This is my function :
static spinlock_t xgr_learn_lock = SPIN_LOCK_UNLOCKED;
static int piga_seq_cpt = 1;
/*
* Function called for each systemcall (Hook SELinux avc function)
*/
int piga_control(u32 ssid, ...., struct av_decision * avd) {
/*
* Here my hypercall work but block my vm with this error :
* " BUG: scheduling while atomic ... "
*/
spin_lock_bh(&xgr_learn_lock);
if ( in_atomic())
kvm_hypercall2 ( 6, (unsigned long)2 ,(unsigned long)piga_seq_cpt);
spin_unlock_bh(&xgr_learn_lock);
if (piga_on == 1) {
/*
* Here my hypercall make a kernel panic with this error:
* " divide error: 0000 [#1] SMP"
*/
spin_lock_bh(&xgr_learn_lock);
set_current_state(TASK_UNINTERRUPTIBLE);
kvm_hypercall2 ( 6, (unsigned long)2 ,(unsigned long)piga_seq_cpt);
set_current_state(TASK_RUNNING);
spin_lock_bh(&xgr_learn_lock);
}
}
> Date: Wed, 8 Jun 2011 12:50:57 +0200
> From: kernelnewbies@mail.i88.de
> To: kernelnewbies@kernelnewbies.org
> Subject: Re: Calling function from address
> CC: mulyadi.santosa@gmail.com
>
> On Wed, Jun 08, 2011 at 04:52:14PM +0700, Mulyadi Santosa wrote:
> > On Wed, Jun 8, 2011 at 03:47, Micha M. <kernelnewbies@mail.i88.de> wrote:
> > > Hi!
> > >
> > >
> > > Is it possible to call a function that is somewere in the physical-address
> > > space? So I'd like to jump to a certain physical address, execute the code
> > > there and then return to my kernel module.
> > > I already tried to ioremap that address and cast the new address to a
> > > funtion pointer and then call the function, but there where some page
> > > faults.
> >
> > Interesting, and after page fault....the code is still not executed?
> >
> > what code(s) do you call? user mode? kernel mode?
>
> I don't think that the code was executed. There was a kernel Ooops direct
> after the page fault and a register dump was printed. The code I what to
> call is located in ROM and is mapped to the physical address space.
> Is it possible to configure the kernel to ignore certain address areas and
> allow calls to that space?
>
> And that code needs to be executed from that place, since it contains
> pointer in the physical address space. (s oremapping won't work because
> there are absolute jumps in that function I'd like to call)
>
> The only solution I kan think of at the moment is to solve it somehow in
> assembly. But I don't know how...
>
>
> regards,
>
> #micha
>
> --
> /* To err is human; to really fuck things up requires the root password */
>
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