Re: The disappearing sys_call_table export.

Terje Eggestad
2003-05-08T09:46:11Z

I guess something like this:

typedef int (*syscall_hook_t)(void * arg1, void * arg2, void * arg3,
void * arg4, void * arg5, void * arg6);

#define HOOK_IN_FLAG 0x1
#define HOOK_OUT_FLAG 0x2

opaquehandle = int register_syscall_hook(int syscall_nr, syscall_hook_t
hook_function, int flags);
int unregister(int opaquehandle);

I'd make a stab at it if I knew that it stood a chance of getting
accepted.

TJ

On Wed, 2003-05-07 at 21:04, Chuck Ebbert wrote:
> >> Preloading libraries, ptracing init, patching g/libc, etc. are
> >> obviously not the way to go.
> >
> > those obviously need to be implemented via the security subsystem (eg
> > LSM). Hooks are obviously the wrong level to do things and I could even
> > tell you that you cannot implement this right from a module actually.
>
> What is really needed is some kind of proper generic hooking setup
> that could be used both by LSM and other things. People doing this
> may need to intercept syscalls both on their way to the kernel and
> on the way back to userland (so they can see return codes.) They may
> also need to say whether they want to be first or last if there are
> multiple users of this facility.
>
> But the real question is why the export of sys_call_table was so
> gratuitously removed without any kind of replacement being offered.
> And the attitude of the developers about it is truly awful. ("Oh, so
> we broke the drivers you depend on for your livelihood? You can just
> go get a new job -- pounding sand down a rathole.")
>
>
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Terje Eggestad mailto:terje.eggestad@scali.no
Scali Scalable Linux Systems http://www.scali.com

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