From: Yang Yingliang yangyingliang@huawei.com
[ Upstream commit 27158c72678b39ee01cc01de1aba6b51c71abe2f ]
get_function_0() calls pci_get_domain_bus_and_slot(), as comment says, it returns a pci device with refcount increment, so after using it, pci_dev_put() needs be called.
Get the device reference when get_function_0() is not called, so pci_dev_put() can be called in the error path and callers unconditionally. And add comment above get_dvsec_vendor0() to tell callers to call pci_dev_put().
Fixes: 87db7579ebd5 ("ocxl: control via sysfs whether the FPGA is reloaded on a link reset") Suggested-by: Andrew Donnellan ajd@linux.ibm.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com Acked-by: Andrew Donnellan ajd@linux.ibm.com Link: https://lore.kernel.org/r/20221121154339.4088935-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/misc/ocxl/config.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c index 4d490b92d951..3ced98b506f4 100644 --- a/drivers/misc/ocxl/config.c +++ b/drivers/misc/ocxl/config.c @@ -204,6 +204,18 @@ static int read_dvsec_vendor(struct pci_dev *dev) return 0; }
+/** + * get_dvsec_vendor0() - Find a related PCI device (function 0) + * @dev: PCI device to match + * @dev0: The PCI device (function 0) found + * @out_pos: The position of PCI device (function 0) + * + * Returns 0 on success, negative on failure. + * + * NOTE: If it's successful, the reference of dev0 is increased, + * so after using it, the callers must call pci_dev_put() to give + * up the reference. + */ static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0, int *out_pos) { @@ -213,10 +225,14 @@ static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0, dev = get_function_0(dev); if (!dev) return -1; + } else { + dev = pci_dev_get(dev); } pos = find_dvsec(dev, OCXL_DVSEC_VENDOR_ID); - if (!pos) + if (!pos) { + pci_dev_put(dev); return -1; + } *dev0 = dev; *out_pos = pos; return 0; @@ -233,6 +249,7 @@ int ocxl_config_get_reset_reload(struct pci_dev *dev, int *val)
pci_read_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD, &reset_reload); + pci_dev_put(dev0); *val = !!(reset_reload & BIT(0)); return 0; } @@ -254,6 +271,7 @@ int ocxl_config_set_reset_reload(struct pci_dev *dev, int val) reset_reload &= ~BIT(0); pci_write_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD, reset_reload); + pci_dev_put(dev0); return 0; }