| /* |
| * 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 <linux/init_task.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"); |
| |
| /* FPU save area for the init task */ |
| __vector128 init_task_fpu_regs[__NUM_VXRS] __init_task_data; |
| |
| /* |
| * 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]; |
| } |
| |
| extern void kernel_thread_starter(void); |
| |
| void flush_thread(void) |
| { |
| } |
| |
| void release_thread(struct task_struct *dead_task) |
| { |
| } |
| |
| void arch_release_task_struct(struct task_struct *tsk) |
| { |
| /* Free either the floating-point or the vector register save area */ |
| kfree(tsk->thread.fpu.regs); |
| runtime_instr_release(tsk); |
| } |
| |
| int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) |
| { |
| size_t fpu_regs_size; |
| |
| *dst = *src; |
| |
| /* |
| * If the vector extension is available, it is enabled for all tasks, |
| * and, thus, the FPU register save area must be allocated accordingly. |
| */ |
| fpu_regs_size = MACHINE_HAS_VX ? sizeof(__vector128) * __NUM_VXRS |
| : sizeof(freg_t) * __NUM_FPRS; |
| dst->thread.fpu.regs = kzalloc(fpu_regs_size, GFP_KERNEL|__GFP_REPEAT); |
| if (!dst->thread.fpu.regs) |
| return -ENOMEM; |
| |
| /* |
| * Save the floating-point or vector register state of the current |
| * task and set the CIF_FPU flag to lazy restore the FPU register |
| * state when returning to user space. |
| */ |
| save_fpu_regs(); |
| dst->thread.fpu.fpc = current->thread.fpu.fpc; |
| memcpy(dst->thread.fpu.regs, current->thread.fpu.regs, fpu_regs_size); |
| |
| return 0; |
| } |
| |
| 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); |
| p->thread.per_flags = 0; |
| /* 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. */ |
| frame->childregs.flags = 0; |
| if (new_stackp) |
| frame->childregs.gprs[15] = new_stackp; |
| |
| /* Don't copy runtime instrumentation info */ |
| p->thread.ri_cb = NULL; |
| frame->childregs.psw.mask &= ~PSW_MASK_RI; |
| |
| /* 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; |
| } |
| } |
| return 0; |
| } |
| |
| asmlinkage void execve_tail(void) |
| { |
| current->thread.fpu.fpc = 0; |
| asm volatile("sfpc %0" : : "d" (0)); |
| } |
| |
| /* |
| * fill in the FPU structure for a core dump. |
| */ |
| int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) |
| { |
| save_fpu_regs(); |
| fpregs->fpc = current->thread.fpu.fpc; |
| fpregs->pad = 0; |
| if (MACHINE_HAS_VX) |
| convert_vx_to_fp((freg_t *)&fpregs->fprs, |
| current->thread.fpu.vxrs); |
| else |
| memcpy(&fpregs->fprs, current->thread.fpu.fprs, |
| sizeof(fpregs->fprs)); |
| 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) |
| { |
| return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; |
| } |
| |
| unsigned long arch_randomize_brk(struct mm_struct *mm) |
| { |
| unsigned long ret; |
| |
| ret = PAGE_ALIGN(mm->brk + brk_rnd()); |
| return (ret > mm->brk) ? ret : mm->brk; |
| } |