Help/Support GDB Error: illegal instruction 4

Valeschi · February 26, 2015

Hi guys

i have problem whit "gdb" terminal commend, when i type gdb give me this error:

Illegal instruction:4

my device is iPad retina iOS 8.1.2

Updated February 26, 2015 by Valeschi

Rook · February 26, 2015

Are you using the gdb from cydia.radare.org repo?

Valeschi · February 26, 2015

no

mehdiphone · February 26, 2015

I had the same issue, i found the solution: you get the “Illegal instruction: 4″ when trying to run within GDB. This is due to old compiled binaries. You can patch the binary with the below command. You have to install sed and ldid(Link Identity Editor).

sed -i'' 's/\x00\x30\x93\xe4/\x00\x30\x93\xe5/g;s/\x00\x30\xd3\xe4/\x00\x30\xd3\xe5/g;' ios_binary

ldid -s ios_binary

Rook · February 26, 2015

no

Use the one from there.

Valeschi · February 26, 2015

I had the same issue, i found the solution: you get the “Illegal instruction: 4″ when trying to run within GDB. This is due to old compiled binaries. You can patch the binary with the below command. You have to install sed and ldid(Link Identity Editor).

sed -i'' 's/\x00\x30\x93\xe4/\x00\x30\x93\xe5/g;s/\x00\x30\xd3\xe4/\x00\x30\xd3\xe5/g;' ios_binary

ldid -s ios_binary

thanks a lot but how can i attach to process by sed