From 5bd2e97c868a8a44470950ed01846cab6328e540 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 12 Apr 2022 10:18:48 -0500 Subject: fork: Generalize PF_IO_WORKER handling Add fn and fn_arg members into struct kernel_clone_args and test for them in copy_thread (instead of testing for PF_KTHREAD | PF_IO_WORKER). This allows any task that wants to be a user space task that only runs in kernel mode to use this functionality. The code on x86 is an exception and still retains a PF_KTHREAD test because x86 unlikely everything else handles kthreads slightly differently than user space tasks that start with a function. The functions that created tasks that start with a function have been updated to set ".fn" and ".fn_arg" instead of ".stack" and ".stack_size". These functions are fork_idle(), create_io_thread(), kernel_thread(), and user_mode_thread(). Link: https://lkml.kernel.org/r/20220506141512.516114-4-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" --- arch/alpha/kernel/process.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'arch/alpha') diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index 732e39217c7f..6cbba7370b4e 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -237,7 +237,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long kthread_arg = args->stack_size; unsigned long tls = args->tls; extern void ret_from_fork(void); extern void ret_from_kernel_thread(void); @@ -251,13 +250,13 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) childti->pcb.ksp = (unsigned long) childstack; childti->pcb.flags = 1; /* set FEN, clear everything else */ - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { /* kernel thread */ memset(childstack, 0, sizeof(struct switch_stack) + sizeof(struct pt_regs)); childstack->r26 = (unsigned long) ret_from_kernel_thread; - childstack->r9 = usp; /* function */ - childstack->r10 = kthread_arg; + childstack->r9 = (unsigned long) args->fn; + childstack->r10 = (unsigned long) args->fn_arg; childregs->hae = alpha_mv.hae_cache; childti->pcb.usp = 0; return 0; -- cgit v1.2.3