Commit Graph

2945 Commits

Author SHA1 Message Date
Fangrui Song 06bb7dfbd4 [ELF] Map the ELF header at imageBase
If there is no readonly section, we map:

* The ELF header at imageBase+maxPageSize
* Program headers at imageBase+maxPageSize+sizeof(Ehdr)
* The first section .text at imageBase+maxPageSize+sizeof(Ehdr)+sizeof(program headers)

Due to the interaction between Writer<ELFT>::fixSectionAlignments and
LinkerScript::allocateHeaders,
`alignDown(p_vaddr(R PT_LOAD)) = alignDown(p_vaddr(RX PT_LOAD))`.
The RX PT_LOAD will override the R PT_LOAD at runtime, which is not ideal:

```
// PHDR at 0x401034, should be 0x400034
  PHDR           0x000034 0x00401034 0x00401034 0x000a0 0x000a0 R   0x4
// R PT_LOAD contains just Ehdr and program headers.
// At 0x401000, should be 0x400000
  LOAD           0x000000 0x00401000 0x00401000 0x000d4 0x000d4 R   0x1000
  LOAD           0x0000d4 0x004010d4 0x004010d4 0x00001 0x00001 R E 0x1000
```

* createPhdrs allocates the headers to the R PT_LOAD.
* fixSectionAlignments assigns `imageBase+maxPageSize+sizeof(Ehdr)+sizeof(program headers)` (formula: `alignTo(dot, maxPageSize) + dot % config->maxPageSize`) to addrExpr of .text
* allocateHeaders computes the minimum address among SHF_ALLOC sections, i.e. addr(.text)
* allocateHeaders sets address of ELF header to `addr(.text)-sizeof(Ehdr)-sizeof(program headers) = imageBase+maxPageSize`

The main observation is that when the SECTIONS command is not used, we
don't have to call allocateHeaders. This requires an assumption that
the presence of PT_PHDR and addresses of headers can be decided
regardless of address information.

This may seem natural because dot is not manipulated by a linker script.
The other thing is that we have to drop the special rule for -T<section>
in `getInitialDot`. If -Ttext is smaller than the image base, the headers
will not be allocated with the old behavior (allocateHeaders is called)
but always allocated with the new behavior.

The behavior change is not a problem. Whether and where headers are
allocated can vary among linkers, or ld.bfd across different versions
(--enable-separate-code or not). It is thus advised to use a linker
script with the PHDRS command to have a consistent behavior across
linkers. If PT_PHDR is needed, an explicit --image-base can be a simpler
alternative.

Differential Revision: https://reviews.llvm.org/D67325

llvm-svn: 371957
2019-09-16 07:04:16 +00:00
Fangrui Song 60ff4dd9cd [ELF] Support -z undefs
-z undefs is the inverse of -z defs. It allows unresolved references
from object files. This can be used to cancel --no-undefined or -z defs.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D67479

llvm-svn: 371715
2019-09-12 08:55:17 +00:00
Fangrui Song 2aace1ea22 [ELF][test] Make tests more tolerant to exact symbol addresses
llvm-svn: 371588
2019-09-11 06:20:14 +00:00
Amy Huang 7b1d793713 Reland "Change the X86 datalayout to add three address spaces
for 32 bit signed, 32 bit unsigned, and 64 bit pointers."
This reverts 57076d3199.

Original review at https://reviews.llvm.org/D64931.
Review for added fix at https://reviews.llvm.org/D66843.

llvm-svn: 371568
2019-09-10 23:15:38 +00:00
Simon Atanasyan 6c6f5a9984 [mips] Allow PT_LOAD to have overlapping p_offset ranges on EM_MIPS
Port the D64906 <https://reviews.llvm.org/D64906> technique to MIPS.

Fix PR33131

llvm-svn: 371554
2019-09-10 20:19:59 +00:00
Fangrui Song 1eda21e214 [ELF][test] Make tests more tolerant to exact symbol addresses
Delete relocation-local.s and relocation-shared.s - covered by various tests

llvm-svn: 371514
2019-09-10 12:28:07 +00:00
Simon Atanasyan 2439b8b0c5 [mips] Make another set of test cases more tolerant to exact symbol addresses. NFC
llvm-svn: 371458
2019-09-09 22:04:20 +00:00
Simon Atanasyan 56e4ea2bff [mips] Fix decoding of microMIPS JALX instruction
microMIPS jump and link exchange instruction stores a target in a
26-bits field. Despite other microMIPS JAL instructions these bits
are target address shifted right 2 bits [1]. The patch fixes the
JALX instruction decoding and uses 2-bit shift.

