Commit 0fcf331b authored by Maciej W. Rozycki's avatar Maciej W. Rozycki
Browse files

VAX/BFD: Do not warn about GOT addend mismatches if no GOT entry is made

Match the condition used in `elf_vax_instantiate_got_entries' for the
creation of GOT entries in the processing of R_VAX_GOT32 relocations in
`elf_vax_check_relocs', removing incorrect warnings about a GOT addend
mismatch like:

./ld-new: tmpdir/got-local-ref-off-r.o: warning: GOT addend of 1 to `bar_hidden' does not match previous GOT addend of 0
./ld-new: tmpdir/got-local-ref-off-r.o: warning: GOT addend of 2 to `bar_hidden' does not match previous GOT addend of 0

and corresponding failures with the test cases newly added here:

FAIL: GOT test (executable hidden reference with offset)
FAIL: GOT test (executable visible reference with offset)

for symbols that are considered local for reasons other than having been
forced local with a version script, which is usually the ELF visibility.
Correct code is produced regardless, but the warning breaks `-Werror'
compilation and may upset people regardless.

Interestingly this shows with executable links only, because in shared
library links code from `elf_link_add_object_symbols' triggers:

	    /* If the symbol already has a dynamic index, but
	       visibility says it should not be visible, turn it into
	       a local symbol.  */
	    switch (ELF_ST_VISIBILITY (h->other))
	      {
	      case STV_INTERNAL:
	      case STV_HIDDEN:
		(*bed->elf_backend_hide_symbol) (info, h, TRUE);
		dynsym = FALSE;
		break;
	      }

that sets `h->forced_local' like with a version script.

Add suitable test cases including disassembly to verify correct code has
been produced where no warnings have been issued, and that warnings do
get issued where necessary.  Do not verify (broken) code produced in the
latter case; we should probably make the warning an error, or preferably
actually start supporting GOT references with different addends as they
appear feasible with explicitly relocated GOT that we use.

	bfd/
	* elf32-vax.c (elf_vax_check_relocs) <R_VAX_GOT32>: Use
	SYMBOL_REFERENCES_LOCAL rather than `h->forced_local' to check
	whether the symbol referred is local or not.

