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/arc/kernel/process.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'arch/arc') diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c index caf948ba647c..3369f0700702 100644 --- a/arch/arc/kernel/process.c +++ b/arch/arc/kernel/process.c @@ -166,7 +166,6 @@ 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; struct pt_regs *c_regs; /* child's pt_regs */ unsigned long *childksp; /* to unwind out of __switch_to() */ @@ -193,11 +192,11 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) childksp[0] = 0; /* fp */ childksp[1] = (unsigned long)ret_from_fork; /* blink */ - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { memset(c_regs, 0, sizeof(struct pt_regs)); - c_callee->r13 = kthread_arg; - c_callee->r14 = usp; /* function */ + c_callee->r13 = (unsigned long)args->fn_arg; + c_callee->r14 = (unsigned long)args->fn; return 0; } -- cgit v1.2.3