The undefweak symbol value of non-default visibility is 0 and does
not use plt entry, and will not be relocated in the relocate_secion
function. As a result, an infinite loop is generated because
bl %plt(sym) => bl 0.
Fix this by converting the call into a jump address 0.
This patch adds support for Guarded Control Stack in AArch64 linker.
This patch implements the following:
1) Defines GNU_PROPERTY_AARCH64_FEATURE_1_GCS bit for GCS in
GNU_PROPERTY_AARCH64_FEATURE_1_AND macro.
2) Adds readelf support to read and print the GCS feature in GNU
properties in AArch64.
Displaying notes found in: .note.gnu.property
[ ]+Owner[ ]+Data size[ ]+Description
GNU 0x00000010 NT_GNU_PROPERTY_TYPE_0
Properties: AArch64 feature: GCS
3) Adds support for the "-z gcs" linker option and document all the values
allowed with this option (-z gcs[=always|never|implicit]) where "-z gcs" is
equivalent to "-z gcs=always". When '-z gcs' option is omitted from the
command line, it defaults to "implicit" and relies on the GCS feature
marking in GNU properties.
4) Adds support for the "-z gcs-report" linker option and document all the
values allowed with this option (-z gcs-report[=none|warning|error]) where
"-z gcs-report" is equivalent to "-z gcs-report=warning". When this option
is omitted from the command line, it defaults to "warning".
The ABI changes adding GNU_PROPERTY_AARCH64_FEATURE_1_GCS to the GNU
property GNU_PROPERTY_AARCH64_FEATURE_1_AND is merged into main and
can be found in [1].
[1] https://github.com/ARM-software/abi-aa/blob/main/sysvabi64/sysvabi64.rst
Co-authored-by: Matthieu Longo <matthieu.longo@arm.com>
Co-authored-by: Yury Khrustalev <yury.khrustalev@arm.com>
The previous message for missing BTI feature in GNU properties was
not very clear. The new message explains that a missing GNU property
marking is lacking on this specific input.
- declare a new struc aarch_protection_opts to store all the
configuration options related to software protections (i.e. bti-plt,
pac-plt, bti-report level).
- add a new option "-z bti-report" to configure the log level of reported
issues when BTI PLT is forced.
- encapsulate the BTI report inside _bfd_aarch64_elf_check_bti_report.
- moved all the BTI and PAC tests into a new subfolder: "protections".
bti-far-*
bti-plt-*
bti-pac-plt-*
- move several procedures used only for AArch64 linker tests to a new exp
library file aarch64-elf-lib.exp in ld/testsuite/ld-aarch64/lib.
- use aarch64-elf-lib.exp in aarch64-ld.exp and aarch64-protections.exp.
The baseline was, afaik, specifically chosen to align with the baseline
ISA of x86-64. It therefore makes no sense to emit that property only
conditionally; if anything it confuses tools analyzing the difference
between generated object files, which may result from just
added / changed / removed (entirely ISA-independent) code, without any
change to the enabled extensions. Compilers, after all, are free to use
these baseline "extensions" when generating 64-bit code.
While changing the one testcase that needs adjustment, also correct its
misleading name (to be in sync with the filename).
Commit 36bbf8646c ("s390: Treat addressing operand sequence as one in
disassembler") changed how plain "nop" gets disassembled and missed to
update any affected linker tests accordingly.
ld/testsuite/
* ld-s390/tlsbin.dd: "nop" disassembles into "nop".
Fixes: 36bbf8646c ("s390: Treat addressing operand sequence as one in disassembler")
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
The Nios II architecture has been EOL'ed by the vendor. This patch
removes all binutils, bfd, gas, binutils, and opcodes support for this
target with the exception of the readelf utility. (The ELF EM_*
number remains valid and the relocation definitions from the Nios II
ABI will never change in future, so retaining the readelf support
seems consistent with its purpose as a utility that tries to parse the
headers in any ELF file provided as an argument regardless of target.)
When handling MS style import libraries (also called short import
libraries, or ILF), we need to detect the kind of library.
So far, this has been done by looking at the member file names
in the import library - in an MS style import library, all the
member files for a specific library have the same member file
name - the name of the runtime module to link against. Usually
this is a DLL - thus we do a case insensitive comparison and
check if the suffix is .dll.
