On Thu, Nov 26, 2009 at 6:31 AM, Fernand LONE SANG <flone_sa@xxxxxxxxx> wrote: > As a consequence, I override the permissions to access to the sys_call_table entries and made them writable using a lkm. After setting the needed permissions on the page, when I overwrite an entry of the sys_call_table, my system hangs (No kernel oops, my system simply freezes). AFAIK there is no lock that protect modification toward sys_call_table. As the consequence, you might overwrite the system call entry while it was currently referenced. Actually, IMO, even on 2.4, loosely replacing certain or all sys_call_table entries are highly discouraged. The reason is similar...you don't know whether they are currently referenced or not, right? Well, maybe you might get better chance if you do it via atomic assembly instruction (i.e the one that can swap values stored between two memory region), but still, I am not whether it's the answer to your problem. -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
