Messages in this thread | | | Subject | Re: Size of pointers in sys_call_table? | From | Andi Kleen <> | Date | 28 Aug 2001 18:54:06 +0200 |
| |
Alan Cox <alan@lxorguk.ukuu.org.uk> writes:
> > The layout of the sys_call_table is totally architecture dependant. The > > question to ask here is why do you need to use it? Modifying it to hook > > into syscalls is frowned upon. > > And potentially unsafe (think about caching, and non atomic writes on > some platforms)
It is ATM impossible to make a module that patches sys_call_table safe against module unload races. The only way is to put a stub into the main kernel that manages the module counters and calls a separate hook (i.e. as done by nfsd's syscall)
[Introducing quiescent states in module unloading would probably fix that, as it has been discussed for a long time now, but I lost hope that it'll ever get implemented in the main kernel]
Other than that on some weird architectures like IA64 it can get quite complicated to patch the syscall table.
-Andi
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |