Commit 27158c72 authored by Yang Yingliang's avatar Yang Yingliang Committed by Greg Kroah-Hartman
Browse files

ocxl: fix pci device refcount leak when calling get_function_0() 



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: 87db7579 ("ocxl: control via sysfs whether the FPGA is reloaded on a link reset")
Suggested-by: default avatarAndrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Acked-by: default avatarAndrew Donnellan <ajd@linux.ibm.com>
Link: https://lore.kernel.org/r/20221121154339.4088935-1-yangyingliang@huawei.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a4cb1004

drivers/misc/ocxl/config.c

+19 −1
Original line number Diff line number Diff line
@@ -193,6 +193,18 @@ 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)

{
@@ -202,10 +214,14 @@ 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;
@@ -222,6 +238,7 @@ 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;

}
@@ -243,6 +260,7 @@ 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;

}