[tglx-devel:msi 100/101] drivers/pci/msi/msi.c:1050 pci_msix_expand_vectors_at() warn: variable dereferenced before check 'dev' (see line 1046)

[tglx-devel:msi 100/101] drivers/pci/msi/msi.c:1050 pci_msix_expand_vectors_at() warn: variable dereferenced before check 'dev' (see line 1046)

[kernel test robot]

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CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Thomas Gleixner <tglx@linutronix.de>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git msi
head:   1fd2d0e8970556f4495ebc122b6e7f249393022e
commit: 4044aa7eefffadc52424d908337708eaa82cf84c [100/101] PCI/MSI: Provide pci_msix_expand_vectors[_at]()
:::::: branch date: 13 hours ago
:::::: commit date: 13 hours ago
config: x86_64-randconfig-m001-20211128 (https://download.01.org/0day-ci/archive/20211130/202111301709.vSHraXYF-lkp(a)intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

New smatch warnings:
drivers/pci/msi/msi.c:1050 pci_msix_expand_vectors_at() warn: variable dereferenced before check 'dev' (see line 1046)

Old smatch warnings:
drivers/pci/msi/msi.c:517 msix_setup_msi_descs() error: uninitialized symbol 'ret'.

vim +/dev +1050 drivers/pci/msi/msi.c

aff171641d181e drivers/pci/msi.c     Christoph Hellwig 2016-07-12  1030  
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1031  /**
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1032   * pci_msix_expand_vectors_at - Expand MSI-X interrupts for a device
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1033   *
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1034   * @dev:	PCI device to operate on
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1035   * @at:		Allocate at MSI-X index.
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1036   * @nvec:	Number of vectors to allocate
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1037   *
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1038   * Expand the MSI-X vectors of a device after an initial enablement and
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1039   * allocation.
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1040   *
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1041   * Return: 0 if the allocation was successful, an error code otherwise.
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1042   */
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1043  int pci_msix_expand_vectors_at(struct pci_dev *dev, unsigned int at, unsigned int nvec)
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1044  {
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1045  	struct msi_range range = MSI_RANGE_LINEAR(at, nvec);
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22 @1046  	struct msi_device_data *md = dev->dev.msi.data;
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1047  	unsigned int max_vecs;
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1048  	int ret;
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1049  
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22 @1050  	if (!pci_msi_enable || !dev || !dev->msix_enabled || !md)
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1051  		return -ENOTSUPP;
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1052  
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1053  	if (!pci_msi_domain_supports_expand(dev))
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1054  		return -ENOTSUPP;
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1055  
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1056  	max_vecs = pci_msix_vec_count(dev);
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1057  	if (!nvec || nvec > max_vecs)
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1058  		return -EINVAL;
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1059  
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1060  	if (at >= max_vecs || nvec > max_vecs - at)
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1061  		return -ENOSPC;
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1062  
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1063  	ret = msix_setup_interrupts(dev, dev->msix_base, &range, NULL, NULL, true);
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1064  	return ret <= 0 ? ret : -ENOSPC;
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1065  }
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1066  EXPORT_SYMBOL_GPL(pci_msix_expand_vectors_at);
4044aa7eefffad drivers/pci/msi/msi.c Thomas Gleixner   2021-11-22  1067  

---
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