| blob | 68cead29e05a3f4e833cc2d9e50b085c1925d915 |
1 /* PowerPC-specific support for 32-bit ELF
2 Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
3 2004, 2005 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))
2435 {
2438 }
2460 }
2462 /* Create .got and the related sections. */
2464 static bfd_boolean
2466 {
2469 flagword flags;
2480 {
2484 }
2485 else
2486 {
2487 /* The powerpc .got has a blrl instruction in it. Mark it
2488 executable. */
2493 }
2503 }
2505 /* We have to create .dynsbss and .rela.sbss here so that they get mapped
2506 to output sections (just like _bfd_elf_create_dynamic_sections has
2507 to create .dynbss and .rela.bss). */
2509 static bfd_boolean
2511 {
2514 flagword flags;
2542 {
2549 }
2562 /* The VxWorks PLT is a loaded section with contents. */
2565 }
2567 /* Copy the extra info we tack onto an elf_link_hash_entry. */
2569 static void
2573 {
2580 {
2582 {
2586 /* Add reloc counts against the indirect sym to the direct sym
2587 list. Merge any entries against the same section. */
2589 {
2594 {
2599 }
2602 }
2604 }
2608 }
2613 /* If called to transfer flags for a weakdef during processing
2614 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
2615 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
2626 /* If we were called to copy over info for a weak sym, that's all. */
2630 /* Copy over the GOT refcount entries that we may have already seen to
2631 the symbol which just became indirect. */
2635 /* And plt entries. */
2637 {
2639 {
2644 {
2649 {
2653 }
2656 }
2658 }
2662 }
2665 {
2673 }
2674 }
2676 /* Return 1 if target is one of ours. */
2678 static bfd_boolean
2680 {
2685 }
2687 /* Hook called by the linker routine which adds symbols from an object
2688 file. We use it to put .comm items in .sbss, and not .bss. */
2690 static bfd_boolean
2698 {
2703 {
2704 /* Common symbols less than or equal to -G nn bytes are automatically
2705 put into .sbss. */
2710 {
2718 flags);
2721 }
2725 }
2728 }
2729 \f
2730 static bfd_boolean
2733 {
2742 }
2744 /* Create a special linker section. */
2746 static bfd_boolean
2749 flagword flags,
2751 {
2758 /* Record the first bfd that needs the special sections. */
2764 flags);
2771 }
2773 /* Find a linker generated pointer with a given addend and type. */
2776 elf_find_pointer_linker_section
2778 bfd_vma addend,
2780 {
2786 }
2788 /* Allocate a pointer to live in a linker created section. */
2790 static bfd_boolean
2795 {
2799 bfd_size_type amt;
2803 /* Is this a global symbol? */
2805 {
2808 /* Has this symbol already been allocated? If so, our work is done. */
2812 lsect))
2816 }
2817 else
2818 {
2819 /* Allocation of a pointer to a local symbol. */
2822 /* Allocate a table to hold the local symbols if first time. */
2824 {
2835 }
2837 /* Has this symbol already been allocated? If so, our work is done. */
2840 lsect))
2844 }
2846 /* Allocate space for a pointer in the linker section, and allocate
2847 a new pointer record from internal memory. */
2863 #ifdef DEBUG
2868 #endif
2871 }
2873 static bfd_boolean
2878 {
2883 {
2891 }
2897 }
2899 static bfd_boolean
2902 {
2911 {
2921 }
2924 }
2928 {
2937 }
2939 static void
2941 {
2944 abfd,
2947 }
2949 /* Look through the relocs for a section during the first phase, and
2950 allocate space in the global offset table or procedure linkage
2951 table. */
2953 static bfd_boolean
2958 {
2969 /* Don't do anything special with non-loaded, non-alloced sections.
2970 In particular, any relocs in such sections should not affect GOT
2971 and PLT reference counting (ie. we don't allow them to create GOT
2972 or PLT entries), there's no possibility or desire to optimize TLS
2973 relocs, and there's not much point in propagating relocs to shared
2974 libs that the dynamic linker won't relocate. */
2978 #ifdef DEBUG
2981 #endif
2983 /* Initialize howto table if not already done. */
2995 {
3004 else
3005 {
3010 }
3012 /* If a relocation refers to _GLOBAL_OFFSET_TABLE_, create the .got.
3013 This shows up in particular in an R_PPC_ADDR32 in the eabi
3014 startup code. */
3018 {
3024 }
3028 {
3058 dogottls:
3060 /* Fall thru */
3062 /* GOT16 relocations */
3067 /* This symbol requires a global offset table entry. */
3069 {
3074 }
3076 {
3079 }
3080 else
3081 /* This is a global offset table entry for a local symbol. */
3086 /* Indirect .sdata relocation. */
3089 {
3092 }
3101 {
3104 }
3107 /* Indirect .sdata2 relocation. */
3110 {
3113 }
3122 {
3125 }
3130 {
3133 }
3138 {
3141 }
3146 {
3149 }
3154 {
3157 }
3163 {
3166 }
3174 {
3177 }
3186 {
3189 }
3200 #ifdef DEBUG
3202 #endif
3203 /* This symbol requires a procedure linkage table entry. We
3204 actually build the entry in finish_dynamic_symbol,
3205 because this might be a case of linking PIC code without
3206 linking in any dynamic objects, in which case we don't
3207 need to generate a procedure linkage table after all. */
3210 {
3211 /* It does not make sense to have a procedure linkage
3212 table entry for a local symbol. */
3215 abfd,
3216 sec,
3221 }
3222 else
3223 {
3229 }
3232 /* The following relocations don't need to propagate the
3233 relocation if linking a shared object since they are
3234 section relative. */
3253 /* These are just markers. */
3260 /* These should only appear in dynamic objects. */
3267 /* These aren't handled yet. We'll report an error later. */
3276 /* This refers only to functions defined in the shared library. */
3282 /* This relocation describes the C++ object vtable hierarchy.
