Commit Graph

4803 Commits

Author SHA1 Message Date
George Rimar
97785af464 [ELF] - Report error when memory region is overflowed by data commands.
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
2018-03-02 08:11:58 +00:00
Rui Ueyama
036ed36f0a Accept both --foo bar and --foo=bar styles options.
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
2018-03-01 23:06:10 +00:00
Rui Ueyama
7c18abf99a Set DF_TEXTREL to executables that need text relocations.
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has been superseded by the DF_TEXTREL flag".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superseded even after 18 years.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
2018-03-01 22:56:52 +00:00
Rafael Espindola
2e4bcb0095 Don't ingoned --enable-new-dtags.
llvm-svn: 326498
2018-03-01 22:23:51 +00:00
Rafael Espindola
e75b42ee4e Don't allocate a header bellow address 0.
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
2018-03-01 15:25:46 +00:00
George Rimar
b068b03793 [ELF] - Don't crash on broken MEMORY declaration.
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
2018-03-01 12:36:01 +00:00
George Rimar
c4df670dea [ELF] - Do not remove empty sections that use symbols in expressions.
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
2018-03-01 12:27:04 +00:00
Rui Ueyama
37ad8161e4 Do not create multiple NOTE segments.
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
2018-03-01 02:31:29 +00:00
Rafael Espindola
852bd5c062 Simplify removing empty output sections.
With this the meaning of the Live bit in output sections is clear: we
have at some point added a input section into it.

llvm-svn: 326401
2018-03-01 01:08:00 +00:00
Rui Ueyama
39ba31ff50 Add "%" operator to the linker script.
This patch improves compatibility with GNU linkers.

Differential Revision: https://reviews.llvm.org/D43883

llvm-svn: 326348
2018-02-28 18:38:13 +00:00
Rui Ueyama
1d20222a48 Inline a trivial function. NFC.
llvm-svn: 326347
2018-02-28 18:25:00 +00:00
Rafael Espindola
367bfce611 Simplify. NFC.
llvm-svn: 326344
2018-02-28 18:05:37 +00:00
Rui Ueyama
ee17371897 Merge {COFF,ELF}/Strings.cpp to Common/Strings.cpp.
This should resolve the issue that lld build fails in some hosts
that uses case-insensitive file system.

Differential Revision: https://reviews.llvm.org/D43788

llvm-svn: 326339
2018-02-28 17:38:19 +00:00
Igor Kudrin
c844524e46 [ELF] Process linker scripts deeper when declaring symbols.
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
2018-02-28 05:55:56 +00:00
Rui Ueyama
f0884e474c Add --dynamic-linker=foo as an alias for --dynamic-linker foo.
This patch fixes a minor compatibility issue with ld.gold and ld.bfd.

llvm-svn: 326243
2018-02-27 20:37:18 +00:00
Rafael Espindola
3f4c673d38 Put undefined symbols from shared libraries in the symbol table.
With the recent fixes these symbols have more in common than not with
regular undefined symbols.

llvm-svn: 326242
2018-02-27 20:31:22 +00:00
Rafael Espindola
b851121130 Fix gcc warning.
Should fix the build in some bots.

llvm-svn: 326209
2018-02-27 17:11:10 +00:00
Rafael Espindola
3bfa8f0120 Add support for SHF_ARM_PURECODE.
Now we don't mark a PT_LOAD as readable if all its sections are
SHF_ARM_PURECODE.

