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Date: Sun, 9 Jun 2024 18:29:48 +0300
From: Dan Carpenter <dan.carpenter@linaro.org>
To: oe-kbuild@lists.linux.dev, Fred Griffoul <fgriffo@amazon.co.uk>,
	griffoul@gmail.com
Cc: lkp@intel.com, oe-kbuild-all@lists.linux.dev,
	Fred Griffoul <fgriffo@amazon.co.uk>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Alex Williamson <alex.williamson@redhat.com>,
	Waiman Long <longman@redhat.com>,
	Zefan Li <lizefan.x@bytedance.com>, Tejun Heo <tj@kernel.org>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Mark Rutland <mark.rutland@arm.com>, Marc Zyngier <maz@kernel.org>,
	Oliver Upton <oliver.upton@linux.dev>,
	Mark Brown <broonie@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
	Joey Gouly <joey.gouly@arm.com>,
	Ryan Roberts <ryan.roberts@arm.com>,
	Jeremy Linton <jeremy.linton@arm.com>,
	Jason Gunthorpe <jgg@ziepe.ca>, Yi Liu <yi.l.liu@intel.com>,
	Kevin Tian <kevin.tian@intel.com>,
	Eric Auger <eric.auger@redhat.com>,
	Stefan Hajnoczi <stefanha@redhat.com>,
	Christian Brauner <brauner@kernel.org>,
	Ankit Agrawal <ankita@nvidia.com>,
	Reinette Chatre <reinette.chatre@intel.com>,
	Ye Bin <yebin10@huawei.com>, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	cgroups@vger.kernel.org
Subject: Re: [PATCH v4 2/2] vfio/pci: add msi interrupt affinity support
Message-ID: <714268da-d199-4371-8360-500e7165119c@moroto.mountain>
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In-Reply-To: <20240607190955.15376-3-fgriffo@amazon.co.uk>

Hi Fred,

kernel test robot noticed the following build warnings:

url:    https://github.com/intel-lab-lkp/linux/commits/Fred-Griffoul/cgroup-cpuset-export-cpuset_cpus_allowed/20240608-031332
base:   cbb325e77fbe62a06184175aa98c9eb98736c3e8
patch link:    https://lore.kernel.org/r/20240607190955.15376-3-fgriffo%40amazon.co.uk
patch subject: [PATCH v4 2/2] vfio/pci: add msi interrupt affinity support
config: mips-randconfig-r081-20240609 (https://download.01.org/0day-ci/archive/20240609/202406092245.Hgx6MqK9-lkp@intel.com/config)
compiler: mips-linux-gcc (GCC) 13.2.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202406092245.Hgx6MqK9-lkp@intel.com/

New smatch warnings:
drivers/vfio/pci/vfio_pci_core.c:1241 vfio_pci_ioctl_set_irqs() warn: maybe return -EFAULT instead of the bytes remaining?

vim +1241 drivers/vfio/pci/vfio_pci_core.c

2ecf3b58ed7bc5 drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1190  static int vfio_pci_ioctl_set_irqs(struct vfio_pci_core_device *vdev,
663eab456e072b drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1191  				   struct vfio_irq_set __user *arg)
2ecf3b58ed7bc5 drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1192  {
2ecf3b58ed7bc5 drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1193  	unsigned long minsz = offsetofend(struct vfio_irq_set, count);
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1194  	struct vfio_irq_set hdr;
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1195  	cpumask_var_t mask;
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1196  	u8 *data = NULL;
05692d7005a364 drivers/vfio/pci/vfio_pci.c      Vlad Tsyrklevich 2016-10-12  1197  	int max, ret = 0;
ef198aaa169c61 drivers/vfio/pci/vfio_pci.c      Kirti Wankhede   2016-11-17  1198  	size_t data_size = 0;
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1199  
663eab456e072b drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1200  	if (copy_from_user(&hdr, arg, minsz))
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1201  		return -EFAULT;
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1202  
05692d7005a364 drivers/vfio/pci/vfio_pci.c      Vlad Tsyrklevich 2016-10-12  1203  	max = vfio_pci_get_irq_count(vdev, hdr.index);
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1204  
ea3fc04d4fad2d drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1205  	ret = vfio_set_irqs_validate_and_prepare(&hdr, max, VFIO_PCI_NUM_IRQS,
ea3fc04d4fad2d drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1206  						 &data_size);
ef198aaa169c61 drivers/vfio/pci/vfio_pci.c      Kirti Wankhede   2016-11-17  1207  	if (ret)
ef198aaa169c61 drivers/vfio/pci/vfio_pci.c      Kirti Wankhede   2016-11-17  1208  		return ret;
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1209  
ef198aaa169c61 drivers/vfio/pci/vfio_pci.c      Kirti Wankhede   2016-11-17  1210  	if (data_size) {
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1211  		if (hdr.flags & VFIO_IRQ_SET_DATA_AFFINITY) {
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1212  			if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1213  				return -ENOMEM;
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1214  
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1215  			ret = copy_from_user(mask, &arg->data, data_size);

copy_from_user() returns the number of bytes remaining to be copied.
This should be:

	if (copy_from_user(mask, &arg->data, data_size)) {
		ret = -EFAULT;
		goto out;
	}

66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1216  			if (ret)
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1217  				goto out;
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1218  
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1219  			data = (u8 *)mask;
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1220  
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1221  		} else {
663eab456e072b drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1222  			data = memdup_user(&arg->data, data_size);
3a1f7041ddd59e drivers/vfio/pci/vfio_pci.c      Fengguang Wu     2012-12-07  1223  			if (IS_ERR(data))
3a1f7041ddd59e drivers/vfio/pci/vfio_pci.c      Fengguang Wu     2012-12-07  1224  				return PTR_ERR(data);
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1225  		}
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1226  	}
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1227  
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1228  	mutex_lock(&vdev->igate);
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1229  
ea3fc04d4fad2d drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1230  	ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index, hdr.start,
ea3fc04d4fad2d drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1231  				      hdr.count, data);
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1232  
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1233  	mutex_unlock(&vdev->igate);
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1234  
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1235  out:
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1236  	if (hdr.flags & VFIO_IRQ_SET_DATA_AFFINITY && data_size)
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1237  		free_cpumask_var(mask);
66c926fb7b2507 drivers/vfio/pci/vfio_pci_core.c Fred Griffoul    2024-06-07  1238  	else
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1239  		kfree(data);
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31  1240  
89e1f7d4c66d85 drivers/vfio/pci/vfio_pci.c      Alex Williamson  2012-07-31 @1241  	return ret;
2ecf3b58ed7bc5 drivers/vfio/pci/vfio_pci_core.c Jason Gunthorpe  2022-08-31  1242  }

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki