mirror of https://gitee.com/openkylin/linux.git
312 lines
7.5 KiB
C
312 lines
7.5 KiB
C
/*
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* OpenRISC process.c
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*
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* Linux architectural port borrowing liberally from similar works of
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* others. All original copyrights apply as per the original source
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* declaration.
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*
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* Modifications for the OpenRISC architecture:
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* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
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* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* This file handles the architecture-dependent parts of process handling...
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*/
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#define __KERNEL_SYSCALLS__
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#include <stdarg.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/stddef.h>
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#include <linux/unistd.h>
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#include <linux/ptrace.h>
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#include <linux/slab.h>
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#include <linux/elfcore.h>
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#include <linux/interrupt.h>
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#include <linux/delay.h>
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#include <linux/init_task.h>
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#include <linux/mqueue.h>
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#include <linux/fs.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/system.h>
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#include <asm/io.h>
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#include <asm/processor.h>
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#include <asm/spr_defs.h>
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#include <linux/smp.h>
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/*
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* Pointer to Current thread info structure.
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*
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* Used at user space -> kernel transitions.
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*/
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struct thread_info *current_thread_info_set[NR_CPUS] = { &init_thread_info, };
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void machine_restart(void)
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{
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printk(KERN_INFO "*** MACHINE RESTART ***\n");
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__asm__("l.nop 1");
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}
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/*
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* Similar to machine_power_off, but don't shut off power. Add code
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* here to freeze the system for e.g. post-mortem debug purpose when
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* possible. This halt has nothing to do with the idle halt.
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*/
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void machine_halt(void)
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{
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printk(KERN_INFO "*** MACHINE HALT ***\n");
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__asm__("l.nop 1");
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}
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/* If or when software power-off is implemented, add code here. */
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void machine_power_off(void)
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{
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printk(KERN_INFO "*** MACHINE POWER OFF ***\n");
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__asm__("l.nop 1");
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}
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void (*pm_power_off) (void) = machine_power_off;
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/*
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* When a process does an "exec", machine state like FPU and debug
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* registers need to be reset. This is a hook function for that.
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* Currently we don't have any such state to reset, so this is empty.
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*/
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void flush_thread(void)
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{
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}
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void show_regs(struct pt_regs *regs)
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{
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extern void show_registers(struct pt_regs *regs);
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/* __PHX__ cleanup this mess */
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show_registers(regs);
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}
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unsigned long thread_saved_pc(struct task_struct *t)
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{
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return (unsigned long)user_regs(t->stack)->pc;
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}
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void release_thread(struct task_struct *dead_task)
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{
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}
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/*
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* Copy the thread-specific (arch specific) info from the current
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* process to the new one p
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*/
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extern asmlinkage void ret_from_fork(void);
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int
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copy_thread(unsigned long clone_flags, unsigned long usp,
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unsigned long unused, struct task_struct *p, struct pt_regs *regs)
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{
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struct pt_regs *childregs;
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struct pt_regs *kregs;
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unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
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struct thread_info *ti;
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unsigned long top_of_kernel_stack;
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top_of_kernel_stack = sp;
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p->set_child_tid = p->clear_child_tid = NULL;
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/* Copy registers */
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/* redzone */
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sp -= STACK_FRAME_OVERHEAD;
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sp -= sizeof(struct pt_regs);
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childregs = (struct pt_regs *)sp;
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/* Copy parent registers */
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*childregs = *regs;
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if ((childregs->sr & SPR_SR_SM) == 1) {
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/* for kernel thread, set `current_thread_info'
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* and stackptr in new task
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*/
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childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
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childregs->gpr[10] = (unsigned long)task_thread_info(p);
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} else {
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childregs->sp = usp;
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}
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childregs->gpr[11] = 0; /* Result from fork() */
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/*
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* The way this works is that at some point in the future
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* some task will call _switch to switch to the new task.
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* That will pop off the stack frame created below and start
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* the new task running at ret_from_fork. The new task will
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* do some house keeping and then return from the fork or clone
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* system call, using the stack frame created above.
