int do_page_fault(unsigned long addr, int error_code, struct pt_regs *regs)
{
struct task_struct *tsk;
struct mm_struct *mm;
int fault;
#if defined(CONFIG_KGDB)
if (kgdb_fault_expected)
kgdb_handle_bus_error();
#endif
tsk = current;
mm = tsk->mm;
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
if (in_interrupt() || !mm)
goto no_context;
TRACE_TRAP_ENTRY(14, instruction_pointer(regs));
down_read(&mm->mmap_sem);
fault = __do_page_fault(mm, addr, error_code, tsk);
up_read(&mm->mmap_sem);
TRACE_EVENT(TRACE_EV_TRAP_EXIT, NULL);
/*
* Handle the "normal" case first
*/
if (fault > 0)
return 0;
/*
* We had some memory, but were unable to
* successfully fix up this page fault.
*/
if (fault == 0)
goto do_sigbus;
/*
* If we are in kernel mode at this point, we
* have no context to handle this fault with.
*/
if (!user_mode(regs))
goto no_context;
if (fault == -3) {
/*
* We ran out of memory, or some other thing happened to
* us that made us unable to handle the page fault gracefully.
*/
printk("VM: killing process %s\n", tsk->comm);
do_exit(SIGKILL);
} else
__do_user_fault(tsk, addr, error_code, fault == -1 ?
SEGV_ACCERR : SEGV_MAPERR, regs);
return 0;
/*
* We ran out of memory, or some other thing happened to us that made
* us unable to handle the page fault gracefully.
*/
do_sigbus:
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
tsk->thread.address = addr;
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 14;
force_sig(SIGBUS, tsk);
#ifdef CONFIG_DEBUG_USER
printk(KERN_DEBUG "%s: sigbus at 0x%08lx, pc=0x%08lx\n",
current->comm, addr, instruction_pointer(regs));
#endif
/* Kernel mode? Handle exceptions or die */
if (user_mode(regs))
return 0;
no_context:
__do_kernel_fault(mm, addr, error_code, regs);
return 0;
}
/*
* s390_do_machine_check
*
* mchine check pre-processor, collecting the machine check info,
* queueing it and posting the machine check handler for processing.
*/
void s390_do_machine_check( void )
{
int crw_count;
mcic_t mcic;
trapid_t ltt_interruption_code;
uint32_t ltt_old_psw;
#ifdef S390_MACHCHK_DEBUG
printk( KERN_INFO "s390_do_machine_check : starting ...\n");
#endif
memcpy( &mcic,
&S390_lowcore.mcck_interruption_code,
sizeof(__u64));
memcpy( <t_interruption_code,
&S390_lowcore.mcck_interruption_code,
sizeof(__u64));
memcpy( <t_old_psw,
&S390_lowcore.mcck_old_psw,
sizeof(uint32_t));
ltt_old_psw &= PSW_ADDR_MASK;
TRACE_TRAP_ENTRY(ltt_interruption_code,ltt_old_psw);
if (mcic.mcc.mcd.sd) /* system damage */
s390_handle_damage("received system damage machine check\n");
if (mcic.mcc.mcd.pd) /* instruction processing damage */
s390_handle_damage("received instruction processing damage machine check\n");
if (mcic.mcc.mcd.se) /* storage error uncorrected */
s390_handle_damage("received storage error uncorrected machine check\n");
if (mcic.mcc.mcd.sc) /* storage error corrected */
printk(KERN_WARNING "received storage error corrected machine check\n");
if (mcic.mcc.mcd.ke) /* storage key-error uncorrected */
s390_handle_damage("received storage key-error uncorrected machine check\n");
if (mcic.mcc.mcd.ds && mcic.mcc.mcd.fa) /* storage degradation */
s390_handle_damage("received storage degradation machine check\n");
if ( mcic.mcc.mcd.cp ) // CRW pending ?
{
crw_count = s390_collect_crw_info();
if ( crw_count )
{
up( &s_sem );
} /* endif */
} /* endif */
#ifdef CONFIG_MACHCHK_WARNING
/*
* The warning may remain for a prolonged period on the bare iron.
* (actually till the machine is powered off, or until the problem is gone)
* So we just stop listening for the WARNING MCH and prevent continuously
* being interrupted. One caveat is however, that we must do this per
* processor and cannot use the smp version of ctl_clear_bit().
* On VM we only get one interrupt per virtally presented machinecheck.
* Though one suffices, we may get one interrupt per (virtual) processor.
*/
if ( mcic.mcc.mcd.w ) // WARNING pending ?
{
// Use single machine clear, as we cannot handle smp right now
__ctl_clear_bit( 14, 24 ); // Disable WARNING MCH
if ( ! mchchk_wng_posted )
{
mchchk_wng_posted = s390_post_warning();
if ( mchchk_wng_posted )
{
up( &s_sem );
} /* endif */
} /* endif */
} /* endif */
#endif
#ifdef S390_MACHCHK_DEBUG
printk( KERN_INFO "s390_do_machine_check : done \n");
#endif
return;
}