3283 Reconstruct it for later use during GC. */
3289 /* This relocation describes which C++ vtable entries are actually
3290 used. Record for later use during GC. */
3296 /* We shouldn't really be seeing these. */
3302 /* Nor these. */
3321 {
3322 /* Old -fPIC gcc code has .long LCTOC1-LCFx just before
3323 the start of a function, which assembles to a REL32
3324 reference to .got2. If we detect one of these, then
3325 force the old PLT layout because the linker cannot
3326 reliably deduce the GOT pointer value needed for
3327 PLT call stubs. */
3331 r_symndx);
3334 }
3335 /* fall through */
3344 {
3347 }
3348 /* fall through */
3362 {
3363 /* We may need a plt entry if the symbol turns out to be
3364 a function defined in a dynamic object. */
3368 /* We may need a copy reloc too. */
3370 }
3372 dodyn:
3373 /* If we are creating a shared library, and this is a reloc
3374 against a global symbol, or a non PC relative reloc
3375 against a local symbol, then we need to copy the reloc
3376 into the shared library. However, if we are linking with
3377 -Bsymbolic, we do not need to copy a reloc against a
3378 global symbol which is defined in an object we are
3379 including in the link (i.e., DEF_REGULAR is set). At
3380 this point we have not seen all the input files, so it is
3381 possible that DEF_REGULAR is not set now but will be set
3382 later (it is never cleared). In case of a weak definition,
3383 DEF_REGULAR may be cleared later by a strong definition in
3384 a shared library. We account for that possibility below by
3385 storing information in the dyn_relocs field of the hash
3386 table entry. A similar situation occurs when creating
3387 shared libraries and symbol visibility changes render the
3388 symbol local.
3390 If on the other hand, we are creating an executable, we
3391 may need to keep relocations for symbols satisfied by a
3392 dynamic library if we manage to avoid copy relocs for the
3393 symbol. */
3400 || (ELIMINATE_COPY_RELOCS
3405 {
3409 #ifdef DEBUG
3411 "ppc_elf_check_relocs needs to "
3415 #endif
3417 {
3420 name = (bfd_elf_string_from_elf_section
3435 {
3436 flagword flags;
3442 name,
3443 flags);
3448 }
3450 }
3452 /* If this is a global symbol, we count the number of
3453 relocations we need for this symbol. */
3455 {
3457 }
3458 else
3459 {
3460 /* Track dynamic relocs needed for local syms too.
3461 We really need local syms available to do this
3462 easily. Oh well. */
3474 }
3478 {
3487 }
3492 }
3495 }
3496 }
3499 }
3500 \f
3501 /* Merge backend specific data from an object file to the output
3502 object file when linking. */
3504 static bfd_boolean
3506 {
3507 flagword old_flags;
3508 flagword new_flags;
3509 bfd_boolean error;
3515 /* Check if we have the same endianess. */
3522 {
3523 /* First call, no flags set. */
3526 }
3528 /* Compatible flags are ok. */
3530 ;
3532 /* Incompatible flags. */
3533 else
3534 {
3535 /* Warn about -mrelocatable mismatch. Allow -mrelocatable-lib
3536 to be linked with either. */
3540 {
3545 }
3548 {
3553 }
3555 /* The output is -mrelocatable-lib iff both the input files are. */
3559 /* The output is -mrelocatable iff it can't be -mrelocatable-lib,
3560 but each input file is either -mrelocatable or -mrelocatable-lib. */
3566 /* Do not warn about eabi vs. V.4 mismatch, just or in the bit if
3567 any module uses it. */
3573 /* Warn about any other mismatches. */
3575 {
3581 }
3584 {
3587 }
3588 }
3591 }
3592 \f
3593 /* Choose which PLT scheme to use, and set .plt flags appropriately.
3594 Returns -1 on error, 0 for old PLT, 1 for new PLT. */
3595 int
3600 {
3602 flagword flags;
3615 {
3619 /* The new PLT is a loaded section. */
3624 /* The new GOT is not executable. */
3628 }
3629 else
3630 {
3631 /* Stop an unused .glink section from affecting .text alignment. */
3635 }
3637 }
3638 \f
3639 /* Return the section that should be marked against GC for a given
3640 relocation. */
3648 {
3650 {
3652 {
3659 {
3669 }
3670 }
3671 }
3672 else
3676 }
3678 /* Update the got, plt and dynamic reloc reference counts for the
3679 section being removed. */
3681 static bfd_boolean
3686 {
3707 {
3714 {
3726 {
3727 /* Everything must go for SEC. */
3730 }
3731 }
3735 {
3741 /* Fall thru */
3760 {
3763 }
3765 {
3768 }
3778 /* Fall thru */
3801 {
3806 }
3811 }
3812 }
3814 }
3815 \f
3816 /* Set htab->tls_get_addr and call the generic ELF tls_setup function. */
3818 asection *
3820 {
3827 {
3830 }
3835 }
3837 /* Run through all the TLS relocs looking for optimization
3838 opportunities. */
3840 bfd_boolean
3843 {
3853 {
3859 {
3863 /* Read the relocations. */
3872 {
3878 bfd_boolean is_local;
3882 {
3890 }
3899 {
3904 /* These relocs should never be against a symbol
3905 defined in a shared lib. Leave them alone if
3906 that turns out to be the case. */
3912 /* LD -> LE */
3923 /* GD -> LE */
3925 else
3926 /* GD -> IE */
3938 {
3939 /* IE -> LE */
3943 }
3944 else
3954 {
3958 }
3965 }
3968 {
3970 {
3971 /* We managed to get rid of a got entry. */
3974 }
3976 }
3977 else
3978 {
3984 {
3991 {
3995 }
3996 }
4002 {
4003 /* We managed to get rid of a got entry. */
4006 }
4009 }
4013 }
4017 }
4021 {
4024 else
4026 }
4027 }
4029 }
4030 \f
4031 /* Adjust a symbol defined by a dynamic object and referenced by a
4032 regular object. The current definition is in some section of the
4033 dynamic object, but we're not including those sections. We have to
4034 change the definition to something the rest of the link can
4035 understand. */
4037 static bfd_boolean
4040 {
4045 #ifdef DEBUG
4048 #endif
4050 /* Make sure we know what is going on here. */
4059 /* Deal with function syms. */
4062 {
4063 /* Clear procedure linkage table information for any symbol that
4064 won't need a .plt entry. */
4073 {
4074 /* A PLT entry is not required/allowed when:
4076 1. We are not using ld.so; because then the PLT entry
4077 can't be set up, so we can't use one. In this case,
4078 ppc_elf_adjust_dynamic_symbol won't even be called.
4080 2. GC has rendered the entry unused.
4082 3. We know for certain that a call to this symbol
4083 will go to this object, or will remain undefined. */
4086 }
4088 }
4089 else
4092 /* If this is a weak symbol, and there is a real definition, the
4093 processor independent code will have arranged for us to see the
4094 real definition first, and we can just use the same value. */
4096 {
4104 }
4106 /* This is a reference to a symbol defined by a dynamic object which
4107 is not a function. */
4109 /* If we are creating a shared library, we must presume that the
4110 only references to the symbol are via the global offset table.
