summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--arch/x86/include/asm/fpu/sched.h2
-rw-r--r--arch/x86/kernel/fpu/context.h2
-rw-r--r--arch/x86/kernel/fpu/core.c2
-rw-r--r--drivers/vhost/vhost.c22
-rw-r--r--fs/coredump.c4
-rw-r--r--include/linux/sched/task.h1
-rw-r--r--include/linux/sched/vhost_task.h15
-rw-r--r--kernel/exit.c5
-rw-r--r--kernel/fork.c13
-rw-r--r--kernel/signal.c8
-rw-r--r--kernel/vhost_task.c92
11 files changed, 89 insertions, 77 deletions
diff --git a/arch/x86/include/asm/fpu/sched.h b/arch/x86/include/asm/fpu/sched.h
index c2d6cd78ed0c..78fcde7b1f07 100644
--- a/arch/x86/include/asm/fpu/sched.h
+++ b/arch/x86/include/asm/fpu/sched.h
@@ -39,7 +39,7 @@ extern void fpu_flush_thread(void);
static inline void switch_fpu_prepare(struct fpu *old_fpu, int cpu)
{
if (cpu_feature_enabled(X86_FEATURE_FPU) &&
- !(current->flags & (PF_KTHREAD | PF_IO_WORKER))) {
+ !(current->flags & (PF_KTHREAD | PF_USER_WORKER))) {
save_fpregs_to_fpstate(old_fpu);
/*
* The save operation preserved register state, so the
diff --git a/arch/x86/kernel/fpu/context.h b/arch/x86/kernel/fpu/context.h
index 9fcfa5c4dad7..af5cbdd9bd29 100644
--- a/arch/x86/kernel/fpu/context.h
+++ b/arch/x86/kernel/fpu/context.h
@@ -57,7 +57,7 @@ static inline void fpregs_restore_userregs(void)
struct fpu *fpu = &current->thread.fpu;
int cpu = smp_processor_id();
- if (WARN_ON_ONCE(current->flags & (PF_KTHREAD | PF_IO_WORKER)))
+ if (WARN_ON_ONCE(current->flags & (PF_KTHREAD | PF_USER_WORKER)))
return;
if (!fpregs_state_valid(fpu, cpu)) {
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index caf33486dc5e..1015af1ae562 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -426,7 +426,7 @@ void kernel_fpu_begin_mask(unsigned int kfpu_mask)
this_cpu_write(in_kernel_fpu, true);
- if (!(current->flags & (PF_KTHREAD | PF_IO_WORKER)) &&
+ if (!(current->flags & (PF_KTHREAD | PF_USER_WORKER)) &&
!test_thread_flag(TIF_NEED_FPU_LOAD)) {
set_thread_flag(TIF_NEED_FPU_LOAD);
save_fpregs_to_fpstate(&current->thread.fpu);
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index a92af08e7864..074273020849 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -256,7 +256,7 @@ void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work)
* test_and_set_bit() implies a memory barrier.
*/
llist_add(&work->node, &dev->worker->work_list);
- wake_up_process(dev->worker->vtsk->task);
+ vhost_task_wake(dev->worker->vtsk);
}
}
EXPORT_SYMBOL_GPL(vhost_work_queue);
@@ -333,31 +333,19 @@ static void vhost_vq_reset(struct vhost_dev *dev,
__vhost_vq_meta_reset(vq);
}
-static int vhost_worker(void *data)
+static bool vhost_worker(void *data)
{
struct vhost_worker *worker = data;
struct vhost_work *work, *work_next;
struct llist_node *node;
- for (;;) {
- /* mb paired w/ kthread_stop */
- set_current_state(TASK_INTERRUPTIBLE);
-
- if (vhost_task_should_stop(worker->vtsk)) {
- __set_current_state(TASK_RUNNING);
- break;
- }
-
- node = llist_del_all(&worker->work_list);
- if (!node)
- schedule();
-
+ node = llist_del_all(&worker->work_list);
+ if (node) {
node = llist_reverse_order(node);
/* make sure flag is seen after deletion */
smp_wmb();
llist_for_each_entry_safe(work, work_next, node, node) {
clear_bit(VHOST_WORK_QUEUED, &work->flags);
- __set_current_state(TASK_RUNNING);
kcov_remote_start_common(worker->kcov_handle);
work->fn(work);
kcov_remote_stop();
@@ -365,7 +353,7 @@ static int vhost_worker(void *data)
}
}
- return 0;
+ return !!node;
}
static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq)
diff --git a/fs/coredump.c b/fs/coredump.c
index ece7badf701b..88740c51b942 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -371,7 +371,9 @@ static int zap_process(struct task_struct *start, int exit_code)
