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-rw-r--r--drivers/base/auxiliary.c10
-rw-r--r--drivers/base/base.h17
-rw-r--r--drivers/base/bus.c2
-rw-r--r--drivers/base/core.c38
-rw-r--r--drivers/base/dd.c7
-rw-r--r--drivers/base/devcoredump.c2
-rw-r--r--drivers/base/devtmpfs.c22
-rw-r--r--drivers/base/memory.c41
-rw-r--r--drivers/base/power/main.c2
-rw-r--r--drivers/base/power/wakeup.c6
-rw-r--r--drivers/base/swnode.c3
11 files changed, 95 insertions, 55 deletions
diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c
index afa4df4c5a3f..95717d509ca9 100644
--- a/drivers/base/auxiliary.c
+++ b/drivers/base/auxiliary.c
@@ -156,6 +156,16 @@
* },
* .ops = my_custom_ops,
* };
+ *
+ * Please note that such custom ops approach is valid, but it is hard to implement
+ * it right without global locks per-device to protect from auxiliary_drv removal
+ * during call to that ops. In addition, this implementation lacks proper module
+ * dependency, which causes to load/unload races between auxiliary parent and devices
+ * modules.
+ *
+ * The most easiest way to provide these ops reliably without needing to
+ * have a lock is to EXPORT_SYMBOL*() them and rely on already existing
+ * modules infrastructure for validity and correct dependencies chains.
*/
static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id,
diff --git a/drivers/base/base.h b/drivers/base/base.h
index 0042e4774b0c..123031a757d9 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -73,6 +73,7 @@ static inline void subsys_put(struct subsys_private *sp)
kset_put(&sp->subsys);
}
+struct subsys_private *bus_to_subsys(const struct bus_type *bus);
struct subsys_private *class_to_subsys(const struct class *class);
struct driver_private {
@@ -180,6 +181,22 @@ int driver_add_groups(const struct device_driver *drv, const struct attribute_gr
void driver_remove_groups(const struct device_driver *drv, const struct attribute_group **groups);
void device_driver_detach(struct device *dev);
+static inline void device_set_driver(struct device *dev, const struct device_driver *drv)
+{
+ /*
+ * Majority (all?) read accesses to dev->driver happens either
+ * while holding device lock or in bus/driver code that is only
+ * invoked when the device is bound to a driver and there is no
+ * concern of the pointer being changed while it is being read.
+ * However when reading device's uevent file we read driver pointer
+ * without taking device lock (so we do not block there for
+ * arbitrary amount of time). We use WRITE_ONCE() here to prevent
+ * tearing so that READ_ONCE() can safely be used in uevent code.
+ */
+ // FIXME - this cast should not be needed "soon"
+ WRITE_ONCE(dev->driver, (struct device_driver *)drv);
+}
+
int devres_release_all(struct device *dev);
void device_block_probing(void);
void device_unblock_probing(void);
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 5ea3b03af9ba..5e75e1bce551 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -57,7 +57,7 @@ static int __must_check bus_rescan_devices_helper(struct device *dev,
* NULL. A call to subsys_put() must be done when finished with the pointer in
* order for it to be properly freed.
*/
-static struct subsys_private *bus_to_subsys(const struct bus_type *bus)
+struct subsys_private *bus_to_subsys(const struct bus_type *bus)
{
struct subsys_private *sp = NULL;
struct kobject *kobj;
diff --git a/drivers/base/core.c b/drivers/base/core.c
index d2f9d3a59d6b..cbc0099d8ef2 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2624,6 +2624,35 @@ static const char *dev_uevent_name(const struct kobject *kobj)
return NULL;
}
+/*
+ * Try filling "DRIVER=<name>" uevent variable for a device. Because this
+ * function may race with binding and unbinding the device from a driver,
+ * we need to be careful. Binding is generally safe, at worst we miss the
+ * fact that the device is already bound to a driver (but the driver
+ * information that is delivered through uevents is best-effort, it may
+ * become obsolete as soon as it is generated anyways). Unbinding is more
+ * risky as driver pointer is transitioning to NULL, so READ_ONCE() should
+ * be used to make sure we are dealing with the same pointer, and to
+ * ensure that driver structure is not going to disappear from under us
+ * we take bus' drivers klist lock. The assumption that only registered
+ * driver can be bound to a device, and to unregister a driver bus code
+ * will take the same lock.
