the appropriate base, and filling in the register
1354 field with the appropriate register (0, 2, or 13). */
1369 /* Relocation not handled: R_PPC_EMB_MRKREF */
1370 /* Relocation not handled: R_PPC_EMB_RELSEC16 */
1371 /* Relocation not handled: R_PPC_EMB_RELST_LO */
1372 /* Relocation not handled: R_PPC_EMB_RELST_HI */
1373 /* Relocation not handled: R_PPC_EMB_RELST_HA */
1374 /* Relocation not handled: R_PPC_EMB_BIT_FLD */
1376 /* PC relative relocation against either _SDA_BASE_ or _SDA2_BASE_, filling
1377 in the 16 bit signed offset from the appropriate base, and filling in the
1378 register field with the appropriate register (0, 2, or 13). */
1407 /* A 16 bit relative relocation. */
1422 /* A 16 bit relative relocation without overflow. */
1437 /* The high order 16 bits of a relative address. */
1452 /* The high order 16 bits of a relative address, plus 1 if the contents of
1453 the low 16 bits, treated as a signed number, is negative. */
1468 /* GNU extension to record C++ vtable hierarchy. */
1483 /* GNU extension to record C++ vtable member usage. */
1498 /* Phony reloc to handle AIX style TOC entries. */
1512 };
1513 \f
1514 /* Initialize the ppc_elf_howto_table, so that linear accesses can be done. */
1516 static void
1518 {
1523 i++)
1524 {
1530 }
1531 }
1535 bfd_reloc_code_real_type code)
1536 {
1539 /* Initialize howto table if not already done. */
1544 {
1635 }
1638 };
1643 {
1648 i++)
1654 }
1656 /* Set the howto pointer for a PowerPC ELF reloc. */
1658 static void
1662 {
1663 /* Initialize howto table if not already done. */
1670 /* Just because the above assert didn't trigger doesn't mean that
1671 ELF32_R_TYPE (dst->r_info) is necessarily a valid relocation. */
1673 {
1679 }
1680 }
1682 /* Handle the R_PPC_ADDR16_HA and R_PPC_REL16_HA relocs. */
1684 static bfd_reloc_status_type
1692 {
1693 bfd_vma relocation;
1696 {
1699 }
1706 else
1718 }
1720 static bfd_reloc_status_type
1728 {
1729 /* If this is a relocatable link (output_bfd test tells us), just
1730 call the generic function. Any adjustment will be done at final
1731 link time. */
1737 {
1742 }
1744 }
1745 \f
1746 /* Sections created by the linker. */
1749 {
1750 /* Pointer to the bfd section. */
1752 /* Section name. */
1754 /* Associated bss section name. */
1756 /* Associated symbol name. */
1758 /* Associated symbol. */
1762 /* Linked list of allocated pointer entries. This hangs off of the
1763 symbol lists, and provides allows us to return different pointers,
1764 based on different addend's. */
1767 {
1768 /* next allocated pointer for this symbol */
1770 /* offset of pointer from beginning of section */
1771 bfd_vma offset;
1772 /* addend used */
1773 bfd_vma addend;
1774 /* which linker section this is */
1778 struct ppc_elf_obj_tdata
1779 {
1782 /* A mapping from local symbols to offsets into the various linker
1783 sections added. This is index by the symbol index. */
1786 /* Flags used to auto-detect plt type. */
1789 };
1791 #define ppc_elf_tdata(bfd) \
1792 ((struct ppc_elf_obj_tdata *) (bfd)->tdata.any)
1794 #define elf_local_ptr_offsets(bfd) \
1795 (ppc_elf_tdata (bfd)->linker_section_pointers)
1797 #define is_ppc_elf(bfd) \
1798 (bfd_get_flavour (bfd) == bfd_target_elf_flavour \
1799 && elf_object_id (bfd) == PPC32_ELF_DATA)
1801 /* Override the generic function because we store some extras. */
1803 static bfd_boolean
1805 {
1807 PPC32_ELF_DATA);
1808 }
1810 /* Fix bad default arch selected for a 32 bit input bfd when the
1811 default is 64 bit. */
1813 static bfd_boolean
1815 {
1817 {
1821 {
1822 /* Relies on arch after 64 bit default being 32 bit default. */
1825 }
1826 }
1828 }
1830 /* Function to set whether a module needs the -mrelocatable bit set. */
1832 static bfd_boolean
1834 {
1841 }
1843 /* Support for core dump NOTE sections. */
1845 static bfd_boolean
1847 {
1852 {
1857 /* pr_cursig */
1860 /* pr_pid */
1863 /* pr_reg */
1868 }
1870 /* Make a ".reg/999" section. */
1873 }
1875 static bfd_boolean
1877 {
1879 {
1888 }
1890 /* Note that for some reason, a spurious space is tacked
1891 onto the end of the args in some (at least one anyway)
1892 implementations, so strip it off if it exists. */
1894 {
1900 }
1903 }
1907 {
1909 {
1914 {
1925 }
1928 {
1947 }
1948 }
1949 }
1951 /* Return address for Ith PLT stub in section PLT, for relocation REL
1952 or (bfd_vma) -1 if it should not be included. */
1954 static bfd_vma
1958 {
1960 }
1962 /* Handle a PowerPC specific section when reading an object file. This
1963 is called when bfd_section_from_shdr finds a section with an unknown
1964 type. */
1966 static bfd_boolean
1971 {
1973 flagword flags;
1988 }
1990 /* Set up any other section flags and such that may be necessary. */
1992 static bfd_boolean
1996 {
2004 }
2006 /* If we have .sbss2 or .PPC.EMB.sbss0 output sections, we
2007 need to bump up the number of section headers. */
2009 static int
2012 {
2025 }
2027 /* Add extra PPC sections -- Note, for now, make .sbss2 and
2028 .PPC.EMB.sbss0 a normal section, and not a bss section so
2029 that the linker doesn't crater when trying to make more than
2030 2 sections. */
2033 {
2044 };
2046 /* This is what we want for new plt/got. */
2052 {
2055 /* See if this is one of the special sections. */
2062 {
2066 }
2069 }
2070 \f
2071 /* Very simple linked list structure for recording apuinfo values. */
2073 {
2076 }
2077 apuinfo_list;
2082 static void
2084 {
2086 }
2088 static void
2090 {
2094 {
2098 }
2107 }
2109 static unsigned
2111 {
2116 entry;
2121 }
2125 {
2131 ;
2134 }
2136 static void
2138 {
2142 {
2146 }
2149 }
2154 /* Scan the input BFDs and create a linked list of
2155 the APUinfo values that will need to be emitted. */
2157 static void
2159 {
2174 /* Read in the input sections contents. */
2176 {
2189 {
2196 }
2200 {
2203 }
2205 /* Verify the contents of the header. Note - we have to
2206 extract the values this way in order to allow for a
2207 host whose endian-ness is different from the target. */
2219 /* Get the number of bytes used for apuinfo entries. */
2224 /* Scan the apuinfo section, building a list of apuinfo numbers. */
2227 }
2231 /* Compute the size of the output section. */
2235 {
2236 /* Set the output section size, if it exists. */
2239 {
2242 }
2243 }
2245 fail:
2251 }
2253 /* Prevent the output section from accumulating the input sections'
2254 contents. We have already stored this in our linked list structure. */
2256 static bfd_boolean
2261 {
2264 }
2266 /* Finally we can generate the output section. */
2268 static void
2270 {
2275 bfd_size_type length;
2290 {
2294 }
2296 /* Create the apuinfo header. */
2305 {
2308 }
2319 }
2320 \f
2321 static bfd_boolean
2323 {
2333 }
2335 static bfd_boolean
2337 {
2342 }
2344 static long
2348 {
2353 bfd_vma stub_vma;
2377 /* Call common code to handle old-style executable PLTs. */
2382 /* If this object was prelinked, the prelinker stored the address
2383 of .glink at got[1]. If it wasn't prelinked, got[1] will be zero. */
2386 {
2400 {
2401 Elf_Internal_Dyn dyn;
2408 {
2416 }
2417 }
2419 }
2421 /* Otherwise we read the first plt entry. */
2423 {
2426 }
2431 /* The .glink section usually does not survive the final
2432 link; search for the section (usually .text) where the
2433 glink stubs now reside. */
2438 /* Determine glink PLT resolver by reading the relative branch
2439 from the first glink stub. */
2442 {
2445 /* The first glink stub may either branch to the resolver ... */
2450 /* ... or fall through a bunch of NOPs. */
2457 {
2460 }
2461 }
2465 /* If the stubs are those for -shared/-pie then we might have
2466 multiple stubs for each plt entry. If that is the case then
2467 there is no way to associate stubs with their plt entries short
2468 of figuring out the GOT pointer value used in the stub. */
2480 {
2484 }
2498 {
2502 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL set. Since
2503 we are defining a symbol, ensure one of them is set. */
2515 {
2520 }
2525 }
2527 /* Add a symbol at the start of the glink branch table. */
2536 s++;
2537 count++;
2540 {
2541 /* Add a symbol for the glink PLT resolver. */
2550 s++;
2551 count++;
2552 }
2555 }
2556 \f
2557 /* The following functions are specific to the ELF linker, while
2558 functions above are used generally. They appear in this file more
2559 or less in the order in which they are called. eg.
