mirror of https://gitee.com/openkylin/linux.git
402 lines
8.5 KiB
C
402 lines
8.5 KiB
C
/*
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* Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
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* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
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* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.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/stddef.h>
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#include <linux/err.h>
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#include <linux/hardirq.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/personality.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 <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/task.h>
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#include <linux/sched/task_stack.h>
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#include <linux/seq_file.h>
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#include <linux/tick.h>
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#include <linux/threads.h>
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#include <linux/tracehook.h>
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#include <asm/current.h>
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#include <asm/pgtable.h>
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#include <asm/mmu_context.h>
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#include <linux/uaccess.h>
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#include <as-layout.h>
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#include <kern_util.h>
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#include <os.h>
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#include <skas.h>
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#include <timer-internal.h>
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/*
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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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static inline int external_pid(void)
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{
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/* FIXME: Need to look up userspace_pid by cpu */
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return userspace_pid[0];
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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)
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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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return page;
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}
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static inline void set_current(struct task_struct *task)
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{
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cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
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{ external_pid(), task });
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}
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extern void arch_switch_to(struct task_struct *to);
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void *__switch_to(struct task_struct *from, struct task_struct *to)
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{
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to->thread.prev_sched = from;
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set_current(to);
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switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
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arch_switch_to(current);
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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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struct pt_regs *regs = ¤t->thread.regs;
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if (need_resched())
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schedule();
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if (test_thread_flag(TIF_SIGPENDING))
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do_signal(regs);
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if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
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tracehook_notify_resume(regs);
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}
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int get_current_pid(void)
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{
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return task_pid_nr(current);
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}
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/*
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* This is called magically, by its address being stuffed in a jmp_buf
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* and being longjmp-d to.
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*/
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void new_thread_handler(void)
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{
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int (*fn)(void *), n;
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void *arg;
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if (current->thread.prev_sched != NULL)
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schedule_tail(current->thread.prev_sched);
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current->thread.prev_sched = NULL;
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fn = current->thread.request.u.thread.proc;
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arg = current->thread.request.u.thread.arg;
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/*
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* callback returns only if the kernel thread execs a process
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*/
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n = fn(arg);
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userspace(¤t->thread.regs.regs);
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}
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/* Called magically, see new_thread_handler above */
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void fork_handler(void)
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{
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force_flush_all();
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schedule_tail(current->thread.prev_sched);
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/*
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* XXX: if interrupt_end() calls schedule, this call to
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* arch_switch_to isn't needed. We could want to apply this to
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* improve performance. -bb
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*/
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arch_switch_to(current);
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current->thread.prev_sched = NULL;
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userspace(¤t->thread.regs.regs);
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}
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int copy_thread(unsigned long clone_flags, unsigned long sp,
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unsigned long arg, struct task_struct * p)
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{
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void (*handler)(void);
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int kthread = current->flags & PF_KTHREAD;
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int ret = 0;
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p->thread = (struct thread_struct) INIT_THREAD;
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if (!kthread) {
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memcpy(&p->thread.regs.regs, current_pt_regs(),
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sizeof(p->thread.regs.regs));
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PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0);
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if (sp != 0)
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REGS_SP(p->thread.regs.regs.gp) = sp;
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handler = fork_handler;
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arch_copy_thread(¤t->thread.arch, &p->thread.arch);
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} else {
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get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp);
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p->thread.request.u.thread.proc = (int (*)(void *))sp;
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p->thread.request.u.thread.arg = (void *)arg;
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handler