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-rw-r--r--drivers/base/core.c83
-rw-r--r--drivers/base/firmware_loader/firmware.h4
-rw-r--r--drivers/base/platform.c9
-rw-r--r--drivers/base/regmap/Kconfig2
-rw-r--r--drivers/base/regmap/regmap-debugfs.c12
-rw-r--r--drivers/base/regmap/regmap-irq.c7
6 files changed, 85 insertions, 32 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index da84a73f2ba6..1669d41fcddc 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1663,6 +1663,9 @@ void device_initialize(struct device *dev)
kobject_init(&dev->kobj, &device_ktype);
INIT_LIST_HEAD(&dev->dma_pools);
mutex_init(&dev->mutex);
+#ifdef CONFIG_PROVE_LOCKING
+ mutex_init(&dev->lockdep_mutex);
+#endif
lockdep_set_novalidate_class(&dev->mutex);
spin_lock_init(&dev->devres_lock);
INIT_LIST_HEAD(&dev->devres_head);
@@ -1820,12 +1823,63 @@ static inline struct kobject *get_glue_dir(struct device *dev)
*/
static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
{
+ unsigned int ref;
+
/* see if we live in a "glue" directory */
if (!live_in_glue_dir(glue_dir, dev))
return;
mutex_lock(&gdp_mutex);
- if (!kobject_has_children(glue_dir))
+ /**
+ * There is a race condition between removing glue directory
+ * and adding a new device under the glue directory.
+ *
+ * CPU1: CPU2:
+ *
+ * device_add()
+ * get_device_parent()
+ * class_dir_create_and_add()
+ * kobject_add_internal()
+ * create_dir() // create glue_dir
+ *
+ * device_add()
+ * get_device_parent()
+ * kobject_get() // get glue_dir
+ *
+ * device_del()
+ * cleanup_glue_dir()
+ * kobject_del(glue_dir)
+ *
+ * kobject_add()
+ * kobject_add_internal()
+ * create_dir() // in glue_dir
+ * sysfs_create_dir_ns()
+ * kernfs_create_dir_ns(sd)
+ *
+ * sysfs_remove_dir() // glue_dir->sd=NULL
+ * sysfs_put() // free glue_dir->sd
+ *
+ * // sd is freed
+ * kernfs_new_node(sd)
+ * kernfs_get(glue_dir)
+ * kernfs_add_one()
+ * kernfs_put()
+ *
+ * Before CPU1 remove last child device under glue dir, if CPU2 add
+ * a new device under glue dir, the glue_dir kobject reference count
+ * will be increase to 2 in kobject_get(k). And CPU2 has been called
+ * kernfs_create_dir_ns(). Meanwhile, CPU1 call sysfs_remove_dir()
+ * and sysfs_put(). This result in glue_dir->sd is freed.
+ *
+ * Then the CPU2 will see a stale "empty" but still potentially used
+ * glue dir around in kernfs_new_node().
+ *
+ * In order to avoid this happening, we also should make sure that
+ * kernfs_node for glue_dir is released in CPU1 only when refcount
+ * for glue_dir kobj is 1.
+ */
+ ref = kref_read(&glue_dir->kref);
+ if (!kobject_has_children(glue_dir) && !--ref)
kobject_del(glue_dir);
kobject_put(glue_dir);
mutex_unlock(&gdp_mutex);
@@ -2211,6 +2265,24 @@ void put_device(struct device *dev)
}
EXPORT_SYMBOL_GPL(put_device);
+bool kill_device(struct device *dev)
+{
+ /*
+ * Require the device lock and set the "dead" flag to guarantee that
+ * the update behavior is consistent with the other bitfields near
+ * it and that we cannot have an asynchronous probe routine trying
+ * to run while we are tearing out the bus/class/sysfs from
+ * underneath the device.
+ */
+ lockdep_assert_held(&dev->mutex);
+
+ if (dev->p->dead)
+ return false;
+ dev->p->dead = true;
+ return true;
+}
+EXPORT_SYMBOL_GPL(kill_device);
+
/**
* device_del - delete device from system.