2560 ppc_elf_check_relocs is called early in the link process,
2561 ppc_elf_finish_dynamic_sections is one of the last functions
2562 called. */
2564 /* The PPC linker needs to keep track of the number of relocs that it
2565 decides to copy as dynamic relocs in check_relocs for each symbol.
2566 This is so that it can later discard them if they are found to be
2567 unnecessary. We store the information in a field extending the
2568 regular ELF linker hash table. */
2570 struct ppc_elf_dyn_relocs
2571 {
2574 /* The input section of the reloc. */
2577 /* Total number of relocs copied for the input section. */
2578 bfd_size_type count;
2580 /* Number of pc-relative relocs copied for the input section. */
2581 bfd_size_type pc_count;
2582 };
2584 /* Track PLT entries needed for a given symbol. We might need more
2585 than one glink entry per symbol when generating a pic binary. */
2586 struct plt_entry
2587 {
2590 /* -fPIC uses multiple GOT sections, one per file, called ".got2".
2591 This field stores the offset into .got2 used to initialise the
2592 GOT pointer reg. It will always be at least 32768. (Current
2593 gcc always uses an offset of 32768, but ld -r will pack .got2
2594 sections together resulting in larger offsets). */
2595 bfd_vma addend;
2597 /* The .got2 section. */
2600 /* PLT refcount or offset. */
2601 union
2602 {
2603 bfd_signed_vma refcount;
2604 bfd_vma offset;
2607 /* .glink stub offset. */
2608 bfd_vma glink_offset;
2609 };
2611 /* Of those relocs that might be copied as dynamic relocs, this function
2612 selects those that must be copied when linking a shared library,
2613 even when the symbol is local. */
2615 static int
2618 {
2620 {
2637 }
2638 }
2640 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
2641 copying dynamic variables from a shared lib into an app's dynbss
2642 section, and instead use a dynamic relocation to point into the
2643 shared lib. */
2644 #define ELIMINATE_COPY_RELOCS 1
2646 /* PPC ELF linker hash entry. */
2648 struct ppc_elf_link_hash_entry
2649 {
2652 /* If this symbol is used in the linker created sections, the processor
2653 specific backend uses this field to map the field into the offset
2654 from the beginning of the section. */
2657 /* Track dynamic relocs copied for this symbol. */
2660 /* Contexts in which symbol is used in the GOT (or TOC).
2661 TLS_GD .. TLS_TLS bits are or'd into the mask as the
2662 corresponding relocs are encountered during check_relocs.
2663 tls_optimize clears TLS_GD .. TLS_TPREL when optimizing to
2664 indicate the corresponding GOT entry type is not needed. */
2674 /* Nonzero if we have seen a small data relocation referring to this
2675 symbol. */
2677 };
2679 #define ppc_elf_hash_entry(ent) ((struct ppc_elf_link_hash_entry *) (ent))
2681 /* PPC ELF linker hash table. */
2683 struct ppc_elf_link_hash_table
2684 {
2687 /* Short-cuts to get to dynamic linker sections. */
2702 /* The (unloaded but important) .rela.plt.unloaded on VxWorks. */
2705 /* The .got.plt section (VxWorks only)*/
2708 /* Shortcut to __tls_get_addr. */
2711 /* The bfd that forced an old-style PLT. */
2714 /* TLS local dynamic got entry handling. */
2716 bfd_signed_vma refcount;
2717 bfd_vma offset;
2720 /* Offset of branch table to PltResolve function in glink. */
2721 bfd_vma glink_pltresolve;
2723 /* Size of reserved GOT entries. */
2725 /* Non-zero if allocating the header left a gap. */
2728 /* The type of PLT we have chosen to use. */
2731 /* Set if we should emit symbols for stubs. */
2734 /* Set if __tls_get_addr optimization should not be done. */
2737 /* True if the target system is VxWorks. */
2740 /* The size of PLT entries. */
2742 /* The distance between adjacent PLT slots. */
2744 /* The size of the first PLT entry. */
2747 /* Small local sym cache. */
2749 };
2751 /* Rename some of the generic section flags to better document how they
2752 are used here. */
2754 /* Nonzero if this section has TLS related relocations. */
2755 #define has_tls_reloc sec_flg0
2757 /* Nonzero if this section has a call to __tls_get_addr. */
2758 #define has_tls_get_addr_call sec_flg1
2760 /* Get the PPC ELF linker hash table from a link_info structure. */
2762 #define ppc_elf_hash_table(p) \
2763 (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \
2764 == PPC32_ELF_DATA ? ((struct ppc_elf_link_hash_table *) ((p)->hash)) : NULL)
2766 /* Create an entry in a PPC ELF linker hash table. */
2772 {
2773 /* Allocate the structure if it has not already been allocated by a
2774 subclass. */
2776 {
2781 }
2783 /* Call the allocation method of the superclass. */
2786 {
2790 }
2793 }
2795 /* Create a PPC ELF linker hash table. */
2799 {
2807 ppc_elf_link_hash_newfunc,
2809 PPC32_ELF_DATA))
2810 {
2813 }
2833 }
2835 /* Create .got and the related sections. */
2837 static bfd_boolean
2839 {
2842 flagword flags;
2853 {
2857 }
2858 else
2859 {
2860 /* The powerpc .got has a blrl instruction in it. Mark it
2861 executable. */
2866 }
2873 }
2875 static bfd_boolean
2877 {
2880 flagword flags;
2905 }
2907 /* We have to create .dynsbss and .rela.sbss here so that they get mapped
2908 to output sections (just like _bfd_elf_create_dynamic_sections has
2909 to create .dynbss and .rela.bss). */
2911 static bfd_boolean
2913 {
2916 flagword flags;
2939 {
2948 }
2961 /* The VxWorks PLT is a loaded section with contents. */
2964 }
2966 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2968 static void
2972 {
2979 {
2981 {
2985 /* Add reloc counts against the indirect sym to the direct sym
2986 list. Merge any entries against the same section. */
2988 {
2993 {
2998 }
3001 }
3003 }
3007 }
3012 /* If called to transfer flags for a weakdef during processing
3013 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
3014 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
3026 /* If we were called to copy over info for a weak sym, that's all. */
3030 /* Copy over the GOT refcount entries that we may have already seen to
3031 the symbol which just became indirect. */
3035 /* And plt entries. */
3037 {
3039 {
3044 {
3049 {
3053 }
3056 }
3058 }
3062 }
3065 {
3073 }
3074 }
3076 /* Hook called by the linker routine which adds symbols from an object
3077 file. We use it to put .comm items in .sbss, and not .bss. */
3079 static bfd_boolean
3087 {
3092 {
3093 /* Common symbols less than or equal to -G nn bytes are automatically
3094 put into .sbss. */
3099 {
3107 flags);
3110 }
3114 }
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 {
4634 /* Make two passes through the relocs. First time check that tls
4635 relocs involved in setting up a tls_get_addr call are indeed
4636 followed by such a call. If they are not, exclude them from
4637 the optimizations done on the second pass. */
4640 {
4647 {
4650 /* Read the relocations. */
4658 {
4664 bfd_boolean is_local;
4670 {
4678 }
4688 {
4692 /* Fall thru */
4696 /* These relocs should never be against a symbol
4697 defined in a shared lib. Leave them alone if
4698 that turns out to be the case. */
4702 /* LD -> LE */
4710 /* Fall thru */
4715 /* GD -> LE */
4717 else
4718 /* GD -> IE */
4728 {
4729 /* IE -> LE */
4733 }
4734 else
4746 }
4749 {
4760 /* Uh oh, we didn't find the expected call. We
4761 could just mark this symbol to exclude it
4762 from tls optimization but it's safer to skip
4763 the entire section. */
4766 }
4769 {
4783 }
4786 {
4789 }
4790 else
4791 {
4798 {
4805 {
4809 }
4810 }
4820 }
4823 {
4824 /* We managed to get rid of a got entry. */
4827 }
4831 }
4835 }
4839 {
4842 else
4844 }
4845 }
4847 }
4848 \f
4849 /* Return true if we have dynamic relocs that apply to read-only sections. */
4851 static bfd_boolean
4853 {
4857 {
4864 }
4866 }
4868 /* Adjust a symbol defined by a dynamic object and referenced by a
4869 regular object. The current definition is in some section of the
4870 dynamic object, but we're not including those sections. We have to
4871 change the definition to something the rest of the link can
4872 understand. */
4874 static bfd_boolean
4877 {
4881 #ifdef DEBUG
4884 #endif
4886 /* Make sure we know what is going on here. */
4896 /* Deal with function syms. */
4900 {
4901 /* Clear procedure linkage table information for any symbol that
4902 won't need a .plt entry. */
4912 {
4913 /* A PLT entry is not required/allowed when:
4915 1. We are not using ld.so; because then the PLT entry
4916 can't be set up, so we can't use one. In this case,
4917 ppc_elf_adjust_dynamic_symbol won't even be called.
