CODEWITHSUNDEEP
gccelfdecompiler
TheCharlatan
TheCharlatan

Reputation: 290

Find Source File Function Declaration Location from ELF

Given an ELF file, I run readelf -sV bin/my_app | grep \ glob on it. This returns:

   205: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND glob@GLIBC_2.27 (6)
   326: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND glob@GLIBC_2.17 (2)
   334: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND globfree@GLIBC_2.17 (2)
 21011: 0000000000cd2748     8 OBJECT  LOCAL  DEFAULT   26 global_mask
 21968: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS globals_io.o
 40039: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND glob@@GLIBC_2.27
 46623: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND glob@GLIBC_2.17
 47377: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND globfree@@GLIBC_2.17

With the information in this output, can I find the location in my source files where this glob symbol is invoked? I would like to find the location to understand why two different versions of GLIBC are linked for the same symbol.

Upvotes: 0

Views: 1080

Answers (1)

Employed Russian
Employed Russian

Reputation: 213526

With the information in this output, can I find the location in my source files where this glob symbol is invoked?

No.

You could do: objdump -d bin/my_app, find CALLs to the two versions of glob, and that will tell you what functions the calls are coming from.

I would like to find the location to understand why two different versions of GLIBC are linked for the same symbol.

It's not "two different versions of GLIBC", it's "two different glob symbols with different ABIs".

I didn't think it was possible to reference different versions of glob in the same ELF binary, unless you do some creative symbol aliasing with asm(".symver ...") directives. Once you know which function references the (old) glob@GLIBC_2.17 symbol, run preprocessor on the file in which that function is defined, and I'd be very surprised if there is no asm(".symversion...") in that file.

Upvotes: 1

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