| blob | 9ee2bcd85732df67164460f44f87a046d4b17496 |
1 /* PowerPC-specific support for 32-bit ELF
2 Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
3 2004, 2005, 2006 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 2 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. */
23 /* This file is based on a preliminary PowerPC ELF ABI. The
24 information may not match the final PowerPC ELF ABI. It includes
25 suggestions from the in-progress Embedded PowerPC ABI, and that
26 information may also not match. */
37 /* RELA relocations are used here. */
39 static bfd_reloc_status_type ppc_elf_addr16_ha_reloc
41 static bfd_reloc_status_type ppc_elf_unhandled_reloc
44 /* Branch prediction bit for branch taken relocs. */
45 #define BRANCH_PREDICT_BIT 0x200000
46 /* Mask to set RA in memory instructions. */
47 #define RA_REGISTER_MASK 0x001f0000
48 /* Value to shift register by to insert RA. */
49 #define RA_REGISTER_SHIFT 16
51 /* The name of the dynamic interpreter. This is put in the .interp
52 section. */
55 /* For old-style PLT. */
56 /* The number of single-slot PLT entries (the rest use two slots). */
57 #define PLT_NUM_SINGLE_ENTRIES 8192
59 /* For new-style .glink and .plt. */
60 #define GLINK_PLTRESOLVE 16*4
61 #define GLINK_ENTRY_SIZE 4*4
63 /* VxWorks uses its own plt layout, filled in by the static linker. */
65 /* The standard VxWorks PLT entry. */
66 #define VXWORKS_PLT_ENTRY_SIZE 32
67 static const bfd_vma ppc_elf_vxworks_plt_entry
69 {
78 };
79 static const bfd_vma ppc_elf_vxworks_pic_plt_entry
81 {
90 };
92 /* The initial VxWorks PLT entry. */
93 #define VXWORKS_PLT_INITIAL_ENTRY_SIZE 32
94 static const bfd_vma ppc_elf_vxworks_plt0_entry
96 {
105 };
106 static const bfd_vma ppc_elf_vxworks_pic_plt0_entry
108 {
117 };
119 /* For executables, we have some additional relocations in
120 .rela.plt.unloaded, for the kernel loader. */
122 /* The number of non-JMP_SLOT relocations per PLT0 slot. */
123 #define VXWORKS_PLT_NON_JMP_SLOT_RELOCS 3
124 /* The number of relocations in the PLTResolve slot. */
125 #define VXWORKS_PLTRESOLVE_RELOCS 2
126 /* The number of relocations in the PLTResolve slot when when creating
127 a shared library. */
128 #define VXWORKS_PLTRESOLVE_RELOCS_SHLIB 0
130 /* Some instructions. */
131 #define ADDIS_11_11 0x3d6b0000
132 #define ADDIS_11_30 0x3d7e0000
133 #define ADDIS_12_12 0x3d8c0000
134 #define ADDI_11_11 0x396b0000
135 #define ADD_0_11_11 0x7c0b5a14
136 #define ADD_11_0_11 0x7d605a14
137 #define B 0x48000000
138 #define BCL_20_31 0x429f0005
139 #define BCTR 0x4e800420
140 #define LIS_11 0x3d600000
141 #define LIS_12 0x3d800000
142 #define LWZU_0_12 0x840c0000
143 #define LWZ_0_12 0x800c0000
144 #define LWZ_11_11 0x816b0000
145 #define LWZ_11_30 0x817e0000
146 #define LWZ_12_12 0x818c0000
147 #define MFLR_0 0x7c0802a6
148 #define MFLR_12 0x7d8802a6
149 #define MTCTR_0 0x7c0903a6
150 #define MTCTR_11 0x7d6903a6
151 #define MTLR_0 0x7c0803a6
152 #define NOP 0x60000000
153 #define SUB_11_11_12 0x7d6c5850
155 /* Offset of tp and dtp pointers from start of TLS block. */
156 #define TP_OFFSET 0x7000
157 #define DTP_OFFSET 0x8000
158 \f
162 /* This reloc does nothing. */
177 /* A standard 32 bit relocation. */
192 /* An absolute 26 bit branch; the lower two bits must be zero.
193 FIXME: we don't check that, we just clear them. */
208 /* A standard 16 bit relocation. */
223 /* A 16 bit relocation without overflow. */
238 /* The high order 16 bits of an address. */
253 /* The high order 16 bits of an address, plus 1 if the contents of
254 the low 16 bits, treated as a signed number, is negative. */
269 /* An absolute 16 bit branch; the lower two bits must be zero.
270 FIXME: we don't check that, we just clear them. */
285 /* An absolute 16 bit branch, for which bit 10 should be set to
286 indicate that the branch is expected to be taken. The lower two
287 bits must be zero. */
302 /* An absolute 16 bit branch, for which bit 10 should be set to
303 indicate that the branch is not expected to be taken. The lower
304 two bits must be zero. */
319 /* A relative 26 bit branch; the lower two bits must be zero. */
334 /* A relative 16 bit branch; the lower two bits must be zero. */
349 /* A relative 16 bit branch. Bit 10 should be set to indicate that
350 the branch is expected to be taken. The lower two bits must be
351 zero. */
366 /* A relative 16 bit branch. Bit 10 should be set to indicate that
367 the branch is not expected to be taken. The lower two bits must
368 be zero. */
383 /* Like R_PPC_ADDR16, but referring to the GOT table entry for the
384 symbol. */
399 /* Like R_PPC_ADDR16_LO, but referring to the GOT table entry for
400 the symbol. */
415 /* Like R_PPC_ADDR16_HI, but referring to the GOT table entry for
416 the symbol. */
431 /* Like R_PPC_ADDR16_HA, but referring to the GOT table entry for
432 the symbol. */
447 /* Like R_PPC_REL24, but referring to the procedure linkage table
448 entry for the symbol. */
463 /* This is used only by the dynamic linker. The symbol should exist
464 both in the object being run and in some shared library. The
465 dynamic linker copies the data addressed by the symbol from the
466 shared library into the object, because the object being
467 run has to have the data at some particular address. */
482 /* Like R_PPC_ADDR32, but used when setting global offset table
483 entries. */
498 /* Marks a procedure linkage table entry for a symbol. */
513 /* Used only by the dynamic linker. When the object is run, this
514 longword is set to the load address of the object, plus the
515 addend. */
530 /* Like R_PPC_REL24, but uses the value of the symbol within the
531 object rather than the final value. Normally used for
532 _GLOBAL_OFFSET_TABLE_. */
547 /* Like R_PPC_ADDR32, but may be unaligned. */
562 /* Like R_PPC_ADDR16, but may be unaligned. */
577 /* 32-bit PC relative */
592 /* 32-bit relocation to the symbol's procedure linkage table.
593 FIXME: not supported. */
608 /* 32-bit PC relative relocation to the symbol's procedure linkage table.