4111 For such cases we need not do anything here; the relocations will
4112 be handled correctly by relocate_section. */
4116 /* If there are no references to this symbol that do not use the
4117 GOT, we don't need to generate a copy reloc. */
4121 /* If we didn't find any dynamic relocs in read-only sections, then we'll
4122 be keeping the dynamic relocs and avoiding the copy reloc. We can't
4123 do this if there are any small data relocations. */
4126 {
4129 {
4133 }
4136 {
4139 }
4140 }
4143 {
4147 }
4149 /* We must allocate the symbol in our .dynbss section, which will
4150 become part of the .bss section of the executable. There will be
4151 an entry for this symbol in the .dynsym section. The dynamic
4152 object will contain position independent code, so all references
4153 from the dynamic object to this symbol will go through the global
4154 offset table. The dynamic linker will use the .dynsym entry to
4155 determine the address it must put in the global offset table, so
4156 both the dynamic object and the regular object will refer to the
4157 same memory location for the variable.
4159 Of course, if the symbol is referenced using SDAREL relocs, we
4160 must instead allocate it in .sbss. */
4164 else
4168 /* We must generate a R_PPC_COPY reloc to tell the dynamic linker to
4169 copy the initial value out of the dynamic object and into the
4170 runtime process image. We need to remember the offset into the
4171 .rela.bss section we are going to use. */
4173 {
4178 else
4183 }
4185 /* We need to figure out the alignment required for this symbol. I
4186 have no idea how ELF linkers handle this. */
4191 /* Apply the required alignment. */
4194 {
4197 }
4199 /* Define the symbol as being at this point in the section. */
4203 /* Increment the section size to make room for the symbol. */
4207 }
4208 \f
4209 /* Generate a symbol to mark plt call stubs. For non-PIC code the sym is
4210 xxxxxxxx.plt_call32.<callee> where xxxxxxxx is a hex number, usually 0,
4211 specifying the addend on the plt relocation. For -fpic code, the sym
4212 is xxxxxxxx.plt_pic32.<callee>, and for -fPIC
4213 xxxxxxxx.got2.plt_pic32.<callee>. */
4215 static bfd_boolean
4219 {
4228 else
4248 {
4257 }
4259 }
4261 /* Allocate NEED contiguous space in .got, and return the offset.
4262 Handles allocation of the got header when crossing 32k. */
4264 static bfd_vma
4266 {
4267 bfd_vma where;
4271 {
4274 }
4275 else
4276 {
4279 {
4282 }
4283 else
4284 {
4287 {
4290 }
4293 }
4294 }
4296 }
4298 /* Allocate space in associated reloc sections for dynamic relocs. */
4300 static bfd_boolean
4302 {
4312 /* When warning symbols are created, they **replace** the "real"
4313 entry in the hash table, thus we never get to see the real
4314 symbol in a hash traversal. So look at it now. */
4319 {
4326 {
4327 /* Make sure this symbol is output as a dynamic symbol. */
4330 {
4333 }
4337 {
4341 {
4343 {
4346 }
4351 {
4354 }
4358 {
4361 }
4367 }
4368 else
4369 {
4371 {
4372 /* If this is the first .plt entry, make room
4373 for the special first entry. */
4377 /* The PowerPC PLT is actually composed of two
4378 parts, the first part is 2 words (for a load
4379 and a jump), and then there is a remaining
4380 word available at the end. */
4387 /* If this symbol is not defined in a regular
4388 file, and we are not generating a shared
4389 library, then set the symbol to this location
4390 in the .plt. This is required to make
4391 function pointers compare as equal between
4392 the normal executable and the shared library. */
4395 {
4398 }
4400 /* Make room for this entry. */
4402 /* After the 8192nd entry, room for two entries
4403 is allocated. */
4409 }
4411 }
4413 /* We also need to make an entry in the .rela.plt section. */
4415 {
4419 {
4420 /* Allocate space for the unloaded relocations. */
4422 {
4425 {
4429 }
4434 }
4436 /* Every PLT entry has an associated GOT entry in
4437 .got.plt. */
4439 }
4441 }
4442 }
4443 else
4447 {
4450 }
4451 }
4452 }
4453 else
4454 {
4457 }
4461 {
4462 /* Make sure this symbol is output as a dynamic symbol. */
4465 {
4468 }
4472 /* If just an LD reloc, we'll just use htab->tlsld_got.offset. */
4474 else
4475 {
4476 bfd_boolean dyn;
4479 {
4488 }
4489 else
4497 {
4498 /* All the entries we allocated need relocs.
4499 Except LD only needs one. */
4503 }
4504 }
4505 }
4506 else
4512 /* In the shared -Bsymbolic case, discard space allocated for
4513 dynamic pc-relative relocs against symbols which turn out to be
4514 defined in regular objects. For the normal shared case, discard
4515 space for relocs that have become local due to symbol visibility
4516 changes. */
4519 {
4520 /* Relocs that use pc_count are those that appear on a call insn,
4521 or certain REL relocs (see MUST_BE_DYN_RELOC) that can be
4522 generated via assembly. We want calls to protected symbols to
4523 resolve directly to the function rather than going via the plt.
4524 If people want function pointer comparisons to work as expected
4525 then they should avoid writing weird assembly. */
4527 {
4531 {
4536 else
4538 }
4539 }
4541 /* Also discard relocs on undefined weak syms with non-default
4542 visibility. */
4545 {
4549 /* Make sure undefined weak symbols are output as a dynamic
4550 symbol in PIEs. */
4553 {
4556 }
4557 }
4558 }
4560 {
4561 /* For the non-shared case, discard space for relocs against
4562 symbols which turn out to need copy relocs or are not
4563 dynamic. */
4568 {
4569 /* Make sure this symbol is output as a dynamic symbol.
