ranal/x86: Fail to set correct name for thunk functions

[tesuji]

Environment

> date
Wed Jan  8 04:47:36 PM UTC 2025
> r2 -v
radare2 5.9.9 579 @ linux-x86-32
birth: git.5.9.9 2025-01-08__15:32:28
commit: d02b7d5eca489ade222ed67cc0c5679f76e8a56e
options: gpl -O1 cs:5 cl:1 meson
> uname -ms
Linux x86_64

Description

radare2 could infer correct names for thunk functions.

See the attached binary

$ r2 ./binary
> aaa
> s main
> pdf
// redacted ...
│           0x08048855      50             push eax
│           0x08048856      e88dfdffff     call fcn.080485e8
│           0x0804885b      83c410         add esp, 0x10
[0x0804882e]> s 0x80485e8
[0x080485e8]> pd 3
            ; CALL XREFS from main @ 0x8048856(x), 0x804886a(x), 0x804887e(x)
            0x080485e8      ff25f09f0408   jmp dword [reloc.setvbuf]   ; 0x8049ff0
            0x080485ee      6690           nop
            ; CALL XREF from sym.leave @ 0x8048796(x)
            0x080485f0      ff25f49f0408   jmp dword [reloc.memset]    ; 0x8049ff4

But with gdb or objdump, it is displayed as:

 8048856:	call   80485e8 <setvbuf@plt>

Test

bin.zip

[tesuji]

Nice! Thank you for fixing this! I wanted to contribute, however I have no clue about the elf parser.

[trufae]

I was about to suggest a workaround until the fix was ready, but its now fixed in master. If you encounter similar issues in the future i would recommend you to use the afna command which analyzes the function relocs, calls and strings referenced and sets a custom name to it