GCC 8 will bring a new warning option which will detect possible
overflow and truncation on string manipulation functions. For more
details, see:
https://gcc.gnu.org/ml/gcc-patches/2017-08/msg00471.html
While compiling BFD with it, I can see one place on bfd/coff-rs6000.c
where the warning is triggered. This:
(void) strncpy (fhdr.magic, XCOFFARMAG, SXCOFFARMAG);
will not include the trailing NUL on fhdr.magic, but that's fine
because it's a magic number. The fix is trivial: just use memcpy
instead.
OK to push?
2018-02-06 Sergio Durigan Junior <sergiodj@redhat.com>
* coff-rs6000.c (xcoff_write_archive_contents_old): Use
'memcpy' instead of 'strncpy' when writing the magic number.
PR 22794
* opncls.c (bfd_get_debug_link_info_1): Check the size of the
section before attempting to read it in.
(bfd_get_alt_debug_link_info): Likewise.
The nm utility supports -l for using debug information to obtain file and line information for each symbol, if available.
We have a tool that consumes this information and displays it.
This identified a problem with the 'nm' utility.
When a source is compiled with -O2, functions can be inlined. The compiler also produces an uninlined copy of the function, normally for linking to other object files.
In the case of DWARF2 debug information, the compiler generates debug information to describe a function. If that function is inlined, the compiler then references that debug information from the inlined and uninlined copies of the routine through the use of the DW_AT_abstract_origin reference.
When nm is used on such a file, it is not able to find file and line information because that information is present in the common debug information and not at each actual implementation of the function.
The 'nm' utility only retrieves the name of the function from the abstract origin debug information and no more.
What I am proposing is to modify the find_abstract_instance_name() function (which I renamed to find_abstract_instance() ) to return the name of the function as well as any file and line information. The routine is already parsing all of the debug information in the abstract instance, so it is easy to pick up the file and line information at that time. If, for some reason, the file and line information is not present, the routine behaves as before.
For example, if I have a simple test case:
int foo(int j)
{
if (j < 15)
j += j << 2;
else
j += j << 6;
return j;
}
int main (int argc,char **argv)
{
int i = argc;
i += foo(i);
return i;
}
If that test case is compiled with -O2 and then 'nm -l' reads that executable, it currently produces this symbol output (ignoring a lot of library symbols):
8048400 T foo
080482e0 T main /scratch/pcarroll/its254/test/mytest.c:12
If I modify 'nm' to return file and line information for abstract instances, it produces the following output:
08048400 T foo /scratch/pcarroll/its254/test/mytest.c:1
080482e0 T main /scratch/pcarroll/its254/test/mytest.c:12
--------------------------------------------------------------------------
bfd * bfd/dwarf2.c (find_abstract_name): Modified to return file and
line information in addition to name, if they can be found.
The assumption that R_AARCH64_ABS16 and R_AARCH64_ABS32 relocation in LP64 abi
will be used to generate an address does not hold for absolute symbol.
In this case, it is a value fixed at static linking time.
The condition to check the relocations is relax to allow absolute symbol and
undefined symbol case.
bfd/
2018-02-05 Renlin Li <renlin.li@arm.com>
PR ld/22764
* elfnn-aarch64.c (elfNN_aarch64_check_relocs): Relax the
R_AARCH64_ABS32 and R_AARCH64_ABS16 for absolute symbol. Apply the
check for writeable section as well.
ld/
2018-02-05 Renlin Li <renlin.li@arm.com>
PR ld/22764
* testsuite/ld-aarch64/emit-relocs-258.s: Define symbol as an address.
* testsuite/ld-aarch64/emit-relocs-259.s: Likewise.
* testsuite/ld-aarch64/aarch64-elf.exp: Run new test.
* testsuite/ld-aarch64/pr22764.s: New.
* testsuite/ld-aarch64/pr22764.d: New.