4570 Undefined weak syms won't yet be marked as dynamic. */
4573 {
4576 }
4578 /* If that succeeded, we know we'll be keeping all the
4579 relocs. */
4582 }
4586 keep: ;
4587 }
4589 /* Finally, allocate space. */
4591 {
4594 }
4597 }
4599 /* Find any dynamic relocs that apply to read-only sections. */
4601 static bfd_boolean
4603 {
4613 {
4619 {
4622 /* Not an error, just cut short the traversal. */
4624 }
4625 }
4627 }
4629 /* Set the sizes of the dynamic sections. */
4631 static bfd_boolean
4634 {
4637 bfd_boolean relocs;
4640 #ifdef DEBUG
4642 #endif
4648 {
4649 /* Set the contents of the .interp section to the interpreter. */
4651 {
4656 }
4657 }
4664 /* Set up .got offsets for local syms, and space for local dynamic
4665 relocs. */
4667 {
4671 bfd_size_type locsymcount;
4678 {
4685 {
4688 {
4689 /* Input section has been discarded, either because
4690 it is a copy of a linkonce section or due to
4691 linker script /DISCARD/, so we'll be discarding
4692 the relocs too. */
4693 }
4695 {
4702 }
4703 }
4704 }
4716 {
4718 {
4719 /* If just an LD reloc, we'll just use
4720 htab->tlsld_got.offset. */
4723 }
4724 else
4725 {
4728 {
4735 }
4736 else
4742 }
4743 }
4744 else
4746 }
4749 {
4753 }
4754 else
4757 /* Allocate space for global sym dynamic relocs. */
4761 {
4764 /* If we haven't allocated the header, do so now. When we get here,
4765 for old plt/got the got size will be 0 to 32764 (not allocated),
4766 or 32780 to 65536 (header allocated). For new plt/got, the
4767 corresponding ranges are 0 to 32768 and 32780 to 65536. */
4769 {
4774 }
4777 }
4780 {
4782 /* Space for the branch table. */
4784 /* Pad out to align the start of PLTresolve. */
4789 {
4796 {
4805 }
4811 {
4820 }
4821 }
4822 }
4824 /* We've now determined the sizes of the various dynamic sections.
4825 Allocate memory for them. */
4828 {
4841 {
4842 /* We'd like to strip these sections if they aren't needed, but if
4843 we've exported dynamic symbols from them we must leave them.
4844 It's too late to tell BFD to get rid of the symbols. */
4847 /* Strip this section if we don't need it; see the
4848 comment below. */
4849 }
4852 {
4853 /* Strip these too. */
4854 }
4856 {
4858 {
4859 /* Remember whether there are any relocation sections. */
4862 /* We use the reloc_count field as a counter if we need
4863 to copy relocs into the output file. */
4865 }
4866 }
4867 else
4868 {
4869 /* It's not one of our sections, so don't allocate space. */
4871 }
4874 {
4875 /* If we don't need this section, strip it from the
4876 output file. This is mostly to handle .rela.bss and
4877 .rela.plt. We must create both sections in
4878 create_dynamic_sections, because they must be created
4879 before the linker maps input sections to output
4880 sections. The linker does that before
4881 adjust_dynamic_symbol is called, and it is that
4882 function which decides whether anything needs to go
4883 into these sections. */
4886 }
4891 /* Allocate memory for the section contents. */
4895 }
4898 {
4899 /* Add some entries to the .dynamic section. We fill in the
4900 values later, in ppc_elf_finish_dynamic_sections, but we
4901 must add the entries now so that we get the correct size for
4902 the .dynamic section. The DT_DEBUG entry is filled in by the
4903 dynamic linker and used by the debugger. */
4904 #define add_dynamic_entry(TAG, VAL) \
4905 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
4908 {
4911 }
4914 {
4920 }
4923 {
4926 }
4929 {
4934 }
4936 /* If any dynamic relocs apply to a read-only section, then we
4937 need a DT_TEXTREL entry. */
4940 info);
4943 {
4946 }
4947 }
4948 #undef add_dynamic_entry
4951 }
4952 \f
4953 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
4956 {
4965 };
4968 {
4973 };
4975 static bfd_boolean
4980 {
4981 struct one_fixup
4982 {
4985 bfd_vma toff;
4986 bfd_vma trampoff;
4987 };
4995 bfd_boolean changed;
4997 bfd_size_type trampoff;
5002 /* Nothing to do if there are no relocations, and no need to do
5003 anything with non-alloc sections. */
5010 /* Space for a branch around any trampolines. */
5015 /* Get a copy of the native relocations. */
5026 {
5038 {
5053 }
5055 /* Get the value of the symbol referred to by the reloc. */
5057 {
5058 /* A local symbol. */
5061 /* Read this BFD's local symbols. */
5063 {
5071 }
5079 else
5084 }
5085 else
5086 {
5087 /* Global symbol handling. */
5102 {
5106 {
5108 {
5111 }
5112 else
5113 {
5116 }
5117 }
5118 }
5120 ;
5123 {
5126 }
5127 else
5131 }
5133 /* If the branch and target are in the same section, you have
5134 no hope of adding stubs. We'll error out later should the
5135 branch overflow. */
5139 /* There probably isn't any reason to handle symbols in
5140 SEC_MERGE sections; SEC_MERGE doesn't seem a likely
5141 attribute for a code section, and we are only looking at
5142 branches. However, implement it correctly here as a
5143 reference for other target relax_section functions. */
5145 {
5146 /* At this stage in linking, no SEC_MERGE symbol has been
5147 adjusted, so all references to such symbols need to be
5148 passed through _bfd_merged_section_offset. (Later, in
5149 relocate_section, all SEC_MERGE symbols *except* for
5150 section symbols have been adjusted.)