4919 2. GC has rendered the entry unused.
4921 3. We know for certain that a call to this symbol
4922 will go to this object, or will remain undefined. */
4925 }
4926 else
4927 {
4928 /* After adjust_dynamic_symbol, non_got_ref set in the
4929 non-shared case means that we have allocated space in
4930 .dynbss for the symbol and thus dyn_relocs for this
4931 symbol should be discarded.
4932 If we get here we know we are making a PLT entry for this
4933 symbol, and in an executable we'd normally resolve
4934 relocations against this symbol to the PLT entry. Allow
4935 dynamic relocs if the reference is weak, and the dynamic
4936 relocs will not cause text relocation. */
4944 }
4946 }
4947 else
4950 /* If this is a weak symbol, and there is a real definition, the
4951 processor independent code will have arranged for us to see the
4952 real definition first, and we can just use the same value. */
4954 {
4962 }
4964 /* This is a reference to a symbol defined by a dynamic object which
4965 is not a function. */
4967 /* If we are creating a shared library, we must presume that the
4968 only references to the symbol are via the global offset table.
4969 For such cases we need not do anything here; the relocations will
4970 be handled correctly by relocate_section. */
4974 /* If there are no references to this symbol that do not use the
4975 GOT, we don't need to generate a copy reloc. */
4979 /* If we didn't find any dynamic relocs in read-only sections, then
4980 we'll be keeping the dynamic relocs and avoiding the copy reloc.
4981 We can't do this if there are any small data relocations. This
4982 doesn't work on VxWorks, where we can not have dynamic
4983 relocations (other than copy and jump slot relocations) in an
4984 executable. */
4990 {
4993 }
4996 {
5000 }
5002 /* We must allocate the symbol in our .dynbss section, which will
5003 become part of the .bss section of the executable. There will be
5004 an entry for this symbol in the .dynsym section. The dynamic
5005 object will contain position independent code, so all references
5006 from the dynamic object to this symbol will go through the global
5007 offset table. The dynamic linker will use the .dynsym entry to
5008 determine the address it must put in the global offset table, so
5009 both the dynamic object and the regular object will refer to the
5010 same memory location for the variable.
5012 Of course, if the symbol is referenced using SDAREL relocs, we
5013 must instead allocate it in .sbss. */
5017 else
5021 /* We must generate a R_PPC_COPY reloc to tell the dynamic linker to
5022 copy the initial value out of the dynamic object and into the
5023 runtime process image. We need to remember the offset into the
5024 .rela.bss section we are going to use. */
5026 {
5031 else
5036 }
5039 }
5040 \f
5041 /* Generate a symbol to mark plt call stubs. For non-PIC code the sym is
5042 xxxxxxxx.plt_call32.<callee> where xxxxxxxx is a hex number, usually 0,
5043 specifying the addend on the plt relocation. For -fpic code, the sym
5044 is xxxxxxxx.plt_pic32.<callee>, and for -fPIC
5045 xxxxxxxx.got2.plt_pic32.<callee>. */
5047 static bfd_boolean
5051 {
5060 else
5080 {
5089 }
5091 }
5093 /* Allocate NEED contiguous space in .got, and return the offset.
5094 Handles allocation of the got header when crossing 32k. */
5096 static bfd_vma
5098 {
5099 bfd_vma where;
5103 {
5106 }
5107 else
5108 {
5111 {
5114 }
5115 else
5116 {
5119 {
5122 }
5125 }
5126 }
5128 }
5130 /* Allocate space in associated reloc sections for dynamic relocs. */
5132 static bfd_boolean
5134 {
5144 /* When warning symbols are created, they **replace** the "real"
5145 entry in the hash table, thus we never get to see the real
5146 symbol in a hash traversal. So look at it now. */
5152 {
5156 bfd_boolean dyn;
5160 {
5161 /* Make sure this symbol is output as a dynamic symbol. */
5166 {
5169 }
5175 {
5181 {
5183 {
5186 }
5191 {
5197 }
5202 {
5205 }
5211 }
5212 else
5213 {
5215 {
5216 /* If this is the first .plt entry, make room
5217 for the special first entry. */
5221 /* The PowerPC PLT is actually composed of two
5222 parts, the first part is 2 words (for a load
5223 and a jump), and then there is a remaining
5224 word available at the end. */
5231 /* If this symbol is not defined in a regular
5232 file, and we are not generating a shared
5233 library, then set the symbol to this location
5234 in the .plt. This is to avoid text
5235 relocations, and is required to make
5236 function pointers compare as equal between
5237 the normal executable and the shared library. */
5241 {
5244 }
5246 /* Make room for this entry. */
5248 /* After the 8192nd entry, room for two entries
5249 is allocated. */
5255 }
5257 }
5259 /* We also need to make an entry in the .rela.plt section. */
5261 {
5265 else
5266 {
5270 {
5271 /* Allocate space for the unloaded relocations. */
5274 {
5277 {
5281 }
5286 }
5288 /* Every PLT entry has an associated GOT entry in
5289 .got.plt. */
5291 }
5292 }
5294 }
5295 }
5296 else
5298 }
5299 else
5303 {
5306 }
5307 }
5308 else
5309 {
5312 }
5316 {
5317 bfd_boolean dyn;
5320 /* Make sure this symbol is output as a dynamic symbol. */
5325 {
5328 }
5332 {
5334 {
5336 /* We'll just use htab->tlsld_got.offset. This should
5337 always be the case. It's a little odd if we have
5338 a local dynamic reloc against a non-local symbol. */
5340 else
5342 }
5349 }
5350 else
5354 else
5355 {
5362 {
5364 /* All the entries we allocated need relocs.
