/* * This file handles the architecture dependent parts of process handling. * *    Copyright IBM Corp. 1999, 2009 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>, *		 Hartmut Penner <hp@de.ibm.com>, *		 Denis Joseph Barrow, */ #include <linux/compiler.h>#include <linux/cpu.h>#include <linux/sched.h>#include <linux/kernel.h>#include <linux/mm.h>#include <linux/elfcore.h>#include <linux/smp.h>#include <linux/slab.h>#include <linux/interrupt.h>#include <linux/tick.h>#include <linux/personality.h>#include <linux/syscalls.h>#include <linux/compat.h>#include <linux/kprobes.h>#include <linux/random.h>#include <linux/module.h>#include <asm/io.h>#include <asm/processor.h>#include <asm/vtimer.h>#include <asm/exec.h>#include <asm/irq.h>#include <asm/nmi.h>#include <asm/smp.h>#include <asm/switch_to.h>#include <asm/runtime_instr.h>#include "entry.h" asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); /* * Return saved PC of a blocked thread. used in kernel/sched. * resume in entry.S does not create a new stack frame, it * just stores the registers %r6-%r15 to the frame given by * schedule. We want to return the address of the caller of * schedule, so we have to walk the backchain one time to * find the frame schedule() store its return address. */unsigned long thread_saved_pc(struct task_struct *tsk){	struct stack_frame *sf, *low, *high; 	if (!tsk || !task_stack_page(tsk))		return 0;	low = task_stack_page(tsk);	high = (struct stack_frame *) task_pt_regs(tsk);	sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN);	if (sf <= low || sf > high)		return 0;	sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);	if (sf <= low || sf > high)		return 0;	return sf->gprs[8];} void arch_cpu_idle(void){	local_mcck_disable();	if (test_thread_flag(TIF_MCCK_PENDING)) {		local_mcck_enable();		local_irq_enable();		return;	}	/* Halt the cpu and keep track of cpu time accounting. */	vtime_stop_cpu();	local_irq_enable();} void arch_cpu_idle_exit(void){	if (test_thread_flag(TIF_MCCK_PENDING))		s390_handle_mcck();} void arch_cpu_idle_dead(void){	cpu_die();} extern void __kprobes kernel_thread_starter(void); /* * Free current thread data structures etc.. */void exit_thread(void){	exit_thread_runtime_instr();} void flush_thread(void){} void release_thread(struct task_struct *dead_task){} int copy_thread(unsigned long clone_flags, unsigned long new_stackp,		unsigned long arg, struct task_struct *p){	struct thread_info *ti;	struct fake_frame	{		struct stack_frame sf;		struct pt_regs childregs;	} *frame; 	frame = container_of(task_pt_regs(p), struct fake_frame, childregs);	p->thread.ksp = (unsigned long) frame;	/* Save access registers to new thread structure. */	save_access_regs(&p->thread.acrs[0]);	/* start new process with ar4 pointing to the correct address space */	p->thread.mm_segment = get_fs();	/* Don't copy debug registers */	memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));	memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));	clear_tsk_thread_flag(p, TIF_SINGLE_STEP);	clear_tsk_thread_flag(p, TIF_PER_TRAP);	/* Initialize per thread user and system timer values */	ti = task_thread_info(p);	ti->user_timer = 0;	ti->system_timer = 0; 	frame->sf.back_chain = 0;	/* new return point is ret_from_fork */	frame->sf.gprs[8] = (unsigned long) ret_from_fork;	/* fake return stack for resume(), don't go back to schedule */	frame->sf.gprs[9] = (unsigned long) frame; 	/* Store access registers to kernel stack of new process. */	if (unlikely(p->flags & PF_KTHREAD)) {		/* kernel thread */		memset(&frame->childregs, 0, sizeof(struct pt_regs));		frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT |				PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;		frame->childregs.psw.addr = PSW_ADDR_AMODE |				(unsigned long) kernel_thread_starter;		frame->childregs.gprs[9] = new_stackp; /* function */		frame->childregs.gprs[10] = arg;		frame->childregs.gprs[11] = (unsigned long) do_exit;		frame->childregs.orig_gpr2 = -1; 		return 0;	}	frame->childregs = *current_pt_regs();	frame->childregs.gprs[2] = 0;	/* child returns 0 on fork. */	if (new_stackp)		frame->childregs.gprs[15] = new_stackp; 	/* Don't copy runtime instrumentation info */	p->thread.ri_cb = NULL;	p->thread.ri_signum = 0;	frame->childregs.psw.mask &= ~PSW_MASK_RI; #ifndef CONFIG_64BIT	/*	 * save fprs to current->thread.fp_regs to merge them with	 * the emulated registers and then copy the result to the child.	 */	save_fp_ctl(&current->thread.fp_regs.fpc);	save_fp_regs(current->thread.fp_regs.fprs);	memcpy(&p->thread.fp_regs, &current->thread.fp_regs,	       sizeof(s390_fp_regs));	/* Set a new TLS ?  */	if (clone_flags & CLONE_SETTLS)		p->thread.acrs[0] = frame->childregs.gprs[6];#else /* CONFIG_64BIT */	/* Save the fpu registers to new thread structure. */	save_fp_ctl(&p->thread.fp_regs.fpc);	save_fp_regs(p->thread.fp_regs.fprs);	p->thread.fp_regs.pad = 0;	/* Set a new TLS ?  */	if (clone_flags & CLONE_SETTLS) {		unsigned long tls = frame->childregs.gprs[6];		if (is_compat_task()) {			p->thread.acrs[0] = (unsigned int)tls;		} else {			p->thread.acrs[0] = (unsigned int)(tls >> 32);			p->thread.acrs[1] = (unsigned int)tls;		}	}#endif /* CONFIG_64BIT */	return 0;} asmlinkage void execve_tail(void){	current->thread.fp_regs.fpc = 0;	if (MACHINE_HAS_IEEE)		asm volatile("sfpc %0,%0" : : "d" (0));} /* * fill in the FPU structure for a core dump. */int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs){#ifndef CONFIG_64BIT	/*	 * save fprs to current->thread.fp_regs to merge them with	 * the emulated registers and then copy the result to the dump.	 */	save_fp_ctl(&current->thread.fp_regs.fpc);	save_fp_regs(current->thread.fp_regs.fprs);	memcpy(fpregs, &current->thread.fp_regs, sizeof(s390_fp_regs));#else /* CONFIG_64BIT */	save_fp_ctl(&fpregs->fpc);	save_fp_regs(fpregs->fprs);#endif /* CONFIG_64BIT */	return 1;}EXPORT_SYMBOL(dump_fpu); unsigned long get_wchan(struct task_struct *p){	struct stack_frame *sf, *low, *high;	unsigned long return_address;	int count; 	if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))		return 0;	low = task_stack_page(p);	high = (struct stack_frame *) task_pt_regs(p);	sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);	if (sf <= low || sf > high)		return 0;	for (count = 0; count < 16; count++) {		sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);		if (sf <= low || sf > high)			return 0;		return_address = sf->gprs[8] & PSW_ADDR_INSN;		if (!in_sched_functions(return_address))			return return_address;	}	return 0;} unsigned long arch_align_stack(unsigned long sp){	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)		sp -= get_random_int() & ~PAGE_MASK;	return sp & ~0xf;} static inline unsigned long brk_rnd(void){	/* 8MB for 32bit, 1GB for 64bit */	if (is_32bit_task())		return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;	else		return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;} unsigned long arch_randomize_brk(struct mm_struct *mm){	unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd()); 	if (ret < mm->brk)		return mm->brk;	return ret;} unsigned long randomize_et_dyn(unsigned long base){	unsigned long ret = PAGE_ALIGN(base + brk_rnd()); 	if (!(current->flags & PF_RANDOMIZE))		return base;	if (ret < base)		return base;	return ret;}