However, an .exe can also export symbols which can be linked
against in the same way. In particular, if linking against
WDK (Windows Driver Kit) import libraries, e.g. wdmsec.lib, the
import libraries can provide imports for ntoskrnl.exe.
Instead of specifically checking for *.dll (and *.exe, etc),
invert the condition and skip archive members named *.o and *.obj.
For any remaining archive members, that do contain .idata
sections, apply the renaming. (The renaming is also mostly
harmless if applied where it isn't needed; if archive members
already have unique file names, their relative ordering should
remain intact except for very contrieved cases.)
Signed-off-by: Martin Storsjö <martin@martin.st>
Since only the abandoned privileged spec v1.9.1 will have conflict csrs, to
keep the compatible we still report warnings when linking privileged spec
v1.9.1 objects with others. But don't report warnings for other compatible
cases because it is actually a bit noisy and useless...
bfd/
* elfnn-riscv.c (riscv_merge_attributes): Only report warnings when
linking the abandoned privileged spec v1.9.1 object with others.
ld/
* testsuite/ld-riscv-elf/attr-merge-priv-spec-failed-01.d: Removed.
* testsuite/ld-riscv-elf/attr-merge-priv-spec-failed-02.d: Removed.
* testsuite/ld-riscv-elf/attr-merge-priv-spec-failed-03.d: Removed.
* testsuite/ld-riscv-elf/attr-merge-priv-spec-failed-04.d: Removed.
* testsuite/ld-riscv-elf/attr-merge-priv-spec-failed-05.d: Removed.
* testsuite/ld-riscv-elf/attr-merge-priv-spec-failed-06.d: Removed.
* testsuite/ld-riscv-elf/ld-riscv-elf.exp: Updated.
There is no overflow check for the relaxation of pcalau12i+ld.d =>
pcalau12i+addi.d. For instruction sequences that can be relaxed,
they are directly relaxed to pcalau12i+addi.d. However, when the
relative distance between the symbol and the pc exceeds the 32-bit
range, the symbol value cannot be obtained correctly.
Adds an overflow check for the relaxation of pcalau12i+ld.d.
If it is found that the relaxation will overflow, it will not
be relaxed.
Specifying the compiler flag `-Wl,--package-metadata=<JSON>` will not
work in case the JSON contains a comma, because compiler drivers eat
commas. Example:
```
$ echo "void main() { }" > test.c
$ gcc '-Wl,--package-metadata={"type":"deb","os":"ubuntu"}' test.c
/usr/bin/ld: cannot find "os":"ubuntu"}: No such file or directory
collect2: error: ld returned 1 exit status
```
The quotation marks in the JSON value do not work well with shell nor
make. Specifying the `--package-metadata` linker flag in a `LDFLAGS`
environment variable might loose its quotation marks when it hits the
final compiler call.
So support percent-encoded and %[string] encoded JSON data in the
`--package-metadata` linker flag. Percent-encoding is used because it is
a standard, simple to implement, and does take too many additional
characters. %[string] encoding is supported for having a more readable
encoding.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32003
Bug-Ubutru: https://bugs.launchpad.net/bugs/2071468
Signed-off-by: Benjamin Drung <benjamin.drung@canonical.com>
GCC trunk now defaults to -std=gnu23. We return false in a few places
which can't work when true/false are a proper type (_Bool). Return NULL
where appropriate instead of false. All callers handle this appropriately.
ChangeLog:
PR ld/32372
* pdb.c (add_stream): Return NULL.
Fix csky-linux-gnu FAIL of ld-elf/pr32341, due to that target having
its own .bss directive.
PR ld/32341
* testsuite/ld-elf/pr32341.s: Don't use .bss directive. Specify
progbits/nobits on all .section directives.
Move note sections after .rodata section so that note sections are
placed in the same PT_LOAD segment together with .rodata section,
instead of a separate PT_LOAD segment.
PR ld/32341
* scripttempl/misc-sections.sc: Move note sections to ...
* scripttempl/elf.sc: Here, after .rodata section.
* testsuite/ld-elf/pr32341.d: New file.
* testsuite/ld-elf/pr32341.s: Likewise.