5365 Except LD only needs one. */
5370 }
5371 }
5372 }
5373 else
5380 /* In the shared -Bsymbolic case, discard space allocated for
5381 dynamic pc-relative relocs against symbols which turn out to be
5382 defined in regular objects. For the normal shared case, discard
5383 space for relocs that have become local due to symbol visibility
5384 changes. */
5387 {
5388 /* Relocs that use pc_count are those that appear on a call insn,
5389 or certain REL relocs (see must_be_dyn_reloc) that can be
5390 generated via assembly. We want calls to protected symbols to
5391 resolve directly to the function rather than going via the plt.
5392 If people want function pointer comparisons to work as expected
5393 then they should avoid writing weird assembly. */
5395 {
5399 {
5404 else
5406 }
5407 }
5410 {
5414 {
5417 else
5419 }
5420 }
5422 /* Discard relocs on undefined symbols that must be local. */
5429 /* Also discard relocs on undefined weak syms with non-default
5430 visibility. */
5433 {
5437 /* Make sure undefined weak symbols are output as a dynamic
5438 symbol in PIEs. */
5442 {
5445 }
5446 }
5447 }
5449 {
5450 /* For the non-shared case, discard space for relocs against
5451 symbols which turn out to need copy relocs or are not
5452 dynamic. */
5456 {
5457 /* Make sure this symbol is output as a dynamic symbol.
5458 Undefined weak syms won't yet be marked as dynamic. */
5461 {
5464 }
5466 /* If that succeeded, we know we'll be keeping all the
5467 relocs. */
5470 }
5474 keep: ;
5475 }
5477 /* Finally, allocate space. */
5479 {
5484 }
5487 }
5489 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
5490 read-only sections. */
5492 static bfd_boolean
5494 {
5502 {
5505 /* Not an error, just cut short the traversal. */
5507 }
5509 }
5511 /* Set the sizes of the dynamic sections. */
5513 static bfd_boolean
5516 {
5519 bfd_boolean relocs;
5522 #ifdef DEBUG
5524 #endif
5530 {
5531 /* Set the contents of the .interp section to the interpreter. */
5533 {
5538 }
5539 }
5546 /* Set up .got offsets for local syms, and space for local dynamic
5547 relocs. */
5549 {
5555 bfd_size_type locsymcount;
5562 {
5569 {
5572 {
5573 /* Input section has been discarded, either because
5574 it is a copy of a linkonce section or due to
5575 linker script /DISCARD/, so we'll be discarding
5576 the relocs too. */
5577 }
5581 {
5582 /* Relocations in vxworks .tls_vars sections are
5583 handled specially by the loader. */
5584 }
5586 {
5595 }
5596 }
5597 }
5612 {
5615 {
5624 }
5625 else
5629 else
5630 {
5635 }
5636 }
5637 else
5643 /* Allocate space for calls to local STT_GNU_IFUNC syms in .iplt. */
5645 {
5652 {
5656 {
5659 }
5664 {
5667 }
5671 {
5674 }
5675 }
5676 else
5678 }
5679 }
5681 /* Allocate space for global sym dynamic relocs. */
5685 {
5689 }
5690 else
5694 {
5697 /* If we haven't allocated the header, do so now. When we get here,
5698 for old plt/got the got size will be 0 to 32764 (not allocated),
5699 or 32780 to 65536 (header allocated). For new plt/got, the
5700 corresponding ranges are 0 to 32768 and 32780 to 65536. */
5702 {
5707 }
5710 }
5712 {
5717 {
5721 }
5722 }
5727 {
5729 /* Space for the branch table. */
5731 /* Pad out to align the start of PLTresolve. */
5736 {
5743 {
5752 }
5758 {
5767 }
5768 }
5769 }
5771 /* We've now determined the sizes of the various dynamic sections.
5772 Allocate memory for them. */
5775 {
5783 {
5784 /* We'd like to strip these sections if they aren't needed, but if
5785 we've exported dynamic symbols from them we must leave them.
5786 It's too late to tell BFD to get rid of the symbols. */
5789 /* Strip this section if we don't need it; see the
5790 comment below. */
5791 }
5800 {
5801 /* Strip these too. */
5802 }
5804 {
5806 {
5807 /* Remember whether there are any relocation sections. */
5810 /* We use the reloc_count field as a counter if we need
5811 to copy relocs into the output file. */
5813 }
5814 }
5815 else
5816 {
5817 /* It's not one of our sections, so don't allocate space. */
5819 }
5822 {
5823 /* If we don't need this section, strip it from the
5824 output file. This is mostly to handle .rela.bss and
5825 .rela.plt. We must create both sections in
5826 create_dynamic_sections, because they must be created
5827 before the linker maps input sections to output
5828 sections. The linker does that before
5829 adjust_dynamic_symbol is called, and it is that
5830 function which decides whether anything needs to go
5831 into these sections. */
5834 }
5839 /* Allocate memory for the section contents. */
5843 }
5846 {
5847 /* Add some entries to the .dynamic section. We fill in the
5848 values later, in ppc_elf_finish_dynamic_sections, but we
5849 must add the entries now so that we get the correct size for
5850 the .dynamic section. The DT_DEBUG entry is filled in by the
5851 dynamic linker and used by the debugger. */
5852 #define add_dynamic_entry(TAG, VAL) \
5853 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
5856 {
5859 }
5862 {
5868 }
5871 {
5879 }
5882 {
5887 }
5889 /* If any dynamic relocs apply to a read-only section, then we
5890 need a DT_TEXTREL entry. */
5893 info);
5896 {
5899 }
5903 }
5904 #undef add_dynamic_entry
5907 }
5909 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
5911 static bfd_boolean
5913 {
5921 }
5922 \f
5923 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
5925 /* Relaxation trampolines. r12 is available for clobbering (r11, is
5926 used for some functions that are allowed to break the ABI). */
5928 {
5937 };
5940 {
5945 };
5947 static bfd_boolean
5952 {
5953 struct one_fixup
5954 {
5957 /* Final link, can use the symbol offset. For a
5958 relocatable link we use the symbol's index. */
5959 bfd_vma toff;
5960 bfd_vma trampoff;
5961 };
5971 bfd_size_type trampoff;
5976 /* Nothing to do if there are no relocations, and no need to do
5977 anything with non-alloc or non-code sections. */
5984 /* We cannot represent the required PIC relocs in the output, so don't
5985 do anything. The linker doesn't support mixing -shared and -r
5986 anyway. */
5991 /* Space for a branch around any trampolines. */
5996 /* Get a copy of the native relocations. */
6007 {
6021 {
6036 }
6038 /* Get the value of the symbol referred to by the reloc. */
6041 {
6042 /* A local symbol. */
6045 /* Read this BFD's local symbols. */
6047 {
6055 }
6063 else
6068 }
6069 else
6070 {
6071 /* Global symbol handling. */
6083 {
6086 }
6089 {
6092 }
6093 else
6097 }
6099 /* The condition here under which we call find_plt_ent must
6100 match that in relocate_section. If we call find_plt_ent here
6101 but not in relocate_section, or vice versa, then the branch
6102 destination used here may be incorrect. */
6105 {
6106 /* We know is_branch_reloc (r_type) is true. */
6110 }
6113 {
6118 }
6120 {
6128 {
6133 {
6136 }
6137 else
6138 {
6141 }
6142 }
6143 }
6145 /* If the branch and target are in the same section, you have
6146 no hope of adding stubs. We'll error out later should the
6147 branch overflow. */
6151 /* There probably isn't any reason to handle symbols in
6152 SEC_MERGE sections; SEC_MERGE doesn't seem a likely
6153 attribute for a code section, and we are only looking at
6154 branches. However, implement it correctly here as a
6155 reference for other target relax_section functions. */
6157 {
6158 /* At this stage in linking, no SEC_MERGE symbol has been
6159 adjusted, so all references to such symbols need to be
6160 passed through _bfd_merged_section_offset. (Later, in
6161 relocate_section, all SEC_MERGE symbols *except* for
6162 section symbols have been adjusted.)
