I have an iPhone3GS with iOs 4.1.. I need that to be jailbreaked into iOs 5.. I got it from japan and it's already jailbreaked.. Is there any safe ways to jail break my phone without facing any freezing or other problems.
Before we get into any updating or Jailbreaking steps.... open Cydia, at the top of Cydia's home page there will be iOS versions listed. What versions do you have listed?
Oh wow... this iPhone's been Jailbroken for quite a while without any Cydia or Jailbreak updates hasn't it. Do you have a computer available to work on your phone?
See if you can install tweaks from Cydia and install mobileterminal. You can use that or you can use SSH to reinstall Cydia to the most updated version
Download tiny umbrella
run it with your phone connected to your computer
Click advanced and select box that says "request SHSH from cydia"
Now press save SHSH and see what SHSH it is able to save.
That will tell you what firmwares you are able to restore to.
Alternatively you should also be able to go into your cydia, go to the changes tab and press refresh. Cydia should give you updates to itself and other things. Do the updates then reopen cydia and it should list what SHSH you have at the top.