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authorMiroslav Benes <mbenes@suse.cz>2019-01-15 17:45:07 +0100
committerJiri Kosina <jkosina@suse.cz>2019-01-16 22:09:33 +0100
commit0b3d52790e1cfd6b80b826a245d24859e89632f7 (patch)
tree8a804f975eeacddea0add44d9b2ad912a9fbc636 /kernel/livepatch
parentcba82dea30613346cf9a0532a41fc118bc3263af (diff)
downloadlinux-0b3d52790e1cfd6b80b826a245d24859e89632f7.tar.bz2
livepatch: Remove signal sysfs attribute
The fake signal is send automatically now. We can rely on it completely and remove the sysfs attribute. Signed-off-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'kernel/livepatch')
-rw-r--r--kernel/livepatch/core.c32
-rw-r--r--kernel/livepatch/transition.c82
-rw-r--r--kernel/livepatch/transition.h1
3 files changed, 41 insertions, 74 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index adca5cf07f7e..fe1993399823 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -313,7 +313,6 @@ static int klp_write_object_relocations(struct module *pmod,
* /sys/kernel/livepatch/<patch>
* /sys/kernel/livepatch/<patch>/enabled
* /sys/kernel/livepatch/<patch>/transition
- * /sys/kernel/livepatch/<patch>/signal
* /sys/kernel/livepatch/<patch>/force
* /sys/kernel/livepatch/<patch>/<object>
* /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
@@ -382,35 +381,6 @@ static ssize_t transition_show(struct kobject *kobj,
patch == klp_transition_patch);
}
-static ssize_t signal_store(struct kobject *kobj, struct kobj_attribute *attr,
- const char *buf, size_t count)
-{
- struct klp_patch *patch;
- int ret;
- bool val;
-
- ret = kstrtobool(buf, &val);
- if (ret)
- return ret;
-
- if (!val)
- return count;
-
- mutex_lock(&klp_mutex);
-
- patch = container_of(kobj, struct klp_patch, kobj);
- if (patch != klp_transition_patch) {
- mutex_unlock(&klp_mutex);
- return -EINVAL;
- }
-
- klp_send_signals();
-
- mutex_unlock(&klp_mutex);
-
- return count;
-}
-
static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t count)
{
@@ -442,12 +412,10 @@ static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr,
static struct kobj_attribute enabled_kobj_attr = __ATTR_RW(enabled);
static struct kobj_attribute transition_kobj_attr = __ATTR_RO(transition);
-static struct kobj_attribute signal_kobj_attr = __ATTR_WO(signal);
static struct kobj_attribute force_kobj_attr = __ATTR_WO(force);
static struct attribute *klp_patch_attrs[] = {
&enabled_kobj_attr.attr,
&transition_kobj_attr.attr,
- &signal_kobj_attr.attr,
&force_kobj_attr.attr,
NULL
};
diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
index ea7697bb753e..183b2086ba03 100644
--- a/kernel/livepatch/transition.c
+++ b/kernel/livepatch/transition.c
@@ -348,6 +348,47 @@ done:
}
/*
+ * Sends a fake signal to all non-kthread tasks with TIF_PATCH_PENDING set.
+ * Kthreads with TIF_PATCH_PENDING set are woken up.
+ */
+static void klp_send_signals(void)
+{
+ struct task_struct *g, *task;
+
+ if (klp_signals_cnt == SIGNALS_TIMEOUT)
+ pr_notice("signaling remaining tasks\n");
+
+ read_lock(&tasklist_lock);
+ for_each_process_thread(g, task) {
+ if (!klp_patch_pending(task))
+ continue;
+
+ /*
+ * There is a small race here. We could see TIF_PATCH_PENDING
+ * set and decide to wake up a kthread or send a fake signal.
+ * Meanwhile the task could migrate itself and the action
+ * would be meaningless. It is not serious though.
+ */
+ if (task->flags & PF_KTHREAD) {
+ /*
+ * Wake up a kthread which sleeps interruptedly and
+ * still has not been migrated.
+ */
+ wake_up_state(task, TASK_INTERRUPTIBLE);
+ } else {
+ /*
+ * Send fake signal to all non-kthread tasks which are
+ * still not migrated.
+ */
+ spin_lock_irq(&task->sighand->siglock);
+ signal_wake_up(task, 0);
+ spin_unlock_irq(&task->sighand->siglock);
+ }
+ }
+ read_unlock(&tasklist_lock);
+}
+
+/*
* Try to switch all remaining tasks to the target patch state by walking the
* stacks of sleeping tasks and looking for any to-be-patched or
* to-be-unpatched functions. If such functions are found, the task can't be
@@ -587,47 +628,6 @@ void klp_copy_process(struct task_struct *child)
}
/*
- * Sends a fake signal to all non-kthread tasks with TIF_PATCH_PENDING set.
- * Kthreads with TIF_PATCH_PENDING set are woken up.
- */
-void klp_send_signals(void)
-{
- struct task_struct *g, *task;
-
- if (klp_signals_cnt == SIGNALS_TIMEOUT)
- pr_notice("signaling remaining tasks\n");
-
- read_lock(&tasklist_lock);
- for_each_process_thread(g, task) {
- if (!klp_patch_pending(task))
- continue;
-
- /*
- * There is a small race here. We could see TIF_PATCH_PENDING
- * set and decide to wake up a kthread or send a fake signal.
- * Meanwhile the task could migrate itself and the action
- * would be meaningless. It is not serious though.
- */
- if (task->flags & PF_KTHREAD) {
- /*
- * Wake up a kthread which sleeps interruptedly and
- * still has not been migrated.
- */
- wake_up_state(task, TASK_INTERRUPTIBLE);
- } else {
- /*
- * Send fake signal to all non-kthread tasks which are
- * still not migrated.
- */
- spin_lock_irq(&task->sighand->siglock);
- signal_wake_up(task, 0);
- spin_unlock_irq(&task->sighand->siglock);
- }
- }
- read_unlock(&tasklist_lock);
-}
-
-/*
* Drop TIF_PATCH_PENDING of all tasks on admin's request. This forces an
* existing transition to finish.
*
diff --git a/kernel/livepatch/transition.h b/kernel/livepatch/transition.h
index f9d0bc016067..322db16233de 100644
--- a/kernel/livepatch/transition.h
+++ b/kernel/livepatch/transition.h
@@ -11,7 +11,6 @@ void klp_cancel_transition(void);
void klp_start_transition(void);
void klp_try_complete_transition(void);
void klp_reverse_transition(void);
-void klp_send_signals(void);
void klp_force_transition(void);
#endif /* _LIVEPATCH_TRANSITION_H */