forked from Minki/linux
e9c5b0b53c
'device_driver_attach()' dereferences its first argument (i.e. 'alt_drv') so it must not be NULL. Simplify the error handling logic about NULL 'alt_drv' in order to be more robust and future-proof. Fixes:568b212646("dmaengine: idxd: fix uninit var for alt_drv") Fixes:6e7f3ee97b("dmaengine: idxd: move dsa_drv support to compatible mode") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/77f0dc4f3966591d1f0cffb614a94085f8895a85.1627560174.git.christophe.jaillet@wanadoo.fr Signed-off-by: Vinod Koul <vkoul@kernel.org>
108 lines
2.5 KiB
C
108 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright(c) 2021 Intel Corporation. All rights rsvd. */
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/device/bus.h>
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#include "idxd.h"
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extern int device_driver_attach(struct device_driver *drv, struct device *dev);
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extern void device_driver_detach(struct device *dev);
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#define DRIVER_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
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struct driver_attribute driver_attr_##_name = \
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__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
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static ssize_t unbind_store(struct device_driver *drv, const char *buf, size_t count)
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{
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struct bus_type *bus = drv->bus;
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struct device *dev;
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int rc = -ENODEV;
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dev = bus_find_device_by_name(bus, NULL, buf);
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if (dev && dev->driver) {
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device_driver_detach(dev);
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rc = count;
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}
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return rc;
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}
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static DRIVER_ATTR_IGNORE_LOCKDEP(unbind, 0200, NULL, unbind_store);
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static ssize_t bind_store(struct device_driver *drv, const char *buf, size_t count)
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{
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struct bus_type *bus = drv->bus;
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struct device *dev;
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struct device_driver *alt_drv = NULL;
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int rc = -ENODEV;
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struct idxd_dev *idxd_dev;
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dev = bus_find_device_by_name(bus, NULL, buf);
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if (!dev || dev->driver || drv != &dsa_drv.drv)
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return -ENODEV;
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idxd_dev = confdev_to_idxd_dev(dev);
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if (is_idxd_dev(idxd_dev)) {
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alt_drv = driver_find("idxd", bus);
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} else if (is_idxd_wq_dev(idxd_dev)) {
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struct idxd_wq *wq = confdev_to_wq(dev);
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if (is_idxd_wq_kernel(wq))
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alt_drv = driver_find("dmaengine", bus);
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else if (is_idxd_wq_user(wq))
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alt_drv = driver_find("user", bus);
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}
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if (!alt_drv)
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return -ENODEV;
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rc = device_driver_attach(alt_drv, dev);
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if (rc < 0)
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return rc;
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return count;
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}
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static DRIVER_ATTR_IGNORE_LOCKDEP(bind, 0200, NULL, bind_store);
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static struct attribute *dsa_drv_compat_attrs[] = {
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&driver_attr_bind.attr,
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&driver_attr_unbind.attr,
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NULL,
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};
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static const struct attribute_group dsa_drv_compat_attr_group = {
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.attrs = dsa_drv_compat_attrs,
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};
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static const struct attribute_group *dsa_drv_compat_groups[] = {
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&dsa_drv_compat_attr_group,
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NULL,
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};
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static int idxd_dsa_drv_probe(struct idxd_dev *idxd_dev)
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{
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return -ENODEV;
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}
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static void idxd_dsa_drv_remove(struct idxd_dev *idxd_dev)
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{
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}
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static enum idxd_dev_type dev_types[] = {
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IDXD_DEV_NONE,
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};
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struct idxd_device_driver dsa_drv = {
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.name = "dsa",
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.probe = idxd_dsa_drv_probe,
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.remove = idxd_dsa_drv_remove,
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.type = dev_types,
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.drv = {
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.suppress_bind_attrs = true,
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.groups = dsa_drv_compat_groups,
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},
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};
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module_idxd_driver(dsa_drv);
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MODULE_IMPORT_NS(IDXD);
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