| blob | 95058a233dbbc6acc7891b982c25810985eaf3b2 |
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 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_TDATA)
1801 /* Override the generic function because we store some extras. */
1803 static bfd_boolean
1805 {
1807 PPC32_ELF_TDATA);
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 {
2164 bfd_size_type output_section_size;
2174 /* Scan the input bfds, looking for apuinfo sections. */
2179 {
2182 {
2185 }
2186 }
2188 /* We need at least one input sections
2189 in order to make merging worthwhile. */
2193 /* Just make sure that the output section exists as well. */
2198 /* Allocate a buffer for the contents of the input sections. */
2206 /* Read in the input sections contents. */
2208 {
2218 {
2221 }
2225 {
2228 }
2230 /* Process the contents of the section. */
2234 /* Verify the contents of the header. Note - we have to
2235 extract the values this way in order to allow for a
2236 host whose endian-ness is different from the target. */
2248 /* Get the number of bytes used for apuinfo entries. */
2253 /* Make sure that we do not run off the end of the section. */
2257 /* Scan the apuinfo section, building a list of apuinfo numbers. */
2261 /* Update the offset. */
2263 }
2267 /* Compute the size of the output section. */
2277 fail:
2282 }
2284 /* Prevent the output section from accumulating the input sections'
2285 contents. We have already stored this in our linked list structure. */
2287 static bfd_boolean
2292 {
2295 }
2297 /* Finally we can generate the output section. */
2299 static void
2301 {
2306 bfd_size_type length;
2321 {
2325 }
2327 /* Create the apuinfo header. */
2336 {
2339 }
2350 }
2351 \f
2352 static bfd_boolean
2354 {
2364 }
2366 static bfd_boolean
2368 {
2373 }
2375 static long
2379 {
2384 bfd_vma stub_vma;
2408 /* Call common code to handle old-style executable PLTs. */
2413 /* If this object was prelinked, the prelinker stored the address
2414 of .glink at got[1]. If it wasn't prelinked, got[1] will be zero. */
2417 {
2431 {
2432 Elf_Internal_Dyn dyn;
2439 {
2447 }
2448 }
2450 }
2452 /* Otherwise we read the first plt entry. */
2454 {
2457 }
2462 /* The .glink section usually does not survive the final
2463 link; search for the section (usually .text) where the
2464 glink stubs now reside. */
2469 /* Determine glink PLT resolver by reading the relative branch
2470 from the first glink stub. */
2473 {
2476 /* The first glink stub may either branch to the resolver ... */
2481 /* ... or fall through a bunch of NOPs. */
2488 {
2491 }
2492 }
2496 /* If the stubs are those for -shared/-pie then we might have
2497 multiple stubs for each plt entry. If that is the case then
2498 there is no way to associate stubs with their plt entries short
2499 of figuring out the GOT pointer value used in the stub. */
2511 {
2515 }
2529 {
2533 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL set. Since
2534 we are defining a symbol, ensure one of them is set. */
2546 {
2551 }
2556 }
2558 /* Add a symbol at the start of the glink branch table. */
2567 s++;
2568 count++;
2571 {
2572 /* Add a symbol for the glink PLT resolver. */
2581 s++;
2582 count++;
2583 }
2586 }
2587 \f
2588 /* The following functions are specific to the ELF linker, while
2589 functions above are used generally. They appear in this file more
2590 or less in the order in which they are called. eg.
2591 ppc_elf_check_relocs is called early in the link process,
2592 ppc_elf_finish_dynamic_sections is one of the last functions
2593 called. */
2595 /* The PPC linker needs to keep track of the number of relocs that it
2596 decides to copy as dynamic relocs in check_relocs for each symbol.
2597 This is so that it can later discard them if they are found to be
2598 unnecessary. We store the information in a field extending the
2599 regular ELF linker hash table. */
2601 struct ppc_elf_dyn_relocs
2602 {
2605 /* The input section of the reloc. */
2608 /* Total number of relocs copied for the input section. */
2609 bfd_size_type count;
2611 /* Number of pc-relative relocs copied for the input section. */
2612 bfd_size_type pc_count;
2613 };
2615 /* Track PLT entries needed for a given symbol. We might need more
2616 than one glink entry per symbol when generating a pic binary. */
2617 struct plt_entry
2618 {
2621 /* -fPIC uses multiple GOT sections, one per file, called ".got2".
2622 This field stores the offset into .got2 used to initialise the
2623 GOT pointer reg. It will always be at least 32768. (Current
2624 gcc always uses an offset of 32768, but ld -r will pack .got2
2625 sections together resulting in larger offsets). */
2626 bfd_vma addend;
2628 /* The .got2 section. */
2631 /* PLT refcount or offset. */
2632 union
2633 {
2634 bfd_signed_vma refcount;
2635 bfd_vma offset;
2638 /* .glink stub offset. */
2639 bfd_vma glink_offset;
2640 };
2642 /* Of those relocs that might be copied as dynamic relocs, this function
2643 selects those that must be copied when linking a shared library,
2644 even when the symbol is local. */
2646 static int
2649 {
2651 {
2668 }
2669 }
2671 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
2672 copying dynamic variables from a shared lib into an app's dynbss
2673 section, and instead use a dynamic relocation to point into the
2674 shared lib. */
2675 #define ELIMINATE_COPY_RELOCS 1
2677 /* PPC ELF linker hash entry. */
2679 struct ppc_elf_link_hash_entry
2680 {
2683 /* If this symbol is used in the linker created sections, the processor
2684 specific backend uses this field to map the field into the offset
2685 from the beginning of the section. */
2688 /* Track dynamic relocs copied for this symbol. */
2691 /* Contexts in which symbol is used in the GOT (or TOC).
2692 TLS_GD .. TLS_TLS bits are or'd into the mask as the
2693 corresponding relocs are encountered during check_relocs.
2694 tls_optimize clears TLS_GD .. TLS_TPREL when optimizing to
2695 indicate the corresponding GOT entry type is not needed. */
2705 /* Nonzero if we have seen a small data relocation referring to this
2706 symbol. */
2708 };
2710 #define ppc_elf_hash_entry(ent) ((struct ppc_elf_link_hash_entry *) (ent))
2712 /* PPC ELF linker hash table. */
2714 struct ppc_elf_link_hash_table
2715 {
2718 /* Short-cuts to get to dynamic linker sections. */
2733 /* The (unloaded but important) .rela.plt.unloaded on VxWorks. */
2736 /* The .got.plt section (VxWorks only)*/
2739 /* Shortcut to __tls_get_addr. */
2742 /* The bfd that forced an old-style PLT. */
2745 /* TLS local dynamic got entry handling. */
2747 bfd_signed_vma refcount;
2748 bfd_vma offset;
2751 /* Offset of branch table to PltResolve function in glink. */
2752 bfd_vma glink_pltresolve;
2754 /* Size of reserved GOT entries. */
2756 /* Non-zero if allocating the header left a gap. */
2759 /* The type of PLT we have chosen to use. */
2762 /* Set if we should emit symbols for stubs. */
2765 /* Set if __tls_get_addr optimization should not be done. */
2768 /* True if the target system is VxWorks. */
2771 /* The size of PLT entries. */
2773 /* The distance between adjacent PLT slots. */
2775 /* The size of the first PLT entry. */
2778 /* Small local sym cache. */
2780 };
2782 /* Get the PPC ELF linker hash table from a link_info structure. */
2784 #define ppc_elf_hash_table(p) \
2785 ((struct ppc_elf_link_hash_table *) (p)->hash)
2787 /* Create an entry in a PPC ELF linker hash table. */
2793 {
2794 /* Allocate the structure if it has not already been allocated by a
2795 subclass. */
2797 {
2802 }
2804 /* Call the allocation method of the superclass. */
2807 {
2811 }
2814 }
2816 /* Create a PPC ELF linker hash table. */
2820 {
2828 ppc_elf_link_hash_newfunc,
2830 {
2833 }
2853 }
2855 /* Create .got and the related sections. */
2857 static bfd_boolean
2859 {
2862 flagword flags;
2873 {
2877 }
2878 else
2879 {
2880 /* The powerpc .got has a blrl instruction in it. Mark it
2881 executable. */
2886 }
2893 }
2895 static bfd_boolean
2897 {
2900 flagword flags;
2925 }
