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authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-26 15:07:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-26 15:07:37 -0700
commit8d7804a2f03dbd34940fcb426450c730adf29dae (patch)
tree749f33776e38f734b81c2a93275b6bf76e96f74e /drivers/base
parentd87823813fe498fdd47894bd28e460a9dee8d771 (diff)
parent0e6c861f73ec42ab5c89fda9892f2173c7aaf6cf (diff)
Merge tag 'driver-core-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH: "Here is the driver core / firmware changes for 4.2-rc1. A number of small changes all over the place in the driver core, and in the firmware subsystem. Nothing really major, full details in the shortlog. Some of it is a bit of churn, given that the platform driver probing changes was found to not work well, so they were reverted. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (31 commits) Revert "base/platform: Only insert MEM and IO resources" Revert "base/platform: Continue on insert_resource() error" Revert "of/platform: Use platform_device interface" Revert "base/platform: Remove code duplication" firmware: add missing kfree for work on async call fs: sysfs: don't pass count == 0 to bin file readers base:dd - Fix for typo in comment to function driver_deferred_probe_trigger(). base/platform: Remove code duplication of/platform: Use platform_device interface base/platform: Continue on insert_resource() error base/platform: Only insert MEM and IO resources firmware: use const for remaining firmware names firmware: fix possible use after free on name on asynchronous request firmware: check for file truncation on direct firmware loading firmware: fix __getname() missing failure check drivers: of/base: move of_init to driver_init drivers/base: cacheinfo: fix annoying typo when DT nodes are absent sysfs: disambiguate between "error code" and "failure" in comments driver-core: fix build for !CONFIG_MODULES driver-core: make __device_attach() static ...
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/base.h1
-rw-r--r--drivers/base/bus.c31
-rw-r--r--drivers/base/cacheinfo.c4
-rw-r--r--drivers/base/cpu.c29
-rw-r--r--drivers/base/dd.c163
-rw-r--r--drivers/base/firmware_class.c63
-rw-r--r--drivers/base/platform.c13
7 files changed, 258 insertions, 46 deletions
diff --git a/drivers/base/base.h b/drivers/base/base.h
index 251c5d30f963..fd3347d9f153 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -116,6 +116,7 @@ static inline int driver_match_device(struct device_driver *drv,
{
return drv->bus->match ? drv->bus->match(dev, drv) : 1;
}
+extern bool driver_allows_async_probing(struct device_driver *drv);
extern int driver_add_groups(struct device_driver *drv,
const struct attribute_group **groups);
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 79bc203f51ef..500592486e88 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -10,6 +10,7 @@
*
*/
+#include <linux/async.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/errno.h>
@@ -549,15 +550,12 @@ void bus_probe_device(struct device *dev)
{
struct bus_type *bus = dev->bus;
struct subsys_interface *sif;
- int ret;
if (!bus)
return;
- if (bus->p->drivers_autoprobe) {
- ret = device_attach(dev);
- WARN_ON(ret < 0);
- }
+ if (bus->p->drivers_autoprobe)
+ device_initial_probe(dev);
mutex_lock(&bus->p->mutex);
list_for_each_entry(sif, &bus->p->interfaces, node)
@@ -659,6 +657,17 @@ static ssize_t uevent_store(struct device_driver *drv, const char *buf,
}
static DRIVER_ATTR_WO(uevent);
+static void driver_attach_async(void *_drv, async_cookie_t cookie)
+{
+ struct device_driver *drv = _drv;
+ int ret;
+
+ ret = driver_attach(drv);
+
+ pr_debug("bus: '%s': driver %s async attach completed: %d\n",
+ drv->bus->name, drv->name, ret);
+}
+
/**
* bus_add_driver - Add a driver to the bus.
* @drv: driver.
