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livepatch: Remove signal sysfs attribute

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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>
This commit is contained in:
Miroslav Benes
2019-01-15 17:45:07 +01:00
committed by Jiri Kosina
parent cba82dea30
commit 0b3d52790e
5 changed files with 48 additions and 95 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/livepatch/transition.c
+41 -41
View File
@@ -347,6 +347,47 @@ 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
@@ -586,47 +627,6 @@ void klp_copy_process(struct task_struct *child)
/* TIF_PATCH_PENDING gets copied in setup_thread_stack() */
}
/*
* 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.