From f7debeebcdeb1bc699fe8c2dcd313d30aec33644 Mon Sep 17 00:00:00 2001 From: Peter Rajnoha Date: Wed, 5 Dec 2018 12:27:44 +0100 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/base/bus.c | 12 ++++++++---- drivers/base/core.c | 8 +++++++- kernel/module.c | 6 ++++-- 3 files changed, 19 insertions(+), 7 deletions(-) diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 585e2e1..e06a579 100644 --- 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 04bbcd7..92e2c32 100644 --- 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 6746c85..38bf28b 100644 --- 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 = -- 2.7.4