609 FIXME: not supported. */
624 /* Like R_PPC_ADDR16_LO, but referring to the PLT table entry for
625 the symbol. */
640 /* Like R_PPC_ADDR16_HI, but referring to the PLT table entry for
641 the symbol. */
656 /* Like R_PPC_ADDR16_HA, but referring to the PLT table entry for
657 the symbol. */
672 /* A sign-extended 16 bit value relative to _SDA_BASE_, for use with
673 small data items. */
688 /* 16-bit section relative relocation. */
703 /* 16-bit lower half section relative relocation. */
718 /* 16-bit upper half section relative relocation. */
733 /* 16-bit upper half adjusted section relative relocation. */
748 /* Marker reloc for TLS. */
763 /* Computes the load module index of the load module that contains the
764 definition of its TLS sym. */
779 /* Computes a dtv-relative displacement, the difference between the value
780 of sym+add and the base address of the thread-local storage block that
781 contains the definition of sym, minus 0x8000. */
796 /* A 16 bit dtprel reloc. */
811 /* Like DTPREL16, but no overflow. */
826 /* Like DTPREL16_LO, but next higher group of 16 bits. */
841 /* Like DTPREL16_HI, but adjust for low 16 bits. */
856 /* Computes a tp-relative displacement, the difference between the value of
857 sym+add and the value of the thread pointer (r13). */
872 /* A 16 bit tprel reloc. */
887 /* Like TPREL16, but no overflow. */
902 /* Like TPREL16_LO, but next higher group of 16 bits. */
917 /* Like TPREL16_HI, but adjust for low 16 bits. */
932 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
933 with values (sym+add)@dtpmod and (sym+add)@dtprel, and computes the offset
934 to the first entry. */
949 /* Like GOT_TLSGD16, but no overflow. */
964 /* Like GOT_TLSGD16_LO, but next higher group of 16 bits. */
979 /* Like GOT_TLSGD16_HI, but adjust for low 16 bits. */
994 /* Allocates two contiguous entries in the GOT to hold a tls_index structure,
995 with values (sym+add)@dtpmod and zero, and computes the offset to the
996 first entry. */
1011 /* Like GOT_TLSLD16, but no overflow. */
1026 /* Like GOT_TLSLD16_LO, but next higher group of 16 bits. */
1041 /* Like GOT_TLSLD16_HI, but adjust for low 16 bits. */
1056 /* Allocates an entry in the GOT with value (sym+add)@dtprel, and computes
1057 the offset to the entry. */
1072 /* Like GOT_DTPREL16, but no overflow. */
1087 /* Like GOT_DTPREL16_LO, but next higher group of 16 bits. */
1102 /* Like GOT_DTPREL16_HI, but adjust for low 16 bits. */
1117 /* Allocates an entry in the GOT with value (sym+add)@tprel, and computes the
1118 offset to the entry. */
1133 /* Like GOT_TPREL16, but no overflow. */
1148 /* Like GOT_TPREL16_LO, but next higher group of 16 bits. */
1163 /* Like GOT_TPREL16_HI, but adjust for low 16 bits. */
1178 /* The remaining relocs are from the Embedded ELF ABI, and are not
1179 in the SVR4 ELF ABI. */
1181 /* 32 bit value resulting from the addend minus the symbol. */
1196 /* 16 bit value resulting from the addend minus the symbol. */
1211 /* 16 bit value resulting from the addend minus the symbol. */
1226 /* The high order 16 bits of the addend minus the symbol. */
1241 /* The high order 16 bits of the result of the addend minus the address,
1242 plus 1 if the contents of the low 16 bits, treated as a signed number,
1243 is negative. */
1258 /* 16 bit value resulting from allocating a 4 byte word to hold an
1259 address in the .sdata section, and returning the offset from
1260 _SDA_BASE_ for that relocation. */
1275 /* 16 bit value resulting from allocating a 4 byte word to hold an
1276 address in the .sdata2 section, and returning the offset from
1277 _SDA2_BASE_ for that relocation. */
1292 /* A sign-extended 16 bit value relative to _SDA2_BASE_, for use with
1293 small data items. */
1308 /* Relocate against either _SDA_BASE_ or _SDA2_BASE_, filling in the 16 bit
1309 signed offset from the appropriate base, and filling in the register
1310 field with the appropriate register (0, 2, or 13). */
1325 /* Relocation not handled: R_PPC_EMB_MRKREF */
1326 /* Relocation not handled: R_PPC_EMB_RELSEC16 */
1327 /* Relocation not handled: R_PPC_EMB_RELST_LO */
1328 /* Relocation not handled: R_PPC_EMB_RELST_HI */
1329 /* Relocation not handled: R_PPC_EMB_RELST_HA */
1330 /* Relocation not handled: R_PPC_EMB_BIT_FLD */
1332 /* PC relative relocation against either _SDA_BASE_ or _SDA2_BASE_, filling
1333 in the 16 bit signed offset from the appropriate base, and filling in the
1334 register field with the appropriate register (0, 2, or 13). */
1349 /* A 16 bit relative relocation. */
1364 /* A 16 bit relative relocation without overflow. */
1379 /* The high order 16 bits of a relative address. */
1394 /* The high order 16 bits of a relative address, plus 1 if the contents of
1395 the low 16 bits, treated as a signed number, is negative. */
1410 /* GNU extension to record C++ vtable hierarchy. */
1425 /* GNU extension to record C++ vtable member usage. */
1440 /* Phony reloc to handle AIX style TOC entries. */
1454 };
1455 \f
1456 /* Initialize the ppc_elf_howto_table, so that linear accesses can be done. */
1458 static void
1460 {
1465 i++)
1466 {
1472 }
1473 }
1477 bfd_reloc_code_real_type code)
1478 {
1481 /* Initialize howto table if not already done. */
1486 {
1575 }
1578 };
1580 /* Set the howto pointer for a PowerPC ELF reloc. */
1582 static void
1586 {
1587 /* Initialize howto table if not already done. */
1593 }
1595 /* Handle the R_PPC_ADDR16_HA and R_PPC_REL16_HA relocs. */
1597 static bfd_reloc_status_type
1605 {
1606 bfd_vma relocation;
1609 {
1612 }
1619 else
1631 }
1633 static bfd_reloc_status_type
1641 {
1642 /* If this is a relocatable link (output_bfd test tells us), just
1643 call the generic function. Any adjustment will be done at final
1644 link time. */
1650 {
1655 }
1657 }
1658 \f
1659 /* Sections created by the linker. */
1662 {
1663 /* Pointer to the bfd section. */
1665 /* Section name. */
1667 /* Associated bss section name. */
1669 /* Associated symbol name. */
1671 /* Associated symbol. */
1675 /* Linked list of allocated pointer entries. This hangs off of the
1676 symbol lists, and provides allows us to return different pointers,
1677 based on different addend's. */
1680 {
1681 /* next allocated pointer for this symbol */
1683 /* offset of pointer from beginning of section */
1684 bfd_vma offset;
1685 /* addend used */
1686 bfd_vma addend;
1687 /* which linker section this is */
1691 struct ppc_elf_obj_tdata
1692 {
1695 /* A mapping from local symbols to offsets into the various linker
1696 sections added. This is index by the symbol index. */
1698 };
1700 #define ppc_elf_tdata(bfd) \
1701 ((struct ppc_elf_obj_tdata *) (bfd)->tdata.any)
1703 #define elf_local_ptr_offsets(bfd) \
1704 (ppc_elf_tdata (bfd)->linker_section_pointers)
1706 /* Override the generic function because we store some extras. */
1708 static bfd_boolean
1710 {
1716 }
1718 /* Fix bad default arch selected for a 32 bit input bfd when the
1719 default is 64 bit. */
1721 static bfd_boolean
1723 {
1725 {
1729 {
1730 /* Relies on arch after 64 bit default being 32 bit default. */
1733 }
1734 }
1736 }
1738 /* Function to set whether a module needs the -mrelocatable bit set. */
1740 static bfd_boolean
1742 {
1749 }
1751 /* Support for core dump NOTE sections. */
1753 static bfd_boolean
1755 {
1760 {
1765 /* pr_cursig */
1768 /* pr_pid */
1771 /* pr_reg */
1776 }
1778 /* Make a ".reg/999" section. */
1781 }
1783 static bfd_boolean
1785 {
1787 {
1796 }
1798 /* Note that for some reason, a spurious space is tacked
1799 onto the end of the args in some (at least one anyway)
1800 implementations, so strip it off if it exists. */
1802 {
1808 }
1811 }
1813 /* Return address for Ith PLT stub in section PLT, for relocation REL
1814 or (bfd_vma) -1 if it should not be included. */
1816 static bfd_vma
1820 {
1822 }
1824 /* Handle a PowerPC specific section when reading an object file. This
1825 is called when bfd_section_from_shdr finds a section with an unknown
1826 type. */
1828 static bfd_boolean
1833 {
1835 flagword flags;
1850 }
1852 /* Set up any other section flags and such that may be necessary. */
1854 static bfd_boolean
1858 {
1866 }
1868 /* If we have .sbss2 or .PPC.EMB.sbss0 output sections, we
1869 need to bump up the number of section headers. */
1871 static int
1873 {
1886 }
1888 /* Add extra PPC sections -- Note, for now, make .sbss2 and
1889 .PPC.EMB.sbss0 a normal section, and not a bss section so
1890 that the linker doesn't crater when trying to make more than
1891 2 sections. */
1894 {
1905 };
1907 /* This is what we want for new plt/got. */
1913 {
1916 /* See if this is one of the special sections. */
1923 {
1927 }
1930 }
1931 \f
1932 /* Very simple linked list structure for recording apuinfo values. */
1934 {
1937 }
1938 apuinfo_list;
1943 static void
1945 {
1947 }
1949 static void
1951 {
1955 {
1959 }
1968 }
1970 static unsigned
1972 {
1977 entry;
1982 }
1986 {
1992 ;
1995 }
1997 static void
1999 {
2003 {
2007 }
2010 }
2015 /* Scan the input BFDs and create a linked list of
2016 the APUinfo values that will need to be emitted. */
2018 static void
2020 {
2025 bfd_size_type output_section_size;
2035 /* Scan the input bfds, looking for apuinfo sections. */
2040 {
2043 {
2046 }
2047 }
2049 /* We need at least one input sections
2050 in order to make merging worthwhile. */
2054 /* Just make sure that the output section exists as well. */
2059 /* Allocate a buffer for the contents of the input sections. */
2067 /* Read in the input sections contents. */
2069 {
2079 {
2082 }
2086 {
2089 }
2091 /* Process the contents of the section. */
2095 /* Verify the contents of the header. Note - we have to
2096 extract the values this way in order to allow for a
2097 host whose endian-ness is different from the target. */
2109 /* Get the number of bytes used for apuinfo entries. */
2114 /* Make sure that we do not run off the end of the section. */
2118 /* Scan the apuinfo section, building a list of apuinfo numbers. */
2122 /* Update the offset. */
2124 }
2128 /* Compute the size of the output section. */
2138 fail:
2143 }
2145 /* Prevent the output section from accumulating the input sections'
2146 contents. We have already stored this in our linked list structure. */
2148 static bfd_boolean
2152 {
2155 }
2157 /* Finally we can generate the output section. */
2159 static void
2161 {
2166 bfd_size_type length;
2181 {
2185 }
2187 /* Create the apuinfo header. */
2196 {
2199 }
2210 }
2211 \f
2212 /* The following functions are specific to the ELF linker, while
2213 functions above are used generally. They appear in this file more
2214 or less in the order in which they are called. eg.
2215 ppc_elf_check_relocs is called early in the link process,
2216 ppc_elf_finish_dynamic_sections is one of the last functions
2217 called. */
2219 /* The PPC linker needs to keep track of the number of relocs that it
2220 decides to copy as dynamic relocs in check_relocs for each symbol.
2221 This is so that it can later discard them if they are found to be
2222 unnecessary. We store the information in a field extending the
2223 regular ELF linker hash table. */
2225 struct ppc_elf_dyn_relocs
2226 {
2229 /* The input section of the reloc. */
2232 /* Total number of relocs copied for the input section. */
2233 bfd_size_type count;
2235 /* Number of pc-relative relocs copied for the input section. */
2236 bfd_size_type pc_count;
2237 };
2239 /* Track PLT entries needed for a given symbol. We might need more
2240 than one glink entry per symbol. */
2241 struct plt_entry
2242 {
2245 /* -fPIC uses multiple GOT sections, one per file, called ".got2".
2246 This field stores the offset into .got2 used to initialise the
2247 GOT pointer reg. It will always be at least 32768 (and for
2248 current gcc this is the only offset used). */
2249 bfd_vma addend;
2251 /* The .got2 section. */
2254 /* PLT refcount or offset. */
2255 union
2256 {
2257 bfd_signed_vma refcount;
2258 bfd_vma offset;
2261 /* .glink stub offset. */
2262 bfd_vma glink_offset;
2263 };
2265 /* Of those relocs that might be copied as dynamic relocs, this macro
2266 selects those that must be copied when linking a shared library,
2267 even when the symbol is local. */
2269 #define MUST_BE_DYN_RELOC(RTYPE) \
2270 ((RTYPE) != R_PPC_REL24 \
2271 && (RTYPE) != R_PPC_REL14 \
2272 && (RTYPE) != R_PPC_REL14_BRTAKEN \
2273 && (RTYPE) != R_PPC_REL14_BRNTAKEN \
2274 && (RTYPE) != R_PPC_REL32)
2276 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
2277 copying dynamic variables from a shared lib into an app's dynbss
2278 section, and instead use a dynamic relocation to point into the
2279 shared lib. */
2280 #define ELIMINATE_COPY_RELOCS 1
2282 /* PPC ELF linker hash entry. */
2284 struct ppc_elf_link_hash_entry
2285 {
2288 /* If this symbol is used in the linker created sections, the processor
2289 specific backend uses this field to map the field into the offset
2290 from the beginning of the section. */
2293 /* Track dynamic relocs copied for this symbol. */
2296 /* Contexts in which symbol is used in the GOT (or TOC).
2297 TLS_GD .. TLS_TLS bits are or'd into the mask as the
2298 corresponding relocs are encountered during check_relocs.
2299 tls_optimize clears TLS_GD .. TLS_TPREL when optimizing to
2300 indicate the corresponding GOT entry type is not needed. */
2309 /* Nonzero if we have seen a small data relocation referring to this
2310 symbol. */
2312 };
2314 #define ppc_elf_hash_entry(ent) ((struct ppc_elf_link_hash_entry *) (ent))
2317 PLT_UNSET,
2318 PLT_OLD,
2319 PLT_NEW,
2320 PLT_VXWORKS
2321 };
2323 /* PPC ELF linker hash table. */
2325 struct ppc_elf_link_hash_table
2326 {
2329 /* Short-cuts to get to dynamic linker sections. */
2342 /* Shortcut to .__tls_get_addr. */
2345 /* TLS local dynamic got entry handling. */
2347 bfd_signed_vma refcount;
2348 bfd_vma offset;
2351 /* Offset of PltResolve function in glink. */
2352 bfd_vma glink_pltresolve;
2354 /* Size of reserved GOT entries. */
2356 /* Non-zero if allocating the header left a gap. */
2359 /* The type of PLT we have chosen to use. */
2362 /* Whether we can use the new PLT layout. */
2365 /* Set if we should emit symbols for stubs. */
2368 /* Small local sym to section mapping cache. */
2371 /* The (unloaded but important) .rela.plt.unloaded on VxWorks. */
2374 /* The .got.plt section (VxWorks only)*/
2377 /* True if the target system is VxWorks. */
2380 /* The size of PLT entries. */
2382 /* The distance between adjacent PLT slots. */
2384 /* The size of the first PLT entry. */
2386 };
2388 /* Get the PPC ELF linker hash table from a link_info structure. */
2390 #define ppc_elf_hash_table(p) \
2391 ((struct ppc_elf_link_hash_table *) (p)->hash)
2393 /* Create an entry in a PPC ELF linker hash table. */
2399 {
2400 /* Allocate the structure if it has not already been allocated by a
2401 subclass. */
2403 {
2408 }
2410 /* Call the allocation method of the superclass. */
2413 {
2417 }
2420 }
2422 /* Create a PPC ELF linker hash table. */
2426 {
2434 ppc_elf_link_hash_newfunc,
2436 {
2439 }
2461 }
2463 /* Create .got and the related sections. */
2465 static bfd_boolean
2467 {
2470 flagword flags;
2481 {
2485 }
2486 else
2487 {
2488 /* The powerpc .got has a blrl instruction in it. Mark it
2489 executable. */
2494 }
2504 }
2506 /* We have to create .dynsbss and .rela.sbss here so that they get mapped
2507 to output sections (just like _bfd_elf_create_dynamic_sections has
2508 to create .dynbss and .rela.bss). */
2510 static bfd_boolean
2512 {
2515 flagword flags;
2543 {
2550 }
2563 /* The VxWorks PLT is a loaded section with contents. */
2566 }
2568 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2570 static void
2574 {
2581 {
2583 {
2587 /* Add reloc counts against the indirect sym to the direct sym
2588 list. Merge any entries against the same section. */
2590 {
2595 {
2600 }
2603 }
2605 }
2609 }
2614 /* If called to transfer flags for a weakdef during processing
2615 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
2616 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
2627 /* If we were called to copy over info for a weak sym, that's all. */
2631 /* Copy over the GOT refcount entries that we may have already seen to
2632 the symbol which just became indirect. */
2636 /* And plt entries. */
2638 {
2640 {
2645 {
2650 {
2654 }
2657 }
2659 }
2663 }
2666 {
2674 }
2675 }
2677 /* Return 1 if target is one of ours. */
2679 static bfd_boolean
2681 {
2689 }
2691 /* Hook called by the linker routine which adds symbols from an object
2692 file. We use it to put .comm items in .sbss, and not .bss. */
2694 static bfd_boolean
2702 {
2707 {
2708 /* Common symbols less than or equal to -G nn bytes are automatically
2709 put into .sbss. */
2714 {
2722 flags);
2725 }
2729 }
2732 }
2733 \f
2734 static bfd_boolean
2737 {
2746 }
2748 /* Create a special linker section. */
2750 static bfd_boolean
2753 flagword flags,
2755 {
2762 /* Record the first bfd that needs the special sections. */
2768 flags);
2775 }
2777 /* Find a linker generated pointer with a given addend and type. */
2780 elf_find_pointer_linker_section
2782 bfd_vma addend,
2784 {
2790 }
2792 /* Allocate a pointer to live in a linker created section. */
2794 static bfd_boolean
2799 {
2803 bfd_size_type amt;
2807 /* Is this a global symbol? */
2809 {
2812 /* Has this symbol already been allocated? If so, our work is done. */
2816 lsect))
2820 }
2821 else
2822 {
2823 /* Allocation of a pointer to a local symbol. */
2826 /* Allocate a table to hold the local symbols if first time. */
2828 {
2839 }
2841 /* Has this symbol already been allocated? If so, our work is done. */
2844 lsect))
2848 }
2850 /* Allocate space for a pointer in the linker section, and allocate
2851 a new pointer record from internal memory. */
2867 #ifdef DEBUG
2872 #endif
2875 }
2877 static bfd_boolean
2882 {
2887 {
2895 }
2901 }
2903 static bfd_boolean
2906 {
2915 {
2925 }
2928 }
2932 {
2941 }
2943 static void
2945 {
2948 abfd,
2951 }
2953 /* Look through the relocs for a section during the first phase, and
2954 allocate space in the global offset table or procedure linkage
2955 table. */
2957 static bfd_boolean
2962 {
2973 /* Don't do anything special with non-loaded, non-alloced sections.
2974 In particular, any relocs in such sections should not affect GOT
2975 and PLT reference counting (ie. we don't allow them to create GOT
2976 or PLT entries), there's no possibility or desire to optimize TLS
2977 relocs, and there's not much point in propagating relocs to shared
2978 libs that the dynamic linker won't relocate. */
2982 #ifdef DEBUG
2985 #endif
2987 /* Initialize howto table if not already done. */
2999 {
3008 else
3009 {
3014 }
3016 /* If a relocation refers to _GLOBAL_OFFSET_TABLE_, create the .got.
