Le 09/03/2022 à 04:24, Michael Ellerman a écrit :
> Hangyu Hua <hbh...@gmail.com> writes:
>> mpc8xx_pic_init() should return -ENOMEM instead of 0 when
>> irq_domain_add_linear() return NULL. This cause mpc8xx_pics_init to continue
>> executing even if mpc8xx_pic_host is NULL.
>>
>> Fixes: cc76404feaed ("powerpc/8xx: Fix possible device node reference leak")
>> Signed-off-by: Hangyu Hua <hbh...@gmail.com>
>> ---
>> arch/powerpc/platforms/8xx/pic.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/powerpc/platforms/8xx/pic.c
>> b/arch/powerpc/platforms/8xx/pic.c
>> index f2ba837249d6..04a6abf14c29 100644
>> --- a/arch/powerpc/platforms/8xx/pic.c
>> +++ b/arch/powerpc/platforms/8xx/pic.c
>> @@ -153,6 +153,7 @@ int __init mpc8xx_pic_init(void)
>
> Expanding the context:
>
> siu_reg = ioremap(res.start, resource_size(&res));
> if (siu_reg == NULL) {
> ret = -EINVAL;
> goto out;
> }
>
> mpc8xx_pic_host = irq_domain_add_linear(np, 64, &mpc8xx_pic_host_ops,
> NULL);
>> if (mpc8xx_pic_host == NULL) {
>> printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
>> ret = -ENOMEM;
>> + goto out;
>> }
>>
>> ret = 0;
>>
> out:
> of_node_put(np);
> return ret;
> }
>
> Proper error cleanup should also undo the ioremap() if
> irq_domain_add_linear() fails.
Uh ...
If siu_reg is NULL, you get a serious problem when __do_irq() calls
mpc8xx_get_irq()
unsigned int mpc8xx_get_irq(void)
{
int irq;
/* For MPC8xx, read the SIVEC register and shift the bits down
* to get the irq number.
*/
irq = in_be32(&siu_reg->sc_sivec) >> 26;
if (irq == PIC_VEC_SPURRIOUS)
return 0;
return irq_linear_revmap(mpc8xx_pic_host, irq);
}
So I'll leave siu_reg as is even if irq_domain_add_linear() fails.
Whatever, if we do something about that it should be done in another
patch I think.
Christophe
