Commit Graph

5 Commits

Author SHA1 Message Date
Fangrui Song 8f10a5f42d [ELF][test] Simplify and reorganize tests
Add file-level comments
Delete insignificant addresses to make them more tolerant to layout changes
Simplify test output
Delete simple Inputs/*.s files

Delete version-script-copy-rel.s - covered by verdef-defaultver.s
Delete version-wildcard.test - covered by version-script-glob.s

llvm-svn: 371213
2019-09-06 15:10:31 +00:00
Fangrui Song b159906a9a [test] Change llvm-readobj -long-option to --long-option or well-known short options. NFC
Also change some options that have different semantics (cause confusion) in llvm-readelf mode:

-s => -S
-t => --symbols
-sd => --section-data

llvm-svn: 359651
2019-05-01 05:49:01 +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
James Henderson 4ba1777a2d [ELF] Remove checking for spurious '@' at the end of dynamic sym names
llvm-readobj currently has a bug (see PR40097) where it prints '@' at
the end of unversioned dynamic symbols. This bug will be fixed in a
separate later commit, but these tests need fixing first.

Reviewed by: ruiu, Higuoxing

Differential Revision: https://reviews.llvm.org/D56388

llvm-svn: 350614
2019-01-08 10:50:59 +00:00
George Rimar d92e1286ed [ELF] - Fix handling of weak symbols from static library when using version script.
When version script was used, binding opf undefined weak symbols sometimes
was calculated as STB_LOCAL, making them non-preemtible what
broke correct relocations handling logic for them.

Fixes PR33738.

Differential revision: https://reviews.llvm.org/D35263

llvm-svn: 307767
2017-07-12 11:09:46 +00:00