2017-07-12 19:09:46 +08:00
|
|
|
# REQUIRES: x86
|
|
|
|
|
|
|
|
|
|
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
|
|
|
|
|
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %S/Inputs/version-script-weak.s -o %tmp.o
|
|
|
|
|
# RUN: rm -f %t.a
|
|
|
|
|
# RUN: llvm-ar rcs %t.a %tmp.o
|
|
|
|
|
# RUN: echo "{ local: *; };" > %t.script
|
|
|
|
|
# RUN: ld.lld -shared --version-script %t.script %t.o %t.a -o %t.so
|
2019-05-01 13:49:01 +08:00
|
|
|
# RUN: llvm-readobj --dyn-syms -r %t.so | FileCheck %s
|
2017-07-12 19:09:46 +08:00
|
|
|
|
|
|
|
|
# CHECK: Relocations [
|
|
|
|
|
# CHECK-NEXT: Section ({{.*}}) .rela.plt {
|
[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 11:47:45 +08:00
|
|
|
# CHECK-NEXT: 0x3018 R_X86_64_JUMP_SLOT foo
|
2017-07-12 19:09:46 +08:00
|
|
|
# CHECK-NEXT: }
|
|
|
|
|
# CHECK-NEXT: ]
|
|
|
|
|
# CHECK: Symbol {
|
2019-01-08 18:50:59 +08:00
|
|
|
# CHECK: Name: foo
|
2017-07-12 19:09:46 +08:00
|
|
|
# CHECK-NEXT: Value: 0x0
|
|
|
|
|
# CHECK-NEXT: Size: 0
|
|
|
|
|
# CHECK-NEXT: Binding: Weak
|
|
|
|
|
# CHECK-NEXT: Type: None
|
|
|
|
|
# CHECK-NEXT: Other: 0
|
|
|
|
|
# CHECK-NEXT: Section: Undefined
|
|
|
|
|
# CHECK-NEXT: }
|
|
|
|
|
|
|
|
|
|
.text
|
|
|
|
|
callq foo@PLT
|
|
|
|
|
.weak foo
|