3017 This shows up in particular in an R_PPC_ADDR32 in the eabi
3018 startup code. */
3022 {
3028 }
3032 {
3062 dogottls:
3064 /* Fall thru */
3066 /* GOT16 relocations */
3071 /* This symbol requires a global offset table entry. */
3073 {
3078 }
3080 {
3083 }
3084 else
3085 /* This is a global offset table entry for a local symbol. */
3090 /* Indirect .sdata relocation. */
3093 {
3096 }
3105 {
3108 }
3111 /* Indirect .sdata2 relocation. */
3114 {
3117 }
3126 {
3129 }
3134 {
3137 }
3142 {
3145 }
3150 {
3153 }
3158 {
3161 }
3167 {
3170 }
3178 {
3181 }
3190 {
3193 }
3204 #ifdef DEBUG
3206 #endif
3207 /* This symbol requires a procedure linkage table entry. We
3208 actually build the entry in finish_dynamic_symbol,
3209 because this might be a case of linking PIC code without
3210 linking in any dynamic objects, in which case we don't
3211 need to generate a procedure linkage table after all. */
3214 {
3215 /* It does not make sense to have a procedure linkage
3216 table entry for a local symbol. */
3219 abfd,
3220 sec,
3225 }
3226 else
3227 {
3233 }
3236 /* The following relocations don't need to propagate the
3237 relocation if linking a shared object since they are
3238 section relative. */
3257 /* These are just markers. */
3264 /* These should only appear in dynamic objects. */
3271 /* These aren't handled yet. We'll report an error later. */
3280 /* This refers only to functions defined in the shared library. */
3286 /* This relocation describes the C++ object vtable hierarchy.
3287 Reconstruct it for later use during GC. */
3293 /* This relocation describes which C++ vtable entries are actually
3294 used. Record for later use during GC. */
3300 /* We shouldn't really be seeing these. */
3306 /* Nor these. */
3325 {
3326 /* Old -fPIC gcc code has .long LCTOC1-LCFx just before
3327 the start of a function, which assembles to a REL32
3328 reference to .got2. If we detect one of these, then
3329 force the old PLT layout because the linker cannot
3330 reliably deduce the GOT pointer value needed for
3331 PLT call stubs. */
3335 r_symndx);
3338 }
3350 {
3354 }
3355 /* fall through */
3368 dodyn1:
3370 {
3371 /* We may need a plt entry if the symbol turns out to be
3372 a function defined in a dynamic object. */
3376 /* We may need a copy reloc too. */
3378 }
3380 dodyn:
3381 /* If we are creating a shared library, and this is a reloc
3382 against a global symbol, or a non PC relative reloc
3383 against a local symbol, then we need to copy the reloc
3384 into the shared library. However, if we are linking with
3385 -Bsymbolic, we do not need to copy a reloc against a
3386 global symbol which is defined in an object we are
3387 including in the link (i.e., DEF_REGULAR is set). At
3388 this point we have not seen all the input files, so it is
3389 possible that DEF_REGULAR is not set now but will be set
3390 later (it is never cleared). In case of a weak definition,
3391 DEF_REGULAR may be cleared later by a strong definition in
3392 a shared library. We account for that possibility below by
3393 storing information in the dyn_relocs field of the hash
3394 table entry. A similar situation occurs when creating
3395 shared libraries and symbol visibility changes render the
3396 symbol local.
3398 If on the other hand, we are creating an executable, we
3399 may need to keep relocations for symbols satisfied by a
3400 dynamic library if we manage to avoid copy relocs for the
3401 symbol. */
3408 || (ELIMINATE_COPY_RELOCS
3413 {
3417 #ifdef DEBUG
3419 "ppc_elf_check_relocs needs to "
3423 #endif
3425 {
3428 name = (bfd_elf_string_from_elf_section
3443 {
3444 flagword flags;
3450 name,
3451 flags);
3456 }
3458 }
3460 /* If this is a global symbol, we count the number of
3461 relocations we need for this symbol. */
3463 {
3465 }
3466 else
3467 {
3468 /* Track dynamic relocs needed for local syms too.
3469 We really need local syms available to do this
3470 easily. Oh well. */
3482 }
3486 {
3495 }
3500 }
3503 }
3504 }
3507 }
3508 \f
3509 /* Merge backend specific data from an object file to the output
3510 object file when linking. */
3512 static bfd_boolean
3514 {
3515 flagword old_flags;
3516 flagword new_flags;
3517 bfd_boolean error;
3523 /* Check if we have the same endianess. */
3530 {
3531 /* First call, no flags set. */
3534 }
3536 /* Compatible flags are ok. */
3538 ;
3540 /* Incompatible flags. */
3541 else
3542 {
3543 /* Warn about -mrelocatable mismatch. Allow -mrelocatable-lib
3544 to be linked with either. */
3548 {
3553 }
3556 {
3561 }
3563 /* The output is -mrelocatable-lib iff both the input files are. */
3567 /* The output is -mrelocatable iff it can't be -mrelocatable-lib,
3568 but each input file is either -mrelocatable or -mrelocatable-lib. */
3574 /* Do not warn about eabi vs. V.4 mismatch, just or in the bit if
3575 any module uses it. */
3581 /* Warn about any other mismatches. */
3583 {
3589 }
3592 {
3595 }
3596 }
3599 }
3600 \f
3601 /* Choose which PLT scheme to use, and set .plt flags appropriately.
3602 Returns -1 on error, 0 for old PLT, 1 for new PLT. */
3603 int
3608 {
3610 flagword flags;
3623 {
3627 /* The new PLT is a loaded section. */
3632 /* The new GOT is not executable. */
3636 }
3637 else
3638 {
3639 /* Stop an unused .glink section from affecting .text alignment. */
3643 }
3645 }
3646 \f
3647 /* Return the section that should be marked against GC for a given
3648 relocation. */
3656 {
3658 {
3660 {
3667 {
3677 }
3678 }
3679 }
3680 else
3684 }
3686 /* Update the got, plt and dynamic reloc reference counts for the
3687 section being removed. */
3689 static bfd_boolean
3694 {
3715 {
3722 {
3734 {
3735 /* Everything must go for SEC. */
3738 }
3739 }
3743 {
3749 /* Fall thru */
3768 {
3771 }
3773 {
3776 }
3786 /* Fall thru */
3809 {
3814 }
3819 }
3820 }
3822 }
3823 \f
3824 /* Set htab->tls_get_addr and call the generic ELF tls_setup function. */
3826 asection *
3828 {
3835 {
3838 }
3843 }
3845 /* Run through all the TLS relocs looking for optimization
3846 opportunities. */
3848 bfd_boolean
3851 {
3861 {
3867 {
3871 /* Read the relocations. */
3880 {
3886 bfd_boolean is_local;
3890 {
3898 }
3907 {
3912 /* These relocs should never be against a symbol
3913 defined in a shared lib. Leave them alone if
3914 that turns out to be the case. */
3920 /* LD -> LE */
3931 /* GD -> LE */
3933 else
3934 /* GD -> IE */
3946 {
3947 /* IE -> LE */
3951 }
3952 else
3962 {
3966 }
3973 }
3976 {
3978 {
3979 /* We managed to get rid of a got entry. */
3982 }
3984 }
3985 else
3986 {
3992 {
3999 {
4003 }
4004 }
4010 {
4011 /* We managed to get rid of a got entry. */
4014 }
4017 }
4021 }
4025 }
4029 {
4032 else
4034 }
4035 }
4037 }
4038 \f
4039 /* Adjust a symbol defined by a dynamic object and referenced by a
4040 regular object. The current definition is in some section of the
4041 dynamic object, but we're not including those sections. We have to
4042 change the definition to something the rest of the link can
4043 understand. */
4045 static bfd_boolean
4048 {
4053 #ifdef DEBUG
4056 #endif
4058 /* Make sure we know what is going on here. */
4067 /* Deal with function syms. */
4070 {
4071 /* Clear procedure linkage table information for any symbol that
4072 won't need a .plt entry. */
4081 {
4082 /* A PLT entry is not required/allowed when:
4084 1. We are not using ld.so; because then the PLT entry
4085 can't be set up, so we can't use one. In this case,
4086 ppc_elf_adjust_dynamic_symbol won't even be called.
4088 2. GC has rendered the entry unused.
4090 3. We know for certain that a call to this symbol
4091 will go to this object, or will remain undefined. */
4094 }
4096 }
4097 else
4100 /* If this is a weak symbol, and there is a real definition, the
4101 processor independent code will have arranged for us to see the
4102 real definition first, and we can just use the same value. */
4104 {
4112 }
4114 /* This is a reference to a symbol defined by a dynamic object which
4115 is not a function. */
4117 /* If we are creating a shared library, we must presume that the
4118 only references to the symbol are via the global offset table.
4119 For such cases we need not do anything here; the relocations will
4120 be handled correctly by relocate_section. */
4124 /* If there are no references to this symbol that do not use the
4125 GOT, we don't need to generate a copy reloc. */
4129 /* If we didn't find any dynamic relocs in read-only sections, then we'll
4130 be keeping the dynamic relocs and avoiding the copy reloc. We can't
4131 do this if there are any small data relocations. */
4134 {
4137 {
4141 }
4144 {
4147 }
4148 }
4151 {
4155 }
4157 /* We must allocate the symbol in our .dynbss section, which will
4158 become part of the .bss section of the executable. There will be
4159 an entry for this symbol in the .dynsym section. The dynamic
4160 object will contain position independent code, so all references
4161 from the dynamic object to this symbol will go through the global
4162 offset table. The dynamic linker will use the .dynsym entry to
4163 determine the address it must put in the global offset table, so
4164 both the dynamic object and the regular object will refer to the
4165 same memory location for the variable.
4167 Of course, if the symbol is referenced using SDAREL relocs, we
4168 must instead allocate it in .sbss. */
4172 else
4176 /* We must generate a R_PPC_COPY reloc to tell the dynamic linker to
4177 copy the initial value out of the dynamic object and into the
4178 runtime process image. We need to remember the offset into the
4179 .rela.bss section we are going to use. */
4181 {
4186 else
4191 }
4193 /* We need to figure out the alignment required for this symbol. I
4194 have no idea how ELF linkers handle this. */
4199 /* Apply the required alignment. */
4202 {
4205 }
4207 /* Define the symbol as being at this point in the section. */
4211 /* Increment the section size to make room for the symbol. */
4215 }
4216 \f
4217 /* Generate a symbol to mark plt call stubs. For non-PIC code the sym is
4218 xxxxxxxx.plt_call32.<callee> where xxxxxxxx is a hex number, usually 0,
4219 specifying the addend on the plt relocation. For -fpic code, the sym
4220 is xxxxxxxx.plt_pic32.<callee>, and for -fPIC
4221 xxxxxxxx.got2.plt_pic32.<callee>. */
4223 static bfd_boolean
4227 {
4236 else
4256 {
4265 }
4267 }
4269 /* Allocate NEED contiguous space in .got, and return the offset.
4270 Handles allocation of the got header when crossing 32k. */
4272 static bfd_vma
4274 {
4275 bfd_vma where;
4279 {
4282 }
4283 else
4284 {
4287 {
4290 }
4291 else
4292 {
4295 {
4298 }
4301 }
4302 }
4304 }
4306 /* Allocate space in associated reloc sections for dynamic relocs. */
4308 static bfd_boolean
4310 {
4320 /* When warning symbols are created, they **replace** the "real"
4321 entry in the hash table, thus we never get to see the real
4322 symbol in a hash traversal. So look at it now. */
4327 {
4334 {
4335 /* Make sure this symbol is output as a dynamic symbol. */
4338 {
4341 }
4345 {
4349 {
4351 {
4354 }
4359 {
4362 }
4366 {
4369 }
4375 }
4376 else
4377 {
4379 {
4380 /* If this is the first .plt entry, make room
4381 for the special first entry. */
4385 /* The PowerPC PLT is actually composed of two
4386 parts, the first part is 2 words (for a load
4387 and a jump), and then there is a remaining
4388 word available at the end. */
4395 /* If this symbol is not defined in a regular
4396 file, and we are not generating a shared
4397 library, then set the symbol to this location
4398 in the .plt. This is required to make
4399 function pointers compare as equal between
4400 the normal executable and the shared library. */
4403 {
4406 }
4408 /* Make room for this entry. */
4410 /* After the 8192nd entry, room for two entries
4411 is allocated. */
4417 }
4419 }
4421 /* We also need to make an entry in the .rela.plt section. */
4423 {
4427 {
4428 /* Allocate space for the unloaded relocations. */
4430 {
4433 {
4437 }
4442 }
4444 /* Every PLT entry has an associated GOT entry in
4445 .got.plt. */
4447 }
4449 }
4450 }
4451 else
4455 {
4458 }
4459 }
4460 }
4461 else
4462 {
4465 }
4469 {
4470 /* Make sure this symbol is output as a dynamic symbol. */
4473 {
4476 }
4480 /* If just an LD reloc, we'll just use htab->tlsld_got.offset. */
4482 else
4483 {
4484 bfd_boolean dyn;
4487 {
4496 }
4497 else
4505 {
4506 /* All the entries we allocated need relocs.
4507 Except LD only needs one. */
4511 }
4512 }
4513 }
4514 else
4520 /* In the shared -Bsymbolic case, discard space allocated for
4521 dynamic pc-relative relocs against symbols which turn out to be
4522 defined in regular objects. For the normal shared case, discard
4523 space for relocs that have become local due to symbol visibility
4524 changes. */
4527 {
4528 /* Relocs that use pc_count are those that appear on a call insn,
4529 or certain REL relocs (see MUST_BE_DYN_RELOC) that can be
4530 generated via assembly. We want calls to protected symbols to
4531 resolve directly to the function rather than going via the plt.
4532 If people want function pointer comparisons to work as expected
4533 then they should avoid writing weird assembly. */
4535 {
4539 {
4544 else
4546 }
4547 }
4549 /* Also discard relocs on undefined weak syms with non-default
4550 visibility. */
4553 {
4557 /* Make sure undefined weak symbols are output as a dynamic
4558 symbol in PIEs. */
4561 {
4564 }
4565 }
4566 }
4568 {
4569 /* For the non-shared case, discard space for relocs against
4570 symbols which turn out to need copy relocs or are not
4571 dynamic. */
4576 {
4577 /* Make sure this symbol is output as a dynamic symbol.
4578 Undefined weak syms won't yet be marked as dynamic. */
4581 {
4584 }
4586 /* If that succeeded, we know we'll be keeping all the
4587 relocs. */
4590 }
4594 keep: ;
4595 }
4597 /* Finally, allocate space. */
4599 {
4602 }
4605 }
4607 /* Find any dynamic relocs that apply to read-only sections. */
4609 static bfd_boolean
4611 {
4621 {
4627 {
4630 /* Not an error, just cut short the traversal. */
4632 }
4633 }
4635 }
4637 /* Set the sizes of the dynamic sections. */
4639 static bfd_boolean
4642 {
4645 bfd_boolean relocs;
4648 #ifdef DEBUG
4650 #endif
4656 {
4657 /* Set the contents of the .interp section to the interpreter. */
4659 {
4664 }
4665 }
4672 /* Set up .got offsets for local syms, and space for local dynamic
4673 relocs. */
4675 {
4679 bfd_size_type locsymcount;
4686 {
4693 {
4696 {
4697 /* Input section has been discarded, either because
4698 it is a copy of a linkonce section or due to
4699 linker script /DISCARD/, so we'll be discarding
4700 the relocs too. */
4701 }
4703 {
4710 }
4711 }
4712 }
4724 {
4726 {
4727 /* If just an LD reloc, we'll just use
4728 htab->tlsld_got.offset. */
4731 }
4732 else
4733 {
4736 {
4743 }
4744 else
4750 }
4751 }
4752 else
4754 }
4757 {
4761 }
4762 else
4765 /* Allocate space for global sym dynamic relocs. */
4769 {
4772 /* If we haven't allocated the header, do so now. When we get here,
4773 for old plt/got the got size will be 0 to 32764 (not allocated),
4774 or 32780 to 65536 (header allocated). For new plt/got, the
4775 corresponding ranges are 0 to 32768 and 32780 to 65536. */
4777 {
4782 }
4785 }
4788 {
4790 /* Space for the branch table. */
4792 /* Pad out to align the start of PLTresolve. */
4797 {
4804 {
4813 }
4819 {
4828 }
4829 }
4830 }
4832 /* We've now determined the sizes of the various dynamic sections.
4833 Allocate memory for them. */
4836 {
4849 {
4850 /* We'd like to strip these sections if they aren't needed, but if
4851 we've exported dynamic symbols from them we must leave them.
4852 It's too late to tell BFD to get rid of the symbols. */
4855 /* Strip this section if we don't need it; see the
4856 comment below. */
4857 }
4860 {
4861 /* Strip these too. */
4862 }
4864 {
4866 {
4867 /* Remember whether there are any relocation sections. */
4870 /* We use the reloc_count field as a counter if we need
4871 to copy relocs into the output file. */
4873 }
4874 }
4875 else
4876 {
4877 /* It's not one of our sections, so don't allocate space. */
4879 }
4882 {
4883 /* If we don't need this section, strip it from the
4884 output file. This is mostly to handle .rela.bss and
4885 .rela.plt. We must create both sections in
4886 create_dynamic_sections, because they must be created
4887 before the linker maps input sections to output
4888 sections. The linker does that before
4889 adjust_dynamic_symbol is called, and it is that
4890 function which decides whether anything needs to go
4891 into these sections. */
4894 }
4899 /* Allocate memory for the section contents. */
4903 }
4906 {
4907 /* Add some entries to the .dynamic section. We fill in the
4908 values later, in ppc_elf_finish_dynamic_sections, but we
4909 must add the entries now so that we get the correct size for
4910 the .dynamic section. The DT_DEBUG entry is filled in by the
4911 dynamic linker and used by the debugger. */
4912 #define add_dynamic_entry(TAG, VAL) \
4913 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
4916 {
4919 }
4922 {
4928 }
4931 {
4934 }
4937 {
4942 }
4944 /* If any dynamic relocs apply to a read-only section, then we
4945 need a DT_TEXTREL entry. */
4948 info);
4951 {
4954 }
4955 }
4956 #undef add_dynamic_entry
4959 }
4960 \f
4961 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
4964 {
4973 };
4976 {
4981 };
4983 static bfd_boolean
4988 {
4989 struct one_fixup
4990 {
4993 bfd_vma toff;
4994 bfd_vma trampoff;
4995 };
5003 bfd_boolean changed;
5005 bfd_size_type trampoff;
5010 /* Nothing to do if there are no relocations, and no need to do
5011 anything with non-alloc sections. */
5018 /* Space for a branch around any trampolines. */
5023 /* Get a copy of the native relocations. */
5034 {
5046 {
5061 }
5063 /* Get the value of the symbol referred to by the reloc. */
5065 {
5066 /* A local symbol. */
5069 /* Read this BFD's local symbols. */
5071 {
5079 }
5087 else
5092 }
5093 else
5094 {
5095 /* Global symbol handling. */
5110 {
5114 {
5116 {
5119 }
5120 else
5121 {
5124 }
5125 }
5126 }
5128 ;
5131 {
5134 }
5135 else
5139 }
5141 /* If the branch and target are in the same section, you have
5142 no hope of adding stubs. We'll error out later should the
5143 branch overflow. */
5147 /* There probably isn't any reason to handle symbols in
5148 SEC_MERGE sections; SEC_MERGE doesn't seem a likely
5149 attribute for a code section, and we are only looking at
5150 branches. However, implement it correctly here as a
5151 reference for other target relax_section functions. */
5153 {
5154 /* At this stage in linking, no SEC_MERGE symbol has been
5155 adjusted, so all references to such symbols need to be
5156 passed through _bfd_merged_section_offset. (Later, in
5157 relocate_section, all SEC_MERGE symbols *except* for
5158 section symbols have been adjusted.)
