MIPS should not be using BFD_RELOC_16 for its R_MIPS_16 relocation,
since R_MIPS_16 specifies a 16-bit field in a 32-bit word.
BFD_RELOC_16, emitted by generic code to handle fixups on 16-bit data
directives, expects fixups to operate on the whole of a 16-bit word.
This patch corrects the problem by using BFD_RELOC_MIPS_16, a new bfd
reloc that is used to generate R_MIPS_16. BFD_RELOC_16 is handled in
md_apply_fix for cases where the fixup can be applied at assembly
time. Like BFD_RELOC_8, BFD_RELOC_16 now has no corresponding object
file relocation, and thus .half, .hword, .short and .dc.w must be
resolved at assembly time. BFD_RELOC_MIPS_REL16 is removed by this
patch since it isn't used.
PR 3243
PR 26542
* reloc.c (BFD_RELOC_MIPS_16): Rename from BFD_RELOC_MIPS_REL16.
* elf32-mips.c (mips_reloc_map): Map BFD_RELOC_MIPS_16 to R_MIPS_16.
* elf64-mips.c (mips_reloc_map): Likewise, delete BFD_RELOC_MIPS_REL16.
* elfn32-mips.c (mips_reloc_map): Likewise.
* libbfd.h: Regenerate.
* bfd-in2.h: Regenerate.
gas/
* config/tc-mips.c (append_insn): Handle BFD_RELOC_MIPS_16.
(macro_build): Likewise.
(mips_percent_op <%half>): Generate BFD_RELOC_MIPS_16.
(md_apply_fix): Handle BFD_RELOC_16 and BFD_RELOC_MIPS_16 when fx_done.
ld/
* testsuite/ld-mips-elf/reloc-local-overflow.d,
* testsuite/ld-mips-elf/reloc-local-overflow.s: Rewrite.
Symbol table entries for section symbols are different between IRIX and
traditional MIPS ELF targets in that IRIX entries have their `st_name'
member pointing at the section's name in the string table section, while
traditional entries have 0 there and the section header string table has
to be referred via the relevant section header's `shn_name' member
instead.
This is chosen with the `elf_backend_name_local_section_symbols' backend
and can be observed with `readelf -s' output for an IRIX object:
Symbol table '.symtab' contains 12 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00000000 0 SECTION LOCAL DEFAULT 1 .text
2: 00000000 0 SECTION LOCAL DEFAULT 3 .data
3: 00000000 0 SECTION LOCAL DEFAULT 4 .bss
4: 00000000 0 SECTION LOCAL DEFAULT 5 .reginfo
5: 00000000 0 SECTION LOCAL DEFAULT 6 .MIPS.abiflags
6: 00000000 0 SECTION LOCAL DEFAULT 7 .pdr
7: 00000000 0 SECTION LOCAL DEFAULT 9 .gnu.attributes
8: 00002000 16 FUNC GLOBAL DEFAULT 1 foo
9: 00004008 0 FUNC LOCAL DEFAULT 1 abar
10: 00002008 0 FUNC LOCAL DEFAULT 1 afoo
11: 00004000 16 FUNC GLOBAL DEFAULT 1 bar
and a corresponding traditional object:
Symbol table '.symtab' contains 12 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00000000 0 SECTION LOCAL DEFAULT 1
2: 00000000 0 SECTION LOCAL DEFAULT 3
3: 00000000 0 SECTION LOCAL DEFAULT 4
4: 00004008 0 FUNC LOCAL DEFAULT 1 abar
5: 00002008 0 FUNC LOCAL DEFAULT 1 afoo
6: 00000000 0 SECTION LOCAL DEFAULT 5
7: 00000000 0 SECTION LOCAL DEFAULT 6
8: 00000000 0 SECTION LOCAL DEFAULT 7
9: 00000000 0 SECTION LOCAL DEFAULT 9
10: 00002000 16 FUNC GLOBAL DEFAULT 1 foo
11: 00004000 16 FUNC GLOBAL DEFAULT 1 bar
respectively. Consequently the right way to retrieve a section symbol's
name has to be chosen in `mips_elf_calculate_relocation' for the purpose
of error reporting.
Originally we produced symbol tables in the traditional object format
only and we handled it correctly until it was lost in a rewrite with:
commit 7403cb6305
Author: Mark Mitchell <mark@codesourcery.com>
Date: Wed Jun 30 20:13:43 1999 +0000
probably because of the extra pointer indirection added which made the
same expression have a different meaning.
With the addition of IRIX symbol table format with:
commit 174fd7f955
Author: Richard Sandiford <rdsandiford@googlemail.com>
Date: Mon Feb 9 08:04:00 2004 +0000
the bug has been partially covered and now when a relocation error is
triggered with an IRIX object the offending section symbol is correctly
reported:
tmpdir/dump0.o: In function `foo':
(.text+0x2000): relocation truncated to fit: R_MIPS_26 against `.text'
tmpdir/dump0.o: In function `bar':
(.text+0x4000): relocation truncated to fit: R_MIPS_26 against `.text'
because `bfd_elf_string_from_elf_section' retrieves the name from the
string table section. With a traditional object however the function
returns an empty string and consequently `no symbol' is printed instead:
tmpdir/dump0.o: In function `foo':
(.text+0x2000): relocation truncated to fit: R_MIPS_26 against `no symbol'
tmpdir/dump0.o: In function `bar':
(.text+0x4000): relocation truncated to fit: R_MIPS_26 against `no symbol'
Restore the original semantics so that the section name is always
correctly retrieved.
bfd/
* elfxx-mips.c (mips_elf_calculate_relocation): Also use the
section name if `bfd_elf_string_from_elf_section' returns an
empty string.
ld/
* testsuite/ld-mips-elf/reloc-local-overflow.d: New test.
* testsuite/ld-mips-elf/reloc-local-overflow.s: Source for the
new test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new test.
Alan Modra