Commit Graph

2932 Commits

Author SHA1 Message Date
Simon Atanasyan 09b3e3685f [ELF] MIPS paired R_MIPS_HI16/LO16 relocations support
Some MIPS relocations including `R_MIPS_HI16/R_MIPS_LO16` use combined
addends. Such addend is calculated using addends of both paired relocations.
Each `R_MIPS_HI16` relocation is paired with the next `R_MIPS_LO16`
relocation. ABI requires to compute such combined addend in case of REL
relocation record format only.

For details see p. 4-17 at
ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf

This patch implements lookup of the next paired relocation suing new
`InputSectionBase::findPairedRelocLocation` method. The primary
disadvantage of this approach is that we put MIPS specific logic into
the common code. The next disadvantage is that we lookup `R_MIPS_LO16`
for each `R_MIPS_HI16` relocation, while in fact multiple `R_MIPS_HI16`
might be paired with the single `R_MIPS_LO16`. From the other side
this way allows us to keep `MipsTargetInfo` class stateless and implement
later relocation handling in parallel.

This patch does not support `R_MIPS_HI16/R_MIPS_LO16` relocations against
`_gp_disp` symbol. In that case the relocations use a special formula for
the calculation. That will be implemented later.

Differential Revision: http://reviews.llvm.org/D15112

llvm-svn: 254461
2015-12-01 21:24:45 +00:00
George Rimar 90cd0a8234 [ELF] - Fixed bug leading to miss of tls relocation when @tlsgd and @gottpoff relocations were used at the same time.
Combination of @tlsgd and @gottpoff at the same time leads to miss of R_X86_64_TPOFF64 dynamic relocation. Patch fixes that.

@tlsgd(%rip) - Allocate two contiguous entries in the GOT to hold a tls index
structure (for passing to tls get addr).
@gottpoff(%rip) - Allocate one GOT entry to hold a variable offset in initial TLS
block (relative to TLS block end, %fs:0).

The same situation can be observed for x86 (probably others too, not sure) with corresponding for that target relocations: @tlsgd, @gotntpoff.

Differential revision: http://reviews.llvm.org/D15105

llvm-svn: 254443
2015-12-01 19:20:26 +00:00
Igor Kudrin fea8ed50ef [ELF/AArch64] Fix overflow checks for R_AARCH64_{ABS,PREL}{16,32} relocations.
ABI specifies the allowed range for these relocations as 2^(n-1) <= X < 2^n.

The patch fixes checks and introduces precise tests for these relocations.

Differential revision: http://reviews.llvm.org/D14957

llvm-svn: 254146
2015-11-26 10:05:24 +00:00
Igor Kudrin 9b7e7db8ca [ELF] Factor out relocation checks into separate functions.
It helps to standardize common checks and unify error messages.

Differential revision: http://reviews.llvm.org/D14943

llvm-svn: 254144
2015-11-26 09:49:44 +00:00
Simon Atanasyan 16b0cc9ee6 [ELF] Reapply r254031 - LinkerScript: lookup absolute paths under sysroot
In case a sysroot prefix is configured, and the filename starts with
the '/' character, and the script being processed was located inside
the sysroot prefix, the file's name will be looked for in the sysroot
prefix. Otherwise, the linker falls to the common lookup scheme.

It is slightly modified version of the commit r254031. The problem of
the initial commit was in the `is_absolute` call. On Windows 'C:\' is
absolute path but we do not need to find it under sysroot. In this patch
linker looks up a path under sysroot only if the paths starts with '/'
character.

llvm-svn: 254135
2015-11-26 05:53:00 +00:00
George Rimar 77b7779b48 Reapply r254098.
Fix is (OutputSections.cpp):
for (std::pair<const SymbolBody *, size_t> &I : Entries) {
 =>
for (std::pair<const SymbolBody *, unsigned> &I : Entries) {

llvm-svn: 254105
2015-11-25 22:15:01 +00:00
George Rimar dbb2f6188d Revert r254098 as it seems broke build bot.
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/3555

llvm-svn: 254103
2015-11-25 22:03:16 +00:00
George Rimar 6713cf8a52 [ELF] - Implemented optimizations for @tlsld and @tlsgd
Implements @tlsld (LD to LE) and @tlsgd (GD to LE) optimizations.
Patch does not implement the GD->IE case for @tlsgd.