+ */
+static void dev_driver_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+ struct subsys_private *sp = bus_to_subsys(dev->bus);
+
+ if (sp) {
+ scoped_guard(spinlock, &sp->klist_drivers.k_lock) {
+ struct device_driver *drv = READ_ONCE(dev->driver);
+ if (drv)
+ add_uevent_var(env, "DRIVER=%s", drv->name);
+ }
+
+ subsys_put(sp);
+ }
+}
+
static int dev_uevent(const struct kobject *kobj, struct kobj_uevent_env *env)
{
const struct device *dev = kobj_to_dev(kobj);
@@ -2655,8 +2684,8 @@ static int dev_uevent(const struct kobject *kobj, struct kobj_uevent_env *env)
if (dev->type && dev->type->name)
add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
- if (dev->driver)
- add_uevent_var(env, "DRIVER=%s", dev->driver->name);
+ /* Add "DRIVER=%s" variable if the device is bound to a driver */
+ dev_driver_uevent(dev, env);
/* Add common DT information about the device */
of_device_uevent(dev, env);
@@ -2726,11 +2755,8 @@ static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
if (!env)
return -ENOMEM;
- /* Synchronize with really_probe() */
- device_lock(dev);
/* let the kset specific function add its keys */
retval = kset->uevent_ops->uevent(&dev->kobj, env);
- device_unlock(dev);
if (retval)
goto out;
@@ -3700,7 +3726,7 @@ done:
device_pm_remove(dev);
dpm_sysfs_remove(dev);
DPMError:
- dev->driver = NULL;
+ device_set_driver(dev, NULL);
bus_remove_device(dev);
BusError:
device_remove_attrs(dev);
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index f0e4b4aba885..b526e0e0f52d 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -550,7 +550,7 @@ static void device_unbind_cleanup(struct device *dev)
arch_teardown_dma_ops(dev);
kfree(dev->dma_range_map);
dev->dma_range_map = NULL;
- dev->driver = NULL;
+ device_set_driver(dev, NULL);
dev_set_drvdata(dev, NULL);
if (dev->pm_domain && dev->pm_domain->dismiss)
dev->pm_domain->dismiss(dev);
@@ -629,8 +629,7 @@ static int really_probe(struct device *dev, const struct device_driver *drv)
}
re_probe:
- // FIXME - this cast should not be needed "soon"
- dev->driver = (struct device_driver *)drv;
+ device_set_driver(dev, drv);
/* If using pinctrl, bind pins now before probing */
ret = pinctrl_bind_pins(dev);
@@ -1014,7 +1013,7 @@ static int __device_attach(struct device *dev, bool allow_async)
if (ret == 0)
ret = 1;
else {
- dev->driver = NULL;
+ device_set_driver(dev, NULL);
ret = 0;
}
} else {
diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c
index 64840e5d5fcc..03a39c417dc4 100644
--- a/drivers/base/devcoredump.c
+++ b/drivers/base/devcoredump.c
@@ -41,7 +41,7 @@ struct devcd_entry {
* devcd_data_write()
* mod_delayed_work()
* try_to_grab_pending()
- * del_timer()
+ * timer_delete()
* debug_assert_init()
* INIT_DELAYED_WORK()
* schedule_delayed_work()
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 6dd1a8860f1c..31bfb3194b4c 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -296,7 +296,7 @@ static int delete_path(const char *nodepath)
return err;
}
-static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *stat)
+static int dev_mynode(struct device *dev, struct inode *inode)
{
/* did we create it */
if (inode->i_private != &thread)
@@ -304,13 +304,13 @@ static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *sta
/* does the dev_t match */
if (is_blockdev(dev)) {
- if (!S_ISBLK(stat->mode))
+ if (!S_ISBLK(inode->i_mode))
return 0;
} else {
- if (!S_ISCHR(stat->mode))
+ if (!S_ISCHR(inode->i_mode))
return 0;
}
- if (stat->rdev != dev->devt)
+ if (inode->i_rdev != dev->devt)
return 0;
/* ours */
@@ -321,20 +321,16 @@ static int handle_remove(const char *nodename, struct device *dev)
{
struct path parent;
struct dentry *dentry;
- struct kstat stat;
- struct path p;
+ struct inode *inode;
int deleted = 0;
- int err;
+ int err = 0;
dentry = kern_path_locked(nodename, &parent);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
- p.mnt = parent.mnt;
- p.dentry = dentry;
- err = vfs_getattr(&p, &stat, STATX_TYPE | STATX_MODE,
- AT_STATX_SYNC_AS_STAT);
- if (!err && dev_mynode(dev, d_inode(dentry), &stat)) {
+ inode = d_inode(dentry);
+ if (dev_mynode(dev, inode)) {
struct iattr newattrs;
/*
* before unlinking this node, reset permissions
