-z wxneeded creates a PHDR PT_OPENBSD_WXNEEDED.
PT_OPENBSD_WXNEEDED
The array element specifies that a process executing this file may need to be able to map or protect memory regions as simultaneously executable and writable. If the system is unable or unwilling to permit that for this executable then it may fail immediately. This segment type is meaningful only for executable files and is ignored in other objects.
http://man.openbsd.org/OpenBSD-current/man5/elf.5
Differential revision: https://reviews.llvm.org/D25472
llvm-svn: 284226
Previously we would fail to synthesise a __start_ or __stop_ symbol if
there existed a definition in a DSO. Instead, we would try to link against
the DSO definition. This became possible after D23552 when linking against
lld-produced DSOs but could in principle also occur when linking against
DSOs produced by other linkers.
Not only does it seem more likely that a user would expect the resolved
definition to be local to the executable, but if a __start_ or __stop_
symbol was synthesised by the linker, it is effectively impossible to link
against correctly from a non-PIC executable in a read-only section. Neither
a PLT nor a copy relocation would give us the right semantics here. The only
way the link could succeed is if the executable provided its own synthetic
definition of the symbol.
The fix is to also synthesise the definition if the only definition comes
from a DSO. Since this is what the addOptionalSynthetic function does,
switch to using that function.
Fixes PR30680.
Differential Revision: https://reviews.llvm.org/D25544
llvm-svn: 284168
Previously, we supported only SHF_COMPRESSED sections because it's
new and it's the ELF standard. But there are object files compressed
in the GNU style out there, so we had to support it.
Sections compressed in the GNU style start with ".zdebug_" and
contain different headers than the ELF standard's one. In this
patch, getRawCompressedData is responsible to handle it.
A tricky thing about GNU-style compressed sections is that we have
to rename them when creating output sections. ".zdebug_" prefix
implies the section is compressed. We need to rename ".zdebug_"
".debug" because our output sections are not compressed.
We do that in this patch.
llvm-svn: 284068
r283984 introduced a problem of too many warning messages being shown
when -ffunction-sections and -fdata-sections were used in conjunction
with --gc-sections linker flag and debugging information present. This
happens because lot of relocations from .debug_line section may become
invalid in such case. The newer fix doesn't show any warning message but
zeroes OutSec pointer in createInputSectionList() to avoid crash, when
relocations are written
llvm-svn: 284010
Following the lazy reference might bring in an object file that depends
on bitcode files that weren't part of the LTO step.
Differential Revision: https://reviews.llvm.org/D25461
llvm-svn: 283989
I don't really understand why we get a larger .rodata section only
on this bot. I guess it may be picking up a library which contains
a .rodata. I removed the specific values since their values are not
important for this test case.
llvm-svn: 283931
This part was splitted from D25016.
When sh_info value was set in the way that non-local symbol was treated as local, lld
was asserting, patch fixes that.
Differential revision: https://reviews.llvm.org/D25371
llvm-svn: 283859
Before the default was whatever number hardware_concurrency() returned.
Users can specify the number of threads via --lto-jobs=X option.
llvm-svn: 283787
Sometimes the very first PT_LOAD segment, created by lld, can be empty.
This happens when (all conditions met):
- Linker script is used
- First section in ELF image is not RO
- Not enough space for program headers.
Differential revision: https://reviews.llvm.org/D25330
llvm-svn: 283760
With fix: commit changes from InputFiles.cpp too.
Original commit message:
We have following code in lld, that truncates the alignment value to 32 bit. Big alignment in this case
may give result 0 and crash later.
template <class ELFT>
CommonInputSection<ELFT>::CommonInputSection(std::vector<DefinedCommon *> Syms)
: InputSection<ELFT>(nullptr, &Hdr, "") {
....
for (DefinedCommon *Sym : Syms) {
this->Alignment = std::max<uintX_t>(this->Alignment, Sym->Alignment);
...
}
}
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D25235
llvm-svn: 283738
.ARM.exidx sections have a reverse dependency on the section they have
a SHF_LINK_ORDER dependency on. In other words a .ARM.exidx section is
live only if the executable section it describes is live. We implement
this with a reverse dependency field in InputSection.