if (t != current && !(t->flags & PF_POSTCOREDUMP)) {
sigaddset(&t->pending.signal, SIGKILL);
signal_wake_up(t, 1);
- nr++;
+ /* The vhost_worker does not particpate in coredumps */
+ if ((t->flags & (PF_USER_WORKER | PF_IO_WORKER)) != PF_USER_WORKER)
+ nr++;
}
}
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 537cbf9a2ade..e0f5ac90a228 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -29,7 +29,6 @@ struct kernel_clone_args {
u32 io_thread:1;
u32 user_worker:1;
u32 no_files:1;
- u32 ignore_signals:1;
unsigned long stack;
unsigned long stack_size;
unsigned long tls;
diff --git a/include/linux/sched/vhost_task.h b/include/linux/sched/vhost_task.h
index 6123c10b99cf..837a23624a66 100644
--- a/include/linux/sched/vhost_task.h
+++ b/include/linux/sched/vhost_task.h
@@ -2,22 +2,13 @@
#ifndef _LINUX_VHOST_TASK_H
#define _LINUX_VHOST_TASK_H
-#include <linux/completion.h>
-struct task_struct;
+struct vhost_task;
-struct vhost_task {
- int (*fn)(void *data);
- void *data;
- struct completion exited;
- unsigned long flags;
- struct task_struct *task;
-};
-
-struct vhost_task *vhost_task_create(int (*fn)(void *), void *arg,
+struct vhost_task *vhost_task_create(bool (*fn)(void *), void *arg,
const char *name);
void vhost_task_start(struct vhost_task *vtsk);
void vhost_task_stop(struct vhost_task *vtsk);
-bool vhost_task_should_stop(struct vhost_task *vtsk);
+void vhost_task_wake(struct vhost_task *vtsk);
#endif
diff --git a/kernel/exit.c b/kernel/exit.c
index 34b90e2e7cf7..edb50b4c9972 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -411,7 +411,10 @@ static void coredump_task_exit(struct task_struct *tsk)
tsk->flags |= PF_POSTCOREDUMP;
core_state = tsk->signal->core_state;
spin_unlock_irq(&tsk->sighand->siglock);
- if (core_state) {
+
+ /* The vhost_worker does not particpate in coredumps */
+ if (core_state &&
+ ((tsk->flags & (PF_IO_WORKER | PF_USER_WORKER)) != PF_USER_WORKER)) {
struct core_thread self;
self.task = current;
diff --git a/kernel/fork.c b/kernel/fork.c
index ed4e01daccaa..81cba91f30bb 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2336,16 +2336,16 @@ __latent_entropy struct task_struct *copy_process(
p->flags &= ~PF_KTHREAD;
if (args->kthread)
p->flags |= PF_KTHREAD;
- if (args->user_worker)
- p->flags |= PF_USER_WORKER;
- if (args->io_thread) {
+ if (args->user_worker) {
/*
- * Mark us an IO worker, and block any signal that isn't
+ * Mark us a user worker, and block any signal that isn't
* fatal or STOP
*/
- p->flags |= PF_IO_WORKER;
+ p->flags |= PF_USER_WORKER;
siginitsetinv(&p->blocked, sigmask(SIGKILL)|sigmask(SIGSTOP));
}
+ if (args->io_thread)
+ p->flags |= PF_IO_WORKER;
if (args->name)
strscpy_pad(p->comm, args->name, sizeof(p->comm));
@@ -2517,9 +2517,6 @@ __latent_entropy struct task_struct *copy_process(
if (retval)
goto bad_fork_cleanup_io;
- if (args->ignore_signals)
- ignore_signals(p);
-
stackleak_task_init(p);
if (pid != &init_struct_pid) {
diff --git a/kernel/signal.c b/kernel/signal.c
index 8f6330f0e9ca..2547fa73bde5 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1368,7 +1368,9 @@ int zap_other_threads(struct task_struct *p)
while_each_thread(p, t) {
task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
- count++;
+ /* Don't require de_thread to wait for the vhost_worker */
+ if ((t->flags & (PF_IO_WORKER | PF_USER_WORKER)) != PF_USER_WORKER)
+ count++;
/* Don't bother with already dead threads */
if (t->exit_state)
@@ -2861,11 +2863,11 @@ relock:
}
/*
- * PF_IO_WORKER threads will catch and exit on fatal signals
+ * PF_USER_WORKER threads will catch and exit on fatal signals
* themselves. They have cleanup that must be performed, so
* we cannot call do_exit() on their behalf.