2927 /* We have to create .dynsbss and .rela.sbss here so that they get mapped
2928 to output sections (just like _bfd_elf_create_dynamic_sections has
2929 to create .dynbss and .rela.bss). */
2931 static bfd_boolean
2933 {
2936 flagword flags;
2959 {
2968 }
2981 /* The VxWorks PLT is a loaded section with contents. */
2984 }
2986 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2988 static void
2992 {
2999 {
3001 {
3005 /* Add reloc counts against the indirect sym to the direct sym
3006 list. Merge any entries against the same section. */
3008 {
3013 {
3018 }
3021 }
3023 }
3027 }
3032 /* If called to transfer flags for a weakdef during processing
3033 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
3034 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
3046 /* If we were called to copy over info for a weak sym, that's all. */
3050 /* Copy over the GOT refcount entries that we may have already seen to
3051 the symbol which just became indirect. */
3055 /* And plt entries. */
3057 {
3059 {
3064 {
3069 {
3073 }
3076 }
3078 }
3082 }
3085 {
3093 }
3094 }
3096 /* Hook called by the linker routine which adds symbols from an object
3097 file. We use it to put .comm items in .sbss, and not .bss. */
3099 static bfd_boolean
3107 {
3112 {
3113 /* Common symbols less than or equal to -G nn bytes are automatically
3114 put into .sbss. */
3119 {
3127 flags);
3130 }
3134 }
3140 }
3141 \f
3142 static bfd_boolean
3144 {
3156 }
3158 /* Create a special linker section. */
3160 static bfd_boolean
3163 flagword flags,
3165 {
3172 /* Record the first bfd that needs the special sections. */
3178 flags);
3185 }
3187 /* Find a linker generated pointer with a given addend and type. */
3190 elf_find_pointer_linker_section
3192 bfd_vma addend,
3194 {
3200 }
3202 /* Allocate a pointer to live in a linker created section. */
3204 static bfd_boolean
3209 {
3213 bfd_size_type amt;
3217 /* Is this a global symbol? */
3219 {
3222 /* Has this symbol already been allocated? If so, our work is done. */
3226 lsect))
3230 }
3231 else
3232 {
3235 /* Allocation of a pointer to a local symbol. */
3238 /* Allocate a table to hold the local symbols if first time. */
3240 {
3251 }
3253 /* Has this symbol already been allocated? If so, our work is done. */
3256 lsect))
3260 }
3262 /* Allocate space for a pointer in the linker section, and allocate
3263 a new pointer record from internal memory. */
3279 #ifdef DEBUG
3284 #endif
3287 }
3294 {
3300 {
3310 }
3318 }
3320 static bfd_boolean
3323 {
3330 {
3340 }
3343 }
3347 {
3356 }
3358 static bfd_boolean
3360 {
3371 }
3373 static void
3375 {
3378 abfd,
3381 }
3383 /* Look through the relocs for a section during the first phase, and
3384 allocate space in the global offset table or procedure linkage
3385 table. */
3387 static bfd_boolean
3392 {
3404 /* Don't do anything special with non-loaded, non-alloced sections.
3405 In particular, any relocs in such sections should not affect GOT
3406 and PLT reference counting (ie. we don't allow them to create GOT
3407 or PLT entries), there's no possibility or desire to optimize TLS
3408 relocs, and there's not much point in propagating relocs to shared
3409 libs that the dynamic linker won't relocate. */
3413 #ifdef DEBUG
3416 #endif
3420 /* Initialize howto table if not already done. */
3426 {
3431 }
3441 {
3451 else
3452 {
3457 }
3459 /* If a relocation refers to _GLOBAL_OFFSET_TABLE_, create the .got.
3460 This shows up in particular in an R_PPC_ADDR32 in the eabi
3461 startup code. */
3465 {
3471 }
3477 {
3479 {
3482 }
3483 else
3484 {
3493 {
3494 bfd_vma addend;
3497 PLT_IFUNC);
3501 /* STT_GNU_IFUNC symbols must have a PLT entry;
3502 In a non-pie executable even when there are
3503 no plt calls. */
3506 {
3510 }
3514 }
3515 }
3516 }
3522 {
3526 /* We have a new-style __tls_get_addr call with a marker
3527 reloc. */
3528 ;
3529 else
3530 /* Mark this section as having an old-style call. */
3532 }
3535 {
3538 /* These special tls relocs tie a call to __tls_get_addr with
3539 its parameter symbol. */
3570 dogottls:
3572 /* Fall thru */
3574 /* GOT16 relocations */
3579 /* This symbol requires a global offset table entry. */
3581 {
3586 }
3588 {
3591 }
3592 else
3593 /* This is a global offset table entry for a local symbol. */
3597 /* We may also need a plt entry if the symbol turns out to be
3598 an ifunc. */
3600 {
3603 }
3606 /* Indirect .sdata relocation. */
3609 {
3612 }
3621 {
3624 }
3627 /* Indirect .sdata2 relocation. */
3630 {
3633 }
3642 {
3645 }
3653 {
3656 }
3661 {
3664 }
3669 {
3672 }
3678 {
3681 }
3689 {
3692 }
3701 {
3704 }
3712 /* Fall through */
3718 #ifdef DEBUG
3720 #endif
3721 /* This symbol requires a procedure linkage table entry. We
3722 actually build the entry in finish_dynamic_symbol,
3723 because this might be a case of linking PIC code without
3724 linking in any dynamic objects, in which case we don't
3725 need to generate a procedure linkage table after all. */
3728 {
3729 /* It does not make sense to have a procedure linkage
3730 table entry for a local symbol. */
3733 abfd,
3734 sec,
3739 }
3740 else
3741 {
3745 {
3749 }
3754 }
3757 /* The following relocations don't need to propagate the
3758 relocation if linking a shared object since they are
3759 section relative. */
3778 /* These are just markers. */
3789 /* These should only appear in dynamic objects. */
3797 /* These aren't handled yet. We'll report an error later. */
3806 /* This refers only to functions defined in the shared library. */
3809 {
3812 }
3815 /* This relocation describes the C++ object vtable hierarchy.
3816 Reconstruct it for later use during GC. */
3822 /* This relocation describes which C++ vtable entries are actually
3823 used. Record for later use during GC. */
3831 /* We shouldn't really be seeing these. */
3841 /* Nor these. */
3852 {
3853 /* Old -fPIC gcc code has .long LCTOC1-LCFx just before
3854 the start of a function, which assembles to a REL32
3855 reference to .got2. If we detect one of these, then
3856 force the old PLT layout because the linker cannot
3857 reliably deduce the GOT pointer value needed for
3858 PLT call stubs. */
3869 {
3872 }
3873 }
3876 /* fall through */
3886 {
3887 /* We may need a plt entry if the symbol turns out to be
3888 a function defined in a dynamic object. */
3892 /* We may need a copy reloc too. */
3895 }
3905 {
3907 {
3910 }
3912 }
3913 /* fall through */
3920 {
3921 /* We may need a plt entry if the symbol turns out to be
3922 a function defined in a dynamic object. */
3927 }
3929 dodyn:
3930 /* If we are creating a shared library, and this is a reloc
3931 against a global symbol, or a non PC relative reloc
3932 against a local symbol, then we need to copy the reloc
3933 into the shared library. However, if we are linking with
3934 -Bsymbolic, we do not need to copy a reloc against a
3935 global symbol which is defined in an object we are
3936 including in the link (i.e., DEF_REGULAR is set). At
3937 this point we have not seen all the input files, so it is
3938 possible that DEF_REGULAR is not set now but will be set
3939 later (it is never cleared). In case of a weak definition,
3940 DEF_REGULAR may be cleared later by a strong definition in
3941 a shared library. We account for that possibility below by
3942 storing information in the dyn_relocs field of the hash
3943 table entry. A similar situation occurs when creating
3944 shared libraries and symbol visibility changes render the
3945 symbol local.
3947 If on the other hand, we are creating an executable, we
3948 may need to keep relocations for symbols satisfied by a
3949 dynamic library if we manage to avoid copy relocs for the
3950 symbol. */
3957 || (ELIMINATE_COPY_RELOCS
3962 {
3966 #ifdef DEBUG
3968 "ppc_elf_check_relocs needs to "
3972 #endif
3974 {
3978 sreloc = _bfd_elf_make_dynamic_reloc_section
3983 }
3985 /* If this is a global symbol, we count the number of
3986 relocations we need for this symbol. */
3988 {
3990 }
3991 else
3992 {
3993 /* Track dynamic relocs needed for local syms too.