@@ -342,7 +338,7 @@ static int handle_remove(const char *nodename, struct device *dev)
*/
newattrs.ia_uid = GLOBAL_ROOT_UID;
newattrs.ia_gid = GLOBAL_ROOT_GID;
- newattrs.ia_mode = stat.mode & ~0777;
+ newattrs.ia_mode = inode->i_mode & ~0777;
newattrs.ia_valid =
ATTR_UID|ATTR_GID|ATTR_MODE;
inode_lock(d_inode(dentry));
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 8f3a41d9bfaa..19469e7f88c2 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -816,21 +816,6 @@ static int add_memory_block(unsigned long block_id, unsigned long state,
return 0;
}
-static int __init add_boot_memory_block(unsigned long base_section_nr)
-{
- unsigned long nr;
-
- for_each_present_section_nr(base_section_nr, nr) {
- if (nr >= (base_section_nr + sections_per_block))
- break;
-
- return add_memory_block(memory_block_id(base_section_nr),
- MEM_ONLINE, NULL, NULL);
- }
-
- return 0;
-}
-
static int add_hotplug_memory_block(unsigned long block_id,
struct vmem_altmap *altmap,
struct memory_group *group)
@@ -957,7 +942,7 @@ static const struct attribute_group *memory_root_attr_groups[] = {
void __init memory_dev_init(void)
{
int ret;
- unsigned long block_sz, nr;
+ unsigned long block_sz, block_id, nr;
/* Validate the configured memory block size */
block_sz = memory_block_size_bytes();
@@ -970,15 +955,23 @@ void __init memory_dev_init(void)
panic("%s() failed to register subsystem: %d\n", __func__, ret);
/*
- * Create entries for memory sections that were found
- * during boot and have been initialized
+ * Create entries for memory sections that were found during boot
+ * and have been initialized. Use @block_id to track the last
+ * handled block and initialize it to an invalid value (ULONG_MAX)
+ * to bypass the block ID matching check for the first present
+ * block so that it can be covered.
*/
- for (nr = 0; nr <= __highest_present_section_nr;
- nr += sections_per_block) {
- ret = add_boot_memory_block(nr);
- if (ret)
- panic("%s() failed to add memory block: %d\n", __func__,
- ret);
+ block_id = ULONG_MAX;
+ for_each_present_section_nr(0, nr) {
+ if (block_id != ULONG_MAX && memory_block_id(nr) == block_id)
+ continue;
+
+ block_id = memory_block_id(nr);
+ ret = add_memory_block(block_id, MEM_ONLINE, NULL, NULL);
+ if (ret) {
+ panic("%s() failed to add memory block: %d\n",
+ __func__, ret);
+ }
}
}
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index ac2a197c1234..c8b0a9e29ed8 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -559,7 +559,7 @@ static void dpm_watchdog_clear(struct dpm_watchdog *wd)
{
struct timer_list *timer = &wd->timer;
- del_timer_sync(timer);
+ timer_delete_sync(timer);
destroy_timer_on_stack(timer);
}
#else
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 752b417e8129..63bf914a4d44 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -197,7 +197,7 @@ void wakeup_source_remove(struct wakeup_source *ws)
raw_spin_unlock_irqrestore(&events_lock, flags);
synchronize_srcu(&wakeup_srcu);
- del_timer_sync(&ws->timer);
+ timer_delete_sync(&ws->timer);
/*
* Clear timer.function to make wakeup_source_not_registered() treat
* this wakeup source as not registered.
@@ -613,7 +613,7 @@ void __pm_stay_awake(struct wakeup_source *ws)
spin_lock_irqsave(&ws->lock, flags);
wakeup_source_report_event(ws, false);
- del_timer(&ws->timer);
+ timer_delete(&ws->timer);
ws->timer_expires = 0;
spin_unlock_irqrestore(&ws->lock, flags);
@@ -693,7 +693,7 @@ static void wakeup_source_deactivate(struct wakeup_source *ws)
ws->max_time = duration;
ws->last_time = now;
- del_timer(&ws->timer);
+ timer_delete(&ws->timer);
ws->timer_expires = 0;
if (ws->autosleep_enabled)
diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index b1726a3515f6..5c78fa6ae772 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -1080,6 +1080,7 @@ void software_node_notify(struct device *dev)
if (!swnode)
return;
+ kobject_get(&swnode->kobj);
ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node");
if (ret)
return;
@@ -1089,8 +1090,6 @@ void software_node_notify(struct device *dev)
sysfs_remove_link(&dev->kobj, "software_node");
return;
}
-
- kobject_get(&swnode->kobj);
}
void software_node_notify_remove(struct device *dev)
generated by cgit v1.2.3 (git 2.46.0) at 2025-04-26 22:26:41 +0000