6164 gas may reduce relocations against symbols in SEC_MERGE
6165 sections to a relocation against the section symbol when
6166 the original addend was zero. When the reloc is against
6167 a section symbol we should include the addend in the
6168 offset passed to _bfd_merged_section_offset, since the
6169 location of interest is the original symbol. On the
6170 other hand, an access to "sym+addend" where "sym" is not
6171 a section symbol should not include the addend; Such an
6172 access is presumed to be an offset from "sym"; The
6173 location of interest is just "sym". */
6179 toff);
6183 }
6184 /* PLTREL24 addends are special. */
6188 /* Attempted -shared link of non-pic code loses. */
6194 /* If the branch is in range, no need to do anything. */
6197 /* A relocatable link may have sections moved during
6198 final link, so do not presume they remain in range. */
6200 {
6207 }
6209 /* Look for an existing fixup to this address. */
6215 {
6221 /* Oh dear, we can't reach a trampoline. Don't try to add
6222 one. We'll report an error later. */
6226 {
6229 }
6230 else
6231 {
6234 }
6238 {
6242 }
6244 /* Hijack the old relocation. Since we need two
6245 relocations for this use a "composite" reloc. */
6247 stub_rtype);
6253 /* Record the fixup so we don't do it again this section. */
6262 changes++;
6263 }
6264 else
6265 {
6270 /* Nop out the reloc, since we're finalizing things here. */
6272 }
6274 /* Get the section contents. */
6276 {
6277 /* Get cached copy if it exists. */
6280 else
6281 {
6282 /* Go get them off disk. */
6285 }
6286 }
6288 /* Fix up the existing branch to hit the trampoline. */
6291 {
6309 }
6310 }
6312 /* Write out the trampolines. */
6314 {
6317 bfd_vma val;
6320 do
6321 {
6325 }
6333 /* Branch around the trampolines. */
6341 {
6344 }
6345 else
6346 {
6349 }
6353 {
6355 i++;
6359 }
6361 }
6365 {
6368 else
6369 {
6370 /* Cache the symbols for elf_link_input_bfd. */
6372 }
6373 }
6377 {
6380 else
6381 {
6382 /* Cache the section contents for elf_link_input_bfd. */
6384 }
6385 }
6388 {
6389 /* Append sufficient NOP relocs so we can write out relocation
6390 information for the trampolines. */
6400 {
6404 }
6411 }
6417 {
6418 /* Convert the internal relax relocs to external form. */
6421 {
6424 /* Rewrite the reloc and convert one of the trailing nop
6425 relocs to describe this relocation. */
6427 /* The relocs are at the bottom 2 bytes */
6433 irel++;
6434 }
6435 }
6439 error_return:
6449 }
6450 \f
6451 /* What to do when ld finds relocations against symbols defined in
6452 discarded sections. */
6454 static unsigned int
6456 {
6464 }
6465 \f
6466 /* Fill in the address for a pointer generated in a linker section. */
6468 static bfd_vma
6472 bfd_vma relocation,
6474 {
6480 {
6481 /* Handle global symbol. */
6487 }
6488 else
6489 {
6490 /* Handle local symbol. */
6496 }
6500 lsect);
6503 /* Offset will always be a multiple of four, so use the bottom bit
6504 as a "written" flag. */
6506 {
6511 }
6518 #ifdef DEBUG
6522 #endif
6525 }
6527 #define PPC_LO(v) ((v) & 0xffff)
6528 #define PPC_HI(v) (((v) >> 16) & 0xffff)
6529 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
6531 static void
6534 {
6537 bfd_vma plt;
6544 {
6557 {
6566 }
6567 else
6568 {
6577 }
6578 }
6579 else
6580 {
6589 }
6590 }
6592 /* Return true if symbol is defined statically. */
6594 static bfd_boolean
6596 {
6601 }
6603 /* If INSN is an opcode that may be used with an @tls operand, return
6604 the transformed insn for TLS optimisation, otherwise return 0. If
6605 REG is non-zero only match an insn with RB or RA equal to REG. */
6607 unsigned int
6609 {
6619 else
6623 /* add -> addi. */
6629 /* load and store indexed -> dform. */
6632 /* ldx, ldux, stdx, stdux -> ld, ldu, std, stdu. */
6635 /* lwax -> lwa. */
6637 else
6641 }
6643 /* If INSN is an opcode that may be used with an @tprel operand, return
6644 the transformed insn for an undefined weak symbol, ie. with the
6645 thread pointer REG operand removed. Otherwise return 0. */
6647 unsigned int
6649 {
6670 {
6672 }
6677 {
6682 }
6683 else
6686 }
6688 /* The RELOCATE_SECTION function is called by the ELF backend linker
6689 to handle the relocations for a section.
6691 The relocs are always passed as Rela structures; if the section
6692 actually uses Rel structures, the r_addend field will always be
6693 zero.
6695 This function is responsible for adjust the section contents as
6696 necessary, and (if using Rela relocs and generating a
6697 relocatable output file) adjusting the reloc addend as
6698 necessary.
6700 This function does not have to worry about setting the reloc
6701 address or the reloc symbol index.
6703 LOCAL_SYMS is a pointer to the swapped in local symbols.
6705 LOCAL_SECTIONS is an array giving the section in the input file
6706 corresponding to the st_shndx field of each local symbol.
6708 The global hash table entry for the global symbols can be found
6709 via elf_sym_hashes (input_bfd).
6711 When generating relocatable output, this function must handle
6712 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
6713 going to be the section symbol corresponding to the output
6714 section, which means that the addend must be adjusted
6715 accordingly. */
6717 static bfd_boolean
6726 {
6732 Elf_Internal_Rela outrel;
6737 bfd_boolean is_vxworks_tls;
6739 #ifdef DEBUG
6745 #endif
6749 /* Initialize howto table if not already done. */
6757 /* We have to handle relocations in vxworks .tls_vars sections
6758 specially, because the dynamic loader is 'weird'. */
6765 {
6767 bfd_vma addend;
6768 bfd_reloc_status_type r;
6775 bfd_vma relocation;
6777 bfd_boolean unresolved_reloc;
6778 bfd_boolean warned;
6791 {
6797 }
6798 else
6799 {
6806 }
6809 {
6810 /* For relocs against symbols from removed linkonce sections,
6811 or sections discarded by a linker script, we just want the
6812 section contents zeroed. Avoid any special processing. */
6820 }
6823 {
6827 {
6828 /* R_PPC_PLTREL24 is rather special. If non-zero, the
6829 addend specifies the GOT pointer offset within .got2. */
6831 }
6833 }
6835 /* TLS optimizations. Replace instruction sequences and relocs
6836 based on information we collected in tls_optimize. We edit
6837 RELOCS so that --emit-relocs will output something sensible
6838 for the final instruction stream. */
6844 {
6847 local_plt
6851 }
6853 /* Ensure reloc mapping code below stays sane. */
6864 {
6872 {
6873 bfd_vma insn;
6881 }
6887 {
6888 bfd_vma insn;
6898 /* Was PPC_TLS which sits on insn boundary, now
6899 PPC_TPREL16_LO which is at low-order half-word. */
6901 }
6914 {
6915 tls_gdld_hi:
6919 else
6920 {
6924 }
6926 }
6939 {
6941 bfd_vma offset;
6943 tls_ldgd_opt:
6945 /* If not using the newer R_PPC_TLSGD/LD to mark
6946 __tls_get_addr calls, we must trust that the call
6947 stays with its arg setup insns, ie. that the next
6948 reloc is the __tls_get_addr call associated with
6949 the current reloc. Edit both insns. */
6956 {
6957 /* IE */
6963 {
6967 }
6971 }
6972 else
6973 {
6974 /* LE */
6977 {
6978 /* Was an LD reloc. */
6981 r_symndx++)
6991 }
6995 {
7001 }
7002 }
7006 {
7007 /* We changed the symbol on an LD reloc. Start over
7008 in order to get h, sym, sec etc. right. */
7009 rel--;
7011 }
7012 }
7017 {
7022 {
7023 /* IE */
7026 }
7027 else
7028 {
7029 /* LE */
7033 }
7036 /* Zap the reloc on the _tls_get_addr call too. */
7039 }
7044 {
7049 r_symndx++)
7065 /* Zap the reloc on the _tls_get_addr call too. */
7068 rel--;
7070 }
7072 }
7074 /* Handle other relocations that tweak non-addend part of insn. */
7077 {
7081 /* Branch taken prediction relocations. */
7085 /* Fall thru */
7087 /* Branch not taken prediction relocations. */
7090 {
7091 bfd_vma insn;
7101 /* Invert 'y' bit if not the default. */
7107 }
7108 }
7112 {
7116 {
7119 }
7122 {
7128 }
7134 {
7139 }
7141 {
7143 {
7144 Elf_Internal_Rela rela;
7158 }
7160 {
7165 }
7174 else
7178 }
7179 }
7187 {
7206 /* GOT16 relocations. Like an ADDR16 using the symbol's
7207 address in the GOT as relocation value instead of the
7208 symbol's value itself. Also, create a GOT entry for the
7209 symbol and put the symbol value there. */
7243 dogot:
7244 {
7245 /* Relocation is to the entry for this symbol in the global
7246 offset table. */
7247 bfd_vma off;
7260 {
7261 bfd_boolean dyn;
7266 /* This is actually a static link, or it is a
7267 -Bsymbolic link and the symbol is defined
7268 locally, or the symbol was forced to be local
7269 because of a version file. */
7270 ;
7271 else
7272 {
7275 }
7277 }
7278 else
7279 {
7283 }
7285 /* The offset must always be a multiple of 4. We use the
7286 least significant bit to record whether we have already
7287 processed this entry. */
7291 else
7292 {
7303 /* We might have multiple got entries for this sym.