* @dev: device.
@@ -2230,15 +2302,8 @@ void device_del(struct device *dev)
struct kobject *glue_dir = NULL;
struct class_interface *class_intf;
- /*
- * Hold the device lock and set the "dead" flag to guarantee that
- * the update behavior is consistent with the other bitfields near
- * it and that we cannot have an asynchronous probe routine trying
- * to run while we are tearing out the bus/class/sysfs from
- * underneath the device.
- */
device_lock(dev);
- dev->p->dead = true;
+ kill_device(dev);
device_unlock(dev);
/* Notify clients of device removal. This call must come
diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
index 7048a41973ed..7ecd590e67fe 100644
--- a/drivers/base/firmware_loader/firmware.h
+++ b/drivers/base/firmware_loader/firmware.h
@@ -141,8 +141,8 @@ int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
int fw_map_paged_buf(struct fw_priv *fw_priv);
#else
static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
-int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
-int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
+static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
+static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
#endif
#endif /* __FIRMWARE_LOADER_H */
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 506a0175a5a7..ec974ba9c0c4 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -157,8 +157,13 @@ int platform_get_irq(struct platform_device *dev, unsigned int num)
* the device will only expose one IRQ, and this fallback
* allows a common code path across either kind of resource.
*/
- if (num == 0 && has_acpi_companion(&dev->dev))
- return acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
+ if (num == 0 && has_acpi_companion(&dev->dev)) {
+ int ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
+
+ /* Our callers expect -ENXIO for missing IRQs. */
+ if (ret >= 0 || ret == -EPROBE_DEFER)
+ return ret;
+ }
return -ENXIO;
#endif
diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
index a4984136c19d..0fd6f97ee523 100644
--- a/drivers/base/regmap/Kconfig
+++ b/drivers/base/regmap/Kconfig
@@ -44,7 +44,7 @@ config REGMAP_IRQ
config REGMAP_SOUNDWIRE
tristate
- depends on SOUNDWIRE_BUS
+ depends on SOUNDWIRE
config REGMAP_SCCB
tristate
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index e5e1b3a01b1a..e72843fe41df 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -588,14 +588,6 @@ void regmap_debugfs_init(struct regmap *map, const char *name)
}
map->debugfs = debugfs_create_dir(name, regmap_debugfs_root);
- if (!map->debugfs) {
- dev_warn(map->dev,
- "Failed to create %s debugfs directory\n", name);
-
- kfree(map->debugfs_name);
- map->debugfs_name = NULL;
- return;
- }
debugfs_create_file("name", 0400, map->debugfs,
map, &regmap_name_fops);
@@ -672,10 +664,6 @@ void regmap_debugfs_initcall(void)
struct regmap_debugfs_node *node, *tmp;
regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
- if (!regmap_debugfs_root) {
- pr_warn("regmap: Failed to create debugfs root\n");
- return;
- }
mutex_lock(&regmap_debugfs_early_lock);
list_for_each_entry_safe(node, tmp, &regmap_debugfs_early_list, link) {
diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index c9dc70ceca5f..3d64c9331a82 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -370,7 +370,6 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
if (ret < 0) {
dev_err(map->dev, "IRQ thread failed to resume: %d\n",
ret);
- pm_runtime_put(map->dev);
goto exit;
}
}
@@ -425,8 +424,6 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
dev_err(map->dev,
"Failed to read IRQ status %d\n",
ret);
- if (chip->runtime_pm)
- pm_runtime_put(map->dev);
goto exit;
}
}
@@ -478,8 +475,6 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
dev_err(map->dev,
"Failed to read IRQ status: %d\n",
ret);
- if (chip->runtime_pm)
- pm_runtime_put(map->dev);
goto exit;
}
}
@@ -513,10 +508,10 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
}
}
+exit:
if (chip->runtime_pm)
pm_runtime_put(map->dev);
-exit:
if (chip->handle_post_irq)
chip->handle_post_irq(chip->irq_drv_data);
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