5160 gas may reduce relocations against symbols in SEC_MERGE
5161 sections to a relocation against the section symbol when
5162 the original addend was zero. When the reloc is against
5163 a section symbol we should include the addend in the
5164 offset passed to _bfd_merged_section_offset, since the
5165 location of interest is the original symbol. On the
5166 other hand, an access to "sym+addend" where "sym" is not
5167 a section symbol should not include the addend; Such an
5168 access is presumed to be an offset from "sym"; The
5169 location of interest is just "sym". */
5175 toff);
5179 }
5180 /* PLTREL24 addends are special. */
5189 /* If the branch is in range, no need to do anything. */
5193 /* Look for an existing fixup to this address. */
5199 {
5205 /* Oh dear, we can't reach a trampoline. Don't try to add
5206 one. We'll report an error later. */
5210 {
5214 }
5215 else
5216 {
5220 }
5229 /* Hijack the old relocation. Since we need two
5230 relocations for this use a "composite" reloc. */
5232 stub_rtype);
5235 /* Record the fixup so we don't do it again this section. */
5244 }
5245 else
5246 {
5251 /* Nop out the reloc, since we're finalizing things here. */
5253 }
5255 /* Get the section contents. */
5257 {
5258 /* Get cached copy if it exists. */
5261 else
5262 {
5263 /* Go get them off disk. */
5266 }
5267 }
5269 /* Fix up the existing branch to hit the trampoline. */
5272 {
5290 }
5291 }
5293 /* Write out the trampolines. */
5296 {
5299 bfd_vma val;
5302 do
5303 {
5307 }
5315 /* Branch around the trampolines. */
5323 {
5326 }
5327 else
5328 {
5331 }
5335 {
5337 i++;
5341 }
5343 }
5347 {
5350 else
5351 {
5352 /* Cache the symbols for elf_link_input_bfd. */
5354 }
5355 }
5359 {
5362 else
5363 {
5364 /* Cache the section contents for elf_link_input_bfd. */
5366 }
5367 }
5370 {
5373 else
5375 }
5380 error_return:
5390 }
5391 \f
5392 /* What to do when ld finds relocations against symbols defined in
5393 discarded sections. */
5395 static unsigned int
5397 {
5405 }
5406 \f
5407 /* Fill in the address for a pointer generated in a linker section. */
5409 static bfd_vma
5413 bfd_vma relocation,
5415 {
5421 {
5422 /* Handle global symbol. */
5428 }
5429 else
5430 {
5431 /* Handle local symbol. */
5436 }
5440 lsect);
5443 /* Offset will always be a multiple of four, so use the bottom bit
5444 as a "written" flag. */
5446 {
5451 }
5457 #ifdef DEBUG
5461 #endif
5463 /* Subtract out the addend, because it will get added back in by the normal
5464 processing. */
5466 }
5468 /* The RELOCATE_SECTION function is called by the ELF backend linker
5469 to handle the relocations for a section.
5471 The relocs are always passed as Rela structures; if the section
5472 actually uses Rel structures, the r_addend field will always be
5473 zero.
5475 This function is responsible for adjust the section contents as
5476 necessary, and (if using Rela relocs and generating a
5477 relocatable output file) adjusting the reloc addend as
5478 necessary.
5480 This function does not have to worry about setting the reloc
5481 address or the reloc symbol index.
5483 LOCAL_SYMS is a pointer to the swapped in local symbols.
5485 LOCAL_SECTIONS is an array giving the section in the input file
5486 corresponding to the st_shndx field of each local symbol.
5488 The global hash table entry for the global symbols can be found
5489 via elf_sym_hashes (input_bfd).
5491 When generating relocatable output, this function must handle
5492 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
5493 going to be the section symbol corresponding to the output
5494 section, which means that the addend must be adjusted
5495 accordingly. */
5497 static bfd_boolean
5506 {
5512 Elf_Internal_Rela outrel;
5518 #ifdef DEBUG
5524 #endif
5529 {
5536 {
5542 {
5543 /* R_PPC_PLTREL24 is rather special. If non-zero, the
5544 addend specifies the GOT pointer offset within .got2. */
5546 }
5547 }
5549 }
5551 /* Initialize howto table if not already done. */
5562 {
5564 bfd_vma addend;
5565 bfd_reloc_status_type r;
5572 bfd_vma relocation;
5574 bfd_boolean unresolved_reloc;
5575 bfd_boolean warned;
5587 {
5593 }
5594 else
5595 {
5602 }
5604 /* TLS optimizations. Replace instruction sequences and relocs
5605 based on information we collected in tls_optimize. We edit
5606 RELOCS so that --emit-relocs will output something sensible
5607 for the final instruction stream. */
5611 {
5615 {
5619 }
5620 }
5622 /* Ensure reloc mapping code below stays sane. */
5633 {
5641 {
5642 bfd_vma insn;
5649 }
5655 {
5664 else
5667 /* add -> addi. */
5673 /* load and store indexed -> dform. */
5677 /* ldx, ldux, stdx, stdux -> ld, ldu, std, stdu. */
5682 /* lwax -> lwa. */
5684 else
5690 /* Was PPC_TLS which sits on insn boundary, now
5691 PPC_TPREL16_LO which is at insn+2. */
5693 }
5706 {
5707 tls_gdld_hi:
5711 else
5712 {
5716 }
5718 }
5731 {
5732 tls_get_addr_check:
5734 {
5739 bfd_vma offset;
5741 /* The next instruction should be a call to
5742 __tls_get_addr. Peek at the reloc to be sure. */
5760 /* OK, it checks out. Replace the call. */
5765 {
5766 /* IE */
5775 }
5776 else
5777 {
5778 /* LE */
5782 {
5783 /* Was an LD reloc. */
5786 }
5790 R_PPC_TPREL16_LO);
5793 }
5797 {
5798 /* We changed the symbol on an LD reloc. Start over
5799 in order to get h, sym, sec etc. right. */
5800 rel--;
5802 }
5803 }
5804 }
5806 }
5808 /* Handle other relocations that tweak non-addend part of insn. */
5811 {
5815 /* Branch taken prediction relocations. */
5819 /* Fall thru */
5821 /* Branch not taken prediction relocations. */
5832 /* Invert 'y' bit if not the default. */
5838 }
5846 {
5863 /* GOT16 relocations. Like an ADDR16 using the symbol's
5864 address in the GOT as relocation value instead of the
5865 symbol's value itself. Also, create a GOT entry for the
5866 symbol and put the symbol value there. */
5899 dogot:
5900 {
5901 /* Relocation is to the entry for this symbol in the global
5902 offset table. */
5903 bfd_vma off;
5916 {
5917 bfd_boolean dyn;
5922 /* This is actually a static link, or it is a
5923 -Bsymbolic link and the symbol is defined
5924 locally, or the symbol was forced to be local
5925 because of a version file. */
5926 ;
5927 else
5928 {
5931 }
5933 }
5934 else
5935 {
5939 }
5941 /* The offset must always be a multiple of 4. We use the
5942 least significant bit to record whether we have already
5943 processed this entry. */
5947 else
5948 {
5959 /* We might have multiple got entries for this sym.
5960 Initialize them all. */
5961 do
5962 {
5966 {
5969 }
5971 {
5974 }
5976 {
5979 }
5981 {
5984 }
5986 /* Generate relocs for the dynamic linker. */
5991 {
5997 {
6000 {
6007 outrel.r_info
6009 }
6010 }
6017 else
6020 {
6024 }
6029 }
6031 /* Init the .got section contents if we're not
6032 emitting a reloc. */
6033 else
6034 {
6040 {
6046 {
6050 }
6051 }
6054 }
6059 }
6064 }
6070 {
6072 {
6078 {
6082 {
6085 }
6086 }
6087 }
6088 }
6093 /* Addends on got relocations don't make much sense.