7304 Initialize them all. */
7305 do
7306 {
7310 {
7313 }
7315 {
7318 }
7320 {
7323 }
7325 {
7328 }
7330 /* Generate relocs for the dynamic linker. */
7336 {
7345 {
7348 {
7355 outrel.r_info
7357 }
7358 }
7367 else
7370 {
7374 }
7379 }
7381 /* Init the .got section contents if we're not
7382 emitting a reloc. */
7383 else
7384 {
7390 {
7396 {
7400 }
7401 }
7404 }
7409 }
7414 }
7420 {
7422 {
7428 {
7432 {
7435 }
7436 }
7437 }
7438 }
7442 + off
7445 /* Addends on got relocations don't make much sense.
7446 x+off@got is actually x@got+off, and since the got is
7447 generated by a hash table traversal, the value in the
7448 got at entry m+n bears little relation to the entry m. */
7452 input_bfd,
7453 input_section,
7456 sym_name);
7457 }
7460 /* Relocations that need no special processing. */
7462 /* It makes no sense to point a local relocation
7463 at a symbol not in this object. */
7465 {
7468 input_bfd,
7469 input_section,
7471 TRUE))
7474 }
7484 /* Relocations that may need to be propagated if this is a shared
7485 object. */
7493 {
7494 /* Make this relocation against an undefined weak symbol
7495 resolve to zero. This is really just a tweak, since
7496 code using weak externs ought to check that they are
7497 defined before using them. */
7504 }
7506 /* The TPREL16 relocs shouldn't really be used in shared
7507 libs as they will result in DT_TEXTREL being set, but
7508 support them anyway. */
7533 /* fall through */
7548 /* If these relocations are not to a named symbol, they can be
7549 handled right here, no need to bother the dynamic linker. */
7553 /* fall through */
7561 /* fall through */
7563 dodyn:
7577 || (ELIMINATE_COPY_RELOCS
7583 {
7586 #ifdef DEBUG
7591 #endif
7593 /* When generating a shared object, these relocations
7594 are copied into the output file to be resolved at run
7595 time. */
7597 {
7603 }
7621 {
7625 }
7626 else
7627 {
7631 {
7635 {
7636 /* If we get here when building a static
7637 executable, then the libc startup function
7638 responsible for applying indirect function
7639 relocations is going to complain about
7640 the reloc type.
7641 If we get here when building a dynamic
7642 executable, it will be because we have
7643 a text relocation. The dynamic loader
7644 will set the text segment writable and
7645 non-executable to apply text relocations.
7646 So we'll segfault when trying to run the
7647 indirection function to resolve the reloc. */
7651 input_bfd,
7652 input_section,
7655 sym_name);
7657 }
7659 ;
7661 {
7664 }
7665 else
7666 {
7669 /* We are turning this relocation into one
7670 against a section symbol. It would be
7671 proper to subtract the symbol's value,
7672 osec->vma, from the emitted reloc addend,
7673 but ld.so expects buggy relocs.
7674 FIXME: Why not always use a zero index? */
7678 {
7681 }
7683 #ifdef DEBUG
7688 #endif
7689 }
7692 }
7695 else
7697 }
7706 /* This reloc will be computed at runtime. We clear the memory
7707 so that it contains predictable value. */
7711 {
7715 }
7716 }
7722 {
7727 {
7731 }
7737 else
7741 }
7742 /* Fall thru */
7750 {
7757 /* We're clearing the bits for R_PPC_ADDR16_HA
7758 and R_PPC_ADDR16_LO here. */
7762 /* t0 is HA, t1 is LO */
7770 /* Rewrite the reloc and convert one of the trailing nop
7771 relocs to describe this relocation. */
7773 /* The relocs are at the bottom 2 bytes */
7779 rel++;
7780 }
7783 /* Indirect .sdata relocation. */
7787 {
7790 }
7791 relocation
7797 /* Indirect .sdata2 relocation. */
7801 {
7804 }
7805 relocation
7811 /* Handle the TOC16 reloc. We want to use the offset within the .got
7812 section, not the actual VMA. This is appropriate when generating
7813 an embedded ELF object, for which the .got section acts like the
7814 AIX .toc section. */
7817 {
7820 }
7830 /* Relocation is to the entry for this symbol in the
7831 procedure linkage table. */
7832 {
7838 {
7839 /* We didn't make a PLT entry for this symbol. This
7840 happens when statically linking PIC code, or when
7841 using -Bsymbolic. */
7843 }
7850 else
7854 }
7857 /* Relocate against _SDA_BASE_. */
7859 {
7866 {
7869 }
7877 {
7881 input_bfd,
7882 sym_name,
7884 name);
7885 }
7886 }
7889 /* Relocate against _SDA2_BASE_. */
7891 {
7898 {
7901 }
7907 {
7911 input_bfd,
7912 sym_name,
7914 name);
7915 }
7916 }
7919 /* Relocate against either _SDA_BASE_, _SDA2_BASE_, or 0. */
7922 {
7928 {
7931 }
7938 {
7941 }
7944 {
7947 }
7950 {
7952 }
7953 else
7954 {
7958 input_bfd,
7959 sym_name,
7961 name);
7966 }
7969 {
7971 {
7974 }
7976 }
7979 {
7985 }
7986 }
7989 /* Relocate against the beginning of the section. */
7995 {
7998 }
8002 /* Negative relocations. */
8029 input_bfd,
8031 sym_name);
8036 }
8038 /* Do any further special processing. */
8040 {
8051 /* It's just possible that this symbol is a weak symbol
8052 that's not actually defined anywhere. In that case,
8053 'sec' would be NULL, and we should leave the symbol
8054 alone (it will be set to zero elsewhere in the link). */
8057 /* Fall thru */
8065 /* Add 0x10000 if sign bit in 0:15 is set.
8066 Bits 0:15 are not used. */
8069 }
8071 #ifdef DEBUG
8076 sym_name,
8077 r_symndx,
8080 #endif
8085 {
8088 input_bfd,
8089 input_section,
8092 sym_name);
8094 }
8097 input_bfd,
8098 input_section,
8099 contents,
8101 relocation,
8102 addend);
8105 {
8107 {
8113 {
8114 /* Assume this is a call protected by other code that
8115 detect the symbol is undefined. If this is the case,
8116 we can safely ignore the overflow. If not, the
8117 program is hosed anyway, and a little warning isn't
8118 going to help. */
8121 }
8125 sym_name,
8128 input_bfd,
8129 input_section,
8132 }
8133 else
8134 {
8140 }
8141 }
8142 }
8144 #ifdef DEBUG
8146 #endif
8149 }
8150 \f
8151 /* Finish up dynamic symbol handling. We set the contents of various
8152 dynamic sections here. */
8154 static bfd_boolean
8159 {
8162 bfd_boolean doneone;
8164 #ifdef DEBUG
8167 #endif
8175 {
8177 {
8178 Elf_Internal_Rela rela;
8180 bfd_vma reloc_index;
8186 else
8187 {
8193 }
8195 /* This symbol has an entry in the procedure linkage table.
