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![Paolo 'Blaisorblade' Giarrusso](/assets/img/avatar_default.png)
Ugly trick to help make malloc not sleeping - we can't do anything else. But this is not yet optimal, since spinlock don't trigger in_atomic() when preemption is disabled. Also, even if ugly, this was already used in one place, and was even more bogus. Fix it. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
471 lines
9.2 KiB
C
471 lines
9.2 KiB
C
/*
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* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
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* Copyright 2003 PathScale, Inc.
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* Licensed under the GPL
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*/
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#include "linux/config.h"
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#include "linux/kernel.h"
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#include "linux/sched.h"
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#include "linux/interrupt.h"
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#include "linux/string.h"
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#include "linux/mm.h"
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#include "linux/slab.h"
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#include "linux/utsname.h"
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#include "linux/fs.h"
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#include "linux/utime.h"
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#include "linux/smp_lock.h"
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#include "linux/module.h"
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#include "linux/init.h"
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#include "linux/capability.h"
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#include "linux/vmalloc.h"
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#include "linux/spinlock.h"
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#include "linux/proc_fs.h"
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#include "linux/ptrace.h"
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#include "linux/random.h"
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#include "asm/unistd.h"
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#include "asm/mman.h"
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#include "asm/segment.h"
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#include "asm/stat.h"
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#include "asm/pgtable.h"
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#include "asm/processor.h"
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#include "asm/tlbflush.h"
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#include "asm/uaccess.h"
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#include "asm/user.h"
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#include "user_util.h"
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#include "kern_util.h"
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#include "kern.h"
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#include "signal_kern.h"
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#include "init.h"
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#include "irq_user.h"
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#include "mem_user.h"
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#include "tlb.h"
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#include "frame_kern.h"
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#include "sigcontext.h"
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#include "os.h"
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#include "mode.h"
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#include "mode_kern.h"
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#include "choose-mode.h"
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/* This is a per-cpu array. A processor only modifies its entry and it only
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* cares about its entry, so it's OK if another processor is modifying its
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* entry.
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*/
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struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
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int external_pid(void *t)
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{
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struct task_struct *task = t ? t : current;
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return(CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task));
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}
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int pid_to_processor_id(int pid)
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{
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int i;
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for(i = 0; i < ncpus; i++){
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if(cpu_tasks[i].pid == pid) return(i);
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}
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return(-1);
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}
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void free_stack(unsigned long stack, int order)
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{
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free_pages(stack, order);
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}
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unsigned long alloc_stack(int order, int atomic)
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{
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unsigned long page;
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gfp_t flags = GFP_KERNEL;
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if (atomic)
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flags = GFP_ATOMIC;
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page = __get_free_pages(flags, order);
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if(page == 0)
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return(0);
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stack_protections(page);
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return(page);
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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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int pid;
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current->thread.request.u.thread.proc = fn;
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current->thread.request.u.thread.arg = arg;
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pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
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¤t->thread.regs, 0, NULL, NULL);
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if(pid < 0)
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panic("do_fork failed in kernel_thread, errno = %d", pid);
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return(pid);
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}
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void set_current(void *t)
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{
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struct task_struct *task = t;
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cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
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{ external_pid(task), task });
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}
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void *_switch_to(void *prev, void *next, void *last)
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{
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struct task_struct *from = prev;
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struct task_struct *to= next;
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to->thread.prev_sched = from;
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set_current(to);
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do {
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current->thread.saved_task = NULL ;
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CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
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if(current->thread.saved_task)
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show_regs(&(current->thread.regs));
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next= current->thread.saved_task;
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prev= current;
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} while(current->thread.saved_task);
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return(current->thread.prev_sched);
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}
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void interrupt_end(void)
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{
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if(need_resched()) schedule();
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if(test_tsk_thread_flag(current, TIF_SIGPENDING)) do_signal();
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}
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void release_thread(struct task_struct *task)
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{
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CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
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}
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void exit_thread(void)
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{
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unprotect_stack((unsigned long) current_thread);
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}
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void *get_current(void)
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{
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return(current);
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}
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int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
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unsigned long stack_top, struct task_struct * p,
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struct pt_regs *regs)
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{
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p->thread = (struct thread_struct) INIT_THREAD;
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return(CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
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clone_flags, sp, stack_top, p, regs));
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}
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void initial_thread_cb(void (*proc)(void *), void *arg)
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{
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int save_kmalloc_ok = kmalloc_ok;
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kmalloc_ok = 0;
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CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
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arg);
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kmalloc_ok = save_kmalloc_ok;
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}
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unsigned long stack_sp(unsigned long page)
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{
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return(page + PAGE_SIZE - sizeof(void *));
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}
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int current_pid(void)
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{
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return(current->pid);
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}
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void default_idle(void)
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{
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CHOOSE_MODE(uml_idle_timer(), (void) 0);
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atomic_inc(&init_mm.mm_count);
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current->mm = &init_mm;
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current->active_mm = &init_mm;
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while(1){
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/* endless idle loop with no priority at all */
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/*
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* although we are an idle CPU, we do not want to
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* get into the scheduler unnecessarily.
