From: Yuan Can <yuancan@huawei.com>
To: <fancer.lancer@gmail.com>, <jdmason@kudzu.us>,
<dave.jiang@intel.com>, <allenbh@gmail.com>,
<ntb@lists.linux.dev>
Cc: <yuancan@huawei.com>
Subject: [PATCH] ntb: idt: Fix error handling in idt_pci_driver_init()
Date: Sat, 5 Nov 2022 09:43:01 +0000 [thread overview]
Message-ID: <20221105094301.106276-1-yuancan@huawei.com> (raw)
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>
---
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 0ed6f809ff2e..51799fccf840 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);
--
2.17.1
next reply other threads:[~2022-11-05 9:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-05 9:43 Yuan Can [this message]
2023-03-09 12:21 ` [PATCH] ntb: idt: Fix error handling in idt_pci_driver_init() Serge Semin
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