[1] MIPS Architecture for Programmers Volume II-B: The microMIPS32 Instruction Set

Differential Revision: https://reviews.llvm.org/D67320

llvm-svn: 371428
2019-09-09 17:28:45 +00:00
Fangrui Song e8c0d93360 [ELF] nmagic or omagic: don't allocate PT_PHDR or PF_R PT_LOAD for the !hasPhdrsCommands case
```
part.phdrs = script->hasPhdrsCommands() ? script->createPhdrs() : createPhdrs(part);
```

createPhdrs() allocates a PT_PHDR and a PF_R PT_LOAD, which will be
deleted later in LinkerScript::allocateHeaders, but leave a gap between
the program headers and the first section. Don't allocate the segments
to avoid the gap. PT_INTERP is likely not needed as well.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D67324

llvm-svn: 371398
2019-09-09 13:08:51 +00:00
Fangrui Song 88796a7988 [ELF][test] Improve and reorganize another set of tests
Add file-level comments
Replace trivial Input/*.s with echo ... | llvm-mc
Delete insignificant addresses to make them more tolerant to layout changes
Simplify test output

Merge merge-section-types.s into compatible-section-types.s and add a missed case
Merge gnu-ifunc-gotpcrel.s (added in D19517) into gnu-ifunc-dso.s (added in D35119) and add missed cases
Delete typed-undef.s - covered by executable-undefined-ignoreall.s
Delete emit-relocs-shared.s - covered by emit-relocs-merge.s

Replace copy-rel-pie.s and copy-rel-pie2.s with canonical-plt-pcrel.s, canonical-plt-symbolic.s and copy-rel.s:
add -no-pie cases.
add a case that a canonical PLT can be created for STT_GNU_IFUNC. The logic in Symbols.h was untested:

  // ctor of SharedSymbol
  if (this->type == llvm::ELF::STT_GNU_IFUNC)
    this->type = llvm::ELF::STT_FUNC;

llvm-svn: 371361
2019-09-09 03:35:14 +00:00
Simon Atanasyan 9443c18704 [mips] Follow-up to r371313 - fix failed test case. NFC
llvm-svn: 371316
2019-09-07 16:31:37 +00:00
Simon Atanasyan fcef13344d [mips] Make another set of test cases more tolerant to exact symbol addresses. NFC
llvm-svn: 371313
2019-09-07 15:44:40 +00:00
Fangrui Song 0e79890d9b [ELF][test] Improve tests
Add file-level comments
Delete insignificant addresses to make them more tolerant to layout changes
Simplify test output

Delete weak-undef-val.s - covered by relocation-undefined-weak.s
Delete weak-undef-export.s - covered by additional test added to weak-undef.s
Delete version-undef-sym.s - covered by undefined-versioned-symbol.s => version-symbol-undef.s
Delete symbol-ordering-file2.s - covered by symbol-ordering-file.s
Delete gotpcrelx.s - covered by gotpc-relax-und-dso.s => x86-64-gotpc-relax-und-dso.s

llvm-svn: 371299
2019-09-07 10:42:11 +00:00
Fangrui Song 89f7859641 [ELF][test] Improve LTO tests
Add file-level comments
Delete insignificant addresses to make them more tolerant to layout changes
Simplify test output

llvm-svn: 371292
2019-09-07 08:20:09 +00:00
Matthew Voss c177919409 Update lld tests dynamic-list.s and symbol-override.s to use llvm-nm
The following tests failed on Windows bots due to nm not being
available:

  lld/test/ELF/dynamic-list.s
  lld/test/ELF/symbol-override.s

llvm-svn: 371267
2019-09-06 22:51:46 +00:00
Fangrui Song 2682bc3c9d [ELF] Replace error() with errorOrWarn() for the ASSERT command
Summary:
ld.bfd produces an output with --noinhibit-exec when an ASSERT fails.
Use errorOrWarn() so that we can produce an output as well.

An interesting case is that symbol assignments may execute multiple
times, so we probably want to suppress errors for non-final runs.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D67285

llvm-svn: 371225
2019-09-06 16:30:22 +00:00
Fangrui Song 8d30c1dcec Reland D66717 [ELF] Do not ICF two sections with different output sections (by SECTIONS commands)
Recommit r370635 (reverted by r371202), with one change: move addOrphanSections() before ICF.

Before, orphan sections in two different partitions may be folded and
moved to the main partition.

Now, InputSection->OutputSection assignment for orphans happens before
ICF. ICF does not fold input sections with different output sections.

With the PR43241 reproduce,
`llvm-objcopy --extract-partition libvr.so libchrome__combined.so libvr.so` => no error

Updated description:

Fixes PR39418. Complements D47241 (the non-linker-script case).

processSectionCommands() assigns input sections to output sections.
ICF is called before it, so .text.foo and .text.bar may be folded even if
their output sections are made different by SECTIONS commands.

```
markLive<ELFT>()
doIcf<ELFT>()                      // During ICF, we don't know the output sections
writeResult()
  combineEhSections<ELFT>()
  script->processSectionCommands() // InputSection -> OutputSection assignment
```

This patch splits processSectionCommands() into processSectionCommands()
and processSymbolAssignments(), and moves
processSectionCommands()/addOrphanSections() before ICF:

```
markLive<ELFT>()
combineEhSections<ELFT>()
script->processSectionCommands()
script->addOrphanSections();
doIcf<ELFT>()                      // should remove folded input sections
writeResult()
  script->processSymbolAssignments()
```

An alternative approach is to unfold a section `sec` in
processSectionCommands() when we find `sec` and `sec->repl` belong to
different output sections. I feel this patch is superior because this
can fold more sections and the decouple of
SectionCommand/SymbolAssignment gives flexibility:

* An ExprValue can't be evaluated before its section is assigned to an
  output section -> we can delete getOutputSectionVA and simplify
  another place where we had to check if the output section is null.
  Moreover, a case in linkerscript/early-assign-symbol.s can be handled
  now.
* processSectionCommands/processSymbolAssignments can be freely moved
  around.

llvm-svn: 371216
2019-09-06 15:57:44 +00:00
Fangrui Song 5d9f419a2e Revert "Revert r370635, it caused PR43241."
This reverts commit 50d2dca22b3b05d0ee4883b0cbf93d7d15f241fc.

llvm-svn: 371215
2019-09-06 15:57:24 +00:00
Fangrui Song 8f10a5f42d [ELF][test] Simplify and reorganize tests
Add file-level comments
Delete insignificant addresses to make them more tolerant to layout changes
Simplify test output
Delete simple Inputs/*.s files

Delete version-script-copy-rel.s - covered by verdef-defaultver.s
Delete version-wildcard.test - covered by version-script-glob.s

llvm-svn: 371213
2019-09-06 15:10:31 +00:00
Nico Weber 8455294f2a Revert r370635, it caused PR43241.
llvm-svn: 371202
2019-09-06 13:23:42 +00:00
Fangrui Song 70e002b50b [ELF][test] Update test after r371185
llvm-svn: 371189
2019-09-06 09:39:48 +00:00
Simon Atanasyan ff2172c9f4 [mips] Make another set of test cases more tolerant to exact symbol addresses. NFC
llvm-svn: 371174
2019-09-06 07:23:02 +00:00
Fangrui Song a2028f73c2 Update SHT_LLVM_PART_EHDR test after r371157
llvm-svn: 371160
2019-09-06 01:18:01 +00:00
Simon Atanasyan 2172f3f49d [mips] Make a few test cases more tolerant to exact symbol addresses. NFC
llvm-svn: 371065
2019-09-05 13:37:16 +00:00
Rui Ueyama e99dc4ba57 Align output segments correctly
Previously, segments were aligned according to their first section's
alignment requirements. That was not correct, but segments are also
aligned to a page boundary, and a page boundary is usually much larger
than a section alignment requirement, so no one noticed this bug before.

Now, lld has --nmagic option which sets maxPageSize to 1 to effectively
disable page alignment, which reveals the issue.