3994 We really need local syms available to do this
3995 easily. Oh well. */
4011 }
4015 {
4024 }
4029 }
4032 }
4033 }
4036 }
4037 \f
4039 /* Merge object attributes from IBFD into OBFD. Raise an error if
4040 there are conflicting attributes. */
4041 static bfd_boolean
4043 {
4048 {
4049 /* This is the first object. Copy the attributes. */
4052 /* Use the Tag_null value to indicate the attributes have been
4053 initialized. */
4057 }
4062 /* Check for conflicting Tag_GNU_Power_ABI_FP attributes and merge
4063 non-conflicting ones. */
4067 {
4072 ;
4074 _bfd_error_handler
4077 _bfd_error_handler
4081 _bfd_error_handler
4085 _bfd_error_handler
4089 _bfd_error_handler
4092 _bfd_error_handler
4095 else
4096 _bfd_error_handler
4099 }
4101 /* Check for conflicting Tag_GNU_Power_ABI_Vector attributes and
4102 merge non-conflicting ones. */
4106 {
4110 {
4114 }
4117 {
4121 }
4127 ;
4128 /* For now, allow generic to transition to AltiVec or SPE
4129 without a warning. If GCC marked files with their stack
4130 alignment and used don't-care markings for files which are
4131 not affected by the vector ABI, we could warn about this
4132 case too. */
4136 ;
4138 _bfd_error_handler
4142 _bfd_error_handler
4145 else
4146 _bfd_error_handler
4149 }
4151 /* Check for conflicting Tag_GNU_Power_ABI_Struct_Return attributes
4152 and merge non-conflicting ones. */
4156 {
4161 ;
4163 _bfd_error_handler
4166 _bfd_error_handler
4169 _bfd_error_handler
4172 else
4173 _bfd_error_handler
4176 }
4178 /* Merge Tag_compatibility attributes and any common GNU ones. */
4182 }
4184 /* Merge backend specific data from an object file to the output
4185 object file when linking. */
4187 static bfd_boolean
4189 {
4190 flagword old_flags;
4191 flagword new_flags;
4192 bfd_boolean error;
4197 /* Check if we have the same endianess. */
4207 {
4208 /* First call, no flags set. */
4211 }
4213 /* Compatible flags are ok. */
4215 ;
4217 /* Incompatible flags. */
4218 else
4219 {
4220 /* Warn about -mrelocatable mismatch. Allow -mrelocatable-lib
4221 to be linked with either. */
4225 {
4230 }
4233 {
4238 }
4240 /* The output is -mrelocatable-lib iff both the input files are. */
4244 /* The output is -mrelocatable iff it can't be -mrelocatable-lib,
4245 but each input file is either -mrelocatable or -mrelocatable-lib. */
4251 /* Do not warn about eabi vs. V.4 mismatch, just or in the bit if
4252 any module uses it. */
4258 /* Warn about any other mismatches. */
4260 {
4266 }
4269 {
4272 }
4273 }
4276 }
4277 \f
4278 /* Choose which PLT scheme to use, and set .plt flags appropriately.
4279 Returns -1 on error, 0 for old PLT, 1 for new PLT. */
4280 int
4285 {
4287 flagword flags;
4294 {
4297 else
4298 {
4302 /* Look through the reloc flags left by ppc_elf_check_relocs.
4303 Use the old style bss plt if a file makes plt calls
4304 without using the new relocs, and if ld isn't given
4305 --secure-plt and we never see REL16 relocs. */
4310 {
4314 {
4318 }
4319 }
4321 }
4322 }
4329 {
4333 /* The new PLT is a loaded section. */
4338 /* The new GOT is not executable. */
4342 }
4343 else
4344 {
4345 /* Stop an unused .glink section from affecting .text alignment. */
4349 }
4351 }
4352 \f
4353 /* Return the section that should be marked against GC for a given
4354 relocation. */
4362 {
4365 {
4369 }
4372 }
4374 /* Update the got, plt and dynamic reloc reference counts for the
4375 section being removed. */
4377 static bfd_boolean
4382 {
4406 {
4413 {
4425 {
4426 /* Everything must go for SEC. */
4429 }
4430 }
4438 {
4444 {
4455 }
4456 }
4459 {
4481 {
4485 {
4491 }
4492 }
4494 {
4497 }
4507 /* Fall thru */
4530 {
4539 }
4544 }
4545 }
4547 }
4548 \f
4549 /* Set plt output section type, htab->tls_get_addr, and call the
4550 generic ELF tls_setup function. */
4552 asection *
4556 {
4563 {
4570 {
4571 /* If glibc supports an optimized __tls_get_addr call stub,
4572 signalled by the presence of __tls_get_addr_opt, and we'll
4573 be calling __tls_get_addr via a plt call stub, then
4574 make __tls_get_addr point to __tls_get_addr_opt. */
4583 {
4588 {
4593 {
4594 /* Use __tls_get_addr_opt in dynamic relocations. */
4600 }
4602 }
4603 }
4604 }
4605 else
4607 }
4612 {
4615 }
4618 }
4620 /* Return TRUE iff REL is a branch reloc with a global symbol matching
4621 HASH. */
4623 static bfd_boolean
4627 {
4633 {
4643 }
4645 }
4647 /* Run through all the TLS relocs looking for optimization
4648 opportunities. */
4650 bfd_boolean
4653 {
4663 /* Make two passes through the relocs. First time check that tls
4664 relocs involved in setting up a tls_get_addr call are indeed
4665 followed by such a call. If they are not, exclude them from
4666 the optimizations done on the second pass. */
4669 {
4675 {
4678 /* Read the relocations. */
4686 {
4692 bfd_boolean is_local;
4698 {
4706 }
4716 {
4720 /* Fall thru */
4724 /* These relocs should never be against a symbol
4725 defined in a shared lib. Leave them alone if
4726 that turns out to be the case. */
4730 /* LD -> LE */
4738 /* Fall thru */
4743 /* GD -> LE */
4745 else
4746 /* GD -> IE */
4756 {
4757 /* IE -> LE */
4761 }
4762 else
4767 }
4770 {
4780 /* Uh oh, we didn't find the expected call. We
4781 could just mark this symbol to exclude it
4782 from tls optimization but it's safer to skip
4783 the entire section. */
4786 }
4789 {
4792 }
4793 else
4794 {
4801 {
4808 {
4812 }
4813 }
4823 }
4826 {
4827 /* We managed to get rid of a got entry. */
4830 }
4833 {
4840 }
4844 }
4848 }
4852 {
4855 else
4857 }
4858 }
4860 }
4861 \f
4862 /* Return true if we have dynamic relocs that apply to read-only sections. */
4864 static bfd_boolean
4866 {
4870 {
4877 }
4879 }
4881 /* Adjust a symbol defined by a dynamic object and referenced by a
4882 regular object. The current definition is in some section of the
4883 dynamic object, but we're not including those sections. We have to
4884 change the definition to something the rest of the link can
4885 understand. */
4887 static bfd_boolean
4890 {
4894 #ifdef DEBUG
4897 #endif
4899 /* Make sure we know what is going on here. */
4909 /* Deal with function syms. */
4913 {
4914 /* Clear procedure linkage table information for any symbol that
4915 won't need a .plt entry. */
4925 {
4926 /* A PLT entry is not required/allowed when:
4928 1. We are not using ld.so; because then the PLT entry
4929 can't be set up, so we can't use one. In this case,
4930 ppc_elf_adjust_dynamic_symbol won't even be called.
4932 2. GC has rendered the entry unused.
4934 3. We know for certain that a call to this symbol
4935 will go to this object, or will remain undefined. */
4938 }
4939 else
4940 {
4941 /* After adjust_dynamic_symbol, non_got_ref set in the
4942 non-shared case means that we have allocated space in
4943 .dynbss for the symbol and thus dyn_relocs for this
4944 symbol should be discarded.
4945 If we get here we know we are making a PLT entry for this
4946 symbol, and in an executable we'd normally resolve
4947 relocations against this symbol to the PLT entry. Allow
4948 dynamic relocs if the reference is weak, and the dynamic
4949 relocs will not cause text relocation. */
4957 }
4959 }
4960 else
4963 /* If this is a weak symbol, and there is a real definition, the
4964 processor independent code will have arranged for us to see the
4965 real definition first, and we can just use the same value. */
4967 {
4975 }
4977 /* This is a reference to a symbol defined by a dynamic object which
4978 is not a function. */
4980 /* If we are creating a shared library, we must presume that the
4981 only references to the symbol are via the global offset table.
4982 For such cases we need not do anything here; the relocations will
4983 be handled correctly by relocate_section. */
4987 /* If there are no references to this symbol that do not use the
4988 GOT, we don't need to generate a copy reloc. */
4992 /* If we didn't find any dynamic relocs in read-only sections, then
4993 we'll be keeping the dynamic relocs and avoiding the copy reloc.
4994 We can't do this if there are any small data relocations. This
4995 doesn't work on VxWorks, where we can not have dynamic
4996 relocations (other than copy and jump slot relocations) in an
4997 executable. */
5003 {
5006 }
5009 {
5013 }
5015 /* We must allocate the symbol in our .dynbss section, which will
5016 become part of the .bss section of the executable. There will be
5017 an entry for this symbol in the .dynsym section. The dynamic
5018 object will contain position independent code, so all references
5019 from the dynamic object to this symbol will go through the global
5020 offset table. The dynamic linker will use the .dynsym entry to
5021 determine the address it must put in the global offset table, so
5022 both the dynamic object and the regular object will refer to the
5023 same memory location for the variable.
