From: Yuan Can yuancan@huawei.com
[ Upstream commit c012968259b451dc4db407f2310fe131eaefd800 ]
A problem about ntb_hw_idt create debugfs failed is triggered with the following log given:
[ 1236.637636] IDT PCI-E Non-Transparent Bridge Driver 2.0 [ 1236.639292] debugfs: Directory 'ntb_hw_idt' with parent '/' already present!
The reason is that idt_pci_driver_init() returns pci_register_driver() directly without checking its return value, if pci_register_driver() failed, it returns without destroy the newly created debugfs, resulting the debugfs of ntb_hw_idt can never be created later.
idt_pci_driver_init() debugfs_create_dir() # create debugfs directory pci_register_driver() driver_register() bus_add_driver() priv = kzalloc(...) # OOM happened # return without destroy debugfs directory
Fix by removing debugfs when pci_register_driver() returns error.
Fixes: bf2a952d31d2 ("NTB: Add IDT 89HPESxNTx PCIe-switches support") Signed-off-by: Yuan Can yuancan@huawei.com Signed-off-by: Jon Mason jdmason@kudzu.us Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ntb/hw/idt/ntb_hw_idt.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/ntb/hw/idt/ntb_hw_idt.c b/drivers/ntb/hw/idt/ntb_hw_idt.c index 733557231ed0b..72060acb9cafc 100644 --- a/drivers/ntb/hw/idt/ntb_hw_idt.c +++ b/drivers/ntb/hw/idt/ntb_hw_idt.c @@ -2891,6 +2891,7 @@ static struct pci_driver idt_pci_driver = {
static int __init idt_pci_driver_init(void) { + int ret; pr_info("%s %s\n", NTB_DESC, NTB_VER);
/* Create the top DebugFS directory if the FS is initialized */ @@ -2898,7 +2899,11 @@ static int __init idt_pci_driver_init(void) dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
/* Register the NTB hardware driver to handle the PCI device */ - return pci_register_driver(&idt_pci_driver); + ret = pci_register_driver(&idt_pci_driver); + if (ret) + debugfs_remove_recursive(dbgfs_topdir); + + return ret; } module_init(idt_pci_driver_init);