5152 gas may reduce relocations against symbols in SEC_MERGE
5153 sections to a relocation against the section symbol when
5154 the original addend was zero. When the reloc is against
5155 a section symbol we should include the addend in the
5156 offset passed to _bfd_merged_section_offset, since the
5157 location of interest is the original symbol. On the
5158 other hand, an access to "sym+addend" where "sym" is not
5159 a section symbol should not include the addend; Such an
5160 access is presumed to be an offset from "sym"; The
5161 location of interest is just "sym". */
5167 toff);
5171 }
5172 /* PLTREL24 addends are special. */
5181 /* If the branch is in range, no need to do anything. */
5185 /* Look for an existing fixup to this address. */
5191 {
5197 /* Oh dear, we can't reach a trampoline. Don't try to add
5198 one. We'll report an error later. */
5202 {
5206 }
5207 else
5208 {
5212 }
5221 /* Hijack the old relocation. Since we need two
5222 relocations for this use a "composite" reloc. */
5224 stub_rtype);
5227 /* Record the fixup so we don't do it again this section. */
5236 }
5237 else
5238 {
5243 /* Nop out the reloc, since we're finalizing things here. */
5245 }
5247 /* Get the section contents. */
5249 {
5250 /* Get cached copy if it exists. */
5253 else
5254 {
5255 /* Go get them off disk. */
5258 }
5259 }
5261 /* Fix up the existing branch to hit the trampoline. */
5264 {
5282 }
5283 }
5285 /* Write out the trampolines. */
5288 {
5291 bfd_vma val;
5294 do
5295 {
5299 }
5307 /* Branch around the trampolines. */
5315 {
5318 }
5319 else
5320 {
5323 }
5327 {
5329 i++;
5333 }
5335 }
5339 {
5342 else
5343 {
5344 /* Cache the symbols for elf_link_input_bfd. */
5346 }
5347 }
5351 {
5354 else
5355 {
5356 /* Cache the section contents for elf_link_input_bfd. */
5358 }
5359 }
5362 {
5365 else
5367 }
5372 error_return:
5382 }
5383 \f
5384 /* What to do when ld finds relocations against symbols defined in
5385 discarded sections. */
5387 static unsigned int
5389 {
5397 }
5398 \f
5399 /* Fill in the address for a pointer generated in a linker section. */
5401 static bfd_vma
5405 bfd_vma relocation,
5407 {
5413 {
5414 /* Handle global symbol. */
5420 }
5421 else
5422 {
5423 /* Handle local symbol. */
5428 }
5432 lsect);
5435 /* Offset will always be a multiple of four, so use the bottom bit
5436 as a "written" flag. */
5438 {
5443 }
5449 #ifdef DEBUG
5453 #endif
5455 /* Subtract out the addend, because it will get added back in by the normal
5456 processing. */
5458 }
5460 /* The RELOCATE_SECTION function is called by the ELF backend linker
5461 to handle the relocations for a section.
5463 The relocs are always passed as Rela structures; if the section
5464 actually uses Rel structures, the r_addend field will always be
5465 zero.
5467 This function is responsible for adjust the section contents as
5468 necessary, and (if using Rela relocs and generating a
5469 relocatable output file) adjusting the reloc addend as
5470 necessary.
5472 This function does not have to worry about setting the reloc
5473 address or the reloc symbol index.
5475 LOCAL_SYMS is a pointer to the swapped in local symbols.
5477 LOCAL_SECTIONS is an array giving the section in the input file
5478 corresponding to the st_shndx field of each local symbol.
5480 The global hash table entry for the global symbols can be found
5481 via elf_sym_hashes (input_bfd).
5483 When generating relocatable output, this function must handle
5484 STB_LOCAL/STT_SECTION symbols specially. The output symbol is
5485 going to be the section symbol corresponding to the output
5486 section, which means that the addend must be adjusted
5487 accordingly. */
5489 static bfd_boolean
5498 {
5504 Elf_Internal_Rela outrel;
5510 #ifdef DEBUG
5516 #endif
5521 {
5528 {
5534 {
5535 /* R_PPC_PLTREL24 is rather special. If non-zero, the
5536 addend specifies the GOT pointer offset within .got2. */
5538 }
5539 }
5541 }
5543 /* Initialize howto table if not already done. */
5554 {
5556 bfd_vma addend;
5557 bfd_reloc_status_type r;
5564 bfd_vma relocation;
5566 bfd_boolean unresolved_reloc;
5567 bfd_boolean warned;
5579 {
5585 }
5586 else
5587 {
5594 }
5596 /* TLS optimizations. Replace instruction sequences and relocs
5597 based on information we collected in tls_optimize. We edit
5598 RELOCS so that --emit-relocs will output something sensible
5599 for the final instruction stream. */
5603 {
5607 {
5611 }
5612 }
5614 /* Ensure reloc mapping code below stays sane. */
5625 {
5633 {
5634 bfd_vma insn;
5641 }
5647 {
5656 else
5659 /* add -> addi. */
5665 /* load and store indexed -> dform. */
5669 /* ldx, ldux, stdx, stdux -> ld, ldu, std, stdu. */
5674 /* lwax -> lwa. */
5676 else
5682 /* Was PPC_TLS which sits on insn boundary, now
5683 PPC_TPREL16_LO which is at insn+2. */
5685 }
5698 {
5699 tls_gdld_hi:
5703 else
5704 {
5708 }
5710 }
5723 {
5724 tls_get_addr_check:
5726 {
5731 bfd_vma offset;
5733 /* The next instruction should be a call to
5734 __tls_get_addr. Peek at the reloc to be sure. */
5752 /* OK, it checks out. Replace the call. */
5757 {
5758 /* IE */
5766 }
5767 else
5768 {
5769 /* LE */
5773 {
5774 /* Was an LD reloc. */
5778 }
5782 R_PPC_TPREL16_LO);
5784 }
5788 {
5789 /* We changed the symbol on an LD reloc. Start over
5790 in order to get h, sym, sec etc. right. */
5791 rel--;
5793 }
5794 }
5795 }
5797 }
5799 /* Handle other relocations that tweak non-addend part of insn. */
5802 {
5806 /* Branch taken prediction relocations. */
5810 /* Fall thru */
5812 /* Branch not taken prediction relocations. */
5823 /* Invert 'y' bit if not the default. */
5829 }
5837 {
5854 /* GOT16 relocations. Like an ADDR16 using the symbol's
5855 address in the GOT as relocation value instead of the
5856 symbol's value itself. Also, create a GOT entry for the
5857 symbol and put the symbol value there. */
5890 dogot:
5891 {
5892 /* Relocation is to the entry for this symbol in the global
5893 offset table. */
5894 bfd_vma off;
5907 {
5908 bfd_boolean dyn;
5913 /* This is actually a static link, or it is a
5914 -Bsymbolic link and the symbol is defined
5915 locally, or the symbol was forced to be local
5916 because of a version file. */
5917 ;
5918 else
5919 {
5922 }
5924 }
5925 else
5926 {
5930 }
5932 /* The offset must always be a multiple of 4. We use the
5933 least significant bit to record whether we have already
5934 processed this entry. */
5938 else
5939 {
5950 /* We might have multiple got entries for this sym.
5951 Initialize them all. */
5952 do
5953 {
5957 {
5960 }
5962 {
5965 }
5967 {
5970 }
5972 {
5975 }
5977 /* Generate relocs for the dynamic linker. */
5982 {
5988 {
5991 {
5998 outrel.r_info
6000 }
6001 }
6008 else
6011 {
6015 }
6020 }
6022 /* Init the .got section contents if we're not
6023 emitting a reloc. */
6024 else
6025 {
6031 {
6037 {
6041 }
6042 }
6045 }
6050 }
6055 }
6061 {
6063 {
6069 {
6073 {
6076 }
6077 }
6078 }
6079 }
6084 /* Addends on got relocations don't make much sense.