llvm-svn: 326207
2018-02-27 16:55:25 +00:00
George Rimar
46045364b2 [ELF] - Format, fix mistype. NFC.
llvm-svn: 326198
2018-02-27 14:06:47 +00:00
George Rimar
a77b963c90 [ELF] - Fix case of using both --icf and --symbol-ordering-file together.
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
2018-02-27 08:26:38 +00:00
Igor Kudrin
3345c9ac18 [ELF] Create and export symbols provided by a linker script if they referenced by DSOs.
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
2018-02-27 07:18:07 +00:00
Rafael Espindola
79c23eec04 Keep flags from phantom synthetic sections.
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
2018-02-26 22:32:15 +00:00
George Rimar
0c97f4eba4 [ELF] - Fix variable name and mistype in comment. NFC.
llvm-svn: 326090
2018-02-26 15:16:03 +00:00
Fangrui Song
ffac3ed341 [ELF] Fix IsPreemptible comment and typo. NFC
llvm-svn: 325963
2018-02-23 21:57:49 +00:00
Simon Atanasyan
a4cde9d2e2 [ELF][MIPS] Set EI_ABIVERSION flag accordingly to MIPS ABIs requirement
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
2018-02-23 11:28:57 +00:00
George Rimar
db1a062447 [ELF] - Do not remove empty output sections that are explicitly assigned to phdr in script.
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
2018-02-23 10:53:04 +00:00
George Rimar
2d53967b48 Recommit "[ELF] - Do not crash with --emit-relocs and --icf=all together."
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
2018-02-23 10:37:33 +00:00
George Rimar
aa359f87e8 [ELF] - Revert r325877 "[ELF] - Do not crash with --emit-relocs and --icf=all together."
Not latest version of patch was committed by mistake.

llvm-svn: 325878
2018-02-23 10:30:31 +00:00
George Rimar
cde84d1cd0 [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: 325877
2018-02-23 10:27:13 +00:00
George Rimar
3cdf0d969a [ELF] - Report error if removed empty output section declaration used undefined symbols.
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
2018-02-23 10:15:54 +00:00
Fangrui Song
9cd5df0e15 [ELF] Add comment for preemptible and fix typo. NFC
Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D43642

llvm-svn: 325855
2018-02-23 02:05:48 +00:00
Rui Ueyama
c30927411c Make undefined symbol in DSO to pull out object files from archive files.
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
2018-02-23 01:16:57 +00:00
George Rimar
925529b821 [ELF] - Rewrote outdated comment. NFC.
llvm-svn: 325809
2018-02-22 17:52:43 +00:00
George Rimar
563e4f2f58 [ELF] - Introduce getInputSections() helper.
We sometimes need to iterate over input sections for a given
output section. It is not very convinent because we have to iterate
over section descriptions.
Patch introduces getInputSections helper, it simplifies things.

Differential revision: https://reviews.llvm.org/D43574

llvm-svn: 325763
2018-02-22 09:55:28 +00:00
Rui Ueyama
9060b57e70 Revert r325679: [ELF] Add -nopie alias for -no-pie (PR36423)
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
2018-02-21 20:08:14 +00:00
Simon Dardis
f5e0b40095 [mips][lld] Address post commit review nit.
Address @ruiu's post commit review comment about a value which is intended
to be a unsigned 32 bit integer as using uint32_t rather than unsigned.

llvm-svn: 325713
2018-02-21 20:01:43 +00:00
George Rimar
5bd90e2db1 [ELF] - Simplify. NFC.
llvm-svn: 325681
2018-02-21 14:21:23 +00:00
Hans Wennborg
82fca76868 [ELF] Add -nopie alias for -no-pie (PR36423)
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
2018-02-21 13:54:26 +00:00
Simon Dardis
cd8758233e [mips][lld] Spectre variant two mitigation for MIPSR2
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
2018-02-20 23:49:17 +00:00
Sam Clegg
f187c4d2e5 Consistent use of header file for ICF and MarkLive
Previously wasm used a separate header to declare markLive
and ELF used to declare ICF.  This change makes each backend
consistently declare these in their own headers.

Differential Revision: https://reviews.llvm.org/D43529

llvm-svn: 325631
2018-02-20 22:09:59 +00:00
Sam Clegg
3141ddc58d Consistent (non) use of empty lines in include blocks
The profailing style in lld seem to be to not include such empty lines.
Clang-tidy/clang-format seem to handle this just fine.