Fixes https://bugs.llvm.org/show_bug.cgi?id=43212

Differential Revision: https://reviews.llvm.org/D67152

llvm-svn: 371013
2019-09-05 05:30:24 +00:00
Fangrui Song 7afffb54ea [ELF] Don't shrink RelrSection
Fixes PR43214.

The size of SHT_RELR may oscillate between 2 numbers (see D53003 for a
similar --pack-dyn-relocs=android issue). This can happen if the shrink
of SHT_RELR causes it to take more words to encode relocation offsets
(this can happen with thunks or segments with overlapping p_offset
ranges), and the expansion of SHT_RELR causes it to take fewer words to
encode relocation offsets.

To avoid the issue, add padding 1s to the end of the relocation section
if its size would decrease. Trailing 1s do not decode to more relocations.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D67164

llvm-svn: 370923
2019-09-04 16:27:35 +00:00
Fangrui Song b4745fad24 [ELF] Add a spell corrector for "undefined symbol" diagnostics
Non-undefined symbols with Levenshtein distance 1 or a transposition are
suggestion candidates. This is probably good enough and it can suggest
some missing/superfluous qualifiers: const, restrict, volatile, & and &&
ref-qualifier, e.g.

   error: undefined symbol: foo(int*)
   >>> referenced by b.o:(.text+0x1)
  +>>> did you mean: foo(int const*)
  +>>> defined in: a.o

   error: undefined symbol: foo(int*&)
   >>> referenced by b.o:(.text+0x1)
  +>>> did you mean: foo(int*)
  +>>> defined in: b.o

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D67039

llvm-svn: 370853
2019-09-04 09:04:26 +00:00
Fangrui Song d8bc6a48ea [ELF] Do not ICF two sections with different output sections (by SECTIONS commands)
Fixes PR39418. Complements D47241 (the non-linker-script case).

processSectionCommands() assigns input sections to output sections.
ICF is called before it, so .text.foo and .text.bar may be folded even if
their output sections are made different by SECTIONS commands.

```
markLive<ELFT>()
doIcf<ELFT>()                      // During ICF, we don't know the output sections
writeResult()
  combineEhSections<ELFT>()
  script->processSectionCommands() // InputSection -> OutputSection assignment
```

This patch splits processSectionCommands() into processSectionCommands() and
processSymbolAssignments(), and moves processSectionCommands() before ICF:

```
markLive<ELFT>()
combineEhSections<ELFT>()
script->processSectionCommands()
doIcf<ELFT>()                      // should remove folded input sections
writeResult()
  script->processSymbolAssignments()
```

An alternative approach is to unfold a section `sec` in
processSectionCommands() when we find `sec` and `sec->repl` belong to
different output sections. I feel this patch is superior because this
can fold more sections and the decouple of
SectionCommand/SymbolAssignment gives flexibility:

* An ExprValue can't be evaluated before its section is assigned to an
  output section -> we can delete getOutputSectionVA and simplify
  another place where we had to check if the output section is null.
  Moreover, a case in linkerscript/early-assign-symbol.s can be handled
  now.
* processSectionCommands/processSymbolAssignments can be freely moved
  around.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D66717

llvm-svn: 370635
2019-09-02 10:33:58 +00:00
Fangrui Song 4514ac7cfb [ELF] Align SHT_LLVM_PART_EHDR to a maximum page size boundary
Fixes https://bugs.chromium.org/p/chromium/issues/detail?id=998712

SHT_LLVM_PART_EHDR marks the start of a partition. The partition
sections will be extracted to a separate file. Align to the next maximum
page size boundary so that we can find the ELF header at the start. We
cannot benefit from overlapping p_offset ranges with the previous
segment anyway.

It seems we lack some llvm-objcopy --extract-main-partition and
--extract-partition sanity checks. It may place EHDR at the start
even if p_offset if non zero. Anyway, the lld change is justified for
the reasons above.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D67032

llvm-svn: 370629
2019-09-02 08:49:50 +00:00
Fangrui Song 688183ec54 [ELF] Set `referenced` bit of Undefined created by BitcodeFile
D64136 and D65584, while fixing STB_WEAK issues and improving our
compatibility with ld.bfd, can cause another STB_WEAK problem related to
LTO:

If %tundef.o has an undefined reference on f,
and %tweakundef.o has a weak undefined reference on f,
%tdef.o has a definition of f

```
ld.lld %tundef.o %tweakundef.o --start-lib %tdef.o --end-lib
```

1) `%tundef.o` doesn't set the `referenced` bit.
2) `%weakundef.o` changes the binding from STB_GLOBAL to STB_WEAK
3) `%tdef.o` is not fetched because the binding is weak.

