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debug/elf: elf.Symbols() incorrectly returns ErrNoSymbols for valid elf binaries. #50626

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ok-john opened this issue Jan 15, 2022 · 2 comments
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debug/elf: elf.Symbols() incorrectly returns ErrNoSymbols for valid elf binaries. #50626

ok-john opened this issue Jan 15, 2022 · 2 comments
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FrozenDueToAge NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one.

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@ok-john
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ok-john commented Jan 15, 2022 •
edited

What version of Go are you using (go version)?

go1.18-3b5eec9

Does this issue reproduce with the latest release?

Yes.

What operating system and processor architecture are you using (go env)?

linux/amd64

What did you do?

Attempted to view the symbol table of both static & dynamically linked binaries compiled with gcc.

For example, readelf -{s, S} /bin/ls (or even readelf -{s, S} /bin/* on most distributions of linux) shows the symbol table of each elf binary without error.

Attempting to view the symbol table of every binary under /bin/* on a basic linux distro by using elf.Symbols() failed in all cases.

See example script here.

What did you expect to see?

A valid return of []elf.Symbol from elf.Symbols() for at least one elf binary.

What did you see instead?

elf.Symbols() returns ErrNoSymbols (ref)
@seankhliao seankhliao added the NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one. label Jan 16, 2022
@ianlancetaylor
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In many Linux distros programs like /bin/ls have no SHT_SYMTAB section, so the debug/elf Symbols method on such a file will return ErrNoSymbols. The readelf -s output that you mention is the dynamic symbols, the SHT_DYNSYM section (readelf -s displays both the normal symbols and the dynamic symbols). With debug/elf you can fetch that information using the DynamicSymbols method.

@ok-john
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ok-john commented Jan 16, 2022

In many Linux distros programs like /bin/ls have no SHT_SYMTAB section, so the debug/elf Symbols method on such a file will return ErrNoSymbols. The readelf -s output that you mention is the dynamic symbols, the SHT_DYNSYM section (readelf -s displays both the normal symbols and the dynamic symbols). With debug/elf you can fetch that information using the DynamicSymbols method.

Thanks for clarifying.

@golang golang locked and limited conversation to collaborators Jan 16, 2023
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