66296dc3e4
We have a few sections that can be added implicitly to the output:
".dynsym", ".dynstr", ".symtab", ".strtab" and ".shstrtab".
Problem appears when such section is listed explicitly in YAML.
In that case it's content is written twice:
first time during writing of regular sections listed in the document
and second time during special handling.
Because of that their file offsets can become unexpectedly broken:
(yaml file for sample below lists .dynsym explicitly before .text.foo)
Before patch:
[Nr] Name Type Address Offset
Size EntSize Flags Link Info Align
[ 0] NULL 0000000000000000 00000000
0000000000000000 0000000000000000 0 0 0
[ 1] .dynsym DYNSYM 0000000000000100 00000250
0000000000000030 0000000000000018 A 6 0 8
[ 2] .text.foo PROGBITS 0000000000000200 00000200
0000000000000000 0000000000000000 AX 0 0 0
After patch:
Section Headers:
[Nr] Name Type Address Offset
Size EntSize Flags Link Info Align
[ 0] NULL 0000000000000000 00000000
0000000000000000 0000000000000000 0 0 0
[ 1] .dynsym DYNSYM 0000000000000100 00000200
0000000000000030 0000000000000018 A 6 0 8
[ 2] .text.foo PROGBITS 0000000000000200 00000230
0000000000000000 0000000000000000 AX 0 0 0
This patch reorganizes our code and fixes the issue described.
Differential revision: https://reviews.llvm.org/D62809
llvm-svn: 362602
87 lines
2.9 KiB
Plaintext
87 lines
2.9 KiB
Plaintext
## Check the section header properties of ".dynsym",
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## ".dynstr", ".symtab", ".strtab", ".shstrtab".
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## These sections sections are usually added implicitly,
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## but here we add them explicitly in YAML and verify.
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## We check their order matches YAML and that file offset is
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## ascending. This is a natural default behavior.
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# RUN: yaml2obj --docnum=1 %s -o %t1
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# RUN: llvm-readelf -S %t1 | FileCheck %s
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# CHECK: Section Headers:
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# CHECK-NEXT: [Nr] Name Type Address Off Size
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# CHECK-NEXT: [ 0] NULL 0000000000000000 000000 000000
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# CHECK-NEXT: [ 1] .dynstr STRTAB 0000000000000100 000200 000009
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# CHECK-NEXT: [ 2] .dynsym DYNSYM 0000000000000150 000209 000030
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# CHECK-NEXT: [ 3] .symtab SYMTAB 0000000000000000 000239 000018
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# CHECK-NEXT: [ 4] .strtab STRTAB 0000000000000000 000251 000001
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# CHECK-NEXT: [ 5] .shstrtab STRTAB 0000000000000000 000252 000035
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# CHECK-NEXT: [ 6] .text.foo PROGBITS 0000000000000200 000287 000000
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--- !ELF
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FileHeader:
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Class: ELFCLASS64
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Data: ELFDATA2LSB
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Type: ET_DYN
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Machine: EM_X86_64
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Sections:
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- Name: .dynstr
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Type: SHT_STRTAB
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Address: 0x100
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- Name: .dynsym
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Type: SHT_DYNSYM
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Address: 0x150
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- Name: .symtab
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Type: SHT_SYMTAB
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- Name: .strtab
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Type: SHT_STRTAB
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- Name: .shstrtab
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Type: SHT_STRTAB
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- Name: .text.foo
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Type: SHT_PROGBITS
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Address: 0x200
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## Symbol is required for the .dynsym to be generated.
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DynamicSymbols:
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- Name: _Z3fooi
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Binding: STB_GLOBAL
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## Check that yaml2obj creates empty .dynstr and .dynsym sections for
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## the case when no dynamic symbols were specified and Content wasn't set,
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## but the sections were explicitly listed. Check their VAs are correct.
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# RUN: yaml2obj --docnum=2 %s -o %t2
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# RUN: llvm-readelf -S %t2 | FileCheck %s --check-prefix=NODYNSYM
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# NODYNSYM: Section Headers:
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# NODYNSYM-NEXT: [Nr] Name Type Address Off Size
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# NODYNSYM-NEXT: [ 0] NULL 0000000000000000 000000 000000
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# NODYNSYM-NEXT: [ 1] .dynstr STRTAB 0000000000000100 000200 000001
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# NODYNSYM-NEXT: [ 2] .dynsym DYNSYM 0000000000000150 000201 000018
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# NODYNSYM-NEXT: [ 3] .symtab SYMTAB 0000000000000000 000219 000018
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# NODYNSYM-NEXT: [ 4] .strtab STRTAB 0000000000000000 000231 000001
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# NODYNSYM-NEXT: [ 5] .shstrtab STRTAB 0000000000000000 000232 000035
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# NODYNSYM-NEXT: [ 6] .text.foo PROGBITS 0000000000000200 000267 000000
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--- !ELF
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FileHeader:
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Class: ELFCLASS64
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Data: ELFDATA2LSB
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Type: ET_DYN
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Machine: EM_X86_64
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Sections:
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- Name: .dynstr
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Type: SHT_STRTAB
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Address: 0x100
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- Name: .dynsym
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Type: SHT_DYNSYM
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Address: 0x150
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- Name: .symtab
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Type: SHT_SYMTAB
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- Name: .strtab
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Type: SHT_STRTAB
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- Name: .shstrtab
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Type: SHT_STRTAB
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- Name: .text.foo
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Type: SHT_PROGBITS
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Address: 0x200
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