Since _GLOBAL_OFFSET_TABLE_ may be referenced implicitly on x86,
checking ref_regular_nonweak leaves the unused _GLOBAL_OFFSET_TABLE_
in output. This patch checks explicit GOT references instead.
ld-i386/discarded1.s and ld-x86-64/discarded1.s are updated to avoid
linker optimization which removes GOT references.
bfd/
PR ld/22782
* elf32-i386.c (elf_i386_check_relocs): Set got_referenced if
_GLOBAL_OFFSET_TABLE_ is referenced or GOT is needed to resolve
undefined weak symbol to 0.
* elf64-x86-64.c (elf_x86_64_check_relocs): Set got_referenced
if _GLOBAL_OFFSET_TABLE_ is referenced.
* elfxx-x86.c (_bfd_x86_elf_size_dynamic_sections): Check
got_referenced instead of ref_regular_nonweak. Remove the
unused _GLOBAL_OFFSET_TABLE_ from symbol table.
* elfxx-x86.h (elf_x86_link_hash_table): Add got_referenced.
ld/
PR ld/22782
* testsuite/ld-i386/discarded1.s: Replace mov with div.
* testsuite/ld-x86-64/discarded1.s: Likewise.
* testsuite/ld-i386/i386.exp: Run pr22782.
* testsuite/ld-i386/load1-nacl.d: Updated for removing
_GLOBAL_OFFSET_TABLE_ from output.
* testsuite/ld-i386/load1.d: Likewise.
* testsuite/ld-x86-64/load1a-nacl.d: Likewise.
* testsuite/ld-x86-64/load1a.d: Likewise.
* testsuite/ld-x86-64/load1b-nacl.d: Likewise.
* testsuite/ld-x86-64/load1b.d: Likewise.
* testsuite/ld-i386/pr22782.d: New file.
* testsuite/ld-i386/pr22782.s: Likewise.
* testsuite/ld-x86-64/pr22782.s: Likewise.
* testsuite/ld-x86-64/pr22782a.d: Likewise.
* testsuite/ld-x86-64/pr22782b.d: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run pr22782a and pr22782b.
Correct a commit 9d06997adb ("RISC-V: Relax RISCV_PCREL_* to
RISCV_GPREL_*") regression and remove a `-Wmissing-field-initializers'
compilation error:
cc1: warnings being treated as errors
.../bfd/elfnn-riscv.c: In function '_bfd_riscv_relax_pc':
.../bfd/elfnn-riscv.c:3117: error: missing initializer
.../bfd/elfnn-riscv.c:3117: error: (near initialization for 'hi_reloc.hi_addend')
make[4]: *** [elf64-riscv.lo] Error 1
which for versions of GCC before 4.7 prevents support for RISC-V targets
from being built. See also GCC PR c/36750.
bfd/
* elfnn-riscv.c (_bfd_riscv_relax_pc): Use `memset' to
initialize `hi_reloc'.
Report an error when an unsupported `.reginfo' section size is found in
`_bfd_mips_elf_section_processing', removing an assertion that triggers
at elfxx-mips.c:7105 in GAS when assembling input like:
.section .reginfo
.word 0xdeadbeef
and in `objcopy --rename-section' when renaming an incorrectly sized
section to `.reginfo'.
bfd/
* elfxx-mips.c (_bfd_mips_elf_section_processing): For
SHT_MIPS_REGINFO sections don't assert the correct size and
report an error instead.
binutils/
* testsuite/binutils-all/mips/mips-reginfo.d: New test.
* testsuite/binutils-all/mips/mips-reginfo-n32.d: New test.
* testsuite/binutils-all/mips/mips-reginfo.s: New test source.
* testsuite/binutils-all/mips/mips.exp: Run the new tests.
gas/
* testsuite/gas/mips/reginfo-2.d: New test.
* testsuite/gas/mips/reginfo-2-n32.d: New test.
* testsuite/gas/mips/reginfo-2.l: New test stderr output.