@@ -691,9 +700,15 @@ int bus_add_driver(struct device_driver *drv)
klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
if (drv->bus->p->drivers_autoprobe) {
- error = driver_attach(drv);
- if (error)
- goto out_unregister;
+ if (driver_allows_async_probing(drv)) {
+ pr_debug("bus: '%s': probing driver %s asynchronously\n",
+ drv->bus->name, drv->name);
+ async_schedule(driver_attach_async, drv);
+ } else {
+ error = driver_attach(drv);
+ if (error)
+ goto out_unregister;
+ }
}
module_add_driver(drv->owner, drv);
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index df0c66cb7ad3..764280a91776 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -191,12 +191,12 @@ static int detect_cache_attributes(unsigned int cpu)
if (ret)
goto free_ci;
/*
- * For systems using DT for cache hierarcy, of_node and shared_cpu_map
+ * For systems using DT for cache hierarchy, of_node and shared_cpu_map
* will be set up here only if they are not populated already
*/
ret = cache_shared_cpu_map_setup(cpu);
if (ret) {
- pr_warn("Unable to detect cache hierarcy from DT for CPU %d\n",
+ pr_warn("Unable to detect cache hierarchy from DT for CPU %d\n",
cpu);
goto free_ci;
}
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index f160ea44a86d..78720e706176 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -16,6 +16,7 @@
#include <linux/acpi.h>
#include <linux/of.h>
#include <linux/cpufeature.h>
+#include <linux/tick.h>
#include "base.h"
@@ -265,6 +266,30 @@ static ssize_t print_cpus_offline(struct device *dev,
}
static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
+static ssize_t print_cpus_isolated(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int n = 0, len = PAGE_SIZE-2;
+
+ n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(cpu_isolated_map));
+
+ return n;
+}
+static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL);
+
+#ifdef CONFIG_NO_HZ_FULL
+static ssize_t print_cpus_nohz_full(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int n = 0, len = PAGE_SIZE-2;
+
+ n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));
+
+ return n;
+}
+static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL);
+#endif
+
static void cpu_device_release(struct device *dev)
{
/*
@@ -431,6 +456,10 @@ static struct attribute *cpu_root_attrs[] = {
&cpu_attrs[2].attr.attr,
&dev_attr_kernel_max.attr,
&dev_attr_offline.attr,
+ &dev_attr_isolated.attr,
+#ifdef CONFIG_NO_HZ_FULL
+ &dev_attr_nohz_full.attr,
+#endif
#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
&dev_attr_modalias.attr,
#endif
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index e843fdbe4925..a638bbb1a27a 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -141,7 +141,7 @@ static bool driver_deferred_probe_enable = false;
* more than one device is probing at the same time, it is possible for one
* probe to complete successfully while another is about to defer. If the second
* depends on the first, then it will get put on the pending list after the
- * trigger event has already occured and will be stuck there.
+ * trigger event has already occurred and will be stuck there.
*
* The atomic 'deferred_trigger_count' is used to determine if a successful
* trigger has occurred in the midst of probing a driver. If the trigger count
@@ -417,31 +417,107 @@ int driver_probe_device(struct device_driver *drv, struct device *dev)
return ret;
}
-static int __device_attach(struct device_driver *drv, void *data)
+bool driver_allows_async_probing(struct device_driver *drv)
{
- struct device *dev = data;
+ switch (drv->probe_type) {
+ case PROBE_PREFER_ASYNCHRONOUS:
+ return true;
+
+ case PROBE_FORCE_SYNCHRONOUS:
+ return false;
+
+ default:
+ if (module_requested_async_probing(drv->owner))
+ return true;
+
+ return false;
+ }
+}
+
+struct device_attach_data {
+ struct device *dev;
+
+ /*
+ * Indicates whether we are are considering asynchronous probing or
+ * not. Only initial binding after device or driver registration
+ * (including deferral processing) may be done asynchronously, the
+ * rest is always synchronous, as we expect it is being done by
+ * request from userspace.
+ */
+ bool check_async;
+
+ /*
+ * Indicates if we are binding synchronous or asynchronous drivers.
+ * When asynchronous probing is enabled we'll execute 2 passes
+ * over drivers: first pass doing synchronous probing and second
+ * doing asynchronous probing (if synchronous did not succeed -
+ * most likely because there was no driver requiring synchronous
+ * probing - and we found asynchronous driver during first pass).
+ * The 2 passes are done because we can't shoot asynchronous
+ * probe for given device and driver from bus_for_each_drv() since
+ * driver pointer is not guaranteed to stay valid once
+ * bus_for_each_drv() iterates to the next driver on the bus.
+ */
+ bool want_async;
+
+ /*
+ * We'll set have_async to 'true' if, while scanning for matching
+ * driver, we'll encounter one that requests asynchronous probing.
+ */
+ bool have_async;
+};
+
+static int __device_attach_driver(struct device_driver *drv, void *_data)
+{
+ struct device_attach_data *data = _data;
+ struct device *dev = data->dev;
+ bool async_allowed;
+
+ /*
+ * Check if device has already been claimed. This may
+ * happen with driver loading, device discovery/registration,
+ * and deferred probe processing happens all at once with
+ * multiple threads.
