xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in xen_pcibk_config_quirks_init
authorJia-Ju Bai <baijiaju1990@gmail.com>
Mon, 9 Apr 2018 15:04:25 +0000 (23:04 +0800)
committerBoris Ostrovsky <boris.ostrovsky@oracle.com>
Mon, 16 Apr 2018 14:20:31 +0000 (10:20 -0400)
xen_pcibk_config_quirks_init() is never called in atomic context.

The call chains ending up at xen_pcibk_config_quirks_init() are:
[1] xen_pcibk_config_quirks_init() <- xen_pcibk_config_init_dev() <-
pcistub_init_device() <- pcistub_seize() <- pcistub_probe()
[2] xen_pcibk_config_quirks_init() <- xen_pcibk_config_init_dev() <-
pcistub_init_device() <- pcistub_init_devices_late() <-
xen_pcibk_init()
pcistub_probe() is only set as ".probe" in struct pci_driver.
xen_pcibk_init() is is only set as a parameter of module_init().
These functions are not called in atomic context.

Despite never getting called from atomic context,
xen_pcibk_config_quirks_init() calls kzalloc() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
drivers/xen/xen-pciback/conf_space_quirks.c

index 89d9744..ed593d1 100644 (file)
@@ -95,7 +95,7 @@ int xen_pcibk_config_quirks_init(struct pci_dev *dev)
        struct xen_pcibk_config_quirk *quirk;
        int ret = 0;
 
-       quirk = kzalloc(sizeof(*quirk), GFP_ATOMIC);
+       quirk = kzalloc(sizeof(*quirk), GFP_KERNEL);
        if (!quirk) {
                ret = -ENOMEM;
                goto out;