* testsuite/gas/mips/reginfo-2.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
Fix the issue of any failure from `->elf_backend_section_processing'
not being propagated by `_bfd_elf_write_object_contents'. The MIPS
`_bfd_mips_elf_section_processing' handler can actually potentially
fail, however the caller currently ignores that.
bfd/
* elf.c (_bfd_elf_write_object_contents): Propagate a failure
status from `->elf_backend_section_processing'.
bfd/
PR ld/22756
* elfnn-riscv.c (riscv_relax_delete_bytes): New parameter link_info.
If link_info->wrap_hash, check for a duplicate symbol and ignore.
(_bfd_riscv_relax_call, bfd_riscv_relax_lui, _bfd_riscv_relax_tls_le):
Pass new argument to riscv_relax_delete_bytes.
(_bfd_riscv_relax_align, _bfd_riscv_relax_delete): Likewise. Remove
ATTRIBUTE_UNUSED from link_info parameter.
This fixes a "bug" in that nops emitted as part of code optimization
were being relocated. As it happens the relocation value was always
zero so the nop wasn't changed. Whew! I've also moved the use of
"howto" later since I was caught out in some recent code changes with
the howto not matching r_type.
* elf64-ppc.c (ppc64_elf_relocate_section): Don't relocate nops
emitted for toc sequence optimization. Set and use "howto" later.
bfdI would like to fix instances of the following warning, when building
with clang with no special CFLAGS other than -g3 -O0.
/home/emaisin/src/binutils-gdb/bfd/elflink.c:5425:45: error: performing pointer arithmetic on a null pointer has undefined behavior [-Werror,-Wnull-pointer-arithmetic]
return (struct elf_link_hash_entry *) 0 - 1;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
Replacing those with "(struct elf_link_hash_entry *) -1" gets rid of the
warning. I wanted to check that it didn't change the resulting code, so
I tried to build this:
$ cat test.c
int *before()
{
return (int *) 0 - 1;
}
int *after()
{
return (int *) - 1;
}
$ gcc -c test.c -g
$ objdump -d test.o
test.o: file format elf64-x86-64
Disassembly of section .text:
0000000000000000 <before>:
0: 55 push %rbp
1: 48 89 e5 mov %rsp,%rbp
4: 48 c7 c0 fc ff ff ff mov $0xfffffffffffffffc,%rax
b: 5d pop %rbp
c: c3 retq
000000000000000d <after>:
d: 55 push %rbp
e: 48 89 e5 mov %rsp,%rbp
11: 48 c7 c0 ff ff ff ff mov $0xffffffffffffffff,%rax
18: 5d pop %rbp
19: c3 retq
This shows that the previous code doesn't actually return -1 as the
function documentation says, but the new one does, so it's kind of a
bugfix.
bfd * elf64-ppc.c (ppc64_elf_archive_symbol_lookup): Avoid pointer
arithmetic on NULL pointer.
* elflink.c (_bfd_elf_archive_symbol_lookup,
elf_link_add_archive_symbols): Likewise.
ld * ldexp.c (fold_name, exp_fold_tree_1): Avoid pointer arithmetic
on NULL pointer.
We really need to check for a dynamic def, not only a ref.
See added testcase.
bfd/
* elflink.c (bfd_elf_define_start_stop): Fix check of
def_dynamic.
ld/
* testsuite/ld-elf/pr21964-5.c: New test.
* testsuite/ld-elf/shared.exp: Run it.
Define __start/__stop symbols if they are referenced by shared objects,
not if they are also defined in shared objects.
bfd/
PR ld/21964
* elflink.c (bfd_elf_define_start_stop): Check if __start and
__stop symbols are referenced by shared objects.
ld/
PR ld/21964
* testsuite/ld-elf/pr21964-4.c: New file.
* testsuite/ld-elf/shared.exp: Run pr21964-4 test on Linux.