5025 Of course, if the symbol is referenced using SDAREL relocs, we
5026 must instead allocate it in .sbss. */
5030 else
5034 /* We must generate a R_PPC_COPY reloc to tell the dynamic linker to
5035 copy the initial value out of the dynamic object and into the
5036 runtime process image. We need to remember the offset into the
5037 .rela.bss section we are going to use. */
5039 {
5044 else
5049 }
5052 }
5053 \f
5054 /* Generate a symbol to mark plt call stubs. For non-PIC code the sym is
5055 xxxxxxxx.plt_call32.<callee> where xxxxxxxx is a hex number, usually 0,
5056 specifying the addend on the plt relocation. For -fpic code, the sym
5057 is xxxxxxxx.plt_pic32.<callee>, and for -fPIC
5058 xxxxxxxx.got2.plt_pic32.<callee>. */
5060 static bfd_boolean
5064 {
5073 else
5093 {
5102 }
5104 }
5106 /* Allocate NEED contiguous space in .got, and return the offset.
5107 Handles allocation of the got header when crossing 32k. */
5109 static bfd_vma
5111 {
5112 bfd_vma where;
5116 {
5119 }
5120 else
5121 {
5124 {
5127 }
5128 else
5129 {
5132 {
5135 }
5138 }
5139 }
5141 }
5143 /* Allocate space in associated reloc sections for dynamic relocs. */
5145 static bfd_boolean
5147 {
5157 /* When warning symbols are created, they **replace** the "real"
5158 entry in the hash table, thus we never get to see the real
5159 symbol in a hash traversal. So look at it now. */
5165 {
5169 bfd_boolean dyn;
5173 {
5174 /* Make sure this symbol is output as a dynamic symbol. */
5179 {
5182 }
5188 {
5194 {
5196 {
5199 }
5204 {
5210 }
5215 {
5218 }
5224 }
5225 else
5226 {
5228 {
5229 /* If this is the first .plt entry, make room
5230 for the special first entry. */
5234 /* The PowerPC PLT is actually composed of two
5235 parts, the first part is 2 words (for a load
5236 and a jump), and then there is a remaining
5237 word available at the end. */
5244 /* If this symbol is not defined in a regular
5245 file, and we are not generating a shared
5246 library, then set the symbol to this location
5247 in the .plt. This is to avoid text
5248 relocations, and is required to make
5249 function pointers compare as equal between
5250 the normal executable and the shared library. */
5254 {
5257 }
5259 /* Make room for this entry. */
5261 /* After the 8192nd entry, room for two entries
5262 is allocated. */
5268 }
5270 }
5272 /* We also need to make an entry in the .rela.plt section. */
5274 {
5278 else
5279 {
5283 {
5284 /* Allocate space for the unloaded relocations. */
5287 {
5290 {
5294 }
5299 }
5301 /* Every PLT entry has an associated GOT entry in
5302 .got.plt. */
5304 }
5305 }
5307 }
5308 }
5309 else
5311 }
5312 else
5316 {
5319 }
5320 }
5321 else
5322 {
5325 }
5329 {
5330 bfd_boolean dyn;
5333 /* Make sure this symbol is output as a dynamic symbol. */
5338 {
5341 }
5345 {
5347 {
5349 /* We'll just use htab->tlsld_got.offset. This should
5350 always be the case. It's a little odd if we have
5351 a local dynamic reloc against a non-local symbol. */
5353 else
5355 }
5362 }
5363 else
5367 else
5368 {
5375 {
5377 /* All the entries we allocated need relocs.
5378 Except LD only needs one. */
5383 }
5384 }
5385 }
5386 else
5393 /* In the shared -Bsymbolic case, discard space allocated for
5394 dynamic pc-relative relocs against symbols which turn out to be
5395 defined in regular objects. For the normal shared case, discard
5396 space for relocs that have become local due to symbol visibility
5397 changes. */
5400 {
5401 /* Relocs that use pc_count are those that appear on a call insn,
5402 or certain REL relocs (see must_be_dyn_reloc) that can be
5403 generated via assembly. We want calls to protected symbols to
5404 resolve directly to the function rather than going via the plt.
5405 If people want function pointer comparisons to work as expected
5406 then they should avoid writing weird assembly. */
5408 {
5412 {
5417 else
5419 }
5420 }
5423 {
5427 {
5430 else
5432 }
5433 }
5435 /* Discard relocs on undefined symbols that must be local. */
5442 /* Also discard relocs on undefined weak syms with non-default
5443 visibility. */
5446 {
5450 /* Make sure undefined weak symbols are output as a dynamic
5451 symbol in PIEs. */
5455 {
5458 }
5459 }
5460 }
5462 {
5463 /* For the non-shared case, discard space for relocs against
5464 symbols which turn out to need copy relocs or are not
5465 dynamic. */
5469 {
5470 /* Make sure this symbol is output as a dynamic symbol.
5471 Undefined weak syms won't yet be marked as dynamic. */
5474 {
5477 }
5479 /* If that succeeded, we know we'll be keeping all the
5480 relocs. */
5483 }
5487 keep: ;
5488 }
5490 /* Finally, allocate space. */
5492 {
5497 }
5500 }
5502 /* Set DF_TEXTREL if we find any dynamic relocs that apply to
5503 read-only sections. */
5505 static bfd_boolean
5507 {
5515 {
5518 /* Not an error, just cut short the traversal. */
5520 }
5522 }
5524 /* Set the sizes of the dynamic sections. */
5526 static bfd_boolean
5529 {
5532 bfd_boolean relocs;
5535 #ifdef DEBUG
5537 #endif
5543 {
5544 /* Set the contents of the .interp section to the interpreter. */
5546 {
5551 }
5552 }
5559 /* Set up .got offsets for local syms, and space for local dynamic
5560 relocs. */
5562 {
5568 bfd_size_type locsymcount;
5575 {
5582 {
5585 {
5586 /* Input section has been discarded, either because
5587 it is a copy of a linkonce section or due to
5588 linker script /DISCARD/, so we'll be discarding
5589 the relocs too. */
5590 }
5594 {
5595 /* Relocations in vxworks .tls_vars sections are
5596 handled specially by the loader. */
5597 }
5599 {
5608 }
5609 }
5610 }
5624 {
5627 {
5636 }
5637 else
5641 else
5642 {
5647 }
5648 }
5649 else
5655 /* Allocate space for calls to local STT_GNU_IFUNC syms in .iplt. */
5657 {
5664 {
5668 {
5671 }
5676 {
5679 }
5683 {
5686 }
5687 }
5688 else
5690 }
5691 }
5693 /* Allocate space for global sym dynamic relocs. */
5697 {
5701 }
5702 else
5706 {
5709 /* If we haven't allocated the header, do so now. When we get here,
5710 for old plt/got the got size will be 0 to 32764 (not allocated),
5711 or 32780 to 65536 (header allocated). For new plt/got, the
5712 corresponding ranges are 0 to 32768 and 32780 to 65536. */
5714 {
5719 }
5722 }
5724 {
5729 {
5733 }
5734 }
5739 {
5741 /* Space for the branch table. */
5743 /* Pad out to align the start of PLTresolve. */
5748 {
5755 {
5764 }
5770 {
5779 }
5780 }
5781 }
5783 /* We've now determined the sizes of the various dynamic sections.
5784 Allocate memory for them. */
5787 {
5795 {
5796 /* We'd like to strip these sections if they aren't needed, but if
5797 we've exported dynamic symbols from them we must leave them.