6094 x+off@got is actually x@got+off, and since the got is
6095 generated by a hash table traversal, the value in the
6096 got at entry m+n bears little relation to the entry m. */
6100 input_bfd,
6101 input_section,
6104 sym_name);
6105 }
6108 /* Relocations that need no special processing. */
6110 /* It makes no sense to point a local relocation
6111 at a symbol not in this object. */
6113 {
6116 input_bfd,
6117 input_section,
6119 TRUE))
6122 }
6132 /* Relocations that may need to be propagated if this is a shared
6133 object. */
6139 /* The TPREL16 relocs shouldn't really be used in shared
6140 libs as they will result in DT_TEXTREL being set, but
6141 support them anyway. */
6168 /* If these relocations are not to a named symbol, they can be
6169 handled right here, no need to bother the dynamic linker. */
6173 /* fall through */
6175 /* Relocations that always need to be propagated if this is a shared
6176 object. */
6188 /* r_symndx will be zero only for relocs against symbols
6189 from removed linkonce sections, or sections discarded by
6190 a linker script. */
6191 dodyn:
6194 /* Fall thru. */
6198 /* Fall thru. */
6206 || (ELIMINATE_COPY_RELOCS
6213 {
6216 #ifdef DEBUG
6221 #endif
6223 /* When generating a shared object, these relocations
6224 are copied into the output file to be resolved at run
6225 time. */
6227 {
6230 name = (bfd_elf_string_from_elf_section
6239 input_section),
6244 }
6260 {
6264 }
6265 else
6266 {
6271 else
6272 {
6278 {
6281 }
6282 else
6283 {
6286 /* We are turning this relocation into one
6287 against a section symbol. It would be
6288 proper to subtract the symbol's value,
6289 osec->vma, from the emitted reloc addend,
6290 but ld.so expects buggy relocs. */
6294 #ifdef DEBUG
6299 #endif
6300 }
6303 }
6304 }
6313 /* This reloc will be computed at runtime. We clear the memory
6314 so that it contains predictable value. */
6318 {
6322 }
6323 }
6328 {
6335 else
6340 }
6343 /* Fall thru */
6349 /* Fall thru */
6352 relax32:
6353 {
6360 /* We're clearing the bits for R_PPC_ADDR16_HA
6361 and R_PPC_ADDR16_LO here. */
6365 /* t0 is HA, t1 is LO */
6372 }
6375 /* Indirect .sdata relocation. */
6378 relocation
6383 /* Indirect .sdata2 relocation. */
6386 relocation
6391 /* Handle the TOC16 reloc. We want to use the offset within the .got
6392 section, not the actual VMA. This is appropriate when generating
6393 an embedded ELF object, for which the .got section acts like the
6394 AIX .toc section. */
6405 /* Relocation is to the entry for this symbol in the
6406 procedure linkage table. */
6407 {
6413 {
6414 /* We didn't make a PLT entry for this symbol. This
6415 happens when statically linking PIC code, or when
6416 using -Bsymbolic. */
6418 }
6425 else
6429 }
6432 /* Relocate against _SDA_BASE_. */
6434 {
6444 {
6448 input_bfd,
6449 sym_name,
6451 name);
6452 }
6457 }
6460 /* Relocate against _SDA2_BASE_. */
6462 {
6470 {
6474 input_bfd,
6475 sym_name,
6477 name);
6482 }
6487 }
6490 /* Relocate against either _SDA_BASE_, _SDA2_BASE_, or 0. */
6493 {
6504 {
6510 }
6514 {
6520 }
6524 {
6526 }
6528 else
6529 {
6533 input_bfd,
6534 sym_name,
6536 name);
6541 }
6548 }
6549 }
6552 /* Relocate against the beginning of the section. */
6561 /* Negative relocations. */
6587 input_bfd,
6589 sym_name);
6594 }
6596 /* Do any further special processing. */
6598 {
6615 /* It's just possible that this symbol is a weak symbol
6616 that's not actually defined anywhere. In that case,
6617 'sec' would be NULL, and we should leave the symbol
6618 alone (it will be set to zero elsewhere in the link). */
6620 /* Add 0x10000 if sign bit in 0:15 is set.
6621 Bits 0:15 are not used. */
6624 }
6626 #ifdef DEBUG
6631 sym_name,
6632 r_symndx,
6635 #endif
6640 {
6643 input_bfd,
6644 input_section,
6647 sym_name);
6649 }
6652 input_bfd,
6653 input_section,
6654 contents,
6656 relocation,
6657 addend);
6660 {
6662 {
6668 {
6669 /* Assume this is a call protected by other code that
6670 detect the symbol is undefined. If this is the case,
6671 we can safely ignore the overflow. If not, the
6672 program is hosed anyway, and a little warning isn't
6673 going to help. */
6676 }
6680 sym_name,
6683 input_bfd,
6684 input_section,
6687 }
6688 else
6689 {
6695 }
6696 }
6697 }
6699 #ifdef DEBUG
6701 #endif
6704 }
6705 \f
6706 #define PPC_LO(v) ((v) & 0xffff)
6707 #define PPC_HI(v) (((v) >> 16) & 0xffff)
6708 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
6710 /* Finish up dynamic symbol handling. We set the contents of various
6711 dynamic sections here. */
6713 static bfd_boolean
6718 {
6721 bfd_boolean doneone;
6723 #ifdef DEBUG
6726 #endif
6734 {
6736 {
6737 Elf_Internal_Rela rela;
6739 bfd_vma reloc_index;
6743 else
6744 {
6750 }
6752 /* This symbol has an entry in the procedure linkage table.
6753 Set it up. */
6755 {
6756 bfd_vma got_offset;
6759 /* The first three entries in .got.plt are reserved. */
6762 /* Use the right PLT. */
6766 /* Fill in the .plt on VxWorks. */
6768 {
6778 }
6779 else
6780 {
6781 bfd_vma got_loc
6782 = (got_offset
6795 }
6802 /* This instruction is an immediate load. The value loaded is
6803 the byte offset of the R_PPC_JMP_SLOT relocation from the
6804 start of the .rela.plt section. The value is stored in the
6805 low-order 16 bits of the load instruction. */
6806 /* NOTE: It appears that this is now an index rather than a
6807 prescaled offset. */
6811 /* This instruction is a PC-relative branch whose target is
6812 the start of the PLT section. The address of this branch
6813 instruction is 20 bytes beyond the start of this PLT entry.
6814 The address is encoded in bits 6-29, inclusive. The value
6815 stored is right-shifted by two bits, permitting a 26-bit
6816 offset. */
6826 /* Fill in the GOT entry corresponding to this PLT slot with
6827 the address immediately after the the "bctr" instruction
6828 in this PLT entry. */
6835 {
6836 /* Fill in a couple of entries in .rela.plt.unloaded. */
6842 /* Provide the @ha relocation for the first instruction. */
6847 R_PPC_ADDR16_HA);
6852 /* Provide the @l relocation for the second instruction. */
6857 R_PPC_ADDR16_LO);
6862 /* Provide a relocation for the GOT entry corresponding to this
6863 PLT slot. Point it at the middle of the .plt entry. */
6868 R_PPC_ADDR32);
6871 }
6873 /* VxWorks uses non-standard semantics for R_PPC_JMP_SLOT.
6874 In particular, the offset for the relocation is not the
6875 address of the PLT entry for this function, as specified
6876 by the ABI. Instead, the offset is set to the address of
6877 the GOT slot for this function. See EABI 4.4.4.1. */
6882 }
6883 else
6884 {
6889 {
6890 /* We don't need to fill in the .plt. The ppc dynamic
6891 linker will fill it in. */
6892 }
6893 else
6894 {
6900 }
6901 }
6903 /* Fill in the entry in the .rela.plt section. */
6912 {
6913 /* Mark the symbol as undefined, rather than as defined in
6914 the .plt section. Leave the value alone. */
6916 /* If the symbol is weak, we do need to clear the value.
6917 Otherwise, the PLT entry would provide a definition for
6918 the symbol even if the symbol wasn't defined anywhere,
6919 and so the symbol would never be NULL. */
6922 }
6924 }
6927 {
6928 bfd_vma plt;
6937 {
6952 {
6961 }
6962 else
6963 {
6972 }
6973 }
6974 else
6975 {
6985 /* We only need one non-PIC glink stub. */
6987 }
6988 }
6989 else
6991 }
6994 {
6996 Elf_Internal_Rela rela;
6999 /* This symbols needs a copy reloc. Set it up. */
7001 #ifdef DEBUG
7003 #endif
7009 else
7020 }
7022 #ifdef DEBUG
7024 #endif
7026 /* Mark some specially defined symbols as absolute. */
7035 }
7036 \f
7037 static enum elf_reloc_type_class
7039 {
7041 {
7052 }
7053 }
7054 \f
7055 /* Finish up the dynamic sections. */
7057 static bfd_boolean
7060 {
7064 bfd_vma got;
7067 #ifdef DEBUG
7069 #endif
7076 else
7086 {
7094 {
7095 Elf_Internal_Dyn dyn;
7101 {
7105 else
7125 {
7129 }
7134 }
7137 }
7138 }
7140 /* Add a blrl instruction at _GLOBAL_OFFSET_TABLE_-4 so that a function can
7141 easily find the address of the _GLOBAL_OFFSET_TABLE_. */
7143 {
7145 bfd_vma val;
7157 }
7159 /* Fill in the first entry in the VxWorks procedure linkage table. */
7161 {
7162 /* Use the right PLT. */
7168 {
7169 bfd_vma got_value =
7179 }
7180 else
7181 {
7184 }
7193 {
7194 Elf_Internal_Rela rela;
7199 /* Output the @ha relocation for the first instruction. */
7208 /* Output the @l relocation for the second instruction. */
7217 /* Fix up the remaining relocations. They may have the wrong
7218 symbol index for _G_O_T_ or _P_L_T_ depending on the order
7219 in which symbols were output. */
7221 {
7222 Elf_Internal_Rela rel;
7238 }
7239 }
7240 }
7243 {
7246 bfd_vma res0;
7249 /*
7250 * PIC glink code is the following:
7251 *
7252 * # ith PLT code stub.