*/
- if (current->flags & PF_IO_WORKER)
+ if (current->flags & PF_USER_WORKER)
goto out;
/*
diff --git a/kernel/vhost_task.c b/kernel/vhost_task.c
index b7cbd66f889e..f80d5c51ae67 100644
--- a/kernel/vhost_task.c
+++ b/kernel/vhost_task.c
@@ -12,58 +12,88 @@ enum vhost_task_flags {
VHOST_TASK_FLAGS_STOP,
};
+struct vhost_task {
+ bool (*fn)(void *data);
+ void *data;
+ struct completion exited;
+ unsigned long flags;
+ struct task_struct *task;
+};
+
static int vhost_task_fn(void *data)
{
struct vhost_task *vtsk = data;
- int ret;
+ bool dead = false;
+
+ for (;;) {
+ bool did_work;
+
+ /* mb paired w/ vhost_task_stop */
+ if (test_bit(VHOST_TASK_FLAGS_STOP, &vtsk->flags))
+ break;
+
+ if (!dead && signal_pending(current)) {
+ struct ksignal ksig;
+ /*
+ * Calling get_signal will block in SIGSTOP,
+ * or clear fatal_signal_pending, but remember
+ * what was set.
+ *
+ * This thread won't actually exit until all
+ * of the file descriptors are closed, and
+ * the release function is called.
+ */
+ dead = get_signal(&ksig);
+ if (dead)
+ clear_thread_flag(TIF_SIGPENDING);
+ }
+
+ did_work = vtsk->fn(vtsk->data);
+ if (!did_work) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ }
+ }
- ret = vtsk->fn(vtsk->data);
complete(&vtsk->exited);
- do_exit(ret);
+ do_exit(0);
+}
+
+/**
+ * vhost_task_wake - wakeup the vhost_task
+ * @vtsk: vhost_task to wake
+ *
+ * wake up the vhost_task worker thread
+ */
+void vhost_task_wake(struct vhost_task *vtsk)
+{
+ wake_up_process(vtsk->task);
}
+EXPORT_SYMBOL_GPL(vhost_task_wake);
/**
* vhost_task_stop - stop a vhost_task
* @vtsk: vhost_task to stop
*
- * Callers must call vhost_task_should_stop and return from their worker
- * function when it returns true;
+ * vhost_task_fn ensures the worker thread exits after
+ * VHOST_TASK_FLAGS_SOP becomes true.
*/
void vhost_task_stop(struct vhost_task *vtsk)
{
- pid_t pid = vtsk->task->pid;
-
set_bit(VHOST_TASK_FLAGS_STOP, &vtsk->flags);
- wake_up_process(vtsk->task);
+ vhost_task_wake(vtsk);
/*
* Make sure vhost_task_fn is no longer accessing the vhost_task before
- * freeing it below. If userspace crashed or exited without closing,
- * then the vhost_task->task could already be marked dead so
- * kernel_wait will return early.
+ * freeing it below.
*/
wait_for_completion(&vtsk->exited);
- /*
- * If we are just closing/removing a device and the parent process is
- * not exiting then reap the task.
- */
- kernel_wait4(pid, NULL, __WCLONE, NULL);
kfree(vtsk);
}
EXPORT_SYMBOL_GPL(vhost_task_stop);
/**
- * vhost_task_should_stop - should the vhost task return from the work function
- * @vtsk: vhost_task to stop
- */
-bool vhost_task_should_stop(struct vhost_task *vtsk)
-{
- return test_bit(VHOST_TASK_FLAGS_STOP, &vtsk->flags);
-}
-EXPORT_SYMBOL_GPL(vhost_task_should_stop);
-
-/**
- * vhost_task_create - create a copy of a process to be used by the kernel
- * @fn: thread stack
+ * vhost_task_create - create a copy of a task to be used by the kernel
+ * @fn: vhost worker function
* @arg: data to be passed to fn
* @name: the thread's name
*
@@ -71,17 +101,17 @@ EXPORT_SYMBOL_GPL(vhost_task_should_stop);
* failure. The returned task is inactive, and the caller must fire it up
* through vhost_task_start().
*/
-struct vhost_task *vhost_task_create(int (*fn)(void *), void *arg,
+struct vhost_task *vhost_task_create(bool (*fn)(void *), void *arg,
const char *name)
{
struct kernel_clone_args args = {
- .flags = CLONE_FS | CLONE_UNTRACED | CLONE_VM,
+ .flags = CLONE_FS | CLONE_UNTRACED | CLONE_VM |
+ CLONE_THREAD | CLONE_SIGHAND,
.exit_signal = 0,
.fn = vhost_task_fn,
.name = name,
.user_worker = 1,
.no_files = 1,
- .ignore_signals = 1,
};
struct vhost_task *vtsk;
struct task_struct *tsk;
generated by cgit (git 2.34.1) at 2024-05-28 16:51:57 +0000