Differential revision: http://reviews.llvm.org/D14870

llvm-svn: 254101
2015-11-25 21:46:05 +00:00
George Rimar 21c0a7131b [ELF] - Lazy relocations support for x86 target.
Patch implements lazy relocations for x86.
One of features of x86 is that executable files and shared object files have separate procedure linkage tables. So patch implements both cases.

Detailed information about instructions used can be found in http://docs.oracle.com/cd/E19620-01/805-3050/chapter6-1235/index.html (search: x86: Procedure Linkage Table).

Differential revision: http://reviews.llvm.org/D14955

llvm-svn: 254098
2015-11-25 21:37:59 +00:00
Simon Atanasyan 96306bbebc [ELF2][MIPS] Support R_MIPS_CALL16 relocation
R_MIPS_CALL16 relocation provides the same result as R_MIPS_GOT16
relocation but does not need to check the result on overflow.

Differential Revision: http://reviews.llvm.org/D14916

llvm-svn: 254092
2015-11-25 20:58:52 +00:00
George Rimar d23970f778 [ELF/x86] Implemented R_386_TLS_LE_32, R_386_TLS_LE relocations.
This patch implements next relocations:
R_386_TLS_LE - Negative offset relative to static TLS (GNU version).
R_386_TLS_LE_32 - Offset relative to static TLS block.

These ones are created when using next code sequences:
* @tpoff - The operator must be used to compute an immediate value. The linker will report
an error if the referenced variable is not defined or it is not code for the executable
itself. No GOT entry is created in this case.
* @ntpoff Calculate the negative offset of the variable it is added to relative to the static TLS block.
The operator must be used to compute an immediate value. The linker will report
an error if the referenced variable is not defined or it is not code for the executable
itself. No GOT entry is created in this case.

Information was found in Ulrich Drepper, ELF Handling For Thread-Local Storage, http://www.akkadia.org/drepper/tls.pdf, (6.2, p76)

Differential revision: http://reviews.llvm.org/D14930

llvm-svn: 254090
2015-11-25 20:41:53 +00:00
George Rimar 70e2508259 [ELF] - R_386_COPY relocation implemented (x86)
Implements R_386_COPY relocation for x86 target.
Similar to one for x64 http://reviews.llvm.org/D14090 which did most of job needed.

Differential revision: http://reviews.llvm.org/D14958

llvm-svn: 254065
2015-11-25 11:27:40 +00:00
Hans Wennborg 82d2d07ced Revert r254031: "ELF2: LinkerScript: lookup absolute paths under sysroot"
The test fails on Windows:

Command 34: "ld.lld" "-o" "D:\src\llvm\build.release\tools\lld\test\ELF\Output\l
inkerscript.s.tmp2" "D:\src\llvm\build.release\tools\lld\test\ELF\Output\linkers
cript.s.tmp.dir/xyz.script" "--sysroot=D:\src\llvm\build.release\tools\lld\test\
ELF\Output\linkerscript.s.tmp.dir"
Command 34 Result: 1
Command 34 Output:

Command 34 Stderr:
Unable to find /libxyz.a

llvm-svn: 254049
2015-11-25 00:58:31 +00:00
Rui Ueyama a46566f2db ELF: Omit PT_GNU_STACK segment if -z execstack is provided.
In the previous patch (r254003), I made the linker emit PT_GNU_STACK
unconditionally. But sometimes you want to have a control over the
presence of the segment. With this patch, you can omit the segment
by passing -z execstack option.

llvm-svn: 254039
2015-11-24 23:42:33 +00:00
Simon Atanasyan 44136b675d ELF2: LinkerScript: lookup absolute paths under sysroot
In case a sysroot prefix is configured, and the filename starts with the
'/' character, and the script being processed was located inside the
sysroot prefix, the file's name will be looked for in the sysroot
prefix. Otherwise, the linker falls to the common lookup scheme.

https://www.sourceware.org/binutils/docs-2.24/ld/File-Commands.html

Differential Revision: http://reviews.llvm.org/D14916

llvm-svn: 254031
2015-11-24 22:16:25 +00:00
Rui Ueyama 7b19c34550 Revert "ELF: Make .note.GNU-stack more compatible with traditional linkers."
This reverts commit r253797 because it was based on a misunderstanding
that lld wouldn't work on NetBSD without this change.

llvm-svn: 254003
2015-11-24 18:48:16 +00:00
George Rimar e3336c0be6 Reapply fixed r253967.
llvm-svn: 253971
2015-11-24 10:15:50 +00:00
George Rimar 11721ce810 Revert r253967 which broke buildbot.
llvm-svn: 253970
2015-11-24 10:04:22 +00:00
George Rimar 63a6ca9150 [ELF] Implements -z relro: create an ELF "PT_GNU_RELRO" segment header in the object.
Partial (-z relro) and full (-z relro, -z now) relro cases are implemented.