5798 It's too late to tell BFD to get rid of the symbols. */
5801 /* Strip this section if we don't need it; see the
5802 comment below. */
5803 }
5812 {
5813 /* Strip these too. */
5814 }
5816 {
5818 {
5819 /* Remember whether there are any relocation sections. */
5822 /* We use the reloc_count field as a counter if we need
5823 to copy relocs into the output file. */
5825 }
5826 }
5827 else
5828 {
5829 /* It's not one of our sections, so don't allocate space. */
5831 }
5834 {
5835 /* If we don't need this section, strip it from the
5836 output file. This is mostly to handle .rela.bss and
5837 .rela.plt. We must create both sections in
5838 create_dynamic_sections, because they must be created
5839 before the linker maps input sections to output
5840 sections. The linker does that before
5841 adjust_dynamic_symbol is called, and it is that
5842 function which decides whether anything needs to go
5843 into these sections. */
5846 }
5851 /* Allocate memory for the section contents. */
5855 }
5858 {
5859 /* Add some entries to the .dynamic section. We fill in the
5860 values later, in ppc_elf_finish_dynamic_sections, but we
5861 must add the entries now so that we get the correct size for
5862 the .dynamic section. The DT_DEBUG entry is filled in by the
5863 dynamic linker and used by the debugger. */
5864 #define add_dynamic_entry(TAG, VAL) \
5865 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
5868 {
5871 }
5874 {
5880 }
5883 {
5891 }
5894 {
5899 }
5901 /* If any dynamic relocs apply to a read-only section, then we
5902 need a DT_TEXTREL entry. */
5905 info);
5908 {
5911 }
5915 }
5916 #undef add_dynamic_entry
5919 }
5921 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
5923 static bfd_boolean
5925 {
5933 }
5934 \f
5935 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
5937 /* Relaxation trampolines. r12 is available for clobbering (r11, is
5938 used for some functions that are allowed to break the ABI). */
5940 {
5949 };
5952 {
5957 };
5959 static bfd_boolean
5964 {
5965 struct one_fixup
5966 {
5969 /* Final link, can use the symbol offset. For a
5970 relocatable link we use the symbol's index. */
5971 bfd_vma toff;
5972 bfd_vma trampoff;
5973 };
5983 bfd_size_type trampoff;
5988 /* Nothing to do if there are no relocations, and no need to do
5989 anything with non-alloc or non-code sections. */
5996 /* We cannot represent the required PIC relocs in the output, so don't
5997 do anything. The linker doesn't support mixing -shared and -r
5998 anyway. */
6003 /* Space for a branch around any trampolines. */
6008 /* Get a copy of the native relocations. */
6019 {
6033 {
6048 }
6050 /* Get the value of the symbol referred to by the reloc. */
6053 {
6054 /* A local symbol. */
6057 /* Read this BFD's local symbols. */
6059 {
6067 }
6075 else
6080 }
6081 else
6082 {
6083 /* Global symbol handling. */
6095 {
6098 }
6101 {
6104 }
6105 else
6109 }
6111 /* The condition here under which we call find_plt_ent must
6112 match that in relocate_section. If we call find_plt_ent here
6113 but not in relocate_section, or vice versa, then the branch
6114 destination used here may be incorrect. */
6117 {
6118 /* We know is_branch_reloc (r_type) is true. */
6122 }
6125 {
6130 }
6132 {
6140 {
6145 {
6148 }
6149 else
6150 {
6153 }
6154 }
6155 }
6157 /* If the branch and target are in the same section, you have
6158 no hope of adding stubs. We'll error out later should the
6159 branch overflow. */
6163 /* There probably isn't any reason to handle symbols in
6164 SEC_MERGE sections; SEC_MERGE doesn't seem a likely
6165 attribute for a code section, and we are only looking at
6166 branches. However, implement it correctly here as a
6167 reference for other target relax_section functions. */
6169 {
6170 /* At this stage in linking, no SEC_MERGE symbol has been
6171 adjusted, so all references to such symbols need to be
6172 passed through _bfd_merged_section_offset. (Later, in
6173 relocate_section, all SEC_MERGE symbols *except* for
6174 section symbols have been adjusted.)
6176 gas may reduce relocations against symbols in SEC_MERGE
6177 sections to a relocation against the section symbol when
6178 the original addend was zero. When the reloc is against
6179 a section symbol we should include the addend in the
6180 offset passed to _bfd_merged_section_offset, since the
6181 location of interest is the original symbol. On the
6182 other hand, an access to "sym+addend" where "sym" is not
6183 a section symbol should not include the addend; Such an
6184 access is presumed to be an offset from "sym"; The
6185 location of interest is just "sym". */
6191 toff);
6195 }
6196 /* PLTREL24 addends are special. */
6200 /* Attempted -shared link of non-pic code loses. */
6207 /* If the branch is in range, no need to do anything. */
6210 /* A relocatable link may have sections moved during
6211 final link, so do not presume they remain in range. */
6213 {
6220 }
6222 /* Look for an existing fixup to this address. */
6228 {
6234 /* Oh dear, we can't reach a trampoline. Don't try to add
6235 one. We'll report an error later. */
6239 {
6243 }
6244 else
6245 {
6249 }
6258 /* Hijack the old relocation. Since we need two
6259 relocations for this use a "composite" reloc. */
6261 stub_rtype);
6266 /* Record the fixup so we don't do it again this section. */
6275 changes++;
6276 }
6277 else
6278 {
6283 /* Nop out the reloc, since we're finalizing things here. */
6285 }
6287 /* Get the section contents. */
6289 {
6290 /* Get cached copy if it exists. */
6293 else
6294 {
6295 /* Go get them off disk. */
6298 }
6299 }
6301 /* Fix up the existing branch to hit the trampoline. */
6304 {
6322 }
6323 }
6325 /* Write out the trampolines. */
6327 {
6330 bfd_vma val;
6333 do
6334 {
6338 }
6346 /* Branch around the trampolines. */
6354 {
6357 }
6358 else
6359 {
6362 }
6366 {
6368 i++;
6372 }
6374 }
6378 {
6381 else
6382 {
6383 /* Cache the symbols for elf_link_input_bfd. */
6385 }
6386 }
6390 {
6393 else
6394 {
6395 /* Cache the section contents for elf_link_input_bfd. */
6397 }
6398 }
6401 {
6402 /* Append sufficient NOP relocs so we can write out relocation
6403 information for the trampolines. */
6413 {
6417 }
6424 }
6430 {
6431 /* Convert the internal relax relocs to external form. */
6434 {
6437 /* Rewrite the reloc and convert one of the trailing nop
6438 relocs to describe this relocation. */
6440 /* The relocs are at the bottom 2 bytes */
6446 irel++;
6447 }
6448 }
6452 error_return:
6462 }
6463 \f
6464 /* What to do when ld finds relocations against symbols defined in
6465 discarded sections. */
6467 static unsigned int
6469 {
6477 }
6478 \f
6479 /* Fill in the address for a pointer generated in a linker section. */
6481 static bfd_vma
6485 bfd_vma relocation,
6487 {
6493 {
6494 /* Handle global symbol. */
6500 }
6501 else
6502 {
6503 /* Handle local symbol. */
6509 }
6513 lsect);
6516 /* Offset will always be a multiple of four, so use the bottom bit
6517 as a "written" flag. */
6519 {
6524 }
6531 #ifdef DEBUG
6535 #endif
6538 }
6540 #define PPC_LO(v) ((v) & 0xffff)
6541 #define PPC_HI(v) (((v) >> 16) & 0xffff)
6542 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
6544 static void
6547 {
6550 bfd_vma plt;
6557 {
6570 {
6579 }
6580 else
6581 {
6590 }
6591 }
6592 else
6593 {
6602 }
6603 }
6605 /* Return true if symbol is defined statically. */
6607 static bfd_boolean
6609 {
6614 }
6616 /* The RELOCATE_SECTION function is called by the ELF backend linker
6617 to handle the relocations for a section.
6619 The relocs are always passed as Rela structures; if the section
6620 actually uses Rel structures, the r_addend field will always be
6621 zero.
6623 This function is responsible for adjust the section contents as
6624 necessary, and (if using Rela relocs and generating a
6625 relocatable output file) adjusting the reloc addend as
6626 necessary.
6628 This function does not have to worry about setting the reloc
6629 address or the reloc symbol index.
6631 LOCAL_SYMS is a pointer to the swapped in local symbols.
6633 LOCAL_SECTIONS is an array giving the section in the input file
6634 corresponding to the st_shndx field of each local symbol.
6636 The global hash table entry for the global symbols can be found
6637 via elf_sym_hashes (input_bfd).
