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PR ld/20125, MMIX weak symbols

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Weak undefineds with PUSHJ relocs were "lost", causing internal
inconsistencies and an abort.
This commit is contained in:
Hans-Peter Nilsson 2017-07-25 04:09:32 +02:00
parent 454c9bb956
commit 284d826d9f
5 changed files with 52 additions and 6 deletions
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6
bfd/ChangeLog
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@ -1,3 +1,9 @@
2017-08-21 Hans-Peter Nilsson <hp@bitrange.com>
PR ld/20125
* elf64-mmix.c (mmix_elf_relax_section): Correct handling of
undefined weak symbols.
2017-08-18 Nick Clifton <nickc@redhat.com>
PR binutils/21962

23
bfd/elf64-mmix.c
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@ -2710,8 +2710,21 @@ mmix_elf_relax_section (bfd *abfd,
indx = ELF64_R_SYM (irel->r_info) - symtab_hdr->sh_info;
h = elf_sym_hashes (abfd)[indx];
BFD_ASSERT (h != NULL);
if (h->root.type != bfd_link_hash_defined
&& h->root.type != bfd_link_hash_defweak)
if (h->root.type == bfd_link_hash_undefweak)
/* FIXME: for R_MMIX_PUSHJ_STUBBABLE, there are alternatives to
the canonical value 0 for an unresolved weak symbol to
consider: as the debug-friendly approach, resolve to "abort"
(or a port-specific function), or as the space-friendly
approach resolve to the next instruction (like some other
ports, notably ARM and AArch64). These alternatives require
matching code in mmix_elf_perform_relocation or its caller. */
symval = 0;
else if (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
symval = (h->root.u.def.value
+ h->root.u.def.section->output_section->vma
+ h->root.u.def.section->output_offset);
else
{
/* This appears to be a reference to an undefined symbol. Just
ignore it--it will be caught by the regular reloc processing.
@ -2725,10 +2738,6 @@ mmix_elf_relax_section (bfd *abfd,
}
continue;
}
symval = (h->root.u.def.value
+ h->root.u.def.section->output_section->vma
+ h->root.u.def.section->output_offset);
}
if (ELF64_R_TYPE (irel->r_info) == (int) R_MMIX_PUSHJ_STUBBABLE)
@ -2866,6 +2875,8 @@ mmix_elf_relax_section (bfd *abfd,
}
}
BFD_ASSERT(pjsno == mmix_elf_section_data (sec)->pjs.n_pushj_relocs);
if (internal_relocs != NULL
&& elf_section_data (sec)->relocs != internal_relocs)
free (internal_relocs);

6
ld/ChangeLog
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@ -1,3 +1,9 @@
2017-08-21 Hans-Peter Nilsson <hp@bitrange.com>
PR ld/20125
* testsuite/ld-mmix/pr20125.d, testsuite/ld-mmix/pr20125.s: New
test.
2017-08-20 A. Wilcox <awilfox@adelielinux.org>
PR ld/21976

21
ld/testsuite/ld-mmix/pr20125.d Normal file
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@ -0,0 +1,21 @@
#as: -no-predefined-syms -x -I$srcdir/$subdir
#ld: -m mmo --defsym __.MMIX.start..text=0x80000
#objdump: -dr
# PUSHJ reloc handling was wrong for weak undefined symbols, causing
# internal inconsistencies, leading to a call to abort.
# Note that we don't keep track of which symbols have pushj-stubs, so
# we get one stub each for the two calls to "foo".
.*: file format mmo
Disassembly of section \.text:
0+80000 <(_start|Main)>:
80000: fe000004 get \$0,rJ
80004: f2010004 pushj \$1,80014 <Main\+0x14>
80008: f2010004 pushj \$1,80018 <Main\+0x18>
8000c: f6040000 put rJ,\$0
80010: f8010000 pop 1,0
80014: f1fdfffb jmp 0 <Main-0x80000>
80018: f1fdfffa jmp 0 <Main-0x80000>

2
ld/testsuite/ld-mmix/pr20125.s Normal file
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@ -0,0 +1,2 @@
.weak bar
.include "pr12815-2.s"