Partial relro:
The ELF sections are reordered so that the ELF internal data sections (.got, .dtors, etc.) precede the program's data sections (.data and .bss).
.got is readonly, .got.plt is still writeable.

Full relro:
Supports all the features of partial RELRO, .got.plt is also readonly.

Differential revision: http://reviews.llvm.org/D14218

llvm-svn: 253967
2015-11-24 09:44:28 +00:00
George Rimar 77d1cb1ddf [ELF2] - Optimization for R_X86_64_GOTTPOFF relocation.
R_X86_64_GOTTPOFF is not always requires GOT entries. Some relocations can be converted to local ones.

Differential revision: http://reviews.llvm.org/D14713

llvm-svn: 253966
2015-11-24 09:00:06 +00:00
Igor Kudrin 5d2bffdd57 [ELF/AArch64] Add support for R_AARCH64_ADR_GOT_PAGE and R_AARCH64_LD64_GOT_LO12_NC.
With these relocations, it is now possible to build a simple "hello world"
program for AArch64 Debian.

Differential revision: http://reviews.llvm.org/D14917

llvm-svn: 253957
2015-11-24 06:48:31 +00:00
Rafael Espindola e02c86812c Fix Elf_Rel processing for .eh_frame.
Thanks to Simon for the bug report.

llvm-svn: 253869
2015-11-23 15:28:28 +00:00
Rui Ueyama e79b09a616 ELF: Make .note.GNU-stack more compatible with traditional linkers.
With this patch, lld creates PT_GNU_STACK segments only when all input
files have .note.GNU-stack sections. This is in line with other linkers
with a minor difference (we don't care about .note.GNU-stack rwx bits as
you can always remove .note.GNU-stack sections instead of setting x bit.)

At least, NetBSD loader does not understand PT_GNU_STACK segments and
reject any executables that have the section. This patch makes lld
compatible with such operating systems.

llvm-svn: 253797
2015-11-21 22:19:32 +00:00
Rui Ueyama 8486a51845 Remove trailing whitespaces and untabify.
llvm-svn: 253727
2015-11-20 22:47:40 +00:00
Davide Italiano dc67f9b7e8 [ELF/AArch64] Add support for LDST8_ABS_LO12_NC/LDST64_ABS_LO12_NC.
These two relocations where the only missing step to get a dynamically
linked (with libc) "hello world" on FreeBSD.

llvm-svn: 253714
2015-11-20 21:35:38 +00:00
Igor Kudrin 2f610d5e13 [ELF/AArch64] Accept -m aarch64linux.
This option is passed by clang driver if the target triple
is "aarch64-unknown-linux".

Differential Revision: http://reviews.llvm.org/D14831

llvm-svn: 253639
2015-11-20 02:48:53 +00:00
Igor Kudrin b044af50f2 [ELF] Define symbols "_end" and "end" if referenced.
These symbols are expected to point to the end of the data segment.

Implements http://llvm.org/pr25528.

Differential Revision: http://reviews.llvm.org/D14833

llvm-svn: 253637
2015-11-20 02:32:35 +00:00
Igor Kudrin 4bc5ad4c37 [ELF] Prevent SEGFAULT in case of conflict with an internally defined symbol.
Differential Revision: http://reviews.llvm.org/D14832

llvm-svn: 253588
2015-11-19 19:08:45 +00:00
Rafael Espindola 9c8904fb38 Rename ld.lld2 to ld.lld since it is the default.
llvm-svn: 253437
2015-11-18 06:11:01 +00:00
David Majnemer 8a4be35c9c Adjust test from fallout due to r253429
As a side note, the jump target is much nicer than before.

We went from: <bar+...> to <.plt>

llvm-svn: 253433
2015-11-18 04:37:23 +00:00
Igor Kudrin db7de9f590 [ELF2/AArch64] Add lazy relocation support for AArch64.
Differential Revision: http://reviews.llvm.org/D14749

llvm-svn: 253352
2015-11-17 18:01:30 +00:00
Rafael Espindola 4b1285c55a Rename test/elf2 to test/ELF.
llvm-svn: 253313
2015-11-17 05:36:42 +00:00