6639 When generating relocatable output, this function must handle
6640 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
6641 going to be the section symbol corresponding to the output
6642 section, which means that the addend must be adjusted
6643 accordingly. */
6645 static bfd_boolean
6654 {
6660 Elf_Internal_Rela outrel;
6666 bfd_boolean is_vxworks_tls;
6668 #ifdef DEBUG
6674 #endif
6678 /* Initialize howto table if not already done. */
6686 /* We have to handle relocations in vxworks .tls_vars sections
6687 specially, because the dynamic loader is 'weird'. */
6694 {
6696 bfd_vma addend;
6697 bfd_reloc_status_type r;
6704 bfd_vma relocation;
6706 bfd_boolean unresolved_reloc;
6707 bfd_boolean warned;
6720 {
6726 }
6727 else
6728 {
6735 }
6738 {
6739 /* For relocs against symbols from removed linkonce sections,
6740 or sections discarded by a linker script, we just want the
6741 section contents zeroed. Avoid any special processing. */
6749 }
6752 {
6756 {
6757 /* R_PPC_PLTREL24 is rather special. If non-zero, the
6758 addend specifies the GOT pointer offset within .got2. */
6760 }
6762 }
6764 /* TLS optimizations. Replace instruction sequences and relocs
6765 based on information we collected in tls_optimize. We edit
6766 RELOCS so that --emit-relocs will output something sensible
6767 for the final instruction stream. */
6773 {
6776 local_plt
6780 }
6782 /* Ensure reloc mapping code below stays sane. */
6793 {
6801 {
6802 bfd_vma insn;
6809 }
6815 {
6824 else
6827 /* add -> addi. */
6833 /* load and store indexed -> dform. */
6837 /* ldx, ldux, stdx, stdux -> ld, ldu, std, stdu. */
6842 /* lwax -> lwa. */
6844 else
6851 /* Was PPC_TLS which sits on insn boundary, now
6852 PPC_TPREL16_LO which is at low-order half-word. */
6854 }
6867 {
6868 tls_gdld_hi:
6872 else
6873 {
6877 }
6879 }
6892 {
6894 bfd_vma offset;
6896 tls_ldgd_opt:
6898 /* If not using the newer R_PPC_TLSGD/LD to mark
6899 __tls_get_addr calls, we must trust that the call
6900 stays with its arg setup insns, ie. that the next
6901 reloc is the __tls_get_addr call associated with
6902 the current reloc. Edit both insns. */
6909 {
6910 /* IE */
6916 {
6919 R_PPC_NONE);
6922 }
6926 }
6927 else
6928 {
6929 /* LE */
6932 {
6933 /* Was an LD reloc. */
6936 r_symndx++)
6946 }
6950 {
6956 }
6957 }
6961 {
6962 /* We changed the symbol on an LD reloc. Start over
6963 in order to get h, sym, sec etc. right. */
6964 rel--;
6966 }
6967 }
6972 {
6977 {
6978 /* IE */
6981 }
6982 else
6983 {
6984 /* LE */
6988 }
6991 /* Zap the reloc on the _tls_get_addr call too. */
6994 R_PPC_NONE);
6995 }
7000 {
7005 r_symndx++)
7021 /* Zap the reloc on the _tls_get_addr call too. */
7024 R_PPC_NONE);
7025 rel--;
7027 }
7029 }
7031 /* Handle other relocations that tweak non-addend part of insn. */
7034 {
7038 /* Branch taken prediction relocations. */
7042 /* Fall thru */
7044 /* Branch not taken prediction relocations. */
7055 /* Invert 'y' bit if not the default. */
7061 }
7065 {
7069 {
7072 }
7075 {
7081 }
7087 {
7092 }
7094 {
7096 {
7097 Elf_Internal_Rela rela;
7111 }
7113 {
7118 }
7127 else
7131 }
7132 }
7140 {
7159 /* GOT16 relocations. Like an ADDR16 using the symbol's
7160 address in the GOT as relocation value instead of the
7161 symbol's value itself. Also, create a GOT entry for the
7162 symbol and put the symbol value there. */
7196 dogot:
7197 {
7198 /* Relocation is to the entry for this symbol in the global
7199 offset table. */
7200 bfd_vma off;
7213 {
7214 bfd_boolean dyn;
7219 /* This is actually a static link, or it is a
7220 -Bsymbolic link and the symbol is defined
7221 locally, or the symbol was forced to be local
7222 because of a version file. */
7223 ;
7224 else
7225 {
7228 }
7230 }
7231 else
7232 {
7236 }
7238 /* The offset must always be a multiple of 4. We use the
7239 least significant bit to record whether we have already
7240 processed this entry. */
7244 else
7245 {
7256 /* We might have multiple got entries for this sym.
7257 Initialize them all. */
7258 do
7259 {
7263 {
7266 }
7268 {
7271 }
7273 {
7276 }
7278 {
7281 }
7283 /* Generate relocs for the dynamic linker. */
7289 {
7297 {
7300 {
7307 outrel.r_info
7309 }
7310 }
7319 else
7322 {
7326 }
7331 }
7333 /* Init the .got section contents if we're not
7334 emitting a reloc. */
7335 else
7336 {
7342 {
7348 {
7352 }
7353 }
7356 }
7361 }
7366 }
7372 {
7374 {
7380 {
7384 {
7387 }
7388 }
7389 }
7390 }
7394 + off
7397 /* Addends on got relocations don't make much sense.
7398 x+off@got is actually x@got+off, and since the got is
7399 generated by a hash table traversal, the value in the
7400 got at entry m+n bears little relation to the entry m. */
7404 input_bfd,
7405 input_section,
7408 sym_name);
7409 }
7412 /* Relocations that need no special processing. */
7414 /* It makes no sense to point a local relocation
7415 at a symbol not in this object. */
7417 {
7420 input_bfd,
7421 input_section,
7423 TRUE))
7426 }
7436 /* Relocations that may need to be propagated if this is a shared
7437 object. */
7443 /* The TPREL16 relocs shouldn't really be used in shared
7444 libs as they will result in DT_TEXTREL being set, but
7445 support them anyway. */
7470 /* fall through */
7485 /* If these relocations are not to a named symbol, they can be
7486 handled right here, no need to bother the dynamic linker. */
7490 /* fall through */
7498 /* fall through */
7500 dodyn:
7514 || (ELIMINATE_COPY_RELOCS
7520 {
7523 #ifdef DEBUG
7528 #endif
7530 /* When generating a shared object, these relocations
7531 are copied into the output file to be resolved at run
7532 time. */
7534 {
7540 }
7558 {
7562 }
7563 else
7564 {
7568 {
7572 {
7573 /* If we get here when building a static
7574 executable, then the libc startup function
7575 responsible for applying indirect function
7576 relocations is going to complain about
7577 the reloc type.
7578 If we get here when building a dynamic
7579 executable, it will be because we have
7580 a text relocation. The dynamic loader
7581 will set the text segment writable and
7582 non-executable to apply text relocations.
7583 So we'll segfault when trying to run the
7584 indirection function to resolve the reloc. */
7588 input_bfd,
7589 input_section,
7592 sym_name);
7594 }
7596 ;
7598 {
7601 }
7602 else
7603 {
7606 /* We are turning this relocation into one
7607 against a section symbol. It would be
7608 proper to subtract the symbol's value,
7609 osec->vma, from the emitted reloc addend,
7610 but ld.so expects buggy relocs.
7611 FIXME: Why not always use a zero index? */
7615 {
7618 }
7620 #ifdef DEBUG
7625 #endif
7626 }
7629 }
7632 else
7634 }
7643 /* This reloc will be computed at runtime. We clear the memory
7644 so that it contains predictable value. */
7648 {
7652 }
7653 }
7659 {
7666 else
7670 }
7673 /* Fall thru */
7679 /* Fall thru */
7682 relax32:
7683 {
7690 /* We're clearing the bits for R_PPC_ADDR16_HA
7691 and R_PPC_ADDR16_LO here. */
7695 /* t0 is HA, t1 is LO */
7703 /* Rewrite the reloc and convert one of the trailing nop
7704 relocs to describe this relocation. */
7706 /* The relocs are at the bottom 2 bytes */
7712 rel++;
7713 }
7716 /* Indirect .sdata relocation. */
7720 {
7723 }
7724 relocation
7730 /* Indirect .sdata2 relocation. */
7734 {
7737 }
7738 relocation
7744 /* Handle the TOC16 reloc. We want to use the offset within the .got
7745 section, not the actual VMA. This is appropriate when generating
7746 an embedded ELF object, for which the .got section acts like the
7747 AIX .toc section. */
7750 {
7753 }
7763 /* Relocation is to the entry for this symbol in the
7764 procedure linkage table. */
7765 {
7771 {
7772 /* We didn't make a PLT entry for this symbol. This
7773 happens when statically linking PIC code, or when
7774 using -Bsymbolic. */
7776 }
7783 else
7787 }
7790 /* Relocate against _SDA_BASE_. */
7792 {
7799 {
7802 }
7810 {
7814 input_bfd,
7815 sym_name,
7817 name);
7818 }
7819 }
7822 /* Relocate against _SDA2_BASE_. */
7824 {
7831 {
7834 }
7840 {
7844 input_bfd,
7845 sym_name,
7847 name);
7848 }
7849 }
7852 /* Relocate against either _SDA_BASE_, _SDA2_BASE_, or 0. */
7855 {
7861 {
7864 }
7871 {
7874 }
7877 {
7880 }
7883 {
7885 }
7886 else
7887 {
7891 input_bfd,
7892 sym_name,
7894 name);
7899 }
7902 {
7904 {
7907 }
7909 }
7916 }
7917 }
7920 /* Relocate against the beginning of the section. */
7926 {
7929 }
7933 /* Negative relocations. */
7960 input_bfd,
7962 sym_name);
7967 }
7969 /* Do any further special processing. */
7971 {
7982 /* It's just possible that this symbol is a weak symbol
7983 that's not actually defined anywhere. In that case,
7984 'sec' would be NULL, and we should leave the symbol
7985 alone (it will be set to zero elsewhere in the link). */
7988 /* Fall thru */
7996 /* Add 0x10000 if sign bit in 0:15 is set.
