Segmentation Fault on jmp instruction

Question

For a project, I write a compiler for a specific langage. I have to handle exceptions. My problem is in the assembly code. I get a segmentation fault on a jmpq instruction and I don't understand why.

This is an extract of the code :

    jmpq *.finally_27
    [...]
.finally_27:
    [...]

ddd pointed me that it is the line jmp that causes a segmentation fault, but I don't understand why. Why a jmpq instruction can fail ?

The full code is here : http://pastebin.com/E2AbW158

The error is at the line 311.

Answer 1

When you use JMP with a label, you shoudn't include the '*', because otherwise, you are telling: "jump to the address location stored in the quadword beginning at memory address finally_27 "

And you want: "jump to the address location whose value is finally_27 " so it is:

JMP .finally_27

Not

JMPQ *.finally_27