Adding the dependency to InputSection is the simplest implementation
but it could be moved out to a separate map if it were found to decrease
performance for non ARM targets.
Differential revision: https://reviews.llvm.org/D25234
llvm-svn: 283734
We have following code in lld, that truncates the alignment value to 32 bit. Big alignment in this case
may give result 0 and crash later.
template <class ELFT>
CommonInputSection<ELFT>::CommonInputSection(std::vector<DefinedCommon *> Syms)
: InputSection<ELFT>(nullptr, &Hdr, "") {
....
for (DefinedCommon *Sym : Syms) {
this->Alignment = std::max<uintX_t>(this->Alignment, Sym->Alignment);
...
}
}
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D25235
llvm-svn: 283733
Absolute local symbols with name staring from ".L" were reason of crash.
The same could happen when using some broken inputs found by AFL.
Patch fixes that.
Differential revision: https://reviews.llvm.org/D25365
llvm-svn: 283731
The .ARM.exidx sections contain a table. Each entry has two fields:
- PREL31 offset to the function the table entry describes
- Action to take, either cantunwind, inline unwind, or PREL31 offset to
.ARM.extab section
The table entries must be sorted in order of the virtual addresses the
first entry of the table describes. Traditionally this is implemented by
the SHF_LINK_ORDER dependency. Instead of implementing this directly we
sort the table entries post relocation.
The .ARM.exidx OutputSection is described by the PT_ARM_EXIDX program
header
Differential revision: https://reviews.llvm.org/D25127
llvm-svn: 283730
When sh_info of sumbol table value was set to zero, lld was asserting.
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D25016
llvm-svn: 283562
I found that this check still may be useful in some cases.
At fact since we use uint32_t alignment, then maximum value
that is valid for us is 0x80000000. But some broken files,
for example file from testcase may have greater value.
Because of that offset calculation overflow and crash happens.
Differential revision: https://reviews.llvm.org/D25324
llvm-svn: 283544
Previously if sh_size of dynamic section was broken,
lld may crash. Or even may not crash if used 32 bits host.
(then value may be truncated to 32 bits when doing pointer arithmetic
and could be just zero).
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D25327
llvm-svn: 283533
createELFObj() may call error(...), for example when file is too short.
In that case header is not set and following line lead to crash:
EMachine = ELFObj.getHeader()->e_machine;
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D25233
llvm-svn: 283532
This patch makes the check for null section stricter,
so it is only allowed for STT_SECTION symbols now.
Differential revision: https://reviews.llvm.org/D25231
llvm-svn: 283426
With this, "llvm-pdbdump yaml -ipi-stream" prints out an IPI stream.
Previously it crashed because it can't handle the case where IPI
stream doesn't exist.
llvm-svn: 283392
Do not merge sections if generating a relocatable object. It makes
the code simpler because we do not need to update relocations addends
to reflect changes introduced by merging. Instead of that we write
such "merge" sections into separate OutputSections and keep SHF_MERGE
/ SHF_STRINGS flags and sh_entsize value to be able to perform merging
later during a final linking.
Differential Revision: http://reviews.llvm.org/D25066
llvm-svn: 283300
If we have input without object files, for example if we have only .so
code crashes in checkFlags(), getPicFlags(), getArchFlags() functions.
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D25237
llvm-svn: 283226
Previously lld would hang in infinite loop in this case,
patch fixes the issue. Object was found during AFL run.
Differential revision: https://reviews.llvm.org/D25229
llvm-svn: 283208
Relative to PR30540.
If .symtab has invalid type in elf, no bodies are created and any relocation
that tries to access them will fail.
The same can happen if symbol index is just incorrect.
This was revealed by "id_000005,sig_11,src_000000,op_flip2,pos_420"
Differential revision: https://reviews.llvm.org/D25025
llvm-svn: 283201
id_000021,sig_11,src_000002,op_flip1,pos_92 from PR30540
does not have TLS sections, but type
of one of the symbol is broken and set to STT_TLS,
what resulted in a crash. Patch fixes crash.
DIfferential revision: https://reviews.llvm.org/D25083
llvm-svn: 283198
Testcase contains a common symbol with zero alignment,
previously lld would crash, patch fixes that.
