PCI: Fix pci_dev_str_match_path() alloc while atomic bug

stable inclusion
from linux-4.19.207
commit 1a091bfd11e61032b6192cf2a1ebb259889f28b3

--------------------------------

[ Upstream commit 7eb6ea41 ]

pci_dev_str_match_path() is often called with a spinlock held so the
allocation has to be atomic.  The call tree is:

  pci_specified_resource_alignment() <-- takes spin_lock();
    pci_dev_str_match()
      pci_dev_str_match_path()

Fixes: 45db3370 ("PCI: Allow specifying devices using a base bus and path of devfns")
Link: https://lore.kernel.org/r/20210812070004.GC31863@kiliSigned-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/pci/pci.c

@@ -224,7 +224,7 @@ static int pci_dev_str_match_path(struct pci_dev *dev, const char *path,
 
 	*endptr = strchrnul(path, ';');
 
-	wpath = kmemdup_nul(path, *endptr - path, GFP_KERNEL);
+	wpath = kmemdup_nul(path, *endptr - path, GFP_ATOMIC);
 	if (!wpath)
 		return -ENOMEM;