7997 Bits 0:15 are not used. */
8000 }
8002 #ifdef DEBUG
8007 sym_name,
8008 r_symndx,
8011 #endif
8016 {
8019 input_bfd,
8020 input_section,
8023 sym_name);
8025 }
8028 input_bfd,
8029 input_section,
8030 contents,
8032 relocation,
8033 addend);
8036 {
8038 {
8044 {
8045 /* Assume this is a call protected by other code that
8046 detect the symbol is undefined. If this is the case,
8047 we can safely ignore the overflow. If not, the
8048 program is hosed anyway, and a little warning isn't
8049 going to help. */
8052 }
8056 sym_name,
8059 input_bfd,
8060 input_section,
8063 }
8064 else
8065 {
8071 }
8072 }
8073 }
8075 #ifdef DEBUG
8077 #endif
8080 }
8081 \f
8082 /* Finish up dynamic symbol handling. We set the contents of various
8083 dynamic sections here. */
8085 static bfd_boolean
8090 {
8093 bfd_boolean doneone;
8095 #ifdef DEBUG
8098 #endif
8106 {
8108 {
8109 Elf_Internal_Rela rela;
8111 bfd_vma reloc_index;
8117 else
8118 {
8124 }
8126 /* This symbol has an entry in the procedure linkage table.
8127 Set it up. */
8131 {
8132 bfd_vma got_offset;
8135 /* The first three entries in .got.plt are reserved. */
8138 /* Use the right PLT. */
8142 /* Fill in the .plt on VxWorks. */
8144 {
8151 }
8152 else
8153 {
8162 }
8169 /* This instruction is an immediate load. The value loaded is
8170 the byte offset of the R_PPC_JMP_SLOT relocation from the
8171 start of the .rela.plt section. The value is stored in the
8172 low-order 16 bits of the load instruction. */
8173 /* NOTE: It appears that this is now an index rather than a
8174 prescaled offset. */
8178 /* This instruction is a PC-relative branch whose target is
8179 the start of the PLT section. The address of this branch
8180 instruction is 20 bytes beyond the start of this PLT entry.
8181 The address is encoded in bits 6-29, inclusive. The value
8182 stored is right-shifted by two bits, permitting a 26-bit
8183 offset. */
8193 /* Fill in the GOT entry corresponding to this PLT slot with
8194 the address immediately after the the "bctr" instruction
8195 in this PLT entry. */
8202 {
8203 /* Fill in a couple of entries in .rela.plt.unloaded. */
8209 /* Provide the @ha relocation for the first instruction. */
8214 R_PPC_ADDR16_HA);
8219 /* Provide the @l relocation for the second instruction. */
8224 R_PPC_ADDR16_LO);
8229 /* Provide a relocation for the GOT entry corresponding to this
8230 PLT slot. Point it at the middle of the .plt entry. */
8235 R_PPC_ADDR32);
8238 }
8240 /* VxWorks uses non-standard semantics for R_PPC_JMP_SLOT.
8241 In particular, the offset for the relocation is not the
8242 address of the PLT entry for this function, as specified
8243 by the ABI. Instead, the offset is set to the address of
8244 the GOT slot for this function. See EABI 4.4.4.1. */
8249 }
8250 else
8251 {
8263 {
8264 /* We don't need to fill in the .plt. The ppc dynamic
8265 linker will fill it in. */
8266 }
8267 else
8268 {
8274 }
8275 }
8277 /* Fill in the entry in the .rela.plt section. */
8281 {
8288 }
8289 else
8297 else
8303 {
8304 /* Mark the symbol as undefined, rather than as
8305 defined in the .plt section. Leave the value if
8306 there were any relocations where pointer equality
8307 matters (this is a clue for the dynamic linker, to
8308 make function pointer comparisons work between an
8309 application and shared library), otherwise set it
8310 to zero. */
8315 {
8316 /* This breaks function pointer comparisons, but
8317 that is better than breaking tests for a NULL
8318 function pointer. */
8320 }
8321 }
8324 {
8325 /* Set the value of ifunc symbols in a non-pie
8326 executable to the glink entry. This is to avoid
8327 text relocations. We can't do this for ifunc in
8328 allocate_dynrelocs, as we do for normal dynamic
8329 function symbols with plt entries, because we need
8330 to keep the original value around for the ifunc
8331 relocation. */
8337 }
8339 }
8344 {
8354 {
8371 }
8376 /* We only need one non-PIC glink stub. */
8378 }
8379 else
8381 }
8384 {
8386 Elf_Internal_Rela rela;
8389 /* This symbols needs a copy reloc. Set it up. */
8391 #ifdef DEBUG
8393 #endif
8399 else
8408 }
8410 #ifdef DEBUG
8412 #endif
8414 /* Mark some specially defined symbols as absolute. */
8423 }
8424 \f
8425 static enum elf_reloc_type_class
8427 {
8429 {
8440 }
8441 }
8442 \f
8443 /* Finish up the dynamic sections. */
8445 static bfd_boolean
8448 {
8452 bfd_vma got;
8456 #ifdef DEBUG
8458 #endif
8465 else
8473 {
8481 {
8482 Elf_Internal_Dyn dyn;
8488 {
8492 else
8512 {
8516 }
8524 }
8527 }
8528 }
8531 {
8534 {
8539 {
8540 /* Add a blrl instruction at _GLOBAL_OFFSET_TABLE_-4
8541 so that a function can easily find the address of
8542 _GLOBAL_OFFSET_TABLE_. */
8546 }
8549 {
8554 }
8555 }
8556 else
8557 {
8564 }
8567 }
8569 /* Fill in the first entry in the VxWorks procedure linkage table. */
8571 {
8572 /* Use the right PLT. */
8578 {
8585 }
8586 else
8587 {
8590 }
8599 {
8600 Elf_Internal_Rela rela;
8605 /* Output the @ha relocation for the first instruction. */
8614 /* Output the @l relocation for the second instruction. */
8623 /* Fix up the remaining relocations. They may have the wrong
8624 symbol index for _G_O_T_ or _P_L_T_ depending on the order
8625 in which symbols were output. */
8627 {
8628 Elf_Internal_Rela rel;
8644 }
8645 }
8646 }
8651 {
8654 bfd_vma res0;
8657 /*
8658 * PIC glink code is the following:
8659 *
8660 * # ith PLT code stub.
8661 * addis 11,30,(plt+(i-1)*4-got)@ha
8662 * lwz 11,(plt+(i-1)*4-got)@l(11)
8663 * mtctr 11
8664 * bctr
8665 *
8666 * # A table of branches, one for each plt entry.
8667 * # The idea is that the plt call stub loads ctr and r11 with these
8668 * # addresses, so (r11 - res_0) gives the plt index * 4.
8669 * res_0: b PLTresolve
8670 * res_1: b PLTresolve
8671 * .
8672 * # Some number of entries towards the end can be nops
8673 * res_n_m3: nop
8674 * res_n_m2: nop
8675 * res_n_m1:
8676 *
8677 * PLTresolve:
8678 * addis 11,11,(1f-res_0)@ha
8679 * mflr 0
8680 * bcl 20,31,1f
8681 * 1: addi 11,11,(1b-res_0)@l
8682 * mflr 12
8683 * mtlr 0
8684 * sub 11,11,12 # r11 = index * 4
8685 * addis 12,12,(got+4-1b)@ha
8686 * lwz 0,(got+4-1b)@l(12) # got[1] address of dl_runtime_resolve
8687 * lwz 12,(got+8-1b)@l(12) # got[2] contains the map address
8688 * mtctr 0
8689 * add 0,11,11
8690 * add 11,0,11 # r11 = index * 12 = reloc offset.
8691 * bctr
8692 */
8694 {
8695 ADDIS_11_11,
8696 MFLR_0,
8697 BCL_20_31,
8698 ADDI_11_11,
8699 MFLR_12,
8700 MTLR_0,
8701 SUB_11_11_12,
8702 ADDIS_12_12,
8703 LWZ_0_12,
8704 LWZ_12_12,
8705 MTCTR_0,
8706 ADD_0_11_11,
8707 ADD_11_0_11,
8708 BCTR,
8709 NOP,
8710 NOP
8711 };
8713 /*
8714 * Non-PIC glink code is a little simpler.
