Calling kobject_put() after a failed kobject_init_and_add() seemed
wrong, and it also appears to be missing a kfree(), so I didn't want
to mess it up any further.
ttm_pool_kobj_release will do that, so no need kfree() here.
I will fix this warning today. Thanks.
Thanks
Roger(Hongbo.He)
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Arnd
Bergmann
Sent: Thursday, January 11, 2018 12:18 AM
To: Koenig, Christian <[email protected]>
Cc: kernelci.org bot <[email protected]>; Kernel Build Reports Mailman List
<[email protected]>; Linux Kernel Mailing List
<[email protected]>; Thomas Hellstrom <[email protected]>; Dave
Airlie <[email protected]>; He, Roger <[email protected]>; Maarten Lankhorst
<[email protected]>; Francisco Jerez <[email protected]>;
Viresh Kumar <[email protected]>; Shiraz Hashim
<[email protected]>; Linus Walleij <[email protected]>;
dri-devel <[email protected]>
Subject: Re: next/master build: 198 builds: 1 failed, 197 passed, 1 error, 148
warnings (next-20180110)
On Wed, Jan 10, 2018 at 4:54 PM, Christian König <[email protected]>
wrote:
> Hi Arnd,
>
> Am 10.01.2018 um 16:45 schrieb Arnd Bergmann:
>>>
>>> 14 drivers/gpu/drm/ttm/ttm_page_alloc_dma.c:1186:2: warning:
>>> ignoring return value of 'register_shrinker', declared with
>>> attribute warn_unused_result [-Wunused-result]
>>> 14 drivers/gpu/drm/ttm/ttm_page_alloc.c:485:2: warning: ignoring
>>> return value of 'register_shrinker', declared with attribute
>>> warn_unused_result [-Wunused-result]
>>
>> ttm and kvm are now the last user of register_shrinker that doesn't
>> propagate the return code to its caller, all other callers got fixed
>> in one way or another.
>>
>> I tried to fix this one too, but couldn't come up with a proper way
>> of unwinding both
>> kobject_init_and_add() and ttm_pool_mm_shrink_init():
>>
>> ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
>> &glob->kobj, "pool");
>> if (unlikely(ret != 0)) {
>> kobject_put(&_manager->kobj);
>> _manager = NULL;
>> return ret;
>> }
>>
>> ttm_pool_mm_shrink_init(_manager);
>>
>> Calling kobject_put() after a failed kobject_init_and_add() seemed
>> wrong, and it also appears to be missing a kfree(), so I didn't want
>> to mess it up any further. Added a few people to Cc that touched this
>> file most, maybe one of them can have a look, or they already have a
>> patch waiting to get merged.
>
>
> That isn't urgent, isn't it? So I would say I put it on my TODO list
> and I'm going to take care of it no later than 4.17.
>
> Otherwise Roger or me could take a look tomorrow.
My understanding is that the warning will be in 4.16, so the fix should be as
well, if only to get a clean build again. There were around a dozen such
warnings when the warn_unused_result got added, but the others are all fixed in
linux-next.
This is how the flag got added:
commit 64067c5cbfa24a2202b92e8fda7323610cad3043
Author: Tetsuo Handa <[email protected]>
Date: Fri Jan 5 13:25:45 2018 +1100
mm,vmscan: mark register_shrinker() as __must_check
There are users not checking for register_shrinker() failure. Continuing
with ignoring failure can lead to later oops at unregister_shrinker().
Link:
http://lkml.kernel.org/r/1511265757-15563-1-git-send-email-penguin-ker...@i-love.sakura.ne.jp
Signed-off-by: Tetsuo Handa <[email protected]>
Arnd
_______________________________________________
dri-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/dri-devel
