Commit Graph

23 Commits

Author SHA1 Message Date
Rafael Espindola 227556e1c7 Add support for a R_X86_64_32 referring to a plt.
This can show up with a non-PIC .o being linked into an executable that uses
shared libraries.

llvm-svn: 250300
2015-10-14 16:15:46 +00:00
Rui Ueyama c58656c7c0 Revert r250169: "This patch implements basic variant of lazy loading for x86_x64 and for X86 targets."
With this patch LLD is not able to self-host on x86-64 Linux.

llvm-svn: 250182
2015-10-13 16:59:30 +00:00
Rui Ueyama adf666010f Remove trailing whitespaces.
llvm-svn: 250170
2015-10-13 16:13:18 +00:00
George Rimar 9fd8fcb5a4 This patch implements basic variant of lazy loading for x86_x64 and for X86 targets.
What was done:
1) .got.plt section is created for functions that requires PLT. .got.plt has 3 predefined empty entries now that are required for dynamic linker.
Also other new items created are configured to have correct jump to PLT[N].
2) PLT section now has PLT[0] entry, also others ones are configured to support PLT->GOT(.got.plt) calls.
3) Implemented .rel[a].plt sections (based on patch http://reviews.llvm.org/D13569).
4) Fixed plt relocations types (based on patch http://reviews.llvm.org/D13589).

NOTES:
The .plt.got zero entry is still empty now. According to ELF specification it should hold the address of the dynamic structure, referenced with the symbol
_DYNAMIC. The _DYNAMIC entry points to the .dynamic section which contains information used by the ELF interpreter to setup the binary.

Differential Revision: http://reviews.llvm.org/D13651

llvm-svn: 250169
2015-10-13 16:09:55 +00:00
Rui Ueyama 69960baad5 ELF2: Write .interp section on the first page in the exectuable.
Previously, we reserved the first page for the program header, so no
sections would be written to very beginning of the output file.
FreeBSD requires .interp section be exist on the first page, so that
was not good.

This patch calculates the size of the program header and then assign
addresses to the sections. Now the first section is located next to
the program header. Because the first section is .interp, it's very
likely to be on the first page.

llvm-svn: 249957
2015-10-10 23:25:39 +00:00
Rafael Espindola d540919ff1 Revert "[ELF2] - Implemented rel[a].plt sections"
This reverts commit r249816.

It broke building llvm with lld:

$ ./bin/FileCheck
./bin/FileCheck: error while loading shared libraries: unexpected PLT reloc type 0x06

I think the only thing that is wrong with this patch is that it is too soon.

The plt we create (and its relocs) don't support lazy loading, so they have
to be relocated as ordinary dynamic relocations.

llvm-svn: 249835
2015-10-09 14:25:49 +00:00
George Rimar b352b9ce69 [ELF2] - Implemented rel[a].plt sections
.rela.plt contains list of elements in the PLT, which are liable to the relocation during the dynamic linking.

Differential Revision: http://reviews.llvm.org/D13569

llvm-svn: 249816
2015-10-09 09:58:08 +00:00
Rui Ueyama 60fe7fcc6b ELF2: Use ld.lld2 instead of lld -flavor gnu2.
llvm-svn: 249573
2015-10-07 17:31:39 +00:00
Rafael Espindola 4b81795c2a Update tests for upcoming change.
I am about to change lld to avoid creating unnecessary got entries for locally
defined symbols when creating executables.

Update tests that were depending on the current behavior.

llvm-svn: 249474
2015-10-06 21:52:48 +00:00
Michael J. Spencer 52bf0ebfdf [lld][elf2] Sort output sections.
Sort by:
ALLOC
ALLOC && NOBITS
ALLOC & EXEC
ALLOC & EXEC && NOBITS
ALLOC & WRITE
ALLOC & WRITE && NOBITS
<nothing> (ignoring NOBITS)

The dynamic section is finalized early because it adds strings to the dynamic string table, which comes before the dynamic table.

llvm-svn: 249071
2015-10-01 21:15:02 +00:00
Rafael Espindola 3ef3a4c9ff Start adding support for static programs using dynamic libraries.
This is just enough for a hello world using a dynamic glibc.

llvm-svn: 248854
2015-09-29 23:22:16 +00:00
Rafael Espindola 6a78fd5f41 This reverts commit r248845 and r248848.
They broke elf2/basic-mips.s.

Revert "[elf2] Sort output sections."
Revert "[elf2] Fix build."

llvm-svn: 248851
2015-09-29 23:19:25 +00:00
Michael J. Spencer fe07bd67fd [elf2] Sort output sections.
Sort by:
ALLOC
ALLOC && NOBITS
ALLOC & EXEC
ALLOC & EXEC && NOBITS
ALLOC & WRITE
ALLOC & WRITE && NOBITS
<nothing> (ignoring NOBITS)

The dynamic section is finalized early because it adds strings to the dynamic string table, which comes before the dynamic table.

llvm-svn: 248845
2015-09-29 23:05:40 +00:00
Rafael Espindola cdfecffd80 Add support for relocating R_X86_64_GOTPCREL.
llvm-svn: 248425
2015-09-23 20:08:25 +00:00
Michael J. Spencer 2f0082424f [elf2] Combine adjacent compatible OutputSections in PT_LOADs.
llvm-svn: 247925
2015-09-17 19:58:07 +00:00
Michael J. Spencer 75e5fda3de [elf2] Add R_X86_64_32S.
llvm-svn: 247758
2015-09-16 00:24:19 +00:00
Rafael Espindola a5c97d9025 Add support for R_X86_64_64.
llvm-svn: 247688
2015-09-15 13:52:06 +00:00
Rafael Espindola d1062bbd89 Make this test a bit more robust in preparation to adding more cases.
The first test (call) is now the only test to use .text, which makes it
resistant to more tests being added.

llvm-objdump -d already prints the addresses of symbols. We can use that in the
tests.

llvm-svn: 247685
2015-09-15 13:30:08 +00:00
Rafael Espindola 0a2e211ace Create a PT_LOAD program header for the start of the file.
With this a trivial dynamic program works with the musl dynamic linker:

LD_LIBRARY_PATH=.  ~/musl/lib/libc.so ./t

llvm-svn: 247290
2015-09-10 15:41:34 +00:00
Rafael Espindola 60252d8feb Change the load addr into something that works on linux x86_64.
With this simple static programs run again.

llvm-svn: 247205
2015-09-09 22:53:55 +00:00
Michael J. Spencer 1d299a8a9d [elf2] Assign output sections to PHDRs.
This is a minimal implementation to produce legal output. Future patches will combine multiple compatible PT_LOADs.

llvm-svn: 247185
2015-09-09 20:48:09 +00:00
Davide Italiano 94f183a696 [ELFv2] Implement R_X86_64_32 relocation.
Differential Revision:	http://reviews.llvm.org/D12436

llvm-svn: 246362
2015-08-29 13:15:42 +00:00
Michael J. Spencer 67bc8d6b3f [elf2] Add basic relocation support for x86-64.
This currently doesn't handle local symbols.

Differential Revision: http://reviews.llvm.org/D11612

llvm-svn: 246234
2015-08-27 23:15:56 +00:00