6085 x+off@got is actually x@got+off, and since the got is
6086 generated by a hash table traversal, the value in the
6087 got at entry m+n bears little relation to the entry m. */
6091 input_bfd,
6092 input_section,
6095 sym_name);
6096 }
6099 /* Relocations that need no special processing. */
6101 /* It makes no sense to point a local relocation
6102 at a symbol not in this object. */
6104 {
6107 input_bfd,
6108 input_section,
6110 TRUE))
6113 }
6123 /* Relocations that may need to be propagated if this is a shared
6124 object. */
6130 /* The TPREL16 relocs shouldn't really be used in shared
6131 libs as they will result in DT_TEXTREL being set, but
6132 support them anyway. */
6159 /* If these relocations are not to a named symbol, they can be
6160 handled right here, no need to bother the dynamic linker. */
6164 /* fall through */
6166 /* Relocations that always need to be propagated if this is a shared
6167 object. */
6179 /* r_symndx will be zero only for relocs against symbols
6180 from removed linkonce sections, or sections discarded by
6181 a linker script. */
6182 dodyn:
6185 /* Fall thru. */
6189 /* Fall thru. */
6197 || (ELIMINATE_COPY_RELOCS
6204 {
6207 #ifdef DEBUG
6212 #endif
6214 /* When generating a shared object, these relocations
6215 are copied into the output file to be resolved at run
6216 time. */
6218 {
6221 name = (bfd_elf_string_from_elf_section
6230 input_section),
6235 }
6251 {
6255 }
6256 else
6257 {
6262 else
6263 {
6269 {
6272 }
6273 else
6274 {
6277 /* We are turning this relocation into one
6278 against a section symbol. It would be
6279 proper to subtract the symbol's value,
6280 osec->vma, from the emitted reloc addend,
6281 but ld.so expects buggy relocs. */
6285 #ifdef DEBUG
6290 #endif
6291 }
6294 }
6295 }
6304 /* This reloc will be computed at runtime. We clear the memory
6305 so that it contains predictable value. */
6309 {
6313 }
6314 }
6319 {
6326 else
6331 }
6334 /* Fall thru */
6340 /* Fall thru */
6343 relax32:
6344 {
6351 /* We're clearing the bits for R_PPC_ADDR16_HA
6352 and R_PPC_ADDR16_LO here. */
6356 /* t0 is HA, t1 is LO */
6363 }
6366 /* Indirect .sdata relocation. */
6369 relocation
6374 /* Indirect .sdata2 relocation. */
6377 relocation
6382 /* Handle the TOC16 reloc. We want to use the offset within the .got
6383 section, not the actual VMA. This is appropriate when generating
6384 an embedded ELF object, for which the .got section acts like the
6385 AIX .toc section. */
6396 /* Relocation is to the entry for this symbol in the
6397 procedure linkage table. */
6398 {
6404 {
6405 /* We didn't make a PLT entry for this symbol. This
6406 happens when statically linking PIC code, or when
6407 using -Bsymbolic. */
6409 }
6416 else
6420 }
6423 /* Relocate against _SDA_BASE_. */
6425 {
6435 {
6439 input_bfd,
6440 sym_name,
6442 name);
6443 }
6448 }
6451 /* Relocate against _SDA2_BASE_. */
6453 {
6461 {
6465 input_bfd,
6466 sym_name,
6468 name);
6473 }
6478 }
6481 /* Relocate against either _SDA_BASE_, _SDA2_BASE_, or 0. */
6484 {
6495 {
6501 }
6505 {
6511 }
6515 {
6517 }
6519 else
6520 {
6524 input_bfd,
6525 sym_name,
6527 name);
6532 }
6539 }
6540 }
6543 /* Relocate against the beginning of the section. */
6552 /* Negative relocations. */
6578 input_bfd,
6580 sym_name);
6585 }
6587 /* Do any further special processing. */
6589 {
6606 /* It's just possible that this symbol is a weak symbol
6607 that's not actually defined anywhere. In that case,
6608 'sec' would be NULL, and we should leave the symbol
6609 alone (it will be set to zero elsewhere in the link). */
6611 /* Add 0x10000 if sign bit in 0:15 is set.
6612 Bits 0:15 are not used. */
6615 }
6617 #ifdef DEBUG
6622 sym_name,
6623 r_symndx,
6626 #endif
6631 {
6634 input_bfd,
6635 input_section,
6638 sym_name);
6640 }
6643 input_bfd,
6644 input_section,
6645 contents,
6647 relocation,
6648 addend);
6651 {
6653 {
6659 {
6660 /* Assume this is a call protected by other code that
6661 detect the symbol is undefined. If this is the case,
6662 we can safely ignore the overflow. If not, the
6663 program is hosed anyway, and a little warning isn't
6664 going to help. */
6667 }
6671 sym_name,
6674 input_bfd,
6675 input_section,
6678 }
6679 else
6680 {
6686 }
6687 }
6688 }
6690 #ifdef DEBUG
6692 #endif
6695 }
6696 \f
6697 #define PPC_LO(v) ((v) & 0xffff)
6698 #define PPC_HI(v) (((v) >> 16) & 0xffff)
6699 #define PPC_HA(v) PPC_HI ((v) + 0x8000)
6701 /* Finish up dynamic symbol handling. We set the contents of various
6702 dynamic sections here. */
6704 static bfd_boolean
6709 {
6712 bfd_boolean doneone;
6714 #ifdef DEBUG
6717 #endif
6725 {
6727 {
6728 Elf_Internal_Rela rela;
6730 bfd_vma reloc_index;
6734 else
6735 {
6741 }
6743 /* This symbol has an entry in the procedure linkage table.
6744 Set it up. */
6746 {
6747 bfd_vma got_offset;
6750 /* The first three entries in .got.plt are reserved. */
6753 /* Use the right PLT. */
6757 /* Fill in the .plt on VxWorks. */
6759 {
6769 }
6770 else
6771 {
6772 bfd_vma got_loc
6773 = (got_offset
6786 }
6793 /* This instruction is an immediate load. The value loaded is
6794 the byte offset of the R_PPC_JMP_SLOT relocation from the
6795 start of the .rela.plt section. The value is stored in the
6796 low-order 16 bits of the load instruction. */
6797 /* NOTE: It appears that this is now an index rather than a
6798 prescaled offset. */
6802 /* This instruction is a PC-relative branch whose target is
6803 the start of the PLT section. The address of this branch
6804 instruction is 20 bytes beyond the start of this PLT entry.