Step (1) is incorrect. This patch sets the `referenced` bit of Undefined
created by bitcode files.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D66992

llvm-svn: 370437
2019-08-30 07:10:30 +00:00
Nico Weber 3c1996a489 lld: Make a test not fail if "repro" is part of the build directory name
r268231 made it so that the name of the --reproduce archive
is no longer listed in the response file. Previously, with
"--reproduce repro.tar" the response file would contain

  repro/home/.../llvm-build-dir/.../foo.o

but after that change it contained

  home/.../llvm-build-dir/.../foo.o

instead. The test added for this in r268231 checked that
the response file doesn't contain the string "repro", but
if the build dir is named e.g. "llvm-build-repro" then the
test fails because of that.

Change the assert to check that "repro" doesn't exist at the
beginning of the line instead. I verified that the test
still fails with r268231 reverted.

The test technically still fails if someone builds llvm in a directory
'/repro' below the root directory. Don't do that :)

llvm-svn: 370211
2019-08-28 14:33:35 +00:00
Fangrui Song 523f999acf [ELF][RISCV] Allow PT_LOAD to have overlapping p_offset ranges on EM_RISCV
Port the D64906 technique to RISC-V. It deletes 3 alignments at
PT_LOAD boundaries for the default case: the size of a RISC-V binary
decreases by at most 12kb.

llvm-svn: 370192
2019-08-28 12:06:06 +00:00
Fangrui Song 54a6f6839b [ELF][AMDGPU][SPARC] Allow PT_LOAD to have overlapping p_offset ranges on EM_AMDGPU and EM_SPARCV9
llvm-svn: 370180
2019-08-28 09:45:06 +00:00
Fangrui Song 8fbe81fb29 [ELF][RISCV] Assign st_shndx of __global_pointer$ to 1 if .sdata does not exist
This essentially reverts the code change of D63132 and switches to a simpler approach.

In an executable/shared object, st_shndx of a symbol can be:

1) SHN_UNDEF: undefined symbol (or canonical PLT)
2) SHN_ABS: absolute symbol
3) any other value (usually a regular section index) represents a relative symbol.
  The actual value does not matter.

Many ld.so (musl, all archs except MIPS of FreeBSD rtld-elf) even treat 2) and 3)
the same. If .sdata does not exist, it does not matter what value/section
__global_pointer$ has, as long as it is relative (otherwise there will be a pedantic
lld error. See D63132). Just set the st_shndx arbitrarily to 1.

Dummy st_shndx=1 may be used by __rela_iplt_start, linker-script-defined symbols outside a section, __dso_handle, etc.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D66798

llvm-svn: 370172
2019-08-28 09:01:03 +00:00
Vlad Tsyrklevich 57076d3199 Revert "Change the X86 datalayout to add three address spaces for 32 bit signed,"
This reverts commit r370083 because it caused check-lld failures on
sanitizer-x86_64-linux-fast.

llvm-svn: 370142
2019-08-28 01:08:54 +00:00
Amy Huang 1299945b81 Change the X86 datalayout to add three address spaces for 32 bit signed,
32 bit unsigned, and 64 bit pointers.

llvm-svn: 370083
2019-08-27 17:46:53 +00:00
Fangrui Song 024bf27ddf [ELF][ARM] Allow PT_LOAD to have overlapping p_offset ranges on EM_ARM
Port the D64906 technique to ARM. It deletes 3 alignments at
PT_LOAD boundaries for the default case: the size of an arm binary
decreases by at most 12kb.

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D66749

llvm-svn: 370049
2019-08-27 11:52:36 +00:00
Fangrui Song fdbc2bd2aa [ELF][ARM] Add --no-show-raw-insn and -soname to some ARM tests
Delete some insignificant addresses to make it simpler for layout
changes.

llvm-svn: 370048
2019-08-27 11:50:27 +00:00
Richard Trieu f837bb4a34 Copy test data so tests don't traverse test directories. NFC
llvm-svn: 369984
2019-08-26 22:41:05 +00:00
Fangrui Song debcac9fef [ELF] Make LinkerScript::assignAddresses iterative
PR42990. For `SECTIONS { b = a; . = 0xff00 + (a >> 8); a = .; }`,
we currently set st_value(a)=0xff00 while st_value(b)=0xffff.