Differential Revision: https://reviews.llvm.org/D43528

llvm-svn: 325629
2018-02-20 21:53:18 +00:00
Teresa Johnson
2c2ed3cf03 [lld/LTO] Remove unused Path parameter to AddBufferFn
Summary:
With D43396, no clients use the Path parameter anymore.
This is the lld side fix with D43400.

Depends on D43396 and D43400.

Reviewers: pcc

Subscribers: emaste, inglorion, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D43401

llvm-svn: 325620
2018-02-20 20:21:59 +00:00
Alexander Richardson
048e2508ad Rename DynamicReloc::getAddend() to computeAddend(). NFC
Summary:
Before the name of the function sounded like it was just a getter for the
private class member Addend. However, it actually calculates the final
value for the r_addend field in Elf_Rela that is used when writing the
.rela.dyn section. I also added a comment to the UseSymVA member to
explain how it interacts with computeAddend().

Differential Revision: https://reviews.llvm.org/D43161

llvm-svn: 325485
2018-02-19 11:00:15 +00:00
Rui Ueyama
ff59a899d6 Use toString to print out garbage-collected sections.
Currently, archive file name is missing in this message. In general,
we should avoid constructing strings in an ad-hoc manner and instead
use toString() to get consistent output strings.

Differential Revision: https://reviews.llvm.org/D43420

llvm-svn: 325416
2018-02-17 00:09:49 +00:00
Rui Ueyama
7c9ad29304 Remove "--full-shutdown" and instead use an environment variable LLD_IN_TEST.
We are running lld tests with "--full-shutdown" option because we don't
want to call _exit() in lld if it is running tests. Regular shutdown
is needed for leak sanitizer.

This patch changes the way how we tell lld that it is running tests.
Now "--full-shutdown" is removed, and LLD_IN_TEST environment variable
is used instead.

This patch enables full shutdown on all ports, e.g. ELF, COFF and wasm.
Previously, we enabled it only for ELF.

Differential Revision: https://reviews.llvm.org/D43410

llvm-svn: 325413
2018-02-16 23:41:48 +00:00
Peter Collingbourne
09e04af42f ELF: Stop collecting a list of symbols in ArchiveFile.
There seems to be no reason to collect this list of symbols.

Also fix a bug where --exclude-libs would apply to all symbols that
appear in an archive's symbol table, even if the relevant archive
member was not added to the link.

Differential Revision: https://reviews.llvm.org/D43369

llvm-svn: 325380
2018-02-16 20:23:54 +00:00
Rafael Espindola
b960325989 Simplify RelocationBaseSection::addReloc.
Now that we have R_ADDEND, UseSymVA was redundant. We only want to
write the symbol virtual address when using an expression other than
R_ADDEND.

llvm-svn: 325360
2018-02-16 16:53:04 +00:00
George Rimar
97f4d158bd [ELF] - Fix comment. NFC.
Addresses forgotten comment for D43071.

llvm-svn: 325332
2018-02-16 10:46:50 +00:00
George Rimar
1c08e9f5ce [ELF] - Support COPY, INFO, OVERLAY output sections attributes.
This is PR36298.

(COPY), (INFO), (OVERLAY) all have the same effect:
section should be marked as non-allocatable.

(https://www.eecs.umich.edu/courses/eecs373/readings/Linker.pdf, 
3.6.8.1 Output Section Type)

Differential revision: https://reviews.llvm.org/D43071

llvm-svn: 325331
2018-02-16 10:42:58 +00:00
Alexander Richardson
cfb6093379 Ensure that Elf_Rel addends are always written for dynamic relocations
Summary:
This follows up on r321889 where writing of Elf_Rel addends was partially
moved to RelocationBaseSection. This patch ensures that the addends are
always written to the output section when a input section uses RELA but the
output is REL.

Differential Revision: https://reviews.llvm.org/D42843

llvm-svn: 325328
2018-02-16 10:01:17 +00:00