6805 The address is encoded in bits 6-29, inclusive. The value
6806 stored is right-shifted by two bits, permitting a 26-bit
6807 offset. */
6817 /* Fill in the GOT entry corresponding to this PLT slot with
6818 the address immediately after the the "bctr" instruction
6819 in this PLT entry. */
6826 {
6827 /* Fill in a couple of entries in .rela.plt.unloaded. */
6833 /* Provide the @ha relocation for the first instruction. */
6838 R_PPC_ADDR16_HA);
6843 /* Provide the @l relocation for the second instruction. */
6848 R_PPC_ADDR16_LO);
6853 /* Provide a relocation for the GOT entry corresponding to this
6854 PLT slot. Point it at the middle of the .plt entry. */
6859 R_PPC_ADDR32);
6862 }
6864 /* VxWorks uses non-standard semantics for R_PPC_JMP_SLOT.
6865 In particular, the offset for the relocation is not the
6866 address of the PLT entry for this function, as specified
6867 by the ABI. Instead, the offset is set to the address of
6868 the GOT slot for this function. See EABI 4.4.4.1. */
6873 }
6874 else
6875 {
6880 {
6881 /* We don't need to fill in the .plt. The ppc dynamic
6882 linker will fill it in. */
6883 }
6884 else
6885 {
6891 }
6892 }
6894 /* Fill in the entry in the .rela.plt section. */
6903 {
6904 /* Mark the symbol as undefined, rather than as defined in
6905 the .plt section. Leave the value alone. */
6907 /* If the symbol is weak, we do need to clear the value.
6908 Otherwise, the PLT entry would provide a definition for
6909 the symbol even if the symbol wasn't defined anywhere,
6910 and so the symbol would never be NULL. */
6913 }
6915 }
6918 {
6919 bfd_vma plt;
6928 {
6943 {
6952 }
6953 else
6954 {
6963 }
6964 }
6965 else
6966 {
6976 /* We only need one non-PIC glink stub. */
6978 }
6979 }
6980 else
6982 }
6985 {
6987 Elf_Internal_Rela rela;
6990 /* This symbols needs a copy reloc. Set it up. */
6992 #ifdef DEBUG
6994 #endif
7000 else
7011 }
7013 #ifdef DEBUG
7015 #endif
7017 /* Mark some specially defined symbols as absolute. */
7026 }
7027 \f
7028 static enum elf_reloc_type_class
7030 {
7032 {
7043 }
7044 }
7045 \f
7046 /* Finish up the dynamic sections. */
7048 static bfd_boolean
7051 {
7055 bfd_vma got;
7058 #ifdef DEBUG
7060 #endif
7067 else
7077 {
7085 {
7086 Elf_Internal_Dyn dyn;
7092 {
7096 else
7116 {
7120 }
7125 }
7128 }
7129 }
7131 /* Add a blrl instruction at _GLOBAL_OFFSET_TABLE_-4 so that a function can
7132 easily find the address of the _GLOBAL_OFFSET_TABLE_. */
7134 {
7136 bfd_vma val;
7148 }
7150 /* Fill in the first entry in the VxWorks procedure linkage table. */
7152 {
7153 /* Use the right PLT. */
7159 {
7160 bfd_vma got_value =
7170 }
7171 else
7172 {
7175 }
7184 {
7185 Elf_Internal_Rela rela;
7190 /* Output the @ha relocation for the first instruction. */
7199 /* Output the @l relocation for the second instruction. */
7208 /* Fix up the remaining relocations. They may have the wrong
7209 symbol index for _G_O_T_ or _P_L_T_ depending on the order
7210 in which symbols were output. */
7212 {
7213 Elf_Internal_Rela rel;
7229 }
7230 }
7231 }
7234 {
7237 bfd_vma res0;
7240 /*
7241 * PIC glink code is the following:
7242 *
7243 * # ith PLT code stub.
7244 * addis 11,30,(plt+(i-1)*4-got)@ha
7245 * lwz 11,(plt+(i-1)*4-got)@l(11)
7246 * mtctr 11
7247 * bctr
7248 *
7249 * # A table of branches, one for each plt entry.
7250 * # The idea is that the plt call stub loads ctr (and r11) with these
7251 * # addresses, so (r11 - res_0) gives the plt index * 4.
7252 * res_0: b PLTresolve
7253 * res_1: b PLTresolve
7254 * .
7255 * # Some number of entries towards the end can be nops
7256 * res_n_m3: nop
7257 * res_n_m2: nop
7258 * res_n_m1:
7259 *
7260 * PLTresolve:
7261 * addis 11,11,(1f-res_0)@ha
7262 * mflr 0
7263 * bcl 20,31,1f
7264 * 1: addi 11,11,(1b-res_0)@l
7265 * mflr 12
7266 * mtlr 0
7267 * sub 11,11,12 # r11 = index * 4
7268 * addis 12,12,(got+4-1b)@ha
7269 * lwz 0,(got+4-1b)@l(12) # got[1] address of dl_runtime_resolve
7270 * lwz 12,(got+8-1b)@l(12) # got[2] contains the map address
7271 * mtctr 0
7272 * add 0,11,11
7273 * add 11,0,11 # r11 = index * 12 = reloc offset.