The following call tree demonstrates the problem:

```
link<ELF64LE>(Args);
  Script->declareSymbols(); // insert a and b as absolute Defined
  Writer<ELFT>().run();
    Script->processSectionCommands();
      addSymbol(cmd);       // a and b are re-inserted. LinkerScript::getSymbolValue
                            // is lazily called by subsequent evaluation
    finalizeSections();
      forEachRelSec(scanRelocations<ELFT>);
        processRelocAux     // another problem PR42506, not affected by this patch
      finalizeAddressDependentContent(); // loop executed once
        script->assignAddresses(); // a = 0, b = 0xff00
    script->assignAddresses(); // a = 0xff00, _end = 0xffff
```

We need another assignAddresses() to finalize the value of `a`.

This patch

1) modifies assignAddress() to track the original section/value of each
  symbol and return a symbol whose section/value has changed.
2) moves the post-finalizeSections assignAddress() inside the loop
  of finalizeAddressDependentContent() and makes it iterative.
  Symbol assignment may not converge so we make a few attempts before
  bailing out.

Note, assignAddresses() must be called at least twice. The penultimate
call finalized section addresses while the last finalized symbol values.
It is somewhat obscure and there was no comment.
linkerscript/addr-zero.test tests this.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D66279

llvm-svn: 369889
2019-08-26 10:23:31 +00:00
Fangrui Song 8e5184af71 [ELF] Error if --strip-all and --emit-relocs are used together
--strip-all suppresses the creation of in.symtab
This can cause a null pointer dereference in OutputSection::finalize()

  // --emit-relocs => copyRelocs is true
  if (!config->copyRelocs || (type != SHT_RELA && type != SHT_REL))
    return;
  ...
  link = in.symTab->getParent()->sectionIndex; // in.symTab is null

Let's just disallow the combination. In some cases the combination can
cause GNU linkers to fail:

* ld.bfd: final link failed: invalid operation
* gold: internal error in set_no_output_symtab_entry, at ../../gold/object.h:1814

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D66704

llvm-svn: 369878
2019-08-26 06:23:53 +00:00
Fangrui Song af47d0021c [ELF] Align the first section of a PT_LOAD even if its type is SHT_NOBITS
Reported at https://reviews.llvm.org/D64930#1642223

If the only section of a PT_LOAD is a SHT_NOBITS section (e.g. .bss), we
may not align its sh_offset. p_offset of the PT_LOAD will be set to
sh_offset, and we will get p_offset!=p_vaddr (mod p_align).  If such
executable is mapped by the Linux kernel, it will segfault.

After D64906, this may happen the non-linker script case.

The linker script case has had this issue for a long time.
This was fixed by rL321657 (but the test linkerscript/nobits-offset.s
failed to test a SHT_NOBITS section), but broken by rL345154.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D66658

llvm-svn: 369828
2019-08-24 00:41:15 +00:00
Fangrui Song 2d37bf843c [ELF][ARM] Simplify some llvm-objdump tests with both ARM/Thumb states
llvm-objdump can switch between ARM/Thumb states after D60927.

In a few lld tests, we run both

* llvm-objdump -d -triple=thumbv7a-none-linux-gnueabi %t
* llvm-objdump -d -triple=armv7a-none-linux-gnueabi %t

to test ARM/Thumb parts of the same file. In many cases we can just
run one command. There is a problem that prevents us from cleaning
more tests (e.g. test/ELF/arm-thumb-interwork-thunk.s):

In llvm-objdump, while we have ARM/Thumb (primary and secondary)
MCDisassembler and MCSubtargetInfo, we have just one MCInstrAnalysis
which is used to resolve the targets of calls in both ARM/Thumb parts.