We can't map different disk pages into the same memory page; The last
page mapped will simply overwrite any previous pages. The
executable/non-executable new_segment test ignored this fact, leading
to a ld.so segfault on hppa when .dynamic is overwritten with zeros.
This patch moves existing tests for demand paging with lma on the same
memory page, to a new test performed before any case where we want a
new segment due to protection or loadable conflicts.
PR 22758
* elf.c (_bfd_elf_map_sections_to_segments): Don't start a new
segment when demand paged with lma on the same page. Test this
before load/non-load, executable/non-executable,
writable/non-writable tests and simplify. Delete bogus relro
condition in writable/non-writable test. Delete outdated
comment. Formatting.
bfd/
* elflink.c (bfd_elf_define_start_stop): Make __start and __stop
symbols dynamic.
ld/
* testsuite/ld-elf/pr21964-3a.c: New file.
* testsuite/ld-elf/pr21964-3c.c: New file.
* testsuite/ld-elf/shared.exp: Run new __start/__stop testcase.
This patch fixes a case where a user had a C-representable named
section in both the executable and shared libraries, and of course
wanted the size of the local section in the executable, not the
dynamic section. It does mean that __start and __stop symbols don't
behave exactly like PROVIDEd symbols, but I think that's a reasonable
difference particularly since this is the way they used to behave.
* elflink.c (bfd_elf_define_start_stop): Override symbols when
they are defined dynamically.
https://bugzilla.redhat.com/show_bug.cgi?id=1523457
I haven't analyzed this myself, I'm relying on Nick's excellent
analysis. What I believe is happening is that after some number of
stub sizing iterations, a long-branch stub needs to be converted to a
plt-branch, but either due to stub alignment or other stubs shrinking
in size, the stub group section size doesn't change.
That means we exit from ppc64_elf_size_stubs after sizing with an
incorrect layout, in fact the additional .branch_lt entry overlays
.got! Since .TOC. is normally set to .got + 0x8000 the stub sizing
code decides that entry is within +/-32k of the TOC pointer and so a
three insn stub is sufficient. When we come to build the stubs using
a correct non-overlaying layout, a four insn plt-branch stub is
generated and the stub group size doesn't match that calculated
earlier.
* elf64-ppc.c (ppc64_elf_size_stubs): Iterate sizing when
.branch_lt changes size.
There are actually 2 different bugs:
1. TLS transition is broken in PIE mode.
2. TLS is broken in PIC/PIE mode when the __tls_get_addr symbol
is versioned (as is the case on Linux and Solaris at least).
The 1st bug is fixed by reverting the problematic change for now
(note that the associated test doesn't pass on SPARC because of another
issue so there is no formal regression in the testsuite). The 2nd bug
is fixed by changing the call to _bfd_generic_link_add_one_symbol
on __tls_get_addr into a mere lookup in _bfd_sparc_elf_check_relocs.
bfd/
* elfxx-sparc.c (_bfd_sparc_elf_check_relocs) <R_SPARC_TLS_GD_CALL>:
Do a mere lookup of the __tls_get_addr symbol instead of adding it.
Revert
2017-10-19 H.J. Lu <hongjiu.lu@intel.com>
PR ld/22263
* elfxx-sparc.c (sparc_elf_tls_transition): Replace
bfd_link_pic with !bfd_link_executable, !bfd_link_pic with
bfd_link_executable for TLS check.
(_bfd_sparc_elf_check_relocs): Likewise.
(allocate_dynrelocs): Likewise.
(_bfd_sparc_elf_relocate_section): Likewise.
ld/
* testsuite/ld-sparc/sparc.exp (32-bit: Helper shared library):
Link with a version script.
(32-bit: TLS -fpie): New test.
(64-bit: Helper shared library): Link with a version script.
(64-bit: TLS -fpie): New test.
(64-bit: GOTDATA relocations): Pass -Av9 to the assembler.
* testsuite/ld-sparc/tlslib.ver: New file.
