On Thu, Aug 08, 2002 at 05:16:52PM +0900, ?????? wrote:
> I am trying to use tasklet_schedule() function.
> CODE 1 works OK.
> but calling tasklet_schedule() via some_bad_function() - like CODE 2
> - results in a system hang with [error messages].
>
> Can anyone tell me why?
> Please help.
> Thanks.
>
> code 1>
>
> void my_tasklet_func(unsigned long data)
> {
> printk("tasklet working...\n");
> }
>
> static int __init init_module_()
> {
> DECLARE_TASKLET(my_tasklet, my_tasklet_func, 0);
> tasklet_schedule(&my_tasklet);
> }
>
> code 2>
>
> void some_bad_function() {
> DECLARE_TASKLET(my_tasklet, my_tasklet_func, 0);
> tasklet_schedule(&my_tasklet);
> }
>
> static int __init init_module_()
> {
> some_bad_function();
> }
>
> [error messages]
First, you should run the trace you got through ksymoops. It will assign
function names to the addresses, so what happened can be seen in the
source.
Second, the tasklet_struct structure is not copied in tasklet_schedule.
So it must still exist when the tasklet runs. Thus it can't be an
automatic variable (which is bug in both pieces of code).
> Unhandled kernel unaligned access in unaligned.c:emulate_load_store_insn,
> line 3
> 72:
> $0 : 00000000 30008401 00000000 00000008
> $4 : ffffffea 80315598 811170c0 8111aac0
> $8 : 00000008 0000000f 00000000 c000008c
> $12: c00002a4 c0000060 00000005 c0000060
> $16: ffffffea 802e6080 00000007 8031559c
> $20: 80315590 00000000 00000000 00000000
> $24: 00000000 2aba4820
> $28: 83b40000 83b41ee8 10001db0 80120b38
> epc : 80120c94
> Status: 30008403
> Cause : 00800010
> Process insmod (pid: 46, stackpage=83b40000)
> Stack: 00000000 00000000 00000000 00000000 00000001 802e60d8 80120b38
> 0080000c
> 10009408 10007e40 100098a0 00000000 10009408 10007e40 100098a0
> 00000000
> 00000310 8010da3c 100198d0 00000fff 10017f10 00000000 100087a0
> 00000000
> 00000000 fefefeff 00000000 ffffffff 10001db0 100098a0 00000000
> 00000000
> 00000000 10009798 2ac44e74 00000045 00000008 2ac44e7c 00000005
> c0000060
> 10009408 ...
> Call Trace: [<80120b38>] [<8010da3c>] [<c0000060>]
> Code: 00408821 02002021 8c820008 <1440000c> 8e100000 c0820004 2401fffe
> 0041
> 1024 e0820004
-------------------------------------------------------------------------------
Jan 'Bulb' Hudec <bulb@ucw.cz>
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