1

Let's take an example of a 64 bits elf executable disassembled with pdf command in radare2:

...
0x00400ac0      0f859c000000   jne 0x400b62
...
0x00400b62      90             nop
...

I want to put a label on 0x00400b62 line. It is called a "flag" in radare2. So i type:

xxxxxx> f mylabel @ 0x00400b62

This is great because i can see my flag when i disassemble again with pdf:

;-- mylabel:
0x00400b62      90       nop

But i still see 0x400b62 in jump instructions:

0x00400ac0      0f859c000000   jne 0x400b62

I would like to see:

0x00400ac0      0f859c000000   jne mylabel

How can i do that ?

Thanks a lot

3

You should use a flag name which is separated by a dot. This is intended since registers and other stuff are also flags and to avoid overriding and confusion.

For example, instead of this:

[0x140008f9c]> f mylabel @ 0x140008fde
[0x140008f9c]> pdf
...
|           0x140008fd5      85c0           test eax, eax
|       ,=< 0x140008fd7      7505           jne 0x140008fde
|       |   0x140008fd9      66895c2470     mov word [local_70h], bx
|       |   ;-- mylabel:
|       `-> 0x140008fde      3d04010000     cmp eax, 0x104             ; 260
|       ,=< 0x140008fe3      7511           jne 0x140008ff6
...

Name it like this (loc.mylabel):

[0x140008f9c]> fr mylabel loc.mylabel
[0x140008f9c]> pdf
...
|           0x140008fd5      85c0           test eax, eax
|       ,=< 0x140008fd7      7505           jne loc.mylabel
|       |   0x140008fd9      66895c2470     mov word [local_70h], bx
|       |   ;-- loc.mylabel:
|       `-> 0x140008fde      3d04010000     cmp eax, 0x104             ; 260
|       ,=< 0x140008fe3      7511           jne 0x140008ff6
...

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