* testsuite/ld-sparc/tlspie32.dd: Likewise.
* testsuite/ld-sparc/tlspie32.s: Likewise.
* testsuite/ld-sparc/tlspie64.dd: Likewise.
* testsuite/ld-sparc/tlspie64.s: Likewise.
* testsuite/ld-sparc/tlssunbin32.dd: Adjust for versioned symbol.
* testsuite/ld-sparc/tlssunbin32.rd: Likewise.
* testsuite/ld-sparc/tlssunbin32.sd: Likewise.
* testsuite/ld-sparc/tlssunbin64.dd: Likewise.
* testsuite/ld-sparc/tlssunbin64.rd: Likewise.
* testsuite/ld-sparc/tlssunbin64.sd: Likewise.
Update a stale reference to `mips_elf32_section_processing', following a
merge of the function into `_bfd_mips_elf_section_processing' made with
commit 103186c62b ("PATCH for MIPS 64-bit ABI suport"),
<https://sourceware.org/ml/binutils/1999-q3/msg00072.html>.
bfd/
* elfxx-mips.c (_bfd_mips_elf_final_link): Update a stale
`mips_elf32_section_processing' comment reference.
We need to check the versioned __tls_get_addr symbol when looking up
"__tls_get_addr".
bfd/
PR ld/22721
* elfxx-x86.c (_bfd_x86_elf_link_check_relocs): Check the
versioned __tls_get_addr symbol.
ld/
PR ld/22721
* testsuite/ld-plugin/lto.exp: Run PR ld/22721 tests.
* testsuite/ld-plugin/pr22721.t: New file.
* testsuite/ld-plugin/pr22721a.s: Likewise.
* testsuite/ld-plugin/pr22721b.c: Likewise.
Asking for ppc32 plt call stubs to be aligned at 32 byte boundaries
didn't quite work. For ld.bfd they were spaced 32 bytes apart, but
only started on a 16 byte boundary. ld.gold also didn't get it right.
Finding that bug made me check over the ppc64 plt stub alignment,
where I found that negative values for alignment (meaning align to
minimize boundary crossing) were not accepted. Since no one has
complained about that, I guess I could have removed the feature from
ld.bfd documentation, but I've opted instead to correct the code.
I've also added an optional alignment paramenter for ppc32
--plt-align, for some consistency with gold and ppc64 ld.bfd.
bfd/
* elf32-ppc.c (ppc_elf_create_glink): Correct alignment of .glink.
* elf64-ppc.c (ppc64_elf_size_stubs): Handle negative plt_stub_align.
(ppc64_elf_build_stubs): Likewise.
gold/
* powerpc.cc (param_plt_align): New function supplying default
--plt-align values. Use it..
(Stub_table::plt_call_align): ..here, and..
(Output_data_glink::global_entry_align): ..here.
(Stub_table::stub_align): Correct 32-bit minimum alignment.
ld/
* emultempl/ppc32elf.em: Support optional --plt-align arg.
* emultempl/ppc64elf.em: Support negative --plt-align arg.
This is in preparation for the next patch adding Spectre variant 2
mitigation for PowerPC and PowerPC64. Besides tidying code involved
in stub output (to reduce the number of places where bctr is output),
the patch adds some user visible features:
1) PowerPC64 ELFv2 global entry stubs now are aligned under the
control of --plt-align, with a default alignment of 32 bytes.
2) PowerPC64 __glink_PLTresolve is no longer padded out with nops.
3) PowerPC32 PLT stubs are aligned under the control of --plt-align,
with the default alignment being 16 bytes as before.
4) The PowerPC32 branch/nop table emitted before __glink_PLTresolve
is now smaller in many cases. It was sized incorrectly when the
__tls_get_addr_opt stub was used, and unnecessarily included space
for local ifuncs.
bfd/
* elf32-ppc.c (GLINK_ENTRY_SIZE): Add parameters, handle
__tls_get_addr_opt, and alignment sizing.
(TLS_GET_ADDR_GLINK_SIZE): Delete.
