Messages in this thread Patch in this message |  | | From | Jia-Ju Bai <> | Subject | [PATCH 2/4] xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in pcistub_init_device | Date | Mon, 9 Apr 2018 23:03:53 +0800 |
| |
pcistub_init_device() is never called in atomic context.
The call chain ending up at pcistub_init_device() is: [1] pcistub_init_device() <- pcistub_seize() <- pcistub_probe() [2] 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, pcistub_init_device() 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.
This is found by a static analysis tool named DCNS written by myself. And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/xen/xen-pciback/pci_stub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c index 9e480fd..bf8c0d3 100644 --- a/drivers/xen/xen-pciback/pci_stub.c +++ b/drivers/xen/xen-pciback/pci_stub.c @@ -364,7 +364,7 @@ static int pcistub_init_device(struct pci_dev *dev) * here and then to call kfree(pci_get_drvdata(psdev->dev)). */ dev_data = kzalloc(sizeof(*dev_data) + strlen(DRV_NAME "[]") - + strlen(pci_name(dev)) + 1, GFP_ATOMIC); + + strlen(pci_name(dev)) + 1, GFP_KERNEL); if (!dev_data) { err = -ENOMEM; goto out; -- 1.9.1
|  |