Co-Authored-By: Nick Clifton <nickc@redhat.com>
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
For any arm elf target, disable an old piece of code that forced disassembly to
disassemble for 'unknown architecture' which once upon a time meant it would
disassemble ANY arm instruction. This is no longer true with the addition of
Armv8.1-M Mainline, as there are conflicting encodings for different thumb
instructions.
BFD however can detect what architecture the object file was assembled for
using information in the notes section. So if available, we use that,
otherwise we default to the old 'unknown' behaviour.
With the changes above code, a mode changing 'bx lr' assembled for armv4 with
the option --fix-v4bx will result in an object file that is recognized by bfd
as one for the armv4 architecture. The disassembler now disassembles this
encoding as a BX even for Armv4 architectures, but warns the user when
disassembling for Armv4 that this instruction is only valid from Armv4T
onwards.
Remove the unused and wrongfully defined ARM_ARCH_V8A_CRC, and
define and use a ARM_ARCH_V8R_CRC to make sure instructions enabled by
-march=armv8-r+crc are disassembled correctly.
Patch up some of the tests cases, see a brief explanation for each below.
inst.d:
This test checks the assembly & disassembly of basic instructions in armv3m. I
changed the expected behaviour for teqp, cmnp cmpp and testp instructions to
properly print p when disassembling, whereas before, in the 'unknown' case it
would disassemble these as UNPREDICTABLE as they were changed in later
architectures.
nops.d:
Was missing an -march, added one to make sure we were testing the right
behavior of NOP<c> instructions.
unpredictable.d:
Was missing an -march, added armv6 as that reproduced the behaviour being
tested.
PR/32298 sframe: no SFrame stack trace info generated for .plt.got
Add support to generate SFrame stack trace info for .plt.got section.
Enhance the current definition of struct elf_x86_sframe_plt to include
initialized SFrame FDE/FREs applicable for .plt.got section. There are
two variants of .plt.got entries: 16 byte and 8 byte.
8 byte:
ff 25 00 00 00 00 jmpq *name@GOTPCREL(%rip)
66 90 xchg %ax,%ax
16 byte:
f3 0f 1e fa endbr64
ff 25 66 2f 00 00 jmpq *name@GOTPCREL(%rip)
66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
For the testcase, define some application symbols such that their PLT
entry is placed in .plt.got and ensure SFrame information is generated
with and without -z ibtplt.
ChangeLog:
PR/32298
* bfd/elf64-x86-64.c (elf_x86_64_link_setup_gnu_properties):
PLT GOT entry size is different for IBT vs non IBT PLTs.
* bfd/elfxx-x86.c (enum dynobj_sframe_plt_type): New enum for
SFRAME_PLT_GOT.
(_bfd_x86_elf_create_sframe_plt): Handle SFRAME_PLT_GOT.
(_bfd_x86_elf_write_sframe_plt): Likewise.
(_bfd_x86_elf_late_size_sections): Likewise.
(_bfd_x86_elf_finish_dynamic_sections): Likewise.
* bfd/elfxx-x86.h (struct elf_x86_sframe_plt): Add new members
to keep information about PLT GOT entries.
(struct elf_x86_link_hash_table): Add support for creating
SFrame section for .plt.got.
* ld/testsuite/ld-x86-64/x86-64.exp: Add new tests.
* ld/testsuite/ld-x86-64/sframe-pltgot-1.d: New test.
* ld/testsuite/ld-x86-64/sframe-pltgot-1.s: New test.
* ld/testsuite/ld-x86-64/sframe-pltgot-2.d: New test.
Fix PR/32296 sframe: wrong SFrame info for pltN and .plt.sec for -z ibtplt
The x86 psABI defines a 2-PLT scheme for IBT which uses .plt and
.plt.sec entries. It was observed that SFrame information for .plt.sec
section was incorrect. The erroneous assumption was that SFrame stack
trace information for .plt.sec with lazy binding is the same as SFrame
stack trace information for .plt with lazy binding. This is corrected
now by initializing a new SFrame PLT helper object
elf_x86_64_sframe_ibt_plt for lazy PLT with IBT.
Add a testcase where linking with -z ibtplt generates .plt.sec entries and
ensure correct SFrame information for it.
Committed by Indu Bhagat.