	ld/
	* testsuite/ld-vax-elf/got-local-exe-off-hidden.dd: New test
	dump.
	* testsuite/ld-vax-elf/got-local-exe-off-visible.dd: New test
	dump.
	* testsuite/ld-vax-elf/got-local-lib-off-hidden.dd: New test
	dump.
	* testsuite/ld-vax-elf/got-local-lib-off-visible.ed: New test
	dump.
	* testsuite/ld-vax-elf/got-local-off-external.ed: New test dump.
	* testsuite/ld-vax-elf/got-local-exe-off.xd: New test dump.
	* testsuite/ld-vax-elf/got-local-lib-off.xd: New test dump.
	* testsuite/ld-vax-elf/got-local.ld: New test linker script.
	* testsuite/ld-vax-elf/got-local-aux-off.s: New test source.
	* testsuite/ld-vax-elf/got-local-def-off.s: New test source.
	* testsuite/ld-vax-elf/got-local-ref-off-external.s: New test
	source.
	* testsuite/ld-vax-elf/got-local-ref-off-hidden.s: New test
	source.
	* testsuite/ld-vax-elf/got-local-ref-off-visible.s: New test
	source.
	* testsuite/ld-vax-elf/vax-elf.exp: Run the new tests.
parent 3c7ba803
2020-12-05 Maciej W. Rozycki <macro@linux-mips.org>
* elf32-vax.c (elf_vax_check_relocs) <R_VAX_GOT32>: Use
SYMBOL_REFERENCES_LOCAL rather than `h->forced_local' to check
whether the symbol referred is local or not.
2020-12-04 H.J. Lu <hongjiu.lu@intel.com>
PR ld/27016
......
......@@ -598,7 +598,7 @@ elf_vax_check_relocs (bfd *abfd, struct bfd_link_info *info, asection *sec,
/* If this is a local symbol, we resolve it directly without
creating a global offset table entry. */
if (h->forced_local
if (SYMBOL_REFERENCES_LOCAL (info, h)
|| h == elf_hash_table (info)->hgot
|| h == elf_hash_table (info)->hplt)
break;
......
2020-12-05 Maciej W. Rozycki <macro@linux-mips.org>
* testsuite/ld-vax-elf/got-local-exe-off-hidden.dd: New test
dump.
* testsuite/ld-vax-elf/got-local-exe-off-visible.dd: New test
dump.
* testsuite/ld-vax-elf/got-local-lib-off-hidden.dd: New test
dump.
* testsuite/ld-vax-elf/got-local-lib-off-visible.ed: New test
dump.
* testsuite/ld-vax-elf/got-local-off-external.ed: New test dump.
* testsuite/ld-vax-elf/got-local-exe-off.xd: New test dump.
* testsuite/ld-vax-elf/got-local-lib-off.xd: New test dump.
* testsuite/ld-vax-elf/got-local.ld: New test linker script.
* testsuite/ld-vax-elf/got-local-aux-off.s: New test source.
* testsuite/ld-vax-elf/got-local-def-off.s: New test source.
* testsuite/ld-vax-elf/got-local-ref-off-external.s: New test
source.
* testsuite/ld-vax-elf/got-local-ref-off-hidden.s: New test
source.
* testsuite/ld-vax-elf/got-local-ref-off-visible.s: New test
source.
* testsuite/ld-vax-elf/vax-elf.exp: Run the new tests.
2020-12-04 H.J. Lu <hongjiu.lu@intel.com>
PR ld/27016
......
.globl baz
.type baz, @object
baz:
.byte 0, 1, 2
.size baz, . - baz
.data
.globl bar_hidden
.type bar_hidden, @object
.hidden bar_hidden
bar_hidden:
.byte 0, 1, 2
.size bar_hidden, . - bar_hidden
.globl bar_visible
.type bar_visible, @object
bar_visible:
.byte 0, 1, 2
.size bar_visible, . - bar_visible
.*: +file format .*vax.*
Disassembly of section \.text:
00000000 <foo>:
0: 00 00 \.word 0x0000 # Entry mask: < >
2: 9e ef f8 1f movab 2000 <bar_hidden>,r0
6: 00 00 50
9: 9e ef f2 1f movab 2001 <bar_hidden\+0x1>,r0
d: 00 00 50
10: 9e ef ec 1f movab 2002 <bar_hidden\+0x2>,r0
14: 00 00 50
17: 9e ef e6 1f movab 2003 <bar_visible>,r1
1b: 00 00 51
1e: 9e ff dc 0f movab \*1000 <baz>,r2
22: 00 00 52
25: 04 ret
.*: +file format .*vax.*
Disassembly of section \.text:
00000000 <foo>:
0: 00 00 \.word 0x0000 # Entry mask: < >
2: 9e ef f8 1f movab 2000 <bar_hidden>,r0
6: 00 00 50
9: 9e ef f4 1f movab 2003 <bar_visible>,r1
d: 00 00 51
10: 9e ef ee 1f movab 2004 <bar_visible\+0x1>,r1
14: 00 00 51
17: 9e ef e8 1f movab 2005 <bar_visible\+0x2>,r1
1b: 00 00 51
1e: 9e ff dc 0f movab \*1000 <baz>,r2
22: 00 00 52
25: 04 ret
# Make sure there's only one GOT entry, for the symbol defined externally.
Hex dump of section '\.got':
0x00001000 00000000 .*
.*: +file format .*vax.*
Disassembly of section \.text:
00000000 <foo>:
0: 00 00 \.word 0x0000 # Entry mask: < >
2: 9e ef f8 1f movab 2000 <bar_hidden>,r0
6: 00 00 50
9: 9e ef f2 1f movab 2001 <bar_hidden\+0x1>,r0
d: 00 00 50
10: 9e ef ec 1f movab 2002 <bar_hidden\+0x2>,r0
14: 00 00 50
17: 9e ff e7 0f movab \*1004 <bar_visible-0xfff>,r1
1b: 00 00 51
1e: 9e ff dc 0f movab \*1000 <baz>,r2
22: 00 00 52
25: 04 ret
\A[^\n]*\.o: warning: GOT addend of 1 to `bar_visible' does not match previous GOT addend of 0
[^\n]*\.o: warning: GOT addend of 2 to `bar_visible' does not match previous GOT addend of 0\Z
# Make sure there are only two GOT entries, for the preemptible symbols.
Hex dump of section '\.got':
0x00001000 00000000 00000000 .*
