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llvm-project/lld/test/ELF/synthetic-got.s

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[ELF] - Add support for access to most of synthetic sections from linkerscript. This is important for cases like: .sdata : { *(.got.plt .got) ... } That was not supported before as there was no way to get access to synthetic sections from script. More details on review page. Differential revision: https://reviews.llvm.org/D27040 llvm-svn: 287913
2016-11-25 16:05:41 +08:00
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
# RUN: echo "SECTIONS { }" > %t0.script
[ELF] - Do --hash-style=both by default. Its PR34712, GNU linkers recently changed default values to "both" of "sysv". Patch do the same for all targets except MIPS, where .gnu.hash section is not yet supported. Code suggested by Rui Ueyama. Differential revision: https://reviews.llvm.org/D38407 llvm-svn: 315051
2017-10-06 17:37:44 +08:00
# RUN: ld.lld --hash-style=sysv -shared %t.o -o %t0.out --script %t0.script
[test] lld/test/: change llvm-objdump single-dash long options to double-dash options
2020-03-16 08:47:44 +08:00
# RUN: llvm-objdump --section-headers %t0.out | FileCheck %s --check-prefix=GOT
# RUN: llvm-objdump -s --section=.got --section=.got.plt %t0.out \
[ELF] - Add support for access to most of synthetic sections from linkerscript. This is important for cases like: .sdata : { *(.got.plt .got) ... } That was not supported before as there was no way to get access to synthetic sections from script. More details on review page. Differential revision: https://reviews.llvm.org/D27040 llvm-svn: 287913
2016-11-25 16:05:41 +08:00
# RUN: | FileCheck %s --check-prefix=GOTDATA
# GOT: Sections:
[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
# GOT: 9 .got 00000008 00000000000001b0 DATA
# GOT: 10 .got.plt 00000020 00000000000001b8 DATA
# GOTDATA: Contents of section .got:
# GOTDATA-NEXT: 01b0 00000000 00000000
# GOTDATA-NEXT: Contents of section .got.plt:
# GOTDATA-NEXT: 01b8 e0000000 00000000 00000000 00000000
# GOTDATA-NEXT: 01c8 00000000 00000000 d6000000 00000000
[ELF] - Add support for access to most of synthetic sections from linkerscript. This is important for cases like: .sdata : { *(.got.plt .got) ... } That was not supported before as there was no way to get access to synthetic sections from script. More details on review page. Differential revision: https://reviews.llvm.org/D27040 llvm-svn: 287913
2016-11-25 16:05:41 +08:00
# RUN: echo "SECTIONS { .mygot : { *(.got) *(.got.plt) } }" > %t1.script
[ELF] - Do --hash-style=both by default. Its PR34712, GNU linkers recently changed default values to "both" of "sysv". Patch do the same for all targets except MIPS, where .gnu.hash section is not yet supported. Code suggested by Rui Ueyama. Differential revision: https://reviews.llvm.org/D38407 llvm-svn: 315051
2017-10-06 17:37:44 +08:00
# RUN: ld.lld --hash-style=sysv -shared %t.o -o %t1.out --script %t1.script
[test] lld/test/: change llvm-objdump single-dash long options to double-dash options
2020-03-16 08:47:44 +08:00
# RUN: llvm-objdump --section-headers %t1.out | FileCheck %s --check-prefix=MYGOT
# RUN: llvm-objdump -s --section=.mygot %t1.out | FileCheck %s --check-prefix=MYGOTDATA
[ELF] - Add support for access to most of synthetic sections from linkerscript. This is important for cases like: .sdata : { *(.got.plt .got) ... } That was not supported before as there was no way to get access to synthetic sections from script. More details on review page. Differential revision: https://reviews.llvm.org/D27040 llvm-svn: 287913
2016-11-25 16:05:41 +08:00
# MYGOT: Sections:
[ELF] Assign RF_EXEC rank even if --no-rosegment or SECTIONS command is used Summary: Currently when --no-rosegment is specified or a linker script with SECTIONS command is used, .rodata (A) .text (AX) are assigned the same rank and .rodata may be placed after .text . This increases the gap between .text and .bss and can cause pc-relative relocation overflow (e.g. gcc crtbegin.o crtbegin.S have R_X86_64_PC32 relocation from .text to .bss). This patch makes SingleRoRx affect only segment layout, not section layout. As a consequence, .rodata will be placed before .text regardless of SingleRoRx. Reviewers: espindola, ruiu, grimar, echristo, javed.absar Subscribers: emaste, arichardson, llvm-commits Differential Revision: https://reviews.llvm.org/D48405 llvm-svn: 335627
2018-06-27 01:04:47 +08:00
# MYGOT: 8 .mygot 00000028 00000000000000e0 DATA
[ELF] - Add support for access to most of synthetic sections from linkerscript. This is important for cases like: .sdata : { *(.got.plt .got) ... } That was not supported before as there was no way to get access to synthetic sections from script. More details on review page. Differential revision: https://reviews.llvm.org/D27040 llvm-svn: 287913
2016-11-25 16:05:41 +08:00
# MYGOT-NOT: .got
# MYGOT-NOT: .got.plt
[ELF] Assign RF_EXEC rank even if --no-rosegment or SECTIONS command is used Summary: Currently when --no-rosegment is specified or a linker script with SECTIONS command is used, .rodata (A) .text (AX) are assigned the same rank and .rodata may be placed after .text . This increases the gap between .text and .bss and can cause pc-relative relocation overflow (e.g. gcc crtbegin.o crtbegin.S have R_X86_64_PC32 relocation from .text to .bss). This patch makes SingleRoRx affect only segment layout, not section layout. As a consequence, .rodata will be placed before .text regardless of SingleRoRx. Reviewers: espindola, ruiu, grimar, echristo, javed.absar Subscribers: emaste, arichardson, llvm-commits Differential Revision: https://reviews.llvm.org/D48405 llvm-svn: 335627
2018-06-27 01:04:47 +08:00
# MYGOTDATA: 00e0 00000000 00000000 08010000 00000000
# MYGOTDATA-NEXT: 00f0 00000000 00000000 00000000 00000000
# MYGOTDATA-NEXT: 0100 d6000000 00000000
[ELF] - Add support for access to most of synthetic sections from linkerscript. This is important for cases like: .sdata : { *(.got.plt .got) ... } That was not supported before as there was no way to get access to synthetic sections from script. More details on review page. Differential revision: https://reviews.llvm.org/D27040 llvm-svn: 287913
2016-11-25 16:05:41 +08:00
mov bar@gotpcrel(%rip), %rax
call foo@plt