7253 * addis 11,30,(plt+(i-1)*4-got)@ha
7254 * lwz 11,(plt+(i-1)*4-got)@l(11)
7255 * mtctr 11
7256 * bctr
7257 *
7258 * # A table of branches, one for each plt entry.
7259 * # The idea is that the plt call stub loads ctr (and r11) with these
7260 * # addresses, so (r11 - res_0) gives the plt index * 4.
7261 * res_0: b PLTresolve
7262 * res_1: b PLTresolve
7263 * .
7264 * # Some number of entries towards the end can be nops
7265 * res_n_m3: nop
7266 * res_n_m2: nop
7267 * res_n_m1:
7268 *
7269 * PLTresolve:
7270 * addis 11,11,(1f-res_0)@ha
7271 * mflr 0
7272 * bcl 20,31,1f
7273 * 1: addi 11,11,(1b-res_0)@l
7274 * mflr 12
7275 * mtlr 0
7276 * sub 11,11,12 # r11 = index * 4
7277 * addis 12,12,(got+4-1b)@ha
7278 * lwz 0,(got+4-1b)@l(12) # got[1] address of dl_runtime_resolve
7279 * lwz 12,(got+8-1b)@l(12) # got[2] contains the map address
7280 * mtctr 0
7281 * add 0,11,11
7282 * add 11,0,11 # r11 = index * 12 = reloc offset.
7283 * bctr
7284 */
7286 {
7287 ADDIS_11_11,
7288 MFLR_0,
7289 BCL_20_31,
7290 ADDI_11_11,
7291 MFLR_12,
7292 MTLR_0,
7293 SUB_11_11_12,
7294 ADDIS_12_12,
7295 LWZ_0_12,
7296 LWZ_12_12,
7297 MTCTR_0,
7298 ADD_0_11_11,
7299 ADD_11_0_11,
7300 BCTR,
7301 NOP,
7302 NOP
7303 };
7306 {
7307 LIS_12,
7308 ADDIS_11_11,
7309 LWZ_0_12,
7310 ADDI_11_11,
7311 MTCTR_0,
7312 ADD_0_11_11,
7313 LWZ_12_12,
7314 ADD_11_0_11,
7315 BCTR,
7316 NOP,
7317 NOP,
7318 NOP,
7319 NOP,
7320 NOP,
7321 NOP,
7322 NOP
7323 };
7330 /* Build the branch table, one for each plt entry (less one),
7331 and perhaps some padding. */
7337 {
7340 }
7342 {
7345 }
7351 /* Last comes the PLTresolve stub. */
7353 {
7354 bfd_vma bcl;
7357 {
7360 }
7374 {
7379 }
7380 else
7381 {
7386 }
7387 }
7388 else
7389 {
7391 {
7394 }
7404 {
7409 }
7410 else
7411 {
7416 }
7417 }
7418 }
7421 }
7422 \f
7423 #define TARGET_LITTLE_SYM bfd_elf32_powerpcle_vec
7425 #define TARGET_BIG_SYM bfd_elf32_powerpc_vec
7427 #define ELF_ARCH bfd_arch_powerpc
7428 #define ELF_MACHINE_CODE EM_PPC
7429 #ifdef __QNXTARGET__
7430 #define ELF_MAXPAGESIZE 0x1000
7431 #else
7432 #define ELF_MAXPAGESIZE 0x10000
7433 #endif
7434 #define ELF_MINPAGESIZE 0x1000
7435 #define elf_info_to_howto ppc_elf_info_to_howto
7437 #ifdef EM_CYGNUS_POWERPC
7438 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
7439 #endif
7441 #ifdef EM_PPC_OLD
7442 #define ELF_MACHINE_ALT2 EM_PPC_OLD
7443 #endif
7445 #define elf_backend_plt_not_loaded 1
7446 #define elf_backend_can_gc_sections 1
7447 #define elf_backend_can_refcount 1
7448 #define elf_backend_rela_normal 1
7450 #define bfd_elf32_mkobject ppc_elf_mkobject
7451 #define bfd_elf32_bfd_merge_private_bfd_data ppc_elf_merge_private_bfd_data
7452 #define bfd_elf32_bfd_relax_section ppc_elf_relax_section
7453 #define bfd_elf32_bfd_reloc_type_lookup ppc_elf_reloc_type_lookup
7454 #define bfd_elf32_bfd_set_private_flags ppc_elf_set_private_flags
7455 #define bfd_elf32_bfd_link_hash_table_create ppc_elf_link_hash_table_create
7457 #define elf_backend_object_p ppc_elf_object_p
7458 #define elf_backend_gc_mark_hook ppc_elf_gc_mark_hook
7459 #define elf_backend_gc_sweep_hook ppc_elf_gc_sweep_hook
7460 #define elf_backend_section_from_shdr ppc_elf_section_from_shdr
7461 #define elf_backend_relocate_section ppc_elf_relocate_section
7462 #define elf_backend_create_dynamic_sections ppc_elf_create_dynamic_sections
7463 #define elf_backend_check_relocs ppc_elf_check_relocs
7464 #define elf_backend_copy_indirect_symbol ppc_elf_copy_indirect_symbol
7465 #define elf_backend_adjust_dynamic_symbol ppc_elf_adjust_dynamic_symbol
7466 #define elf_backend_add_symbol_hook ppc_elf_add_symbol_hook
7467 #define elf_backend_size_dynamic_sections ppc_elf_size_dynamic_sections
7468 #define elf_backend_finish_dynamic_symbol ppc_elf_finish_dynamic_symbol
7469 #define elf_backend_finish_dynamic_sections ppc_elf_finish_dynamic_sections
7470 #define elf_backend_fake_sections ppc_elf_fake_sections
7471 #define elf_backend_additional_program_headers ppc_elf_additional_program_headers
7472 #define elf_backend_grok_prstatus ppc_elf_grok_prstatus
7473 #define elf_backend_grok_psinfo ppc_elf_grok_psinfo
7474 #define elf_backend_reloc_type_class ppc_elf_reloc_type_class
7475 #define elf_backend_begin_write_processing ppc_elf_begin_write_processing
7476 #define elf_backend_final_write_processing ppc_elf_final_write_processing
7477 #define elf_backend_write_section ppc_elf_write_section
7478 #define elf_backend_get_sec_type_attr ppc_elf_get_sec_type_attr
7479 #define elf_backend_plt_sym_val ppc_elf_plt_sym_val
7480 #define elf_backend_action_discarded ppc_elf_action_discarded
7484 /* VxWorks Target */
7486 #undef TARGET_LITTLE_SYM
7487 #undef TARGET_LITTLE_NAME
7489 #undef TARGET_BIG_SYM
7490 #define TARGET_BIG_SYM bfd_elf32_powerpc_vxworks_vec
7491 #undef TARGET_BIG_NAME
7494 /* VxWorks uses the elf default section flags for .plt. */
7497 {
7505 }
7507 /* Like ppc_elf_link_hash_table_create, but overrides
7508 appropriately for VxWorks. */
7511 {
7516 {
7524 }
7526 }
7528 /* Tweak magic VxWorks symbols as they are loaded. */
7529 static bfd_boolean
7537 {
7539 valp))
7543 }
7545 static void
7547 {
7550 }
7552 /* On VxWorks, we emit relocations against _PROCEDURE_LINKAGE_TABLE_, so
7553 define it. */
7554 #undef elf_backend_want_plt_sym
7555 #define elf_backend_want_plt_sym 1
7556 #undef elf_backend_want_got_plt
7557 #define elf_backend_want_got_plt 1
7558 #undef elf_backend_got_symbol_offset
7559 #define elf_backend_got_symbol_offset 0
7560 #undef elf_backend_plt_not_loaded
7561 #define elf_backend_plt_not_loaded 0
7562 #undef elf_backend_plt_readonly
7563 #define elf_backend_plt_readonly 1
7564 #undef elf_backend_got_header_size
7565 #define elf_backend_got_header_size 12
7567 #undef bfd_elf32_bfd_link_hash_table_create
7568 #define bfd_elf32_bfd_link_hash_table_create \
7569 ppc_elf_vxworks_link_hash_table_create
7570 #undef elf_backend_add_symbol_hook
7571 #define elf_backend_add_symbol_hook \
7572 ppc_elf_vxworks_add_symbol_hook
7573 #undef elf_backend_link_output_symbol_hook
7574 #define elf_backend_link_output_symbol_hook \
7575 elf_vxworks_link_output_symbol_hook
7576 #undef elf_backend_final_write_processing
7577 #define elf_backend_final_write_processing \
7578 ppc_elf_vxworks_final_write_processing
7579 #undef elf_backend_get_sec_type_attr
7580 #define elf_backend_get_sec_type_attr \
7581 ppc_elf_vxworks_get_sec_type_attr
7582 #undef elf_backend_emit_relocs
7583 #define elf_backend_emit_relocs \
7584 elf_vxworks_emit_relocs
7586 #undef elf32_bed
7587 #define elf32_bed ppc_elf_vxworks_bed