Re: Syscall table AKA hijacking syscalls
From: Libor Vanek
Date: Fri Jan 02 2004 - 18:48:32 EST
I'm writing some project which needs to hijack some syscalls in VFS
layer. AFAIK in 2.6 is this "not-wanted" solution (even that there are
some very nasty ways of doing it - see
http://mail.nl.linux.org/kernelnewbies/2002-12/msg00266.html )
And it will fail miserably on many non x86 architectures for
various reasons:
1. ppc64 and ia64 use function descriptors
2. sparc64 uses a 32bit call out table
In short its not only an awful hack, its horribly non portable :)
But in short you always get some syscall from userspace and have some table with function vectors assigned to each syscall, don't you?
So you can have something like "append_this_function_before_syscall_sys_open" and "append_this_function_after_syscall_sys_open" which would be platform independent but will have platform dependent implementation.
--
Libor Vanek
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/