Merge tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-block.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index 124829ed01632303b1b2f9614f1275809fb506ba..9d44f2d46c6964d5cf7e29e06ad377b03fe25dc2 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1982,7 +1982,7 @@ static __latent_entropy struct task_struct *copy_process(
        struct task_struct *p;
        struct multiprocess_signals delayed;
        struct file *pidfile = NULL;
-       u64 clone_flags = args->flags;
+       const u64 clone_flags = args->flags;
        struct nsproxy *nsp = current->nsproxy;
 
        /*
@@ -2071,6 +2071,9 @@ static __latent_entropy struct task_struct *copy_process(
        p = dup_task_struct(current, node);
        if (!p)
                goto fork_out;
+       p->flags &= ~PF_KTHREAD;
+       if (args->kthread)
+               p->flags |= PF_KTHREAD;
        if (args->io_thread) {
                /*
                 * Mark us an IO worker, and block any signal that isn't
@@ -2160,7 +2163,7 @@ static __latent_entropy struct task_struct *copy_process(
        p->io_context = NULL;
        audit_set_context(p, NULL);
        cgroup_fork(p);
-       if (p->flags & PF_KTHREAD) {
+       if (args->kthread) {
                if (!set_kthread_struct(p))
                        goto bad_fork_cleanup_delayacct;
        }
@@ -2243,7 +2246,7 @@ static __latent_entropy struct task_struct *copy_process(
        retval = copy_io(clone_flags, p);
        if (retval)
                goto bad_fork_cleanup_namespaces;
-       retval = copy_thread(clone_flags, args->stack, args->stack_size, p, args->tls);
+       retval = copy_thread(p, args);
        if (retval)
                goto bad_fork_cleanup_io;
 
@@ -2547,11 +2550,21 @@ static inline void init_idle_pids(struct task_struct *idle)
        }
 }
 
+static int idle_dummy(void *dummy)
+{
+       /* This function is never called */
+       return 0;
+}
+
 struct task_struct * __init fork_idle(int cpu)
 {
        struct task_struct *task;
        struct kernel_clone_args args = {
-               .flags = CLONE_VM,
+               .flags          = CLONE_VM,
+               .fn             = &idle_dummy,
+               .fn_arg         = NULL,
+               .kthread        = 1,
+               .idle           = 1,
        };
 
        task = copy_process(&init_struct_pid, 0, cpu_to_node(cpu), &args);
@@ -2582,8 +2595,8 @@ struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node)
                .flags          = ((lower_32_bits(flags) | CLONE_VM |
                                    CLONE_UNTRACED) & ~CSIGNAL),
                .exit_signal    = (lower_32_bits(flags) & CSIGNAL),
-               .stack          = (unsigned long)fn,
-               .stack_size     = (unsigned long)arg,
+               .fn             = fn,
+               .fn_arg         = arg,
                .io_thread      = 1,
        };
 
@@ -2687,8 +2700,25 @@ pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
                .flags          = ((lower_32_bits(flags) | CLONE_VM |
                                    CLONE_UNTRACED) & ~CSIGNAL),
                .exit_signal    = (lower_32_bits(flags) & CSIGNAL),
-               .stack          = (unsigned long)fn,
-               .stack_size     = (unsigned long)arg,
+               .fn             = fn,
+               .fn_arg         = arg,
+               .kthread        = 1,
+       };
+
+       return kernel_clone(&args);
+}
+
+/*
+ * Create a user mode thread.
+ */
+pid_t user_mode_thread(int (*fn)(void *), void *arg, unsigned long flags)
+{
+       struct kernel_clone_args args = {
+               .flags          = ((lower_32_bits(flags) | CLONE_VM |
+                                   CLONE_UNTRACED) & ~CSIGNAL),
+               .exit_signal    = (lower_32_bits(flags) & CSIGNAL),
+               .fn             = fn,
+               .fn_arg         = arg,
        };
 
        return kernel_clone(&args);