summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorMichael Marineau <mike@marineau.org>2014-04-10 14:09:31 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-04-25 12:00:49 -0700
commit86d56134f1b67d0c18025ba5cade95c048ed528d (patch)
treecaa4346965954ded259784e3b68af159e3161aeb
parentd911d98748018f7c8facc035ba39c30f5cce6f9c (diff)
downloadlinux-sh-86d56134f1b67d0c18025ba5cade95c048ed528d.tar.gz
kobject: Make support for uevent_helper optional.
Support for uevent_helper, aka hotplug, is not required on many systems these days but it can still be enabled via sysfs or sysctl. Reported-by: Darren Shepherd <darren.s.shepherd@gmail.com> Signed-off-by: Michael Marineau <mike@marineau.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/base/Kconfig17
-rw-r--r--include/linux/kobject.h2
-rw-r--r--kernel/ksysfs.c5
-rw-r--r--kernel/sysctl.c4
-rw-r--r--lib/kobject_uevent.c6
5 files changed, 25 insertions, 9 deletions
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 8fa8deab6449..4b7b4522b64f 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -1,10 +1,10 @@
menu "Generic Driver Options"
-config UEVENT_HELPER_PATH
- string "path to uevent helper"
- default ""
+config UEVENT_HELPER
+ bool "Support for uevent helper"
+ default y
help
- Path to uevent helper program forked by the kernel for
+ The uevent helper program is forked by the kernel for
every uevent.
Before the switch to the netlink-based uevent source, this was
used to hook hotplug scripts into kernel device events. It
@@ -15,8 +15,13 @@ config UEVENT_HELPER_PATH
that it creates a high system load, or on smaller systems
it is known to create out-of-memory situations during bootup.
- To disable user space helper program execution at early boot
- time specify an empty string here. This setting can be altered
+config UEVENT_HELPER_PATH
+ string "path to uevent helper"
+ depends on UEVENT_HELPER
+ default ""
+ help
+ To disable user space helper program execution at by default
+ specify an empty string here. This setting can still be altered
via /proc/sys/kernel/hotplug or via /sys/kernel/uevent_helper
later at runtime.
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index f896a33e8341..2d61b909f414 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -32,8 +32,10 @@
#define UEVENT_NUM_ENVP 32 /* number of env pointers */
#define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */
+#ifdef CONFIG_UEVENT_HELPER
/* path to the userspace helper executed on an event */
extern char uevent_helper[];
+#endif
/* counter to tag the uevent, read only except for the kobject core */
extern u64 uevent_seqnum;
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 2495a9b14ac8..6683ccef9fff 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -37,6 +37,7 @@ static ssize_t uevent_seqnum_show(struct kobject *kobj,
}
KERNEL_ATTR_RO(uevent_seqnum);
+#ifdef CONFIG_UEVENT_HELPER
/* uevent helper program, used during early boot */
static ssize_t uevent_helper_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
@@ -56,7 +57,7 @@ static ssize_t uevent_helper_store(struct kobject *kobj,
return count;
}
KERNEL_ATTR_RW(uevent_helper);
-
+#endif
#ifdef CONFIG_PROFILING
static ssize_t profiling_show(struct kobject *kobj,
@@ -189,7 +190,9 @@ EXPORT_SYMBOL_GPL(kernel_kobj);
static struct attribute * kernel_attrs[] = {
&fscaps_attr.attr,
&uevent_seqnum_attr.attr,
+#ifdef CONFIG_UEVENT_HELPER
&uevent_helper_attr.attr,
+#endif
#ifdef CONFIG_PROFILING
&profiling_attr.attr,
#endif
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 74f5b580fe34..bc966a8ffc3e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -643,7 +643,7 @@ static struct ctl_table kern_table[] = {
.extra2 = &one,
},
#endif
-
+#ifdef CONFIG_UEVENT_HELPER
{
.procname = "hotplug",
.data = &uevent_helper,
@@ -651,7 +651,7 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = proc_dostring,
},
-
+#endif
#ifdef CONFIG_CHR_DEV_SG
{
.procname = "sg-big-buff",
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 4e3bd71bd949..9ebf9e20de53 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -29,7 +29,9 @@
u64 uevent_seqnum;
+#ifdef CONFIG_UEVENT_HELPER
char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
+#endif
#ifdef CONFIG_NET
struct uevent_sock {
struct list_head list;
@@ -109,6 +111,7 @@ static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data)
}
#endif
+#ifdef CONFIG_UEVENT_HELPER
static int kobj_usermode_filter(struct kobject *kobj)
{
const struct kobj_ns_type_operations *ops;
@@ -147,6 +150,7 @@ static void cleanup_uevent_env(struct subprocess_info *info)
{
kfree(info->data);
}
+#endif
/**
* kobject_uevent_env - send an uevent with environmental data
@@ -323,6 +327,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
#endif
mutex_unlock(&uevent_sock_mutex);
+#ifdef CONFIG_UEVENT_HELPER
/* call uevent_helper, usually only enabled during early boot */
if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
struct subprocess_info *info;
@@ -347,6 +352,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
env = NULL; /* freed by cleanup_uevent_env */
}
}
+#endif
exit:
kfree(devpath);