(is_nonpic_glink_stub): Don't use GLINK_ENTRY_SIZE.
(ppc_elf_get_synthetic_symtab): Recognize stubs spaced at 4, 6,
or 8 insns.
(ppc_elf_link_hash_table_create): Init new ppc_elf_params field.
(allocate_dynrelocs): Use new GLINK_ENTRY_SIZE.
(ppc_elf_size_dynamic_sections): Likewise. Size branch table
by PLT reloc count.
(write_glink_stub): Handle __tls_get_addr_opt stub.
Pad out to size given by GLINK_ENTRY_SIZE.
(ppc_elf_relocate_section): Adjust write_glink_stub call.
(ppc_elf_finish_dynamic_symbol): Likewise.
(ppc_elf_finish_dynamic_sections): Write PLTresolve without using
insn array since so many need rewriting.
* elf32-ppc.h (struct ppc_elf_params): Add plt_stub_align.
* elf64-ppc.c (GLINK_PLTRESOLVE_SIZE): Rename from
GLINK_CALL_STUB_SIZE. Add htab param and evaluate to size without
nops. Adjust all uses.
(ppc64_elf_get_synthetic_symtab): Don't use GLINK_CALL_STUB_SIZE
in glink_vma calculation.
(struct ppc_link_hash_table): Add global_entry section pointer.
(create_linkage_sections): Create separate section for global
entry stubs.
(PPC_LO, PPC_HI, PPC_HA): Move earlier.
(size_global_entry_stubs): Handle sizing for aligned stubs.
(ppc64_elf_size_dynamic_sections): Handle global_entry alloc,
and don't stash end of glink branch table in rawsize.
(ppc_build_one_stub): Rewrite stub size calculations.
(build_global_entry_stubs): Use new section.
(ppc64_elf_build_stubs): Don't pad __glink_PLTresolve with nops.
Build lazy link stubs out to end of section. Build global entry
stubs in new section.
gold/
* options.h (plt_align): Support for PowerPC32 too.
* powerpc.cc (Stub_table::stub_align): Heed --plt-align for 32-bit.
(Stub_table::plt_call_size, branch_stub_size): Tidy.
(Stub_table::plt_call_align): Implement using stub_align.
(Output_data_glink::global_entry_align): New function.
(Output_data_glink::global_entry_off): New function.
(Output_data_glink::global_entry_address): Use global_entry_off.
(Output_data_glink::pltresolve_size): New function, replacing
pltresolve_size_ constant. Update all uses.
(Output_data_glink::add_global_entry): Align offset.
(Output_data_glink::set_final_data_size): Use global_entry_align.
(Stub_table::do_write): Don't pad __glink_PLTrelsolve with nops.
Tidy stub output. Use global_entry_off.
ld/
* emultempl/ppc32elf.em (params): Init new field.
(enum ppc32_opt): New enum to define OPTION_* values. Add
OPTION_PLT_ALIGN and OPTION_NO_PLT_ALIGN.
(PARSE_AND_LIST_LONGOPTS): Handle new options.
(PARSE_AND_LIST_ARGS_CASES): Likewise.
(PARSE_AND_LIST_OPTIONS): Likewise. Break up help output.
* emultempl/ppc64elf.em (ppc_add_stub_section): Init alignment
correctly for negative --plt-stub-align.
* testsuite/ld-powerpc/elfv2exe.d,
* testsuite/ld-powerpc/elfv2so.d,
* testsuite/ld-powerpc/relbrlt.d,
* testsuite/ld-powerpc/relbrlt.s,
* testsuite/ld-powerpc/tlsexe.d,
* testsuite/ld-powerpc/tlsexe.r,
* testsuite/ld-powerpc/tlsexe32.d,
* testsuite/ld-powerpc/tlsexe32.g,
* testsuite/ld-powerpc/tlsexe32.r,
* testsuite/ld-powerpc/tlsexetoc.d,
* testsuite/ld-powerpc/tlsexetoc.r,
* testsuite/ld-powerpc/tlsopt5_32.d,
* testsuite/ld-powerpc/tlsso.d,
* testsuite/ld-powerpc/tlstocso.d: Update for changed stub order.
When processing a section that is a member of a group, the group
that contains it is looked up using a linear search. The resulting
O(n^2) complexity causes significant performance issues when
dealing with object files with very many groups.
By remembering the index of the last found group and restarting
the next search from that index, the search instead becomes O(n)
in common cases.
* elf.c (setup_group): Optimize search for group by remembering
last found group and restarting search at that index.
* elf-bfd.h (struct elf_obj_tdata): Add group_search_offset field.
The default should be bfd_link_common_skip_none, as in the original
patch at https://sourceware.org/ml/binutils/2002-07/msg00717.html
* aoutx.h (aout_link_check_ar_symbols): Remove default and handle
bfd_link_common_skip_none in switch.
PowerPC64 has its own mark_dynamic_ref, which needs the same change as
made by d664fd41e1 to the generic ELF version. Some other targets
discard more than just .data, so allow for that too in expected ld
messages.
bfd/
PR ld/22649
* elf64-ppc.c (ppc64_elf_gc_mark_dynamic_ref): Ignore dynamic
references on forced local symbols.
ld/
PR ld/22649
* testsuite/ld-elf/pr22649.msg: Allow other messages.
* testsuite/ld-elf/shared.exp: Check that --gc-sections is
supported before running ld/22649 tests.
One of assertions in _bfd_mips_elf_final_link could be triggered by
a combination of input files and a linker script. This happens when
either the input doesn't contain .reginfo section or when this section
is oversized. This patch replaces the assertion with a more useful
error message.
* elfxx-mips.c (_bfd_mips_elf_final_link): Notify user when
.reginfo section has wrong size.
When generating separate code LOAD segment, create a new LOAD segment
if the previous section contains text and the current section doesn't
or vice versa:
Elf file type is DYN (Shared object file)
Entry point 0x200020
There are 7 program headers, starting at offset 52
Program Headers:
Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
LOAD 0x000000 0x00000000 0x00000000 0x00200 0x00200 R 0x200000
LOAD 0x200000 0x00200000 0x00200000 0x00036 0x00036 R E 0x200000
LOAD 0x400000 0x00400000 0x00400000 0x00064 0x00064 R 0x200000
LOAD 0x400f80 0x00600f80 0x00600f80 0x000a0 0x000a0 RW 0x200000
DYNAMIC 0x400f80 0x00600f80 0x00600f80 0x00080 0x00080 RW 0x4
GNU_STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RW 0x10
GNU_RELRO 0x400f80 0x00600f80 0x00600f80 0x00080 0x00080 R 0x1
Section to Segment mapping:
Segment Sections...
00 .hash .gnu.hash .dynsym .dynstr .rela.plt
01 .plt .text
02 .rodata .eh_frame
03 .dynamic .got.plt
04 .dynamic
05
06 .dynamic
to prevent fetching or executing data in code pages as instructions.
Also don't put a writable section in a read-only segment if there is a
RELRO segment.
Since code segment is aligned and padded to the maximum page size on
disk, the minimum file size is bigger than the maximum page size which
is 2MB (0x200000):
-rwxr-xr-x 1 hjl hjl 4201932 Jan 10 10:41 libfoo.so
"-z max-page-size=0x1000" can be used to reduce the maximum page size to
4KB (0x1000):
-rwxr-xr-x 1 hjl hjl 15820 Jan 10 10:44 libfoo.so
PR ld/22393
* elf.c (_bfd_elf_map_sections_to_segments): When generating
separate code and read-only data LOAD segments, create a new
LOAD segment if the previous section contains text and the
current section doesn't or vice versa. Don't put a writable
section in a read-only segment if there is a RELRO segment.
