Commit Graph

10 Commits

Author SHA1 Message Date
Fangrui Song 660b753e28 [ELF][test] Convert --start-address= and --stop-address= values to hexadecimal
so that readers can connect them with the hexadecimal addresses in the output.
2021-07-28 12:55:09 -07:00
Fangrui Song 66bcbdbc9c [AArch64InstPrinter] Change printADRPLabel to print the target address in hexadecimal form
Similar to D77853. Change ADRP to print the target address in hex, instead of the raw immediate.
The behavior is similar to GNU objdump but we also include `0x`.

Note: GNU objdump is not consistent whether or not to emit `0x` for different architectures. We try emitting 0x consistently for all targets.

```
GNU objdump:       adrp x16, 10000000
Old llvm-objdump:  adrp x16, #0
New llvm-objdump:  adrp x16, 0x10000000
```

`adrp Xd, 0x...` assembles to a relocation referencing `*ABS*+0x10000` which is not intended. We need to use a linker or use yaml2obj.
The main test is `test/tools/llvm-objdump/ELF/AArch64/pcrel-address.yaml`

Differential Revision: https://reviews.llvm.org/D93241
2020-12-16 09:20:55 -08:00
Fangrui Song 6d637fa560 [ELF][test] Delete large temporary files and make some temporary files smaller with two text segments
Large files are cumbersome on some filesystems and can more easily trigger ENOSPC.

Some tests use two text sections with output section addresses to test branch ranges.
Use two text segments to prevent LLD from filling the gap and unnecessarily increasing the output size.

With this change, there is no test/ELF temporary file larger than 100MiB.

Reviewed By: psmith

Differential Revision: https://reviews.llvm.org/D88037
2020-09-21 12:09:17 -07:00
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
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 f60cdce087 [ELF] Add missing test from r320800
Forgot to svn add the additional test for the commit. Adding with this one.

llvm-svn: 320802
2017-12-15 11:02:50 +00:00