Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 63f7eb3..508fe52 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -1,13 +1,17 @@
// SPDX-License-Identifier: GPL-2.0-only
/* Kernel thread helper functions.
* Copyright (C) 2004 IBM Corporation, Rusty Russell.
+ * Copyright (C) 2009 Red Hat, Inc.
*
* Creation is done via kthreadd, so that we get a clean environment
* even if we're invoked from userspace (think modprobe, hotplug cpu,
* etc.).
*/
#include <uapi/linux/sched/types.h>
+#include <linux/mm.h>
+#include <linux/mmu_context.h>
#include <linux/sched.h>
+#include <linux/sched/mm.h>
#include <linux/sched/task.h>
#include <linux/kthread.h>
#include <linux/completion.h>
@@ -23,8 +27,10 @@
#include <linux/ptrace.h>
#include <linux/uaccess.h>
#include <linux/numa.h>
+#include <linux/sched/isolation.h>
#include <trace/events/sched.h>
+
static DEFINE_SPINLOCK(kthread_create_lock);
static LIST_HEAD(kthread_create_list);
struct task_struct *kthreadd_task;
@@ -46,7 +52,9 @@
struct kthread {
unsigned long flags;
unsigned int cpu;
+ int (*threadfn)(void *);
void *data;
+ mm_segment_t oldfs;
struct completion parked;
struct completion exited;
#ifdef CONFIG_BLK_CGROUP
@@ -172,6 +180,21 @@
EXPORT_SYMBOL_GPL(kthread_freezable_should_stop);
/**
+ * kthread_func - return the function specified on kthread creation
+ * @task: kthread task in question
+ *
+ * Returns NULL if the task is not a kthread.
+ */
+void *kthread_func(struct task_struct *task)
+{
+ struct kthread *kthread = __to_kthread(task);
+ if (kthread)
+ return kthread->threadfn;
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(kthread_func);
+
+/**
* kthread_data - return data value specified on kthread creation
* @task: kthread task in question
*
@@ -183,6 +206,7 @@
{
return to_kthread(task)->data;
}
+EXPORT_SYMBOL_GPL(kthread_data);
/**
* kthread_probe_data - speculative version of kthread_data()
@@ -199,7 +223,7 @@
void *data = NULL;
if (kthread)
- probe_kernel_read(&data, &kthread->data, sizeof(data));
+ copy_from_kernel_nofault(&data, &kthread->data, sizeof(data));
return data;
}
@@ -264,6 +288,7 @@
do_exit(-ENOMEM);
}
+ self->threadfn = threadfn;
self->data = data;
init_completion(&self->exited);
init_completion(&self->parked);
@@ -380,7 +405,8 @@
* The kernel thread should not inherit these properties.
*/
sched_setscheduler_nocheck(task, SCHED_NORMAL, ¶m);
- set_cpus_allowed_ptr(task, cpu_all_mask);
+ set_cpus_allowed_ptr(task,
+ housekeeping_cpumask(HK_FLAG_KTHREAD));
}
kfree(create);
return task;
@@ -475,7 +501,6 @@
* to "name.*%u". Code fills in cpu number.
*
* Description: This helper function creates and names a kernel thread
- * The thread will be woken and put into park mode.
*/
struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
void *data, unsigned int cpu,
@@ -630,7 +655,7 @@
/* Setup a clean context for our children to inherit. */
set_task_comm(tsk, "kthreadd");
ignore_signals(tsk);
- set_cpus_allowed_ptr(tsk, cpu_all_mask);
+ set_cpus_allowed_ptr(tsk, housekeeping_cpumask(HK_FLAG_KTHREAD));
set_mems_allowed(node_states[N_MEMORY]);
current->flags |= PF_NOFREEZE;
@@ -796,7 +821,7 @@
/**
* kthread_create_worker_on_cpu - create a kthread worker and bind it
- * it to a given CPU and the associated NUMA node.
+ * to a given CPU and the associated NUMA node.
* @cpu: CPU number
* @flags: flags modifying the default behavior of the worker
* @namefmt: printf-style name for the kthread worker (task).
@@ -1279,6 +1304,65 @@
}
EXPORT_SYMBOL(kthread_destroy_worker);
+/**
+ * kthread_use_mm - make the calling kthread operate on an address space
+ * @mm: address space to operate on
+ */
+void kthread_use_mm(struct mm_struct *mm)
+{
+ struct mm_struct *active_mm;
+ struct task_struct *tsk = current;
+
+ WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD));
+ WARN_ON_ONCE(tsk->mm);
+
+ task_lock(tsk);
+ /* Hold off tlb flush IPIs while switching mm's */
+ local_irq_disable();
+ active_mm = tsk->active_mm;
+ if (active_mm != mm) {
+ mmgrab(mm);
+ tsk->active_mm = mm;
+ }
+ tsk->mm = mm;
+ switch_mm_irqs_off(active_mm, mm, tsk);
+ local_irq_enable();
+ task_unlock(tsk);
+#ifdef finish_arch_post_lock_switch
+ finish_arch_post_lock_switch();
+#endif
+
+ if (active_mm != mm)
+ mmdrop(active_mm);
+
+ to_kthread(tsk)->oldfs = force_uaccess_begin();
+}
+EXPORT_SYMBOL_GPL(kthread_use_mm);
+
+/**
+ * kthread_unuse_mm - reverse the effect of kthread_use_mm()
+ * @mm: address space to operate on
+ */
+void kthread_unuse_mm(struct mm_struct *mm)
+{
+ struct task_struct *tsk = current;
+
+ WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD));
+ WARN_ON_ONCE(!tsk->mm);
+
+ force_uaccess_end(to_kthread(tsk)->oldfs);
+
+ task_lock(tsk);
+ sync_mm_rss(mm);
+ local_irq_disable();
+ tsk->mm = NULL;
+ /* active_mm is still 'mm' */
+ enter_lazy_tlb(mm, tsk);
+ local_irq_enable();
+ task_unlock(tsk);
+}
+EXPORT_SYMBOL_GPL(kthread_unuse_mm);
+
#ifdef CONFIG_BLK_CGROUP
/**
* kthread_associate_blkcg - associate blkcg to current kthread
@@ -1292,9 +1376,11 @@
*/
void kthread_associate_blkcg(struct cgroup_subsys_state *css)
{
- struct kthread *kthread = __to_kthread(current);
+ struct kthread *kthread;
-
+ if (!(current->flags & PF_KTHREAD))
+ return;
+ kthread = to_kthread(current);
if (!kthread)
return;
@@ -1316,10 +1402,13 @@
*/
struct cgroup_subsys_state *kthread_blkcg(void)
{
- struct kthread *kthread = __to_kthread(current);
+ struct kthread *kthread;
- if (kthread)
- return kthread->blkcg_css;
+ if (current->flags & PF_KTHREAD) {
+ kthread = to_kthread(current);
+ if (kthread)
+ return kthread->blkcg_css;
+ }
return NULL;
}
EXPORT_SYMBOL(kthread_blkcg);