H.J. Lu [Wed, 9 Feb 2022 23:51:22 +0000 (15:51 -0800)]
x86: Disallow invalid relocation against protected symbol
I am checking this into master and will backport it to 2.38 branch.
H.J
----
On x86, GCC 12 supports -mno-direct-extern-access to enable canonical
reference to protected function and disable copy relocation. With
-mno-direct-extern-access, the canonical protected function symbols must
be accessed via canonical reference and the protected data symbols in
shared libraries are non-copyable. Under glibc 2.35, non-canonical
reference to the canonical protected function will get the run-time error:
./y: internal_f: ./libfoo.so: non-canonical reference to canonical protected function
and copy relocations against the non-copyable protected symbols will get
the run-time error:
./x: internal_i: ./libfoo.so: copy relocation against non-copyable protected symbol
Update x86 linker to disallow non-canonical reference to the canonical
protected function:
ld: plt.o: non-canonical reference to canonical protected function `internal_f' in libfoo.so
ld: failed to set dynamic section sizes: bad value
and copy relocation against the non-copyable protected symbol:
ld: main.o: copy relocation against non-copyable protected symbol `internal_i' in libfoo.so
Palmer Dabbelt [Mon, 7 Feb 2022 20:14:30 +0000 (12:14 -0800)]
RISC-V: Stop reporting warnings for mismatched extension versions
The extension version checking logic is really just too complicated to
encode into the linker, trying to do so causes more harm than good.
This removes the checks and the associated tests, leaving the logic to
keep the largest version of each extension linked into the target.
bfd/
* elfnn-riscv.c (riscv_version_mismatch): Rename to
riscv_update_subset_version, and stop reporting warnings on
version mismatches.
(riscv_merge_std_ext): Adjust calls to riscv_version_mismatch.
(riscv_merge_multi_letter_ext): Likewise.
Alan Modra [Fri, 4 Feb 2022 09:00:47 +0000 (19:30 +1030)]
Detect .eh_frame_hdr earlier for SIZEOF_HEADERS
Current code detects the need for PT_GNU_EH_FRAME using a field set by
_bfd_elf_discard_section_eh_frame_hdr, which is called fairly late in
the linking process. Use the elf hash table eh_info instead, which is
set up earlier by size_dynamic_sections.
Alan Modra [Wed, 26 Jan 2022 00:01:36 +0000 (10:31 +1030)]
PowerPC64 treatment of absolute symbols
Supporting -static-pie on PowerPC64 requires the linker to properly
treat SHN_ABS symbols for cases like glibc's _nl_current_LC_CTYPE_used
absolute symbol. I've been slow to fix the linker on powerpc because
there is some chance that this will break some shared libraries or
PIEs.
bfd/
* elf64-ppc.c (ppc64_elf_check_relocs): Consolidate local sym
handling code. Don't count dyn relocs against non-dynamic
absolute symbols.
(dec_dynrel_count): Adjust to suit.
(ppc64_elf_edit_toc): Don't remove entries for absolute symbols
when pic.
(allocate_got): Don't allocate space for got relocs against
non-dynamic absolute syms.
(ppc64_elf_layout_multitoc): Likewise.
(got_and_plt_relr): Likewise.
(ppc64_elf_size_dynamic_sections): Likewise for local got.
(got_and_plt_relr_for_local_syms): Likewise.
(ppc64_elf_size_stubs): Don't allocate space for relr either.
(ppc64_elf_relocate_section): Don't write relocs against non-dynamic
absolute symbols. Don't optimise got and toc code sequences
loading absolute symbol entries.
ld/
* testsuite/ld-powerpc/abs-reloc.s,
* testsuite/ld-powerpc/abs-static.d,
* testsuite/ld-powerpc/abs-static.r,
* testsuite/ld-powerpc/abs-pie.d,
* testsuite/ld-powerpc/abs-pie.r,
* testsuite/ld-powerpc/abs-shared.d,
* testsuite/ld-powerpc/abs-shared.r,
* testsuite/ld-powerpc/abs-pie-relr.d,
* testsuite/ld-powerpc/abs-pie-relr.r,
* testsuite/ld-powerpc/abs-shared-relr.d,
* testsuite/ld-powerpc/abs-shared-relr.r: New tests.
* testsuite/ld-powerpc/powerpc.exp: Run them.
Alan Modra [Thu, 27 Jan 2022 23:16:13 +0000 (09:46 +1030)]
PR28827, assertion building LLVM 9 on powerpc64le-linux-gnu
The assertion is this one in ppc_build_one_stub
BFD_ASSERT (stub_entry->stub_offset >= stub_entry->group->stub_sec->size);
It is checking that a stub doesn't overwrite the tail of a previous
stub, so not something trivial.