Differential revision: https://reviews.llvm.org/D25085
llvm-svn: 283197
Follow-up to r282716. Reject input files with non-zero GP0 value only in
case of relocatable object generation. In other case we can handle
arbitrary GP0 value so it does not have a sense to make the restriction
so wide.
llvm-svn: 283194
Case was revealed by id_000010,sig_08,src_000000,op_havoc,rep_4 from PR30540.
Out implementation uses uint32 for storing section alignment value,
what seems reasonable, though if value exceeds 32 bits bounds we have
truncation and final value of 0.
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D25082
llvm-svn: 283097
Previously, it warned on any archive file that has no symbol.
It turned out that that is too noisy.
With this patch, it warns on such archive file that contains no file.
Differential Revision: https://reviews.llvm.org/D25111
llvm-svn: 282885
We would crash when a non-alloca section pointed to a gced part of a
merge section.
That can happen when a C/c++ constant in put in a merge section and
debug info is present.
llvm-svn: 282845
We were implicitly creating space for the headers. That is not the
behaviour of bfd, which requires the script to use SIZEOF_HEADERS. The
difference is important for scripts that don't use SIZEOF_HEADERS and
expect the first section to be at 0.
llvm-svn: 282818
Currently lld will implicitly reserve space for the headers. This is
not the case is bfd, where it is the script responsibility to use
SIZEOF_HEADERS. This means that a script not using SIZEOF_HEADERS and
expecting the address of the first section to be 0 would fail with lld.
I am fixing that is the next commit. This one just makes the tests
explicitly use SIZEOF_HEADERS to avoid the dependency on the current
behaviour.
llvm-svn: 282814
Since they end up going on the same PT_LOAD, there is no reason to
sort them. This matches bfd's behaviour and is user visible in the
placement of orphan sections.
llvm-svn: 282799
If there is not sufficient address space, just give up and don't put
the header in the PT_LOAD.
This matches bfd behaviour and I found at least one script that
depends on having a section at address 0.
llvm-svn: 282750
LLD does not update relocations addends when generate a relocatable
object. That is why we should not write a non-zero GP0 value into
the .reginfo and .MIPS.options sections. And we should not accept input
object files with non-zero GP0 value because we cannot handle them
properly.
llvm-svn: 282716
In case of linking PIC and non-PIC code together and generation of a
relocatable object, all PIC symbols should have STO_MIPS_PIC flag in the
symbol table of the ouput file.
llvm-svn: 282714
If we two sections reside in the same PT_LOAD segment,
we compute second section using the following formula:
Off2 = Off1 + VA2 - VA1. This allows OS kernel allocating
sections correctly when loading an image.
Differential revision: https://reviews.llvm.org/D25014
llvm-svn: 282705
This subfolder just like "linkerscript" subfolder keeps
testcases with invalid input. According to PR30540 it seems
we might have many new ones soon, so it is seems reasonable to
separate them from regular testcases.
Differential revision: https://reviews.llvm.org/D25010
llvm-svn: 282595
This matches the behavior of Binutils linkers. We also change the
default MaxPageSize on x86-64 to 0x1000 to preserver the current
behavior, which is the same as the behavior implemented by gold.
https://llvm.org/bugs/show_bug.cgi?id=30541
Differential Revision: https://reviews.llvm.org/D24987
llvm-svn: 282560
Handle this in the exact same way as IMAGE_REL_AMD64_SECREL
and IMAGE_REL_I386_SECREL.
Differential revision: https://reviews.llvm.org/D24608
llvm-svn: 282531
r282444 introduced new issue, sample program below
fails to link on
assert(Piece.Live);
int main() { return 0; }
clang test.cpp -c -o out.o -g
ld.lld -flavor gnu --gc-sections out.o -o out
Problem is that .debug_info contains relocations to .debug_str:
Section (7) .rela.debug_info {
..
0xC R_X86_64_32 .debug_str 0x0
0x12 R_X86_64_32 .debug_str 0x37
..
But we do not preserve .debug_str in a right way now.