7274 * bctr
7275 */
7277 {
7278 ADDIS_11_11,
7279 MFLR_0,
7280 BCL_20_31,
7281 ADDI_11_11,
7282 MFLR_12,
7283 MTLR_0,
7284 SUB_11_11_12,
7285 ADDIS_12_12,
7286 LWZ_0_12,
7287 LWZ_12_12,
7288 MTCTR_0,
7289 ADD_0_11_11,
7290 ADD_11_0_11,
7291 BCTR,
7292 NOP,
7293 NOP
7294 };
7297 {
7298 LIS_12,
7299 ADDIS_11_11,
7300 LWZ_0_12,
7301 ADDI_11_11,
7302 MTCTR_0,
7303 ADD_0_11_11,
7304 LWZ_12_12,
7305 ADD_11_0_11,
7306 BCTR,
7307 NOP,
7308 NOP,
7309 NOP,
7310 NOP,
7311 NOP,
7312 NOP,
7313 NOP
7314 };
7321 /* Build the branch table, one for each plt entry (less one),
7322 and perhaps some padding. */
7328 {
7331 }
7333 {
7336 }
7342 /* Last comes the PLTresolve stub. */
7344 {
7345 bfd_vma bcl;
7348 {
7351 }
7365 {
7370 }
7371 else
7372 {
7377 }
7378 }
7379 else
7380 {
7382 {
7385 }
7395 {
7400 }
7401 else
7402 {
7407 }
7408 }
7409 }
7412 }
7413 \f
7414 #define TARGET_LITTLE_SYM bfd_elf32_powerpcle_vec
7416 #define TARGET_BIG_SYM bfd_elf32_powerpc_vec
7418 #define ELF_ARCH bfd_arch_powerpc
7419 #define ELF_MACHINE_CODE EM_PPC
7420 #ifdef __QNXTARGET__
7421 #define ELF_MAXPAGESIZE 0x1000
7422 #else
7423 #define ELF_MAXPAGESIZE 0x10000
7424 #endif
7425 #define ELF_MINPAGESIZE 0x1000
7426 #define elf_info_to_howto ppc_elf_info_to_howto
7428 #ifdef EM_CYGNUS_POWERPC
7429 #define ELF_MACHINE_ALT1 EM_CYGNUS_POWERPC
7430 #endif
7432 #ifdef EM_PPC_OLD
7433 #define ELF_MACHINE_ALT2 EM_PPC_OLD
7434 #endif
7436 #define elf_backend_plt_not_loaded 1
7437 #define elf_backend_can_gc_sections 1
7438 #define elf_backend_can_refcount 1
7439 #define elf_backend_rela_normal 1
7441 #define bfd_elf32_mkobject ppc_elf_mkobject
7442 #define bfd_elf32_bfd_merge_private_bfd_data ppc_elf_merge_private_bfd_data
7443 #define bfd_elf32_bfd_relax_section ppc_elf_relax_section
7444 #define bfd_elf32_bfd_reloc_type_lookup ppc_elf_reloc_type_lookup
7445 #define bfd_elf32_bfd_set_private_flags ppc_elf_set_private_flags
7446 #define bfd_elf32_bfd_link_hash_table_create ppc_elf_link_hash_table_create
7448 #define elf_backend_object_p ppc_elf_object_p
7449 #define elf_backend_gc_mark_hook ppc_elf_gc_mark_hook
7450 #define elf_backend_gc_sweep_hook ppc_elf_gc_sweep_hook
7451 #define elf_backend_section_from_shdr ppc_elf_section_from_shdr
7452 #define elf_backend_relocate_section ppc_elf_relocate_section
7453 #define elf_backend_create_dynamic_sections ppc_elf_create_dynamic_sections
7454 #define elf_backend_check_relocs ppc_elf_check_relocs
7455 #define elf_backend_copy_indirect_symbol ppc_elf_copy_indirect_symbol
7456 #define elf_backend_adjust_dynamic_symbol ppc_elf_adjust_dynamic_symbol
7457 #define elf_backend_add_symbol_hook ppc_elf_add_symbol_hook
7458 #define elf_backend_size_dynamic_sections ppc_elf_size_dynamic_sections
7459 #define elf_backend_finish_dynamic_symbol ppc_elf_finish_dynamic_symbol
7460 #define elf_backend_finish_dynamic_sections ppc_elf_finish_dynamic_sections
7461 #define elf_backend_fake_sections ppc_elf_fake_sections
7462 #define elf_backend_additional_program_headers ppc_elf_additional_program_headers
7463 #define elf_backend_grok_prstatus ppc_elf_grok_prstatus
7464 #define elf_backend_grok_psinfo ppc_elf_grok_psinfo
7465 #define elf_backend_reloc_type_class ppc_elf_reloc_type_class
7466 #define elf_backend_begin_write_processing ppc_elf_begin_write_processing
7467 #define elf_backend_final_write_processing ppc_elf_final_write_processing
7468 #define elf_backend_write_section ppc_elf_write_section
7469 #define elf_backend_get_sec_type_attr ppc_elf_get_sec_type_attr
7470 #define elf_backend_plt_sym_val ppc_elf_plt_sym_val
7471 #define elf_backend_action_discarded ppc_elf_action_discarded
7475 /* VxWorks Target */
7477 #undef TARGET_LITTLE_SYM
7478 #undef TARGET_LITTLE_NAME
7480 #undef TARGET_BIG_SYM
7481 #define TARGET_BIG_SYM bfd_elf32_powerpc_vxworks_vec
7482 #undef TARGET_BIG_NAME
7485 /* VxWorks uses the elf default section flags for .plt. */
7488 {
7496 }
7498 /* Like ppc_elf_link_hash_table_create, but overrides
7499 appropriately for VxWorks. */
7502 {
7507 {
7515 }
7517 }
7519 /* Tweak magic VxWorks symbols as they are loaded. */
7520 static bfd_boolean
7528 {
7530 valp))
7534 }
7536 static void
7538 {
7541 }
7543 /* On VxWorks, we emit relocations against _PROCEDURE_LINKAGE_TABLE_, so
7544 define it. */
7545 #undef elf_backend_want_plt_sym
7546 #define elf_backend_want_plt_sym 1
7547 #undef elf_backend_want_got_plt
7548 #define elf_backend_want_got_plt 1
7549 #undef elf_backend_got_symbol_offset
7550 #define elf_backend_got_symbol_offset 0
7551 #undef elf_backend_plt_not_loaded
7552 #define elf_backend_plt_not_loaded 0
7553 #undef elf_backend_plt_readonly
7554 #define elf_backend_plt_readonly 1
7555 #undef elf_backend_got_header_size
7556 #define elf_backend_got_header_size 12
7558 #undef bfd_elf32_bfd_link_hash_table_create
7559 #define bfd_elf32_bfd_link_hash_table_create \
7560 ppc_elf_vxworks_link_hash_table_create
7561 #undef elf_backend_add_symbol_hook
7562 #define elf_backend_add_symbol_hook \
7563 ppc_elf_vxworks_add_symbol_hook
7564 #undef elf_backend_link_output_symbol_hook
7565 #define elf_backend_link_output_symbol_hook \
7566 elf_vxworks_link_output_symbol_hook
7567 #undef elf_backend_final_write_processing
7568 #define elf_backend_final_write_processing \
7569 ppc_elf_vxworks_final_write_processing
7570 #undef elf_backend_get_sec_type_attr
7571 #define elf_backend_get_sec_type_attr \
7572 ppc_elf_vxworks_get_sec_type_attr
7573 #undef elf_backend_emit_relocs
7574 #define elf_backend_emit_relocs \
7575 elf_vxworks_emit_relocs
7577 #undef elf32_bed
7578 #define elf32_bed ppc_elf_vxworks_bed