Normally, stub sizing iterates until no stubs are added, detected by
no change in stub section size. Iteration also continues if no stubs
are added but one or more stubs increases in size, which also can be
detected by a change in stub section size. But there is a
pathological case where stub section sizing decreases one iteration
then increases the next. To handle that situation, stub sizing also
stops at more than STUB_SHRINK_ITER (20) iterations when calculated
stub section size is smaller. The previous larger size is kept for
the actual layout (so that building the stubs, which behaves like
another iteration of stub sizing, will see the stub section sizes
shrink). The problem with that stopping condition is that it assumes
that stub sizing is only affected by addresses external to the stub
sections, which isn't always true.
This patch fixes that by also keeping larger individual stub_offset
addresses past STUB_SHRINK_ITER. It also catches a further
pathological case where one stub shrinks and another expands in such a
way that no stub section size change is seen.
PR 28827
* elf64-ppc.c (struct ppc_link_hash_table): Add stub_changed.
(STUB_SHRINK_ITER): Move earlier in file.
(ppc_size_one_stub): Detect any change in stub_offset. Keep
larger one if past STUB_SHRINK_ITER.
(ppc64_elf_size_stubs): Iterate on stub_changed too.
Re: PR28827, assertion building LLVM 9 on powerpc64le-linux-gnu
The previous patch wasn't quite correct. The size and padding depends
on offset used in the current iteration, and if we're fudging the
offset past STUB_SHRINK_ITER then we'd better use that offset. We
can't have plt_stub_pad using stub_sec->size as the offset.
PR 28827
* elf64-ppc.c (plt_stub_pad): Add stub_off param.
(ppc_size_one_stub): Set up stub_offset to value used in this
iteration before sizing the stub. Adjust plt_stub_pad calls.
Re: PR28827, assertion building LLVM 9 on powerpc64le-linux-gnu
In trying to find a testcase for PR28827, I managed to hit a linker
error in bfd_set_section_contents with a .branch_lt input section
being too large for the output .branch_lt.
bfd/
PR 28827
* elf64-ppc.c (ppc64_elf_size_stubs): Set section size to
maxsize past STUB_SHRINK_ITER before laying out. Remove now
unnecessary conditional setting of maxsize at start of loop.
ld/
* testsuite/ld-powerpc/pr28827-2.d,
* testsuite/ld-powerpc/pr28827-2.lnk,
* testsuite/ld-powerpc/pr28827-2.s: New test.
* testsuite/ld-powerpc/powerpc.exp: Run it.
Alan Modra [Wed, 19 Jan 2022 13:17:41 +0000 (23:47 +1030)]
Update PowerPC64 symtocbase test
Using a symbol other than .TOC. with @tocbase is an extension to the
ABI. It is never valid to use a symbol without a definition in the
binary, and symbols on these expressions cannot be overridden. Make
this explicit by using ".hidden" in the testcase.
* testsuite/ld-powerpc/symtocbase-1.s: Align data. Make function
entry symbol hidden.
* testsuite/ld-powerpc/symtocbase-2.s: Likewise.
* testsuite/ld-powerpc/symtocbase.d: Adjust expected output.
Alan Modra [Fri, 28 Jan 2022 12:38:27 +0000 (23:08 +1030)]
objcopy --only-keep-debug
From: Peilin Ye <peilin.ye@bytedance.com>
objcopy's --only-keep-debug option has been broken for ELF files since
commit 8c803a2dd7d3.
1. binutils/objcopy.c:setup_section() marks non-debug sections as
SHT_NOBITS, then calls bfd_copy_private_section_data();
2. If ISEC and OSEC share the same section flags,
bfd/elf.c:_bfd_elf_init_private_section_data() restores OSEC's
section type back to ISEC's section type, effectively undoing
"make_nobits".
* objcopy.c (setup_section): Act on make_nobits after calling
bfd_copy_private_section_data.
Nick Clifton [Mon, 31 Jan 2022 14:38:12 +0000 (14:38 +0000)]
Import a patch from the GCC mainline to fix an infinite recursion in the Rust demangler.
PR 98886
PR 99935
* rust-demangle.c (struct rust_demangler): Add a recursion
counter.
(demangle_path): Increment/decrement the recursion counter upon
entry and exit. Fail if the counter exceeds a fixed limit.
(demangle_type): Likewise.
(rust_demangle_callback): Initialise the recursion counter,
disabling if requested by the option flags.
H.J. Lu [Fri, 14 Jan 2022 21:48:36 +0000 (13:48 -0800)]
ld: Rewrite lang_size_relro_segment_1
1. Compute the desired PT_GNU_RELRO segment base and find the maximum
section alignment of sections starting from the PT_GNU_RELRO segment.
2. Find the first preceding load section.
3. Don't add the 1-page gap between the first preceding load section and
the relro segment if the maximum page size >= the maximum section
alignment. Align the PT_GNU_RELRO segment first. Subtract the maximum
page size if therer is still a 1-page gap.
PR ld/28743
PR ld/28819
* ldlang.c (lang_size_relro_segment_1): Rewrite.
* testsuite/ld-x86-64/pr28743-1.d: New file.