    // ThumbMCInstrAnalysis evaluating ARM parts or ARMMCInstrAnalysis evaluating Thumb parts
    // will have incorrect offsets.
    // An example of llvm-objdump -d -triple=thumbv7a on ARM part:
    1304: 3d ff ff fa  blx     #-780                 # no <...>
    1308: 06 00 00 ea  b        <arm_caller+0x24> # wrong target due to wrong offset

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D66539

llvm-svn: 369535
2019-08-21 15:30:55 +00:00
George Rimar a50f115d36 [LLD][ELF] - Simplify the bad-archive.s test case.
This removes the precompiled binary and improves the
check of the error reported.

Differential revision: https://reviews.llvm.org/D66523

llvm-svn: 369516
2019-08-21 11:19:50 +00:00
Fangrui Song 2d337fdc95 Reland D65242 "[ELF] More dynamic relocation packing""
This fixed a bug in r369488. When config->isRela is false, i->r_addend
is not initialized (see encodeDynamicReloc). So we should check
config->isRela before accessing r_addend:

- if (j - i < 3 || i->r_addend)
+ if (j - i < 3 || (config->isRela && i->r_addend != 0))

Original description:

Currently, with Android dynamic relocation packing, only relative
relocations are grouped together. This patch implements similar
packing for non-relative relocations.

The implementation groups non-relative relocations with the same
r_info and r_addend, if using RELA. By requiring a minimum group
size of 3, this achieves smaller relocation sections. Building Android
for an ARM32 device, I see the total size of /system/lib decrease by
392 KB.

Grouping by r_info also allows the runtime dynamic linker to implement
an 1-entry cache to reduce the number of symbol lookup required. With
such 1-entry cache implemented on Android, I'm seeing 10% to 20%
reduction in total time spent in runtime linker for several executables
that I tested.

As a simple correctness check, I've also built x86_64 Android and booted
successfully.

Differential Revision: https://reviews.llvm.org/D65242
Patch by Vic Yang

llvm-svn: 369507
2019-08-21 09:21:37 +00:00
Fangrui Song b2895a8cdc Revert D65242 "[ELF] More dynamic relocation packing"
This reverts r369488 and r369489. The change broke build bots:

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-ubsan/builds/14511
http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/34407

llvm-svn: 369497
2019-08-21 06:50:08 +00:00
Fangrui Song d840a9cbed [ELF][test] Add CHECK lines omitted in r369488
Add append .o to some object file names

llvm-svn: 369489
2019-08-21 03:15:57 +00:00
Fangrui Song 35f9a84a15 [ELF] More dynamic relocation packing
Currently, with Android dynamic relocation packing, only relative
relocations are grouped together. This patch implements similar
packing for non-relative relocations.

The implementation groups non-relative relocations with the same
r_info and r_addend, if using RELA. By requiring a minimum group
size of 3, this achieves smaller relocation sections. Building Android
for an ARM32 device, I see the total size of /system/lib decrease by
392 KB.

Grouping by r_info also allows the runtime dynamic linker to implement
an 1-entry cache to reduce the number of symbol lookup required. With
such 1-entry cache implemented on Android, I'm seeing 10% to 20%
reduction in total time spent in runtime linker for several executables
that I tested.

As a simple correctness check, I've also built x86_64 Android and booted
successfully.

Differential Revision: https://reviews.llvm.org/D66491
Patch by Vic Yang!

llvm-svn: 369488
2019-08-21 03:02:08 +00:00
Fangrui Song 12d83b4270 [ELF][PPC] Allow PT_LOAD to have overlapping p_offset ranges on EM_PPC
Ported the D64906 technique to EM_PPC.

Delete ppc-rela.s that is covered by ppc32-abs-pic.s

llvm-svn: 369351
2019-08-20 09:20:05 +00:00
Fangrui Song 9c371309f3 [ELF][X86] Allow PT_LOAD to have overlapping p_offset ranges on EM_386
Ported the D64906 technique to EM_386.

If `sh_addralign(.tdata) < sh_addralign(.tbss)`,
we can potentially make `p_vaddr(PT_TLS)%p_align(PT_TLS) != 0`.

ld.so that are known to have problems if p_vaddr%p_align!=0:

* FreeBSD 13.0-CURRENT rtld-elf
* glibc https://sourceware.org/bugzilla/show_bug.cgi?id=24606

New test i386-tls-vaddr-align.s checks our workaround makes p_vaddr%p_align = 0.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D65865

llvm-svn: 369347
2019-08-20 08:43:47 +00:00