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Hi, I try this : local_irq_save(flags); kvm_hypercall2 ( 6, 2, 2); local_irq_restore(flags); But I still have my kernel panic with "divide error: 0000 [#1] SMP" that I don't understand! with or without lock, nothing change, the same when I change the current state. I tried to move my hypercall and I still don't understand why it works just before my test "if (piga_on == 1)" without any protections (like disable interrupts) and not after.. Thank you for trying to help me > Date: Thu, 9 Jun 2011 09:46:12 +0800 > Subject: Re: Problems with hypercalls > From: htmldeveloper@xxxxxxxxx > To: tricheurs@xxxxxxxxxx > CC: kernelnewbies@xxxxxxxxxxxxxxxxx > > perhaps this example will provide u with more info: > > http://a380.informatik.uni-bremen.de/lxr/source/arch/x86/lguest/boot.c > > I think the correct step is to disable IRQ instead - before every call > to kvm_hypercallX(). The reason is given in the remark: > > 110 /* > 111 * Disable interrupts if not already disabled: we don't want an > 112 * interrupt handler making a hypercall while we're already doing > 113 * one! > 114 */ > > On Wed, Jun 8, 2011 at 10:54 PM, emilie lefebvre <tricheurs@xxxxxxxxxx> wrote: > > > > 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); > > } > > } > > > > > > I think u generally set TASK_UNINTERRUPTIBLE whenever about to modify > the scheduling task list (eg, wait queue manipulation) or about to > call "schedule()" (ie, doing your own scheduling). The function > set_current_state() literally just set the variable value only, it > does not disable interrupt. > > -- > Regards, > Peter Teoh > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies |
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