* testsuite/ld-x86-64/pr28743-1.s: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run pr28743-1.
Simon Marchi [Fri, 21 Jan 2022 16:33:29 +0000 (11:33 -0500)]
gdb: include gdbsupport/buildargv.h in ser-mingw.c
Fixes:
CXX ser-mingw.o
/home/simark/src/binutils-gdb/gdb/ser-mingw.c: In function ‘int pipe_windows_open(serial*, const char*)’:
/home/simark/src/binutils-gdb/gdb/ser-mingw.c:870:3: error: ‘gdb_argv’ was not declared in this scope
870 | gdb_argv argv (name);
| ^~~~~~~~
Andrew Burgess [Fri, 21 Jan 2022 12:49:48 +0000 (12:49 +0000)]
gdb/doc: fill in two missing @r
I noticed two places in the docs where we appear to be missing @r.
makeinfo seems to do the correct things despite these being
missing (at least, I couldn't see any difference in the pdf or info
output), but it doesn't hurt to have the @r in place.
Tom Tromey [Thu, 13 Jan 2022 16:48:18 +0000 (09:48 -0700)]
Avoid bad breakpoints with --gc-sections
We found a case where --gc-sections can cause gdb to set an invalid
breakpoint. In the included test case, gdb will set a breakpoint with
two locations, one of which is 0x0.
The code in lnp_state_machine::check_line_address is intended to
filter out this sort of problem, but in this case, the entire CU is
empty, causing unrelocated_lowpc==0x0 -- which circumvents the check.
It seems to me that if a CU is empty like this, then it is ok to
simply ignore the line table, as there won't be any locations anyway.
Respect `set print array-indexes' with Fortran arrays
Add `set print array-indexes' handling for Fortran arrays. Currently
the setting is ignored and indices are never shown.
Keep track of the most recent index handled so that any outstanding
repeated elements printed when the limit set by `set print elements' is
hit have the correct index shown.
Add `set print repeats' tests for C/C++ arrays, complementing one for
Fortran arrays and covering the different interpretation of the `set
print elements' setting in particular where the per-dimension count of
the elements handled is matched against the trigger rather than the
total element count as with Fortran arrays.
Implement `set print repeats' handling for Fortran arrays. Currently
the setting is ignored and always treated as if no limit was set.
Unlike the generic array walker implemented decades ago the Fortran one
is a proper C++ class. Rather than trying to mimic the old walker then,
which turned out a bit of a challenge where interacting with the `set
print elements' setting, write it entirely from scratch, by adding an
extra specialization handler method for processing dimensions other than
the innermost one and letting the specialization class call the `walk_1'
method from the handler as it sees fit. This way repeats can be tracked
and the next inner dimension recursed into as a need arises only, or
unconditionally in the base class.
Keep track of the dimension number being handled in the class rather as
a parameter to the walker so that it does not have to be passed across
by the specialization class.
Use per-dimension element count tracking, needed to terminate processing
early when the limit set by `set print elements' is hit. This requires
extra care too where the limit triggers exactly where another element
that is a subarray begins. In that case rather than recursing we need
to terminate processing or lone `(...)' would be printed. Additionally
if the skipped element is the last one in the current dimension we need
to print `...' by hand, because `continue_walking' won't print it at the
upper level, because it can see the last element has already been taken
care of.
Preserve the existing semantics of `set print elements' where the total
count of the elements handled is matched against the trigger level which
is unlike with the C/C++ array printer where the per-dimension element
count is used instead.
Amend existing test cases accordingly that rely on the current incorrect
behavior and explicitly request that there be no limit for printing
repeated elements there.
Add suitable test cases as well covering sliced arrays in particular.
Co-Authored-By: Andrew Burgess <andrew.burgess@embecosm.com>
Alan Modra [Wed, 19 Jan 2022 02:49:51 +0000 (13:19 +1030)]
PowerPC64 DT_RELR ELFv1
More fun with R_PPC64_NONE found in .opd. Fixed by the
allocate_dynrelocs and ppc64_elf_size_dynamic_sections changes, and
since we are doing ifunc, opd and SYMBOL_REFERENCES_LOCAL tests later,
don't duplicate that work in check_relocs.
* elf64-ppc.c (ppc64_elf_check_relocs): Remove opd and ifunc
conditions for rel_count.
(dec_dynrel_count): Likewise.
(allocate_dynrelocs): Test for opd and ifunc when allocating
relative relocs.
(ppc64_elf_size_dynamic_sections): Likewise.
Alan Modra [Wed, 19 Jan 2022 00:23:53 +0000 (10:53 +1030)]
PowerPC64 DT_RELR local GOT
Fixes another case where we end up with superfluous R_PPC64_NONE.
* elf64-ppc.c (ppc64_elf_size_dynamic_sections): Don't allocate
space for GOT relocs against non-TLS local syms when enable_dt_relr.
(ppc64_elf_layout_multitoc): Likewise.