8715 *
8716 * # ith PLT code stub.
8717 * lis 11,(plt+(i-1)*4)@ha
8718 * lwz 11,(plt+(i-1)*4)@l(11)
8719 * mtctr 11
8720 * bctr
8721 *
8722 * The branch table is the same, then comes
8723 *
8724 * PLTresolve:
8725 * lis 12,(got+4)@ha
8726 * addis 11,11,(-res_0)@ha
8727 * lwz 0,(got+4)@l(12) # got[1] address of dl_runtime_resolve
8728 * addi 11,11,(-res_0)@l # r11 = index * 4
8729 * mtctr 0
8730 * add 0,11,11
8731 * lwz 12,(got+8)@l(12) # got[2] contains the map address
8732 * add 11,0,11 # r11 = index * 12 = reloc offset.
8733 * bctr
8734 */
8736 {
8737 LIS_12,
8738 ADDIS_11_11,
8739 LWZ_0_12,
8740 ADDI_11_11,
8741 MTCTR_0,
8742 ADD_0_11_11,
8743 LWZ_12_12,
8744 ADD_11_0_11,
8745 BCTR,
8746 NOP,
8747 NOP,
8748 NOP,
8749 NOP,
8750 NOP,
8751 NOP,
8752 NOP
8753 };
8760 /* Build the branch table, one for each plt entry (less one),
8761 and perhaps some padding. */
8767 {
8770 }
8772 {
8775 }
8781 /* Last comes the PLTresolve stub. */
8783 {
8784 bfd_vma bcl;
8787 {
8790 }
8804 {
8809 }
8810 else
8811 {
8816 }
8817 }
8818 else
8819 {
8821 {
8824 }
8834 {
8839 }
8840 else
8841 {
8846 }
8847 }
8848 }
8851 }
8852 \f
8853 #define TARGET_LITTLE_SYM bfd_elf32_powerpcle_vec
8855 #define TARGET_BIG_SYM bfd_elf32_powerpc_vec
8857 #define ELF_ARCH bfd_arch_powerpc
8858 #define ELF_MACHINE_CODE EM_PPC
8859 #ifdef __QNXTARGET__
8860 #define ELF_MAXPAGESIZE 0x1000
8861 #else
8862 #define ELF_MAXPAGESIZE 0x10000
8863 #endif
8864 #define ELF_MINPAGESIZE 0x1000
8865 #define ELF_COMMONPAGESIZE 0x1000
8866 #define elf_info_to_howto ppc_elf_info_to_howto
8868 #ifdef EM_CYGNUS_POWERPC
8869 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
8870 #endif
8872 #ifdef EM_PPC_OLD
8873 #define ELF_MACHINE_ALT2 EM_PPC_OLD
8874 #endif
8876 #define elf_backend_plt_not_loaded 1
8877 #define elf_backend_can_gc_sections 1
8878 #define elf_backend_can_refcount 1
8879 #define elf_backend_rela_normal 1
8881 #define bfd_elf32_mkobject ppc_elf_mkobject
8882 #define bfd_elf32_bfd_merge_private_bfd_data ppc_elf_merge_private_bfd_data
8883 #define bfd_elf32_bfd_relax_section ppc_elf_relax_section
8884 #define bfd_elf32_bfd_reloc_type_lookup ppc_elf_reloc_type_lookup
8885 #define bfd_elf32_bfd_reloc_name_lookup ppc_elf_reloc_name_lookup
8886 #define bfd_elf32_bfd_set_private_flags ppc_elf_set_private_flags
8887 #define bfd_elf32_bfd_link_hash_table_create ppc_elf_link_hash_table_create
8888 #define bfd_elf32_get_synthetic_symtab ppc_elf_get_synthetic_symtab
8890 #define elf_backend_object_p ppc_elf_object_p
8891 #define elf_backend_gc_mark_hook ppc_elf_gc_mark_hook
8892 #define elf_backend_gc_sweep_hook ppc_elf_gc_sweep_hook
8893 #define elf_backend_section_from_shdr ppc_elf_section_from_shdr
8894 #define elf_backend_relocate_section ppc_elf_relocate_section
8895 #define elf_backend_create_dynamic_sections ppc_elf_create_dynamic_sections
8896 #define elf_backend_check_relocs ppc_elf_check_relocs
8897 #define elf_backend_copy_indirect_symbol ppc_elf_copy_indirect_symbol
8898 #define elf_backend_adjust_dynamic_symbol ppc_elf_adjust_dynamic_symbol
8899 #define elf_backend_add_symbol_hook ppc_elf_add_symbol_hook
8900 #define elf_backend_size_dynamic_sections ppc_elf_size_dynamic_sections
8901 #define elf_backend_hash_symbol ppc_elf_hash_symbol
8902 #define elf_backend_finish_dynamic_symbol ppc_elf_finish_dynamic_symbol
8903 #define elf_backend_finish_dynamic_sections ppc_elf_finish_dynamic_sections
8904 #define elf_backend_fake_sections ppc_elf_fake_sections
8905 #define elf_backend_additional_program_headers ppc_elf_additional_program_headers
8906 #define elf_backend_grok_prstatus ppc_elf_grok_prstatus
8907 #define elf_backend_grok_psinfo ppc_elf_grok_psinfo
8908 #define elf_backend_write_core_note ppc_elf_write_core_note
8909 #define elf_backend_reloc_type_class ppc_elf_reloc_type_class
8910 #define elf_backend_begin_write_processing ppc_elf_begin_write_processing
8911 #define elf_backend_final_write_processing ppc_elf_final_write_processing
8912 #define elf_backend_write_section ppc_elf_write_section
8913 #define elf_backend_get_sec_type_attr ppc_elf_get_sec_type_attr
8914 #define elf_backend_plt_sym_val ppc_elf_plt_sym_val
8915 #define elf_backend_action_discarded ppc_elf_action_discarded
8916 #define elf_backend_init_index_section _bfd_elf_init_1_index_section
8917 #define elf_backend_post_process_headers _bfd_elf_set_osabi
8921 /* VxWorks Target */
8923 #undef TARGET_LITTLE_SYM
8924 #undef TARGET_LITTLE_NAME
8926 #undef TARGET_BIG_SYM
8927 #define TARGET_BIG_SYM bfd_elf32_powerpc_vxworks_vec
8928 #undef TARGET_BIG_NAME
8931 /* VxWorks uses the elf default section flags for .plt. */
8934 {
8942 }
8944 /* Like ppc_elf_link_hash_table_create, but overrides
8945 appropriately for VxWorks. */
8948 {
8953 {
8961 }
8963 }
8965 /* Tweak magic VxWorks symbols as they are loaded. */
8966 static bfd_boolean
8974 {
8976 valp))
8980 }
8982 static void
8984 {
8987 }
8989 /* On VxWorks, we emit relocations against _PROCEDURE_LINKAGE_TABLE_, so
8990 define it. */
8991 #undef elf_backend_want_plt_sym
8992 #define elf_backend_want_plt_sym 1
8993 #undef elf_backend_want_got_plt
8994 #define elf_backend_want_got_plt 1
8995 #undef elf_backend_got_symbol_offset
8996 #define elf_backend_got_symbol_offset 0
8997 #undef elf_backend_plt_not_loaded
8998 #define elf_backend_plt_not_loaded 0
8999 #undef elf_backend_plt_readonly
9000 #define elf_backend_plt_readonly 1
9001 #undef elf_backend_got_header_size
9002 #define elf_backend_got_header_size 12
9004 #undef bfd_elf32_get_synthetic_symtab
9006 #undef bfd_elf32_bfd_link_hash_table_create
9007 #define bfd_elf32_bfd_link_hash_table_create \
9008 ppc_elf_vxworks_link_hash_table_create
9009 #undef elf_backend_add_symbol_hook
9010 #define elf_backend_add_symbol_hook \
9011 ppc_elf_vxworks_add_symbol_hook
9012 #undef elf_backend_link_output_symbol_hook
9013 #define elf_backend_link_output_symbol_hook \
9014 elf_vxworks_link_output_symbol_hook
9015 #undef elf_backend_final_write_processing
9016 #define elf_backend_final_write_processing \
9017 ppc_elf_vxworks_final_write_processing
9018 #undef elf_backend_get_sec_type_attr
9019 #define elf_backend_get_sec_type_attr \
9020 ppc_elf_vxworks_get_sec_type_attr
9021 #undef elf_backend_emit_relocs
9022 #define elf_backend_emit_relocs \
9023 elf_vxworks_emit_relocs
9025 #undef elf32_bed
9026 #define elf32_bed ppc_elf_vxworks_bed
9027 #undef elf_backend_post_process_headers