ChangeLog:
PR/32296
* bfd/elf64-x86-64.c (elf_x86_64_sframe_ibt_pltn_fre2): New
definition elf_x86_64_sframe_ibt_plt. Use it in
elf_x86_64_sframe_plt.
(elf_x86_64_link_setup_gnu_properties): Lazy IBT PLT entries are
different from lazy PLT.
* bfd/elfxx-x86.c (_bfd_x86_elf_create_sframe_plt): Adjust for
SFrame for IBT PLT.
* ld/testsuite/ld-x86-64/x86-64.exp: Add new test.
* ld/testsuite/ld-x86-64/sframe-ibt-plt-1.d: New test.
Linker should report an error for hidden undefined symbol when building
a shared library without the "recompile with -fPIC" message:
$ cat x.c
extern int foo __attribute__ ((visibility ("hidden")));
int
func (void)
{
return foo;
}
$ gcc -c -fPIC -O2 x.c
$ objdump -dwr x.o
x.o: file format elf64-x86-64
Disassembly of section .text:
0000000000000000 <func>:
0: 8b 05 00 00 00 00 mov 0x0(%rip),%eax # 6 <func+0x6> 2: R_X86_64_PC32 foo-0x4
6: c3 ret
$ ld -shared -o x.so x.o
ld: x.o: in function `func':
x.c:(.text+0x2): undefined reference to `foo'
ld: x.o: relocation R_X86_64_PC32 against undefined hidden symbol `foo' can not be used when making a shared object
ld: final link failed: bad value
$
since -fPIC has been used.
* testsuite/ld-x86-64/hidden6.d: New file.
* testsuite/ld-x86-64/hidden6.s: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run hidden6.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Pass --no-rosegment to ld to support linker configured with
--enable-rosegment,
PR ld/25207
* ld-elf/pr25207.d: Pass --no-rosegment to ld.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
LLD has dropped the option -Ttext-segment for specifying image base
addresses, instead forcing the use of the --image-base option for both
ELF and PE targets. As it stands, GNU LD and LLVM LLD are incompatible,
having two different options for the same functionality.
This patch enables the use of --image-base on ELF targets, advancing
consistency and compatibility.
See: https://reviews.llvm.org/D70468https://maskray.me/blog/2020-11-15-explain-gnu-linker-options#address-relatedhttps://sourceware.org/bugzilla/show_bug.cgi?id=25207
Moreover, a new test has been added to ensure -z separate-code behaviour
when used with -Ttext-segment stays the same. When this combination is
used, -Ttext-segment sets the address of the first segment (R), not the
text segment (RX), and like with -z noseparate-code, no segments lesser
than the specified address are created. If this behaviour was to change,
the first (R) segment of the ELF file would begin in a lesser address
than the specified text (RX) segment, breaking traditional use of this
option for specifying image base address.
Building shared libraries should not be allowed for PC-relative
relocations against external symbols.
Currently LoongArch has no corresponding checks and silently
generates wrong shared libraries.
However, In the first version of the medium cmodel, pcalau12i+jirl was
used for function calls, in which case PC-relative relocations were
allowed.
The noxfail option is useful in situations like pr23658-1e which
fails on all microblaze ELF targets except microblaze-linux. This was
possible to handle by writing a small proc and use that as an xfail
predicate, or painstakingly listing all microblaze ELF targets, but
this is simpler. The patch also fixes some other FAILs and XPASSes of
the pr23658 tests.
binutils/
* testsuite/lib/binutils-common.exp (run_dump_test): Support
noxfail.
ld/
* testsuite/ld-elf/pr23658-1a.d: Don't xfail m68hc12.
* testsuite/ld-elf/pr23658-1e.d: Likewise. xfail xstormy16
and correct microblaze xfails.
Add relaxation support for call36 that jump to PLT entry.
Add relaxation support for call36 with IFUNC symbol.
Add relaxation support for call36 that jump to undefweak symbol.
For undefweak symbol, it can always be relaxed if it have no PLT entry.
Because we set the address of undefweak symbol without PLT entry to PC
like relocate_section.
While for executables properly aligning sections within the file can be
quite relevant, the same is of pretty little importance for relocatable
object files. Avoid passing "true" into
_bfd_elf_assign_file_position_for_section() when dealing with object
files, but compensate minimally by applying log_file_align in such
cases as a cap to the alignment put in place.
