Commit Graph

12 Commits

Author SHA1 Message Date
Fangrui Song 7f36cb1f1a [AArch64InstPrinter] Change printAlignedLabel to print the target address in hexadecimal form
Similar to D76580 (x86) and D76591 (PPC).

```
// llvm-objdump -d output (before)
10000: 08 00 00 94                   bl      #32
10004: 08 00 00 94                   bl      #32

// llvm-objdump -d output (after)
10000: 08 00 00 94                   bl      0x10020
10004: 08 00 00 94                   bl      0x10024

// GNU objdump -d. The lack of 0x is not ideal due to ambiguity.
10000:       94000008        bl      10020 <bar+0x18>
10004:       94000008        bl      10024 <bar+0x1c>
```

The new output makes it easier to find the jump target.

Differential Revision: https://reviews.llvm.org/D77853
2020-04-10 09:21:09 -07:00
Fangrui Song f0374e7db2 [test] lld/test/: change llvm-objdump single-dash long options to double-dash options 2020-03-15 17:48:36 -07:00
Fangrui Song 71e2ca6e32 [llvm-objdump] -d: print `00000000 <foo>:` instead of `00000000 foo:`
The new behavior matches GNU objdump. A pair of angle brackets makes tests slightly easier.

`.foo:` is not unique and thus cannot be used in a `CHECK-LABEL:` directive.
Without `-LABEL`, the CHECK line can match the `Disassembly of section`
line and causes the next `CHECK-NEXT:` to fail.

```
Disassembly of section .foo:

0000000000001634 .foo:
```

Bdragon: <> has metalinguistic connotation. it just "feels right"

Reviewed By: rupprecht

Differential Revision: https://reviews.llvm.org/D75713
2020-03-05 18:05:28 -08:00
Eli Friedman c81fe34718 [lld][ELF] Don't apply --fix-cortex-a53-843419 to relocatable links.
The code doesn't apply the fix correctly to relocatable links. I could
try to fix the code that applies the fix, but it's pointless: we don't
actually know what the offset will be in the final executable. So just
ignore the flag for relocatable links.

Issue discovered building Android.

Differential Revision: https://reviews.llvm.org/D72968
2020-01-20 15:27:41 -08:00
Fangrui Song f66b767abe [ELF][AArch64] Allow PT_LOAD to have overlapping p_offset ranges
Ported the D64906 technique to AArch64. It deletes 3 alignments at
PT_LOAD boundaries for the default case: the size of an aarch64 binary
decreases by at most 192kb.

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:

* musl<=1.1.22
* FreeBSD 13.0-CURRENT (and before) rtld-elf arm64

New test aarch64-tls-vaddr-align.s checks that our workaround makes p_vaddr%p_align = 0.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D64930

llvm-svn: 369344
2019-08-20 08:34:56 +00:00
Fangrui Song 07f8daf05e [ELF] Simplify RelRo, TLS, NOBITS section ranks and make RW PT_LOAD start with RelRo
Old: PT_LOAD(.data | PT_GNU_RELRO(.data.rel.ro .bss.rel.ro) | .bss)
New: PT_LOAD(PT_GNU_RELRO(.data.rel.ro .bss.rel.ro) | .data .bss)

The placement of | indicates page alignment caused by PT_GNU_RELRO. The
new layout has simpler rules and saves space for many cases.

Old size: roundup(.data) + roundup(.data.rel.ro)
New size: roundup(.data.rel.ro + .bss.rel.ro) + .data

Other advantages:

* At runtime the 3 memory mappings decrease to 2.
* start(PT_TLS) = start(PT_GNU_RELRO) = start(RW PT_LOAD). This
  simplifies binary manipulation tools.
  GNU strip before 2.31 discards PT_GNU_RELRO if its
  address is not equal to the start of its associated PT_LOAD.
  This has been fixed by https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=f2731e0c374e5323ce4cdae2bcc7b7fe22da1a6f
  But with this change, we will be compatible with GNU strip before 2.31
* Before, .got.plt (non-relro by default) was placed before .got (relro
  by default), which made it impossible to have _GLOBAL_OFFSET_TABLE_
  (start of .got.plt on x86-64) equal to the end of .got (R_GOT*_FROM_END)
  (https://bugs.llvm.org/show_bug.cgi?id=36555). With the new ordering, we
  can improve on this regard if we'd like to.

Reviewers: ruiu, espindola, pcc

Subscribers: emaste, arichardson, llvm-commits, joerg, jdoerfert

Differential Revision: https://reviews.llvm.org/D56828

llvm-svn: 356117
2019-03-14 03:47:45 +00:00
Dimitry Andric c9de3b4d26 Align AArch64 and i386 image base to superpage
Summary:

As for x86_64, the default image base for AArch64 and i386 should be
aligned to a superpage appropriate for the architecture.

On AArch64, this is 2 MiB, on i386 it is 4 MiB.

Reviewers: emaste, grimar, javed.absar, espindola, ruiu, peter.smith, srhines, rprichard

Reviewed By: ruiu, peter.smith

Subscribers: jfb, markj, arichardson, krytarowski, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D50297

llvm-svn: 342746
2018-09-21 16:58:13 +00:00
Peter Smith 13a7b37ad4 [ELF][AArch64] Add test case for load/store exclusive instructions [NFC]
The AArch64 -fix-cortex-a53-843419 is missing a test case for the load and
store exclusive instructions. This was leading to a function not being
covered in the codebase. This change adds two new instruction sequences to
be recognised as an instance of the erratum, one with a load exclusive the
other with a store exclusive.

Differential Revision: https://reviews.llvm.org/D48840

llvm-svn: 336181
2018-07-03 08:53:41 +00:00
Peter Smith 24d906630b [LLD][ELF][AArch64] Increase test coverage of AArch64ErrataFix [NFC]
In the recognise test convert some ST1 multiple structure to ST1 single
structure to test the isST1SingleOpcode() function.

Differential Revision: https://reviews.llvm.org/D46263

llvm-svn: 331752
2018-05-08 09:36:24 +00:00
Rui Ueyama cd7a415938 Use log to print out a verbose message.
llvm-svn: 324688
2018-02-09 00:15:12 +00:00
Peter Smith cf354873c1 [ELF] Complete implementation of --fix-cortex-a53-843419
This patch provides the mechanism to fix instances of the instruction
sequence that may trigger the cortex-a53 843419 erratum. The fix is
provided by an alternative instruction sequence to remove one of the
erratum conditions. To reach this alternative instruction sequence we
replace the original instruction with a branch to the alternative
sequence. The alternative sequence is responsible for branching back to
the original.

As there is only erratum to fix the implementation is specific to
AArch64 and the specific erratum conditions. It should be generalizable
to other targets and erratum if needed.

Differential Revision: https://reviews.llvm.org/D36749

llvm-svn: 320800
2017-12-15 10:32:34 +00:00
Peter Smith 732cd8cbef [ELF] Implement scanner for Cortex-A53 Erratum 843419
Add a new file AArch64ErrataFix.cpp that implements the logic to scan for
the Cortex-A53 Erratum 843419. This involves finding all the executable
code, disassembling the instructions that might trigger the erratum and
reporting a message if the sequence is detected.

At this stage we do not attempt to fix the erratum, this functionality
will be added in a later patch. See D36749 for proposal.

Differential Revision: https://reviews.llvm.org/D36742

llvm-svn: 319780
2017-12-05 15:59:05 +00:00