We should ignore dynamic references on forced local symbols during
garbage collection since they can never be referenced dynamically.
bfd/
PR ld/22649
* elflink.c (bfd_elf_gc_mark_dynamic_ref_symbol): Ignore dynamic
references on forced local symbols.
ld/
PR ld/22649
* testsuite/ld-elf/pr22649-1.s: New file.
* testsuite/ld-elf/pr22649-2a.s: Likewise.
* testsuite/ld-elf/pr22649-2b.s: Likewise.
* testsuite/ld-elf/pr22649.msg: Likewise.
* testsuite/ld-elf/shared.exp: Run ld/22649 tests.
We must keep all PREINIT_ARRAY, INIT_ARRAY as well as FINI_ARRAY sections
for ld -r --gc-sections.
bfd/
PR ld/22677
* elflink.c (bfd_elf_gc_sections): Keep all PREINIT_ARRAY,
INIT_ARRAY as well as FINI_ARRAY sections for ld -r --gc-sections.
ld/
PR ld/22677
* scripttempl/elf.sc (PREINIT_ARRAY): New.
Don't add .preinit_array for ld -r.
* testsuite/ld-elf/pr22677.d: New file.
* testsuite/ld-elf/pr22677.s: Likewise.
_bfd_elf_link_renumber_dynsyms is called twice by the linker. The
first call in bfd_elf_size_dynamic_sections is just to answer the
question as to whether there are there any dynamic symbols. The
second call in bfd_elf_size_dynsym_hash_dynstr sets the st_shndx value
that dynamic symbols will have. strip_excluded_output_sections is
called between these two calls. So sections seen on the first
_bfd_elf_link_renumber_dynsyms pass might differ from those seen on
the second pass. Unfortunately, that can result in a stripped
section's dynamic symbol being assigned a dynindx on the first pass
but not corrected to the final value (of zero, ie. not dynamic) on the
second pass. PowerPC, x86, mips, and most other targets that emit
dynamic section symbols, just test that section symbol dynindx is
non-zero before using a given section symbol in dynamic relocations.
This patch prevents _bfd_elf_link_renumber_dynsyms from setting any
section symbol dynindx on the first pass.
PR 22626
* elflink.c (_bfd_elf_link_renumber_dynsyms): Don't set section
dynindx when section_sym_count is NULL.
(bfd_elf_size_dynamic_sections): Pass NULL section_sym_count to
preliminary _bfd_elf_link_renumber_dynsyms call.
PR 22571
* archive.c (bfd_openr_next_archived_file): Extend the
documentation to note that it is necessary to call
bfd_check_format on the rrturned bfd before using it.
R_AARCH64_ABS64, R_AARCH64_ABS32 and R_AARCH64_ABS16 are data relocations
supported in AArch64 elf ABI.
R_AARCH64_ABS64 under LP64 is allowed in shared object and a dynamic relocation entry
will be generated. This allows the dynamic linker to do further symbol resolution.
R_AARCH64_ABS32 likewise is allowed in shared object, however under ILP32 abi.
The original behavior for R_AARCH64_ABS32 under LP64 is that, it's allowed
in shared object and silently resolved at static linking time.
No dynamic relocation entry is generate for it.
R_AARCH64_ABS16 is allowed in shared object under both L64 and ILP32.
It's resolved at static linking time as well.
Under LP64, the address should be 64-bit. R_AARCH64_ABS32 relocation indicates
an address that is only sized 32 bits which is meaningless in LP64 shared object.
It's useful to error out.
I have checked glibc dynamic linker code, R_AARCH64_ABS16 is not supported at all. So
R_AARCH64_ABS16 should be reject in shared object completely.
In this patch, R_AARCH64_ABS32 is rejected under LP64 in constant section of shared object.
R_AARCH64_ABS16 is rejected in constant section of shared object in both ABI.
This will sometimes provide useful information for buggy code.