+ */
+ if (dev->driver)
+ return -EBUSY;
if (!driver_match_device(drv, dev))
return 0;
+ async_allowed = driver_allows_async_probing(drv);
+
+ if (async_allowed)
+ data->have_async = true;
+
+ if (data->check_async && async_allowed != data->want_async)
+ return 0;
+
return driver_probe_device(drv, dev);
}
-/**
- * device_attach - try to attach device to a driver.
- * @dev: device.
- *
- * Walk the list of drivers that the bus has and call
- * driver_probe_device() for each pair. If a compatible
- * pair is found, break out and return.
- *
- * Returns 1 if the device was bound to a driver;
- * 0 if no matching driver was found;
- * -ENODEV if the device is not registered.
- *
- * When called for a USB interface, @dev->parent lock must be held.
- */
-int device_attach(struct device *dev)
+static void __device_attach_async_helper(void *_dev, async_cookie_t cookie)
+{
+ struct device *dev = _dev;
+ struct device_attach_data data = {
+ .dev = dev,
+ .check_async = true,
+ .want_async = true,
+ };
+
+ device_lock(dev);
+
+ bus_for_each_drv(dev->bus, NULL, &data, __device_attach_driver);
+ dev_dbg(dev, "async probe completed\n");
+
+ pm_request_idle(dev);
+
+ device_unlock(dev);
+
+ put_device(dev);
+}
+
+static int __device_attach(struct device *dev, bool allow_async)
{
int ret = 0;
@@ -459,15 +535,59 @@ int device_attach(struct device *dev)
ret = 0;
}
} else {
- ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
- pm_request_idle(dev);
+ struct device_attach_data data = {
+ .dev = dev,
+ .check_async = allow_async,
+ .want_async = false,
+ };
+
+ ret = bus_for_each_drv(dev->bus, NULL, &data,
+ __device_attach_driver);
+ if (!ret && allow_async && data.have_async) {
+ /*
+ * If we could not find appropriate driver
+ * synchronously and we are allowed to do
+ * async probes and there are drivers that
+ * want to probe asynchronously, we'll
+ * try them.
+ */
+ dev_dbg(dev, "scheduling asynchronous probe\n");
+ get_device(dev);
+ async_schedule(__device_attach_async_helper, dev);
+ } else {
+ pm_request_idle(dev);
+ }
}
out_unlock:
device_unlock(dev);
return ret;
}
+
+/**
+ * device_attach - try to attach device to a driver.
+ * @dev: device.
+ *
+ * Walk the list of drivers that the bus has and call
+ * driver_probe_device() for each pair. If a compatible
+ * pair is found, break out and return.
+ *
+ * Returns 1 if the device was bound to a driver;
+ * 0 if no matching driver was found;
+ * -ENODEV if the device is not registered.
+ *
+ * When called for a USB interface, @dev->parent lock must be held.
+ */
+int device_attach(struct device *dev)
+{
+ return __device_attach(dev, false);
+}
EXPORT_SYMBOL_GPL(device_attach);
+void device_initial_probe(struct device *dev)
+{
+ __device_attach(dev, true);
+}
+
static int __driver_attach(struct device *dev, void *data)
{
struct device_driver *drv = data;
@@ -522,6 +642,9 @@ static void __device_release_driver(struct device *dev)
drv = dev->driver;
if (drv) {
+ if (driver_allows_async_probing(drv))
+ async_synchronize_full();
+
pm_runtime_get_sync(dev);
driver_sysfs_remove(dev);
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 171841ad1008..9c4288362a8e 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -150,17 +150,17 @@ struct firmware_buf {
int page_array_size;
struct list_head pending_list;
#endif
- char fw_id[];
+ const char *fw_id;
};
struct fw_cache_entry {
struct list_head list;
- char name[];
+ const char *name;
};
struct fw_name_devm {
unsigned long magic;
- char name[];
+ const char *name;
};
#define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
@@ -181,13 +181,17 @@ static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
{
struct firmware_buf *buf;
- buf = kzalloc(sizeof(*buf) + strlen(fw_name) + 1, GFP_ATOMIC);
-
+ buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
if (!buf)
- return buf;
+ return NULL;
+
+ buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC);
+ if (!buf->fw_id) {
+ kfree(buf);
+ return NULL;
+ }
kref_init(&buf->ref);
- strcpy(buf->fw_id, fw_name);
buf->fwc = fwc;
init_completion(&buf->completion);
#ifdef CONFIG_FW_LOADER_USER_HELPER
@@ -257,6 +261,7 @@ static void __fw_free_buf(struct kref *ref)
} else
#endif
vfree(buf->data);
+ kfree_const(buf->fw_id);
kfree(buf);
}
@@ -320,9 +325,13 @@ fail:
static int fw_get_filesystem_firmware(struct device *device,
struct firmware_buf *buf)
{
- int i;
+ int i, len;
int rc = -ENOENT;
- char *path = __getname();
+ char *path;
+
+ path = __getname();
+ if (!path)
+ return -ENOMEM;
for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
struct file *file;
@@ -331,7 +340,12 @@ static int fw_get_filesystem_firmware(struct device *device,
if (!fw_path[i][0])
continue;
- snprintf(path, PATH_MAX, "%s/%s", fw_path[i], buf->fw_id);
+ len = snprintf(path, PATH_MAX, "%s/%s",
+ fw_path[i], buf->fw_id);
+ if (len >= PATH_MAX) {
+ rc = -ENAMETOOLONG;
+ break;
+ }
file = filp_open(path, O_RDONLY, 0);
if (IS_ERR(file))
@@ -392,6 +406,7 @@ static void fw_name_devm_release(struct device *dev, void *res)
if (fwn->magic == (unsigned long)&fw_cache)
pr_debug("%s: fw_name-%s devm-%p released\n",
__func__, fwn->name, res);
+ kfree_const(fwn->name);
}
static int fw_devm_match(struct device *dev, void *res,
@@ -422,13 +437,17 @@ static int fw_add_devm_name(struct device *dev, const char *name)
if (fwn)
return 1;
- fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm) +
- strlen(name) + 1, GFP_KERNEL);
+ fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
+ GFP_KERNEL);
if (!fwn)
return -ENOMEM;
+ fwn->name = kstrdup_const(name, GFP_KERNEL);
+ if (!fwn->name) {
+ kfree(fwn);
+ return -ENOMEM;
+ }
fwn->magic = (unsigned long)&fw_cache;
- strcpy(fwn->name, name);
devres_add(dev, fwn);
return 0;
@@ -1247,6 +1266,7 @@ static void request_firmware_work_func(struct work_struct *work)
put_device(fw_work->device); /* taken in request_firmware_nowait() */
module_put(fw_work->module);
+ kfree_const(fw_work->name);
kfree(fw_work);
}
@@ -1286,7 +1306,11 @@ request_firmware_nowait(
return -ENOMEM;
fw_work->module = module;
- fw_work->name = name;
+ fw_work->name = kstrdup_const(name, gfp);
+ if (!fw_work->name) {
+ kfree(fw_work);
+ return -ENOMEM;
+ }
fw_work->device = device;
fw_work->context = context;
fw_work->cont = cont;
@@ -1294,6 +1318,7 @@ request_firmware_nowait(
(uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
if (!try_module_get(module)) {
+ kfree_const(fw_work->name);
kfree(fw_work);
return -EFAULT;
}
@@ -1384,11 +1409,16 @@ static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
{
struct fw_cache_entry *fce;
- fce = kzalloc(sizeof(*fce) + strlen(name) + 1, GFP_ATOMIC);
+ fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
if (!fce)
goto exit;
- strcpy(fce->name, name);
+ fce->name = kstrdup_const(name, GFP_ATOMIC);
+ if (!fce->name) {
+ kfree(fce);
+ fce = NULL;
+ goto exit;
+ }
exit:
return fce;
}
@@ -1428,6 +1458,7 @@ found:
static void free_fw_cache_entry(struct fw_cache_entry *fce)
{
+ kfree_const(fce->name);
kfree(fce);
}
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index ebf034b97278..063f0ab15259 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -613,6 +613,19 @@ int __init_or_module __platform_driver_probe(struct platform_driver *drv,
{
int retval, code;
+ if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
+ pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
+ drv->driver.name, __func__);
+ return -EINVAL;
+ }
+
+ /*
+ * We have to run our probes synchronously because we check if
+ * we find any devices to bind to and exit with error if there
+ * are any.
+ */
+ drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
+
/*
* Prevent driver from requesting probe deferral to avoid further
* futile probe attempts.