From 7147e215480323bb2617fcebf585c447188ff760 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 14 Oct 2012 01:41:42 -0400 Subject: sh: switch to generic kernel_thread()/kernel_execve() Signed-off-by: Al Viro --- arch/sh/kernel/process_64.c | 60 ++++++++++++--------------------------------- 1 file changed, 16 insertions(+), 44 deletions(-) (limited to 'arch/sh/kernel/process_64.c') diff --git a/arch/sh/kernel/process_64.c b/arch/sh/kernel/process_64.c index 98a709f0c3c4..fd338b030fd9 100644 --- a/arch/sh/kernel/process_64.c +++ b/arch/sh/kernel/process_64.c @@ -284,39 +284,6 @@ void show_regs(struct pt_regs *regs) } } -/* - * Create a kernel thread - */ -__noreturn void kernel_thread_helper(void *arg, int (*fn)(void *)) -{ - do_exit(fn(arg)); -} - -/* - * This is the mechanism for creating a new kernel thread. - * - * NOTE! Only a kernel-only process(ie the swapper or direct descendants - * who haven't done an "execve()") should use this: it will work within - * a system call from a "real" process, but the process memory space will - * not be freed until both the parent and the child have exited. - */ -int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) -{ - struct pt_regs regs; - - memset(®s, 0, sizeof(regs)); - regs.regs[2] = (unsigned long)arg; - regs.regs[3] = (unsigned long)fn; - - regs.pc = (unsigned long)kernel_thread_helper; - regs.sr = (1 << 30); - - /* Ok, create the new process.. */ - return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, - ®s, 0, NULL, NULL); -} -EXPORT_SYMBOL(kernel_thread); - /* * Free current thread data structures etc.. */ @@ -401,15 +368,17 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) EXPORT_SYMBOL(dump_fpu); asmlinkage void ret_from_fork(void); +asmlinkage void ret_from_kernel_thread(void); int copy_thread(unsigned long clone_flags, unsigned long usp, - unsigned long unused, + unsigned long arg, struct task_struct *p, struct pt_regs *regs) { struct pt_regs *childregs; #ifdef CONFIG_SH_FPU - if(last_task_used_math == current) { + /* can't happen for a kernel thread */ + if (last_task_used_math == current) { enable_fpu(); save_fpu(current); disable_fpu(); @@ -419,7 +388,17 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, #endif /* Copy from sh version */ childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1; + p->thread.sp = (unsigned long) childregs; + if (unlikely(p->flags & PF_KTHREAD)) { + memset(childregs, 0, sizeof(struct pt_regs)); + childregs->regs[2] = (unsigned long)arg; + childregs->regs[3] = (unsigned long)fn; + childregs->sr = (1 << 30); /* not user_mode */ + childregs->sr |= SR_FD; /* Invalidate FPU flag */ + p->thread.pc = (unsigned long) ret_from_kernel_thread; + return 0; + } *childregs = *regs; /* @@ -428,19 +407,12 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, * 32-bit wide and context switch must take care * of NEFF sign extension. */ - if (user_mode(regs)) { - childregs->regs[15] = neff_sign_extend(usp); - p->thread.uregs = childregs; - } else { - childregs->regs[15] = - neff_sign_extend((unsigned long)task_stack_page(p) + - THREAD_SIZE); - } + childregs->regs[15] = neff_sign_extend(usp); + p->thread.uregs = childregs; childregs->regs[9] = 0; /* Set return value for child */ childregs->sr |= SR_FD; /* Invalidate FPU flag */ - p->thread.sp = (unsigned long) childregs; p->thread.pc = (unsigned long) ret_from_fork; return 0; -- cgit v1.2.1