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*/
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/* redzone */
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sp -= STACK_FRAME_OVERHEAD;
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sp -= sizeof(struct pt_regs);
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kregs = (struct pt_regs *)sp;
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ti = task_thread_info(p);
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ti->ksp = sp;
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/* kregs->sp must store the location of the 'pre-switch' kernel stack
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* pointer... for a newly forked process, this is simply the top of
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* the kernel stack.
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*/
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kregs->sp = top_of_kernel_stack;
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kregs->gpr[3] = (unsigned long)current; /* arg to schedule_tail */
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kregs->gpr[10] = (unsigned long)task_thread_info(p);
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kregs->gpr[9] = (unsigned long)ret_from_fork;
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return 0;
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}
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/*
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* Set up a thread for executing a new program
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*/
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void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
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{
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unsigned long sr = regs->sr & ~SPR_SR_SM;
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set_fs(USER_DS);
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memset(regs->gpr, 0, sizeof(regs->gpr));
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regs->pc = pc;
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regs->sr = sr;
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regs->sp = sp;
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/* printk("start thread, ksp = %lx\n", current_thread_info()->ksp);*/
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}
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/* Fill in the fpu structure for a core dump. */
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int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu)
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{
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/* TODO */
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return 0;
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}
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extern struct thread_info *_switch(struct thread_info *old_ti,
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struct thread_info *new_ti);
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struct task_struct *__switch_to(struct task_struct *old,
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struct task_struct *new)
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{
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struct task_struct *last;
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struct thread_info *new_ti, *old_ti;
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unsigned long flags;
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local_irq_save(flags);
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/* current_set is an array of saved current pointers
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* (one for each cpu). we need them at user->kernel transition,
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* while we save them at kernel->user transition
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*/
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new_ti = new->stack;
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old_ti = old->stack;
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current_thread_info_set[smp_processor_id()] = new_ti;
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last = (_switch(old_ti, new_ti))->task;
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local_irq_restore(flags);
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return last;
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}
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/*
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* Write out registers in core dump format, as defined by the
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* struct user_regs_struct
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*/
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void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs)
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{
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dest[0] = 0; /* r0 */
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memcpy(dest+1, regs->gpr+1, 31*sizeof(unsigned long));
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dest[32] = regs->pc;
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dest[33] = regs->sr;
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dest[34] = 0;
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dest[35] = 0;
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}
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extern void _kernel_thread_helper(void);
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void __noreturn kernel_thread_helper(int (*fn) (void *), void *arg)
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{
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do_exit(fn(arg));
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}
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/*
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* Create a kernel thread.
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*/
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int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
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{
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struct pt_regs regs;
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memset(®s, 0, sizeof(regs));
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regs.gpr[20] = (unsigned long)fn;
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regs.gpr[22] = (unsigned long)arg;
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regs.sr = mfspr(SPR_SR);
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regs.pc = (unsigned long)_kernel_thread_helper;
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return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
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0, ®s, 0, NULL, NULL);
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}
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/*
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* sys_execve() executes a new program.
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*/
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asmlinkage long _sys_execve(const char __user *name,
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const char __user * const __user *argv,
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const char __user * const __user *envp,
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struct pt_regs *regs)
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{
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int error;
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char *filename;
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filename = getname(name);
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error = PTR_ERR(filename);
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if (IS_ERR(filename))
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goto out;
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error = do_execve(filename, argv, envp, regs);
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putname(filename);
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out:
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return error;
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}
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unsigned long get_wchan(struct task_struct *p)
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{
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/* TODO */
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return 0;
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}
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int kernel_execve(const char *filename, char *const argv[], char *const envp[])
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{
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register long __res asm("r11") = __NR_execve;
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register long __a asm("r3") = (long)(filename);
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register long __b asm("r4") = (long)(argv);
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register long __c asm("r5") = (long)(envp);
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__asm__ volatile ("l.sys 1"
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: "=r" (__res), "=r"(__a), "=r"(__b), "=r"(__c)
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: "0"(__res), "1"(__a), "2"(__b), "3"(__c)
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: "r6", "r7", "r8", "r12", "r13", "r15",
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"r17", "r19", "r21", "r23", "r25", "r27",
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"r29", "r31");
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__asm__ volatile ("l.nop");
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return __res;
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}
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