From: Jason Wang <jasowang@redhat.com>
To: Dan Carpenter <dan.carpenter@oracle.com>,
kbuild@lists.01.org, Zhu Lingshan <lingshan.zhu@intel.com>,
mst@redhat.com, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Cc: lkp@intel.com, kbuild-all@lists.01.org, lulu@redhat.com,
dan.daly@intel.com, cunming.liang@intel.com
Subject: Re: [PATCH] vdpa: bypass waking up vhost_woker for vdpa vq kick
Date: Tue, 2 Jun 2020 19:10:38 +0800 [thread overview]
Message-ID: <c2f3cd6c-6f75-15db-080e-9895a35a0456@redhat.com> (raw)
In-Reply-To: <b8ccbccf-f667-8d15-8de2-b87da5f51ec3@redhat.com>
On 2020/6/2 下午6:16, Jason Wang wrote:
>
> On 2020/6/2 下午5:42, Dan Carpenter wrote:
>> Hi Zhu,
>>
>> url:
>> https://github.com/0day-ci/linux/commits/Zhu-Lingshan/vdpa-bypass-waking-up-vhost_woker-for-vdpa-vq-kick/20200526-133819
>>
>> base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git
>> linux-next
>> config: x86_64-randconfig-m001-20200529 (attached as .config)
>> compiler: gcc-9 (Debian 9.3.0-13) 9.3.0
>>
>> If you fix the issue, kindly add following tag as appropriate
>> Reported-by: kbuild test robot <lkp@intel.com>
>> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>>
>> smatch warnings:
>> drivers/vhost/vdpa.c:348 vhost_vdpa_set_vring_kick() error:
>> uninitialized symbol 'r'.
>>
>> #
>> https://github.com/0day-ci/linux/commit/a84ddbf1ef29f18aafb2bb8a93bcedd4a29a967d
>>
>> git remote add linux-review https://github.com/0day-ci/linux
>> git remote update linux-review
>> git checkout a84ddbf1ef29f18aafb2bb8a93bcedd4a29a967d
>> vim +/r +348 drivers/vhost/vdpa.c
>>
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 316 static long
>> vhost_vdpa_set_vring_kick(struct vhost_virtqueue *vq,
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 317
>> void __user *argp)
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 318 {
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 319 bool pollstart =
>> false, pollstop = false;
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 320 struct file
>> *eventfp, *filep = NULL;
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 321 struct
>> vhost_vring_file f;
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 322 long r;
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 323
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 324 if
>> (copy_from_user(&f, argp, sizeof(f)))
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 325 return -EFAULT;
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 326
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 327 eventfp = f.fd == -1
>> ? NULL : eventfd_fget(f.fd);
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 328 if (IS_ERR(eventfp)) {
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 329 r =
>> PTR_ERR(eventfp);
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 330 return r;
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 331 }
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 332
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 333 if (eventfp !=
>> vq->kick) {
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 334 pollstop =
>> (filep = vq->kick) != NULL;
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 335 pollstart =
>> (vq->kick = eventfp) != NULL;
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 336 } else
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 337 filep = eventfp;
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 338
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 339 if (pollstop &&
>> vq->handle_kick)
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 340 vhost_vdpa_poll_stop(vq);
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 341
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 342 if (filep)
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 343 fput(filep);
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 344
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 345 if (pollstart &&
>> vq->handle_kick)
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 346 r =
>> vhost_vdpa_poll_start(vq);
>>
>> "r" not initialized on else path.
>>
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 347
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 @348 return r;
>> a84ddbf1ef29f1 Zhu Lingshan 2020-05-26 349 }
>
>
> Will fix.
>
> Thanks
Lingshan reminds me that we've posted V2 which reuses the vhost.c
implementation for polling.
So there's no need for the fix.
Thanks
prev parent reply other threads:[~2020-06-02 11:10 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-26 5:32 [PATCH] vdpa: bypass waking up vhost_woker for vdpa vq kick Zhu Lingshan
2020-05-26 22:53 ` kbuild test robot
2020-05-27 9:16 ` [RFC PATCH] vdpa: vhost_vdpa_poll_stop() can be static kbuild test robot
2020-05-28 10:06 ` [PATCH] vdpa: bypass waking up vhost_woker for vdpa vq kick Jason Wang
2020-06-02 9:42 ` Dan Carpenter
2020-06-02 10:16 ` Jason Wang
2020-06-02 11:10 ` Jason Wang [this message]
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