Christophe Leroy <christophe.le...@csgroup.eu> writes:
> Le 09/03/2022 à 11:46, Michael Ellerman a écrit :
>> Christophe Leroy <christophe.le...@csgroup.eu> writes:
>>> 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()
>>
>> Arguably it shouldn't be assigned to ppc_md.get_irq unless
>> mpc8xx_pic_init() succeeds. See eg. xics_init().
>
> I agree with that, but it's a huge work I guess. Most platforms set
> .get_irq in ppc_md() at buildtime. See the generic mpic_get_irq() which
> has a BUG_ON() in call mpic_primary is NULL. There are 50 platforms with
> buildtime assignment.
Yes I agree. And __do_irq() will just oops if ppc_md.get_irq() is NULL,
so it's a bit of a mess.
> That would however be a good opportunity to switch get_irq() to a static
> call. I'll open a github issue to follow it.
Thanks.
cheers