\A[^\n]*\.o: warning: GOT addend of 1 to `baz' does not match previous GOT addend of 0
[^\n]*\.o: warning: GOT addend of 2 to `baz' does not match previous GOT addend of 0\Z
.text
.globl foo
.type foo, @function
foo:
.word 0
movab bar_hidden, %r0
movab bar_visible, %r1
movab baz, %r2
movab baz + 1, %r2
movab baz + 2, %r2
ret
.size foo, . - foo
.text
.globl foo
.type foo, @function
foo:
.word 0
movab bar_hidden, %r0
movab bar_hidden + 1, %r0
movab bar_hidden + 2, %r0
movab bar_visible, %r1
movab baz, %r2
ret
.size foo, . - foo
.text
.globl foo
.type foo, @function
foo:
.word 0
movab bar_hidden, %r0
movab bar_visible, %r1
movab bar_visible + 1, %r1
movab bar_visible + 2, %r1
movab baz, %r2
ret
.size foo, . - foo
SECTIONS
{
.text : { *(.text) }
.hash : { *(.hash) }
.dynsym : { *(.dynsym) }
.dynstr : { *(.dynstr) }
.rela.dyn : { *(.rela.*) }
. = ALIGN (0x1000);
.got : { *(.got) }
. = ALIGN (0x1000);
.data : { *(.data) }
.dynamic : { *(.dynamic) }
.symtab : { *(.symtab) }
.strtab : { *(.strtab) }
.shstrtab : { *(.shstrtab) }
/DISCARD/ : { *(*) }
}
......@@ -51,7 +51,7 @@ run_ld_link_tests [list \
"plt-local"]]
# Global offset table tests. Make sure hidden symbols do not get GOT
# assignments.
# assignments. Also verify offset references.
run_ld_link_tests [list \
[list "GOT test (auxiliary shared library)" \
"-shared" "" \
......@@ -59,18 +59,48 @@ run_ld_link_tests [list \
{ got-local-aux.s } \
{} \
"got-local-aux.so"] \
[list "GOT test (auxiliary shared library for offsets)" \
"-shared" "" \
"-k" \
{ got-local-aux-off.s } \
{} \
"got-local-aux-off.so"] \
[list "GOT test (object 1)" \
"-r" "" \
"-k" \
{ got-local-ref.s } \
{} \
"got-local-ref-r.o"] \
[list "GOT test (object 1 hidden reference with offset)" \
"-r" "" \
"-k" \
{ got-local-ref-off-hidden.s } \
{} \
"got-local-ref-off-hidden-r.o"] \
[list "GOT test (object 1 visible reference with offset)" \
"-r" "" \
"-k" \
{ got-local-ref-off-visible.s } \
{} \
"got-local-ref-off-visible-r.o"] \
[list "GOT test (object 1 external reference with offset)" \
"-r" "" \
"-k" \
{ got-local-ref-off-external.s } \
{} \
"got-local-ref-off-external-r.o"] \
[list "GOT test (object 2)" \
"-r" "" \
"-k" \
{ got-local-def.s } \
{} \
"got-local-def-r.o"] \
[list "GOT test (object 2 for offsets)" \
"-r" "" \
"-k" \
{ got-local-def-off.s } \
{} \
"got-local-def-off-r.o"] \
[list "GOT test (executable)" \
"-e 0 tmpdir/got-local-aux.so tmpdir/got-local-ref-r.o \
tmpdir/got-local-def-r.o" "" \
......@@ -84,7 +114,58 @@ run_ld_link_tests [list \
"" \
{} \
{ { readelf "-x .got" got-local-lib.xd } } \
"got-local-lib.so"]]
"got-local-lib.so"] \
[list "GOT test (executable hidden reference with offset)" \
"-e 0 -T got-local.ld tmpdir/got-local-aux-off.so \
tmpdir/got-local-ref-off-hidden-r.o \
tmpdir/got-local-def-off-r.o" "" \
"" \
{} \
{ { readelf "-x .got" got-local-exe-off.xd } \
{ objdump -d got-local-exe-off-hidden.dd } } \
"got-local-exe-off-hidden"] \
[list "GOT test (shared library hidden reference with offset)" \
"-shared -T got-local.ld tmpdir/got-local-aux-off.so \
tmpdir/got-local-ref-off-hidden-r.o \
tmpdir/got-local-def-off-r.o" "" \
"" \
{} \
{ { readelf "-x .got" got-local-lib-off.xd } \
{ objdump -d got-local-lib-off-hidden.dd } } \
"got-local-lib-off-hidden.so"] \
[list "GOT test (executable visible reference with offset)" \
"-e 0 -T got-local.ld tmpdir/got-local-aux-off.so \
tmpdir/got-local-ref-off-visible-r.o \
tmpdir/got-local-def-off-r.o" "" \
"" \
{} \
{ { readelf "-x .got" got-local-exe-off.xd } \
{ objdump -d got-local-exe-off-visible.dd } } \
"got-local-exe-off-visible"] \
[list "GOT test (shared library visible reference with offset)" \
"-shared -T got-local.ld tmpdir/got-local-aux-off.so \
tmpdir/got-local-ref-off-visible-r.o \
tmpdir/got-local-def-off-r.o" "" \
"" \
{} \
{ { ld got-local-lib-off-visible.ed } } \
"got-local-lib-off-visible.so"] \
[list "GOT test (executable external reference with offset)" \
"-e 0 -T got-local.ld tmpdir/got-local-aux-off.so \
tmpdir/got-local-ref-off-external-r.o \
tmpdir/got-local-def-off-r.o" "" \
"" \
{} \
{ { ld got-local-off-external.ed } } \
"got-local-exe-off-external"] \
[list "GOT test (shared library external reference with offset)" \
"-shared -T got-local.ld tmpdir/got-local-aux-off.so \
tmpdir/got-local-ref-off-external-r.o \
tmpdir/got-local-def-off-r.o" "" \
"" \
{} \
{ { ld got-local-off-external.ed } } \
"got-local-lib-off-external.so"]]
# Export class relocation tests.
run_ld_link_tests [list \
......
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