To fix this we should ignore relocations from non-allocatable sections to allocatable
to allow GC work at full power, but still should proccess relocations from non-allocatable to non-allocatable sections
as usual to mark some parts of debug sections alive to keep them so we do not end
up with such assert when trying to access dead pieces. That looks like what gold/ld do, they do
not strip .debug_str section from what I saw using sample provided.
Thanks to Evgeny Leviant for suggestions about how to fix this.
Differential revision: https://reviews.llvm.org/D24967
llvm-svn: 282495
The BYTE, SHORT, LONG, and QUAD commands store one, two, four, and eight bytes (respectively).
After storing the bytes, the location counter is incremented by the number of bytes
stored.
Previously our scripts handles these commands incorrectly. For example:
SECTIONS {
.foo : {
*(.foo.1)
BYTE(0x11)
...
We accepted the script above treating BYTE as input section description.
These commands are used in the wild though.
Differential revision: https://reviews.llvm.org/D24830
llvm-svn: 282429
PR30521 was about linking shared library. After r282295 code when linking -shared produced
"entry symbol not found" warning, what in combination with --fatal-errors failed linkage.
Patch fixes logic (and adds testcases) to follow next rules:
1) If entry was specified and not found report warning.
2) If entry was not specified then:
a) Emit warning if not -shared.
b) Do not emit warning if -shared.
Differential revision: https://reviews.llvm.org/D24913
llvm-svn: 282427
I found out this wasn't tested when looking at Vedant's coverage bot
numbers, so, thanks to him. While I'm here, switch the error message
to be lld-compliant (first letter lowercase).
llvm-svn: 282335
We were counting the size of the bss section holding common symbols twice:
Dot += CurOutSec->getSize();
flush();
The new code is also simpler as now flush is the only function that
inserts in AlreadyOutputOS, which makes sense since the set hold fully
output sections.
llvm-svn: 282285
If we pass --gc-sections to lld and .tbss is not referenced,
the section is reclaimed and lld doesn't create a TLS program header.
R_TLS tries to access the program header -> lld crashes.
Mimic what bfd/gold do in this case and resolve a weak undefined
TLS symbol to the base of the TLS block, i.e. give it a value of zero.
Differential Revision: https://reviews.llvm.org/D24832
llvm-svn: 282279
It would fail for example if the directory contained an @. Both gold
and bfd require quotes for @, so just change the test to quote the
directory name.
Thanks to Vedant Kumar for the bug report.
llvm-svn: 282256
The ARM TLS relocations are placed on literal data and not the
code-sequence, it is therefore not possible to implement the relaxTls*
functions. This change updates handleMipsTlsRelocation() to
handleNoRelaxTlsRelocation() and incorporates ARM as well as Mips.
The ARM support in handleNoRelaxTlsRelocation() currently needs to ouput
the module index dynamic relocation in all cases as it is relying on the
dynamic linker to set the module index in the got.
Should address PR30218
Differential Revision: https://reviews.llvm.org/D24827
llvm-svn: 282250
Previously we failed to parse next scripts because disallowed
a space between filler value and '=':
.text : {
...
} :text = 0x9090
Differential revision: https://reviews.llvm.org/D24831
llvm-svn: 282248
DEFINED(symbol)
Return 1 if symbol is in the linker global symbol table and is defined before
the statement using DEFINED in the script, otherwise return 0.
Can be used to define default values for symbols. Found it in the wild.
Differential revision: https://reviews.llvm.org/D24858
llvm-svn: 282245
If section contains local symbols ldd crashes, because local
symbols are added to symbol table before section is discarded
by linker script processor. This patch calls copyLocalSymbols()
after createSections, so discarded section symbols are not copied
llvm-svn: 282244
Found this operators used in the wild scripts, for example:
__got2_entries = (_FIXUP_TABLE_ - _GOT2_TABLE_) >>2;
__fixup_entries = (. - _FIXUP_TABLE_)>>2;
Differential revision: https://reviews.llvm.org/D24860
llvm-svn: 282243
The ELF spec doesn't allow relocations to point directly to
a deduplicated COMDAT section but this unfortunately happens in
practice. Bail out early instead of crashing.
Differential Revision: https://reviews.llvm.org/D24750
llvm-svn: 282197
George Rimar