LLD can not catch a memory area overflow when using a data command.
If we have the script below:
.foo :
{
*(.foo)
BYTE(0x1)
} > ram
where BYTE overflows the ram region, we do not report it currently.
Patch fixes that.
Differential revision: https://reviews.llvm.org/D43948
llvm-svn: 326545
GNU linkers by convention supports both `--foo bar` and `--foo=bar` styles
for all long options that take arguments.
Differential Revision: https://reviews.llvm.org/D43972
llvm-svn: 326506
Summary:
If an executable needs text relocations, it should be marked as such so
that the loader can prepare for text relocations. We currently create a
dummy segment with DT_TEXTREL for that purpose.
Generic ABI as of 2000 [1] mentioned that "Its [DT_TEXTREL's] use
has been superseded by the DF_TEXTREL flag". However, it's actually not
superseded even after 18 years. OpenBSD and musl recognize only DT_TEXTREL.
So we still need to set both.
[1] http://www.sco.com/developers/gabi/2000-07-17/ch5.dynamic.html
Reviewers: rafael
Subscribers: emaste, llvm-commits, arichardson
Differential Revision: https://reviews.llvm.org/D43920
llvm-svn: 326503
With the current code if the script has a PHDRS we always obey and try
to allocate a header. This can cause Min - HeaderSize to underflow.
It looks like bfd actually prints an error for this case. With this
patch we do the same.
Found while looking at pr36515.
llvm-svn: 326441
LLD crashes with broken scripts shown in testcase,
because fails to read memory regon name and accesses
MemoryRegions's element which is nullptr.
Patch fixes it.
Differential revision: https://reviews.llvm.org/D43866
llvm-svn: 326431
This is PR36515.
Currenly if we have a script like .debug_info 0 : { *(.debug_info) },
we would not remove this section and keep it in the output.
That does not work, because it is common case for
debug sections to have a zero address expression.
Patch changes behavior so that we remove only sections
that do not use symbols in its expressions.
Differential revision: https://reviews.llvm.org/D43863
llvm-svn: 326430
Previously, we didn't try to make effort to put .note sections next
to each other in the output file, so two .note sections were likely
to be stored to two separate NOTE segments. That's undesirable because
we should create as few segments as possible in general.
Differential Revision: https://reviews.llvm.org/D43858
llvm-svn: 326410
It now includes both linkerscript and non linkerscript variants.
Extracted from a patch by Rui while I was trying to figure out what
exactly was changing.
llvm-svn: 326409
Summary:
This change removes large "echo" commands from the test by writing
tests themselves as linker scripts.
Reviewers: rafael
Subscribers: emaste, javed.absar, llvm-commits, arichardson
Differential Revision: https://reviews.llvm.org/D43900
llvm-svn: 326403
Some linker script test cases contain only a few lines of assembly
and a long linker script. Such tests are easier to maintain if we
write the main test file as a linkier script instead of assembly.
Differential Revision: https://reviews.llvm.org/D43887
llvm-svn: 326363
Update LLD test expectations for new symbol ordering introduced by
Differential D43685.
Differential Revision: https://reviews.llvm.org/D43875
llvm-svn: 326335
We should process symbols inside output section declarations the same way as top-level ones.
Differential Revision: https://reviews.llvm.org/D43008
llvm-svn: 326305
This means we don't need to write the linking metadata section
at all for executable (non-relocatable) output.
Differential Revision: https://reviews.llvm.org/D42869
llvm-svn: 326268
Summary:
Some of the tests invoke llvm-readelf. This currently appears to work
probably because the LLVM binary directory is included in $PATH. However,
this is quite fragile so let's just make lit expand the full path.
Reviewers: ruiu, espindola
Reviewed By: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43827
llvm-svn: 326257
Imagine that we have sections A, B, C, where A == C and
symbol ordering file containing symbols: symC, symB, symA
Previously because of ICF it was possible that final order would be
B, A or B, C. That violates order specified in ordering file.
Patch changes that.
Differential revision: https://reviews.llvm.org/D43234
llvm-svn: 326179
It should be possible to resolve undefined symbols in dynamic libraries
using symbols defined in a linker script.
Differential Revision: https://reviews.llvm.org/D43011
llvm-svn: 326176
This fixes pr36475.
I think this code can be simplified a bit, but I would like to check
in the more direct fix if we are in agreement on the direction and
then refactor.
This is not something that bfd does. The issue is not noticed in bfd
because it keeps fewer sections from the linkerscript in the output.
The reasons why it seems reasonable to do this:
- As George noticed, we would still keep the flags if the output
section had both an empty synthetic section and a regular section
- We need an heuristic to find the flags of output sections. Using the
flags of a synthetic section that would have been there seems a
reasonable heuristic.
llvm-svn: 326137
MIPS ABIs require that if an executable file uses non-PIC model, the
EI_ABIVERSION entry in the ELF header should be incremented from 0 to 1.
That allows obsoleted / limited dynamic linkers refuse to link them.
llvm-svn: 325890
This continues direction started in D43069.
We can keep sections that are explicitly assigned to segment in script.
It helps to simplify code.