8196 Set it up. */
8200 {
8201 bfd_vma got_offset;
8204 /* The first three entries in .got.plt are reserved. */
8207 /* Use the right PLT. */
8211 /* Fill in the .plt on VxWorks. */
8213 {
8220 }
8221 else
8222 {
8231 }
8238 /* This instruction is an immediate load. The value loaded is
8239 the byte offset of the R_PPC_JMP_SLOT relocation from the
8240 start of the .rela.plt section. The value is stored in the
8241 low-order 16 bits of the load instruction. */
8242 /* NOTE: It appears that this is now an index rather than a
8243 prescaled offset. */
8247 /* This instruction is a PC-relative branch whose target is
8248 the start of the PLT section. The address of this branch
8249 instruction is 20 bytes beyond the start of this PLT entry.
8250 The address is encoded in bits 6-29, inclusive. The value
8251 stored is right-shifted by two bits, permitting a 26-bit
8252 offset. */
8262 /* Fill in the GOT entry corresponding to this PLT slot with
8263 the address immediately after the the "bctr" instruction
8264 in this PLT entry. */
8271 {
8272 /* Fill in a couple of entries in .rela.plt.unloaded. */
8278 /* Provide the @ha relocation for the first instruction. */
8283 R_PPC_ADDR16_HA);
8288 /* Provide the @l relocation for the second instruction. */
8293 R_PPC_ADDR16_LO);
8298 /* Provide a relocation for the GOT entry corresponding to this
8299 PLT slot. Point it at the middle of the .plt entry. */
8304 R_PPC_ADDR32);
8307 }
8309 /* VxWorks uses non-standard semantics for R_PPC_JMP_SLOT.
8310 In particular, the offset for the relocation is not the
8311 address of the PLT entry for this function, as specified
8312 by the ABI. Instead, the offset is set to the address of
8313 the GOT slot for this function. See EABI 4.4.4.1. */
8318 }
8319 else
8320 {
8332 {
8333 /* We don't need to fill in the .plt. The ppc dynamic
8334 linker will fill it in. */
8335 }
8336 else
8337 {
8343 }
8344 }
8346 /* Fill in the entry in the .rela.plt section. */
8350 {
8357 }
8358 else
8366 else
8372 {
8373 /* Mark the symbol as undefined, rather than as
8374 defined in the .plt section. Leave the value if
8375 there were any relocations where pointer equality
8376 matters (this is a clue for the dynamic linker, to
8377 make function pointer comparisons work between an
8378 application and shared library), otherwise set it
8379 to zero. */
8384 {
8385 /* This breaks function pointer comparisons, but
8386 that is better than breaking tests for a NULL
8387 function pointer. */
8389 }
8390 }
8393 {
8394 /* Set the value of ifunc symbols in a non-pie
8395 executable to the glink entry. This is to avoid
8396 text relocations. We can't do this for ifunc in
8397 allocate_dynrelocs, as we do for normal dynamic
8398 function symbols with plt entries, because we need
8399 to keep the original value around for the ifunc
8400 relocation. */
8406 }
8408 }
8413 {
8423 {
8440 }
8445 /* We only need one non-PIC glink stub. */
8447 }
8448 else
8450 }
8453 {
8455 Elf_Internal_Rela rela;
8458 /* This symbols needs a copy reloc. Set it up. */
8460 #ifdef DEBUG
8462 #endif
8468 else
8477 }
8479 #ifdef DEBUG
8481 #endif
8483 /* Mark some specially defined symbols as absolute. */
8492 }
8493 \f
8494 static enum elf_reloc_type_class
8496 {
8498 {
8509 }
8510 }
8511 \f
8512 /* Finish up the dynamic sections. */
8514 static bfd_boolean
8517 {
8521 bfd_vma got;
8525 #ifdef DEBUG
8527 #endif
8534 else
8542 {
8550 {
8551 Elf_Internal_Dyn dyn;
8557 {
8561 else
8581 {
8585 }
8593 }
8596 }
8597 }
8600 {
8603 {
8608 {
8609 /* Add a blrl instruction at _GLOBAL_OFFSET_TABLE_-4
8610 so that a function can easily find the address of
8611 _GLOBAL_OFFSET_TABLE_. */
8615 }
8618 {
8623 }
8624 }
8625 else
8626 {
8633 }
8636 }
8638 /* Fill in the first entry in the VxWorks procedure linkage table. */
8640 {
8641 /* Use the right PLT. */
8647 {
8654 }
8655 else
8656 {
8659 }
8668 {
8669 Elf_Internal_Rela rela;
8674 /* Output the @ha relocation for the first instruction. */
8683 /* Output the @l relocation for the second instruction. */
8692 /* Fix up the remaining relocations. They may have the wrong
8693 symbol index for _G_O_T_ or _P_L_T_ depending on the order
8694 in which symbols were output. */
8696 {
8697 Elf_Internal_Rela rel;
8713 }
8714 }
8715 }
8720 {
8723 bfd_vma res0;
8726 /*
8727 * PIC glink code is the following:
8728 *
8729 * # ith PLT code stub.
8730 * addis 11,30,(plt+(i-1)*4-got)@ha
8731 * lwz 11,(plt+(i-1)*4-got)@l(11)
8732 * mtctr 11
8733 * bctr
8734 *
8735 * # A table of branches, one for each plt entry.
8736 * # The idea is that the plt call stub loads ctr and r11 with these
8737 * # addresses, so (r11 - res_0) gives the plt index * 4.
8738 * res_0: b PLTresolve
8739 * res_1: b PLTresolve
8740 * .
8741 * # Some number of entries towards the end can be nops
8742 * res_n_m3: nop
8743 * res_n_m2: nop
8744 * res_n_m1:
8745 *
8746 * PLTresolve:
8747 * addis 11,11,(1f-res_0)@ha
8748 * mflr 0
8749 * bcl 20,31,1f
8750 * 1: addi 11,11,(1b-res_0)@l
8751 * mflr 12
8752 * mtlr 0
8753 * sub 11,11,12 # r11 = index * 4
8754 * addis 12,12,(got+4-1b)@ha
8755 * lwz 0,(got+4-1b)@l(12) # got[1] address of dl_runtime_resolve
8756 * lwz 12,(got+8-1b)@l(12) # got[2] contains the map address
8757 * mtctr 0
8758 * add 0,11,11
8759 * add 11,0,11 # r11 = index * 12 = reloc offset.
8760 * bctr
8761 */
8763 {
8764 ADDIS_11_11,
8765 MFLR_0,
8766 BCL_20_31,
8767 ADDI_11_11,
8768 MFLR_12,
8769 MTLR_0,
8770 SUB_11_11_12,
8771 ADDIS_12_12,
8772 LWZ_0_12,
8773 LWZ_12_12,
8774 MTCTR_0,
8775 ADD_0_11_11,
8776 ADD_11_0_11,
8777 BCTR,
8778 NOP,
8779 NOP
8780 };
8782 /*
8783 * Non-PIC glink code is a little simpler.
8784 *
8785 * # ith PLT code stub.
8786 * lis 11,(plt+(i-1)*4)@ha
8787 * lwz 11,(plt+(i-1)*4)@l(11)
8788 * mtctr 11
8789 * bctr
8790 *
8791 * The branch table is the same, then comes
8792 *
8793 * PLTresolve:
8794 * lis 12,(got+4)@ha
8795 * addis 11,11,(-res_0)@ha
8796 * lwz 0,(got+4)@l(12) # got[1] address of dl_runtime_resolve
8797 * addi 11,11,(-res_0)@l # r11 = index * 4
8798 * mtctr 0
8799 * add 0,11,11
8800 * lwz 12,(got+8)@l(12) # got[2] contains the map address
8801 * add 11,0,11 # r11 = index * 12 = reloc offset.
8802 * bctr
8803 */
8805 {
8806 LIS_12,
8807 ADDIS_11_11,
8808 LWZ_0_12,
8809 ADDI_11_11,
8810 MTCTR_0,
8811 ADD_0_11_11,
8812 LWZ_12_12,
8813 ADD_11_0_11,
8814 BCTR,
8815 NOP,
8816 NOP,
8817 NOP,
8818 NOP,
8819 NOP,
8820 NOP,
8821 NOP
8822 };
8829 /* Build the branch table, one for each plt entry (less one),
8830 and perhaps some padding. */
8836 {
8839 }
8841 {
8844 }
8850 /* Last comes the PLTresolve stub. */
8852 {
8853 bfd_vma bcl;
8856 {
8859 }
8873 {
8878 }
8879 else
8880 {
8885 }
8886 }
8887 else
8888 {
8890 {
8893 }
8903 {
8908 }
8909 else
8910 {
8915 }
8916 }
8917 }
8920 }
8921 \f
8922 #define TARGET_LITTLE_SYM bfd_elf32_powerpcle_vec
8924 #define TARGET_BIG_SYM bfd_elf32_powerpc_vec
8926 #define ELF_ARCH bfd_arch_powerpc
8927 #define ELF_MACHINE_CODE EM_PPC
8928 #ifdef __QNXTARGET__
8929 #define ELF_MAXPAGESIZE 0x1000
8930 #else
8931 #define ELF_MAXPAGESIZE 0x10000
8932 #endif
8933 #define ELF_MINPAGESIZE 0x1000
8934 #define ELF_COMMONPAGESIZE 0x1000
8935 #define elf_info_to_howto ppc_elf_info_to_howto
8937 #ifdef EM_CYGNUS_POWERPC
8938 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
8939 #endif
8941 #ifdef EM_PPC_OLD
8942 #define ELF_MACHINE_ALT2 EM_PPC_OLD
8943 #endif
8945 #define elf_backend_plt_not_loaded 1
8946 #define elf_backend_can_gc_sections 1
8947 #define elf_backend_can_refcount 1
8948 #define elf_backend_rela_normal 1
8950 #define bfd_elf32_mkobject ppc_elf_mkobject
8951 #define bfd_elf32_bfd_merge_private_bfd_data ppc_elf_merge_private_bfd_data
8952 #define bfd_elf32_bfd_relax_section ppc_elf_relax_section
8953 #define bfd_elf32_bfd_reloc_type_lookup ppc_elf_reloc_type_lookup
8954 #define bfd_elf32_bfd_reloc_name_lookup ppc_elf_reloc_name_lookup
8955 #define bfd_elf32_bfd_set_private_flags ppc_elf_set_private_flags
8956 #define bfd_elf32_bfd_link_hash_table_create ppc_elf_link_hash_table_create
8957 #define bfd_elf32_get_synthetic_symtab ppc_elf_get_synthetic_symtab
8959 #define elf_backend_object_p ppc_elf_object_p
8960 #define elf_backend_gc_mark_hook ppc_elf_gc_mark_hook
8961 #define elf_backend_gc_sweep_hook ppc_elf_gc_sweep_hook
8962 #define elf_backend_section_from_shdr ppc_elf_section_from_shdr
8963 #define elf_backend_relocate_section ppc_elf_relocate_section
8964 #define elf_backend_create_dynamic_sections ppc_elf_create_dynamic_sections
8965 #define elf_backend_check_relocs ppc_elf_check_relocs
8966 #define elf_backend_copy_indirect_symbol ppc_elf_copy_indirect_symbol
8967 #define elf_backend_adjust_dynamic_symbol ppc_elf_adjust_dynamic_symbol
8968 #define elf_backend_add_symbol_hook ppc_elf_add_symbol_hook
8969 #define elf_backend_size_dynamic_sections ppc_elf_size_dynamic_sections
8970 #define elf_backend_hash_symbol ppc_elf_hash_symbol
8971 #define elf_backend_finish_dynamic_symbol ppc_elf_finish_dynamic_symbol
8972 #define elf_backend_finish_dynamic_sections ppc_elf_finish_dynamic_sections
8973 #define elf_backend_fake_sections ppc_elf_fake_sections
8974 #define elf_backend_additional_program_headers ppc_elf_additional_program_headers
8975 #define elf_backend_grok_prstatus ppc_elf_grok_prstatus
8976 #define elf_backend_grok_psinfo ppc_elf_grok_psinfo
8977 #define elf_backend_write_core_note ppc_elf_write_core_note
8978 #define elf_backend_reloc_type_class ppc_elf_reloc_type_class
8979 #define elf_backend_begin_write_processing ppc_elf_begin_write_processing
8980 #define elf_backend_final_write_processing ppc_elf_final_write_processing
8981 #define elf_backend_write_section ppc_elf_write_section
8982 #define elf_backend_get_sec_type_attr ppc_elf_get_sec_type_attr
8983 #define elf_backend_plt_sym_val ppc_elf_plt_sym_val
8984 #define elf_backend_action_discarded ppc_elf_action_discarded
8985 #define elf_backend_init_index_section _bfd_elf_init_1_index_section
8986 #define elf_backend_post_process_headers _bfd_elf_set_osabi
8990 /* VxWorks Target */
8992 #undef TARGET_LITTLE_SYM
8993 #undef TARGET_LITTLE_NAME
8995 #undef TARGET_BIG_SYM
8996 #define TARGET_BIG_SYM bfd_elf32_powerpc_vxworks_vec
8997 #undef TARGET_BIG_NAME
9000 /* VxWorks uses the elf default section flags for .plt. */
9003 {
9011 }
9013 /* Like ppc_elf_link_hash_table_create, but overrides
9014 appropriately for VxWorks. */
9017 {
9022 {
9030 }
9032 }
9034 /* Tweak magic VxWorks symbols as they are loaded. */
9035 static bfd_boolean
9043 {
9045 valp))
9049 }
9051 static void
9053 {
9056 }
9058 /* On VxWorks, we emit relocations against _PROCEDURE_LINKAGE_TABLE_, so
9059 define it. */
9060 #undef elf_backend_want_plt_sym
9061 #define elf_backend_want_plt_sym 1
9062 #undef elf_backend_want_got_plt
9063 #define elf_backend_want_got_plt 1
9064 #undef elf_backend_got_symbol_offset
9065 #define elf_backend_got_symbol_offset 0
9066 #undef elf_backend_plt_not_loaded
9067 #define elf_backend_plt_not_loaded 0
9068 #undef elf_backend_plt_readonly
9069 #define elf_backend_plt_readonly 1
9070 #undef elf_backend_got_header_size
9071 #define elf_backend_got_header_size 12
9073 #undef bfd_elf32_get_synthetic_symtab
9075 #undef bfd_elf32_bfd_link_hash_table_create
9076 #define bfd_elf32_bfd_link_hash_table_create \
9077 ppc_elf_vxworks_link_hash_table_create
9078 #undef elf_backend_add_symbol_hook
9079 #define elf_backend_add_symbol_hook \
9080 ppc_elf_vxworks_add_symbol_hook
9081 #undef elf_backend_link_output_symbol_hook
9082 #define elf_backend_link_output_symbol_hook \
9083 elf_vxworks_link_output_symbol_hook
9084 #undef elf_backend_final_write_processing
9085 #define elf_backend_final_write_processing \
9086 ppc_elf_vxworks_final_write_processing
9087 #undef elf_backend_get_sec_type_attr
9088 #define elf_backend_get_sec_type_attr \
9089 ppc_elf_vxworks_get_sec_type_attr
9090 #undef elf_backend_emit_relocs
9091 #define elf_backend_emit_relocs \
9092 elf_vxworks_emit_relocs
9094 #undef elf32_bed
9095 #define elf32_bed ppc_elf_vxworks_bed
9096 #undef elf_backend_post_process_headers