000909
r1  : a000000100fbbff0 r2  : 0000000000010002 r3  : 0000000000010001
r8  : fffffffffffbffff r9  : a000000100bd8060 r10 : a000000100dd83b8
r11 : fffffffffffeffff r12 : a000000100bcbbb0 r13 : a000000100bc4000
r14 : 0000000000010000 r15 : 0000000000010000 r16 : a000000100c01aa8
r17 : a000000100d2c350 r18 : 0000000000000000 r19 : a000000100d2c300
r20 : a000000100c01a88 r21 : 0000000080010100 r22 : a000000100c01ac0
r23 : a0000001000108e0 r24 : e000000477980004 r25 : 0000000000000000
r26 : 0000000000000000 r27 : e00000000913400c r28 : e0000004799ee51c
r29 : e0000004778b87f0 r30 : a000000100d2c300 r31 : a00000010005c7e0

Call Trace:
 [<a000000100014600>] show_stack+0x40/0xa0
                                sp=a000000100bcb760 bsp=a000000100bc4f40
 [<a000000100014f00>] show_regs+0x840/0x880
                                sp=a000000100bcb930 bsp=a000000100bc4ee8
 [<a000000100037fb0>] die+0x250/0x320
                                sp=a000000100bcb930 bsp=a000000100bc4ea0
 [<a00000010005e5f0>] ia64_do_page_fault+0x8d0/0xa20
                                sp=a000000100bcb950 bsp=a000000100bc4e50
 [<a00000010000caa0>] ia64_leave_kernel+0x0/0x290
                                sp=a000000100bcb9e0 bsp=a000000100bc4e50
 [<a0000001000e1410>] __do_IRQ+0x370/0x3e0
                                sp=a000000100bcbbb0 bsp=a000000100bc4df0
 [<a000000100011f50>] ia64_handle_irq+0x170/0x220
                                sp=a000000100bcbbb0 bsp=a000000100bc4dc0
 [<a00000010000caa0>] ia64_leave_kernel+0x0/0x290
                                sp=a000000100bcbbb0 bsp=a000000100bc4dc0
 [<a000000100012390>] ia64_pal_call_static+0x90/0xc0
                                sp=a000000100bcbd80 bsp=a000000100bc4d78
 [<a000000100015630>] default_idle+0x90/0x160
                                sp=a000000100bcbd80 bsp=a000000100bc4d58
 [<a000000100014290>] cpu_idle+0x1f0/0x440
                                sp=a000000100bcbe20 bsp=a000000100bc4d18
 [<a000000100009980>] rest_init+0xc0/0xe0
                                sp=a000000100bcbe20 bsp=a000000100bc4d00
 [<a0000001009f8ea0>] start_kernel+0x6a0/0x6c0
                                sp=a000000100bcbe20 bsp=a000000100bc4ca0
 [<a0000001000089f0>] __end_ivt_text+0x6d0/0x6f0
                                sp=a000000100bcbe30 bsp=a000000100bc4c00
 <0>Kernel panic - not syncing: Aiee, killing interrupt handler!

The root cause is that some irq_chip variables, especially ia64_msi_chip,
initiate their memeber end to point to NULL. __do_IRQ doesn't check
if irq_chip->end is null and just calls it after processing the interrupt.

As irq_chip->end is called at many places, so I fix it by reinitiating
irq_chip->end to dummy_irq_chip.end, e.g., a noop function.

Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>