From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/s390/kernel/process.c | 226 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 226 insertions(+) create mode 100644 arch/s390/kernel/process.c (limited to 'arch/s390/kernel/process.c') diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c new file mode 100644 index 000000000..dc5edc29b --- /dev/null +++ b/arch/s390/kernel/process.c @@ -0,0 +1,226 @@ +/* + * This file handles the architecture dependent parts of process handling. + * + * Copyright IBM Corp. 1999, 2009 + * Author(s): Martin Schwidefsky , + * Hartmut Penner , + * Denis Joseph Barrow, + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#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]; +} + +extern void 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) +{ +} + +void arch_release_task_struct(struct task_struct *tsk) +{ + if (tsk->thread.vxrs) + kfree(tsk->thread.vxrs); +} + +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); + /* 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; + p->thread.ri_signum = 0; + frame->childregs.psw.mask &= ~PSW_MASK_RI; + + /* 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; + p->thread.vxrs = NULL; + /* 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.fp_regs.fpc = 0; + 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) +{ + save_fp_ctl(&fpregs->fpc); + save_fp_regs(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) +{ + /* 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; + + ret = PAGE_ALIGN(mm->brk + brk_rnd()); + return (ret > mm->brk) ? ret : mm->brk; +} -- cgit v1.2.3-54-g00ecf