kobject: return error code if writing /sys/.../uevent fails

[ Upstream commit df44b479654f62b478c18ee4d8bc4e9f897a9844 ]

Propagate error code back to userspace if writing the /sys/.../uevent
file fails. Before, the write operation always returned with success,
even if we failed to recognize the input string or if we failed to
generate the uevent itself.

With the error codes properly propagated back to userspace, we are
able to react in userspace accordingly by not assuming and awaiting
a uevent that is not delivered.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 585e2e1c9c8f4760309e47f052e377da56135e9b..e06a57936cc969b7de81b00efce504a4185dbc99 100644 (file)
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -614,8 +614,10 @@ static void remove_probe_files(struct bus_type *bus)
 static ssize_t uevent_store(struct device_driver *drv, const char *buf,
                            size_t count)
 {
-       kobject_synth_uevent(&drv->p->kobj, buf, count);
-       return count;
+       int rc;
+
+       rc = kobject_synth_uevent(&drv->p->kobj, buf, count);
+       return rc ? rc : count;
 }
 static DRIVER_ATTR_WO(uevent);
 
@@ -831,8 +833,10 @@ static void klist_devices_put(struct klist_node *n)
 static ssize_t bus_uevent_store(struct bus_type *bus,
                                const char *buf, size_t count)
 {
-       kobject_synth_uevent(&bus->p->subsys.kobj, buf, count);
-       return count;
+       int rc;
+
+       rc = kobject_synth_uevent(&bus->p->subsys.kobj, buf, count);
+       return rc ? rc : count;
 }
 static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
 

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 04bbcd779e114ef1ecad0df77591c0801a0bf84b..92e2c32c2227015140ecad6def65e765b54942ed 100644 (file)
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1067,8 +1067,14 @@ out:
 static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
                            const char *buf, size_t count)
 {
-       if (kobject_synth_uevent(&dev->kobj, buf, count))
+       int rc;
+
+       rc = kobject_synth_uevent(&dev->kobj, buf, count);
+
+       if (rc) {
                dev_err(dev, "uevent: failed to send synthetic uevent\n");
+               return rc;
+       }
 
        return count;
 }

diff --git a/kernel/module.c b/kernel/module.c
index 49a4058915870cac3c54f336ff252703594e3bf0..0812a7f80fa740e00f6ea5d754d5403cdef1d557 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1207,8 +1207,10 @@ static ssize_t store_uevent(struct module_attribute *mattr,
                            struct module_kobject *mk,
                            const char *buffer, size_t count)
 {
-       kobject_synth_uevent(&mk->kobj, buffer, count);
-       return count;
+       int rc;
+
+       rc = kobject_synth_uevent(&mk->kobj, buffer, count);
+       return rc ? rc : count;
 }
 
 struct module_attribute module_uevent =