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*/
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if(need_resched())
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schedule();
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idle_sleep(10);
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}
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}
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void cpu_idle(void)
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{
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CHOOSE_MODE(init_idle_tt(), init_idle_skas());
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}
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int page_size(void)
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{
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return(PAGE_SIZE);
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}
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void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
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pte_t *pte_out)
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{
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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pte_t ptent;
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if(task->mm == NULL)
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return(ERR_PTR(-EINVAL));
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pgd = pgd_offset(task->mm, addr);
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if(!pgd_present(*pgd))
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return(ERR_PTR(-EINVAL));
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pud = pud_offset(pgd, addr);
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if(!pud_present(*pud))
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return(ERR_PTR(-EINVAL));
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pmd = pmd_offset(pud, addr);
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if(!pmd_present(*pmd))
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return(ERR_PTR(-EINVAL));
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pte = pte_offset_kernel(pmd, addr);
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ptent = *pte;
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if(!pte_present(ptent))
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return(ERR_PTR(-EINVAL));
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if(pte_out != NULL)
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*pte_out = ptent;
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return((void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK));
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}
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char *current_cmd(void)
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{
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#if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
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return("(Unknown)");
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#else
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void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
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return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
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#endif
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}
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void force_sigbus(void)
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{
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printk(KERN_ERR "Killing pid %d because of a lack of memory\n",
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current->pid);
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lock_kernel();
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sigaddset(¤t->pending.signal, SIGBUS);
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recalc_sigpending();
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current->flags |= PF_SIGNALED;
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do_exit(SIGBUS | 0x80);
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}
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void dump_thread(struct pt_regs *regs, struct user *u)
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{
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}
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void enable_hlt(void)
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{
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panic("enable_hlt");
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}
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EXPORT_SYMBOL(enable_hlt);
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void disable_hlt(void)
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{
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panic("disable_hlt");
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}
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EXPORT_SYMBOL(disable_hlt);
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void *um_kmalloc(int size)
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{
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return kmalloc(size, GFP_KERNEL);
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}
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void *um_kmalloc_atomic(int size)
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{
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return kmalloc(size, GFP_ATOMIC);
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}
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void *um_vmalloc(int size)
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{
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return vmalloc(size);
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}
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void *um_vmalloc_atomic(int size)
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{
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return __vmalloc(size, GFP_ATOMIC | __GFP_HIGHMEM, PAGE_KERNEL);
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}
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int __cant_sleep(void) {
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return in_atomic() || irqs_disabled() || in_interrupt();
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/* Is in_interrupt() really needed? */
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}
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unsigned long get_fault_addr(void)
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{
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return((unsigned long) current->thread.fault_addr);
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}
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EXPORT_SYMBOL(get_fault_addr);
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void not_implemented(void)
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{
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printk(KERN_DEBUG "Something isn't implemented in here\n");
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}
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EXPORT_SYMBOL(not_implemented);
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int user_context(unsigned long sp)
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{
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unsigned long stack;
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stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
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return(stack != (unsigned long) current_thread);
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}
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extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
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void do_uml_exitcalls(void)
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{
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exitcall_t *call;
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call = &__uml_exitcall_end;
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while (--call >= &__uml_exitcall_begin)
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(*call)();
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}
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char *uml_strdup(char *string)
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{
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return kstrdup(string, GFP_KERNEL);
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}
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int copy_to_user_proc(void __user *to, void *from, int size)
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{
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return(copy_to_user(to, from, size));
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}
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int copy_from_user_proc(void *to, void __user *from, int size)
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{
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return(copy_from_user(to, from, size));
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}
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int clear_user_proc(void __user *buf, int size)
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{
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return(clear_user(buf, size));
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}
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int strlen_user_proc(char __user *str)
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{
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return(strlen_user(str));
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}
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int smp_sigio_handler(void)
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{
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#ifdef CONFIG_SMP
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int cpu = current_thread->cpu;
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IPI_handler(cpu);
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if(cpu != 0)
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return(1);
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#endif
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return(0);
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}
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int cpu(void)
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{
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return(current_thread->cpu);
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}
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static atomic_t using_sysemu = ATOMIC_INIT(0);
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int sysemu_supported;
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void set_using_sysemu(int value)
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{
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if (value > sysemu_supported)
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return;
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atomic_set(&using_sysemu, value);
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}
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int get_using_sysemu(void)
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{
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return atomic_read(&using_sysemu);
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}
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static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
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{
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if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
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*eof = 1;
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return strlen(buf);
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}
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static int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
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{
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char tmp[2];
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if (copy_from_user(tmp, buf, 1))
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return -EFAULT;
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if (tmp[0] >= '0' && tmp[0] <= '2')
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set_using_sysemu(tmp[0] - '0');
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return count; /*We use the first char, but pretend to write everything*/
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}
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int __init make_proc_sysemu(void)
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{
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struct proc_dir_entry *ent;
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if (!sysemu_supported)
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return 0;
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ent = create_proc_entry("sysemu", 0600, &proc_root);
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if (ent == NULL)
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{
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printk(KERN_WARNING "Failed to register /proc/sysemu\n");
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return(0);
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}
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ent->read_proc = proc_read_sysemu;
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ent->write_proc = proc_write_sysemu;
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return 0;
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}
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late_initcall(make_proc_sysemu);
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int singlestepping(void * t)
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{
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struct task_struct *task = t ? t : current;
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if ( ! (task->ptrace & PT_DTRACE) )
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return(0);
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if (task->thread.singlestep_syscall)
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return(1);
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return 2;
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}
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/*
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* Only x86 and x86_64 have an arch_align_stack().
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* All other arches have "#define arch_align_stack(x) (x)"
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* in their asm/system.h
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* As this is included in UML from asm-um/system-generic.h,
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* we can use it to behave as the subarch does.
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*/
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#ifndef arch_align_stack
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unsigned long arch_align_stack(unsigned long sp)
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{
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if (randomize_va_space)
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sp -= get_random_int() % 8192;
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return sp & ~0xf;
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}
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#endif
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