[bug] fasm automatic entry address above 4G

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revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 19284
Location: In your JS exploiting you and your system

revolution 20 Apr 2020, 09:47

This code works fine. The entry address is correct at 0x80000078:

Code:

format elf64 executable at 1 shl 31
segment executable
mov eax,60
xor edi,edi
syscall

This code fails. The entry address is only 0x78:

Code:

format elf64 executable at 1 shl 32
segment executable
mov eax,60
xor edi,edi
syscall

We can manually make it work by adding the entry point. Now the entry address is correct at 0x100000078:

Code:

format elf64 executable at 1 shl 32
segment executable
entry $
mov eax,60
xor edi,edi
syscall

20 Apr 2020, 09:47

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8146
Location: Kraków, Poland

Tomasz Grysztar 20 Apr 2020, 11:11

Thank you! A bug is further confirmed by assembling the same source with fasmg, which produces a correct executable.

20 Apr 2020, 11:11

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