Differential revision: https://reviews.llvm.org/D43571
llvm-svn: 325887
Latest patch version now.
Original commit message:
[ELF] - Do not crash with --emit-relocs and --icf=all together.
Previously we would crash because did not mark .rel[a] sections
as dead and they tried to access parent which was not live
after ICF and therefore was null.
Differential revision: https://reviews.llvm.org/D43241
llvm-svn: 325879
Previously we would crash because did not mark .rel[a] sections
as dead and they tried to access parent which was not live
after ICF and therefore was null.
Differential revision: https://reviews.llvm.org/D43241
llvm-svn: 325877
This is for fixing PR36297.
Issue itself is that if we have SECTIONS { .bar (a+b) : { *(.stub) } };
script and no section .stub, when LLD will remove .bar, but
produce output with undefined symbols a and b.
Differential revision: https://reviews.llvm.org/D43069
llvm-svn: 325875
This is relative to "Bug 36166 - tools/gold/X86/comdat.ll is failing only on Debian Unstable" (PR36166).
Something changed in newer versions of gold and now together with gold-plugin
there is an issue shown in PR, symbol may get wrong visibility.
LLD works fine, but we have no testcase for the same use case, patch adds it.
Differential revision: https://reviews.llvm.org/D43193
llvm-svn: 325874
This responds to PR36475,
r325763 led to unexprected layout change, though
new behavior seems to be more correct.
Previously we could have following script:
.foo : { *(.foo) }
.bar : { *(.synthetic_empty) BYTE(0x11) }}
where synthetic_empty is a synthetic section which is empty and
hence removed by linker.
Before r325763 .bar would receive section flags from .synthetic_empty,
but after this revision it receives flags the same as .foo section has.
It is the same as if there would not be any synthetic_empty section in a script,
so looks reasonable and consistent behavior:
.foo : { *(.foo) }
.bar : { BYTE(0x11) }}
Patch adds testcase to document it.
Differential revision: https://reviews.llvm.org/D43632
llvm-svn: 325873
We have an internal program that does't link without this patch. I don't
know of any open-source program that needs this, but there might be.
Since this patch improves compatibility with GNU linkers with a few lines
of code, I think it's worth to be committed.
The problem is about undefined symbols in DSOs. Some programs depend on
the GNU linkers' behavior that they pull out object files from archive
files to resolve undefined symbols in DSOs. We already allow that kind of
"reverse" dependency (from DSOs to the main executable) for regular
symbols, in particular, for "__progname" symbol (which is usually in
crt0.o), but that doesn't work if the symbol is in an archive file.
This patch is to make it work.
Differential Revision: https://reviews.llvm.org/D43658
llvm-svn: 325849
This reverts commit r325679 that was committed without discussion.
Actually, in the discussion thread, most people opposed to have this
option in lld. Reverting that change doesn't mean that this is a
final decision, but that needs to be discussed first.
llvm-svn: 325714
In r324043, --nopie was renamed to --no-pie to presumably fix a typo.
As it turns out, "nopie" wasn't a typo but the spelling used by
OpenBSD's binutils ld. Gold on the other hand spells the flag "no-pie".
(Vanilla binutils doesn't have a flag like this at all.)
Since they do the same thing, let's support both spellings.
llvm-svn: 325679
This removes script input file and inlines script into
testcase body. That is consistent with othet LS tests
and makes testcase easier to read.
llvm-svn: 325673
Summary:
This fixes two failing tests on Windows with an installed version of python that has spaces in the path.
* elf/lto/cache.ll
* mach-o/dependency_info.yaml
Reviewers: zturner, llvm-commits, stella.stamenova
Subscribers: emaste, arichardson
Differential Revision: https://reviews.llvm.org/D43265
llvm-svn: 325650
This patch provides migitation for CVE-2017-5715, Spectre variant two,
which affects the P5600 and P6600. It implements the LLD part of
-z hazardplt. Like the Clang part of this patch, I have opted for that
specific option name in case alternative migitation methods are required
in the future.
The mitigation strategy suggested by MIPS for these processors is to use
hazard barrier instructions. 'jalr.hb' and 'jr.hb' are hazard
barrier variants of the 'jalr' and 'jr' instructions respectively.
These instructions impede the execution of instruction stream until
architecturally defined hazards (changes to the instruction stream,
privileged registers which may affect execution) are cleared. These
instructions in MIPS' designs are not speculated past.
These instructions are defined by the MIPS32R2 ISA, so this mitigation
method is not compatible with processors which implement an earlier
revision of the MIPS ISA.
For LLD, this changes PLT stubs to use 'jalr.hb' and 'jr.hb'.
Reviewers: atanasyan, ruiu
Differential Revision: https://reviews.llvm.org/D43488
llvm-svn: 325647
Purely a rename in preparation for adding new global symbol type.
We want to use GlobalSymbol to represent real wasm globals and
DataSymbol for pointers to things in linear memory (what ELF would
call STT_OBJECT).
This reduces the size the patch to add the explicit symbol table
which is coming soon!
Differential Revision: https://reviews.llvm.org/D43476
llvm-svn: 325645