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| author | Sid Manning <sidneym@quicinc.com> | 2019-11-05 11:13:18 -0800 |
|---|---|---|
| committer | Fangrui Song <maskray@google.com> | 2019-11-05 11:14:12 -0800 |
| commit | 6cd47f9dd7dd664ff855fb0d1ed26bf5e4bb77fc (patch) | |
| tree | 14e23da581acc68fcb6095d0c73c9290339e1b4d | |
| parent | f1b4c4bfd0b55c3c0abbc73e1159117f8533aca3 (diff) | |
| download | bcm5719-llvm-6cd47f9dd7dd664ff855fb0d1ed26bf5e4bb77fc.tar.gz bcm5719-llvm-6cd47f9dd7dd664ff855fb0d1ed26bf5e4bb77fc.zip | |
[llvm-objdump] Fix spurious "The end of the file was unexpectedly encountered" if a SHT_NOBITS sh_offset is larger than the file size
llvm-objdump -D this file:
int a[100000];
int main() { return 0; }
Will produce an error: "The end of the file was unexpectedly encountered".
This happens because of a check in Binary.h checkOffset. (Addr + Size > M.getBufferEnd()).
The sh_offset and sh_size fields can be ignored for SHT_NOBITS sections.
Fix the error by changing ELFObjectFile<ELFT>::getSectionContents to use
the file base for SHT_NOBITS sections.
Reviewed By: grimar, MaskRay
Differential Revision: https://reviews.llvm.org/D69192
| -rw-r--r-- | llvm/include/llvm/Object/ELFObjectFile.h | 2 | ||||
| -rw-r--r-- | llvm/test/tools/llvm-objdump/X86/elf-disassemble-bss.test | 37 |
2 files changed, 39 insertions, 0 deletions
diff --git a/llvm/include/llvm/Object/ELFObjectFile.h b/llvm/include/llvm/Object/ELFObjectFile.h index 424289a9cca..8a68e49477f 100644 --- a/llvm/include/llvm/Object/ELFObjectFile.h +++ b/llvm/include/llvm/Object/ELFObjectFile.h @@ -723,6 +723,8 @@ template <class ELFT> Expected<ArrayRef<uint8_t>> ELFObjectFile<ELFT>::getSectionContents(DataRefImpl Sec) const { const Elf_Shdr *EShdr = getSection(Sec); + if (EShdr->sh_type == ELF::SHT_NOBITS) + return makeArrayRef((const uint8_t *)base(), 0); if (std::error_code EC = checkOffset(getMemoryBufferRef(), (uintptr_t)base() + EShdr->sh_offset, EShdr->sh_size)) diff --git a/llvm/test/tools/llvm-objdump/X86/elf-disassemble-bss.test b/llvm/test/tools/llvm-objdump/X86/elf-disassemble-bss.test new file mode 100644 index 00000000000..01d3a49c9b5 --- /dev/null +++ b/llvm/test/tools/llvm-objdump/X86/elf-disassemble-bss.test @@ -0,0 +1,37 @@ +## Check that when BSS is larger than the file llvm-objdump doesn't +## assert with an unexpected end of file error. +# RUN: yaml2obj --docnum=1 %s > %t +# RUN: yaml2obj --docnum=2 %s > %t.2 +# RUN: llvm-objdump -D %t | FileCheck %s +# RUN: llvm-objdump -D %t.2 | FileCheck %s + +# CHECK: Disassembly of section .bss: +# CHECK: .bss: +# CHECK-NEXT: ... + +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_EXEC + Machine: EM_X86_64 +Sections: + - Name: .bss + Type: SHT_NOBITS + Flags: [ SHF_WRITE, SHF_ALLOC ] + Size: 0x0000000000001000 +... + +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_EXEC + Machine: EM_X86_64 +Sections: + - Name: .bss + Type: SHT_NOBITS + Flags: [ SHF_WRITE, SHF_ALLOC ] + Size: 0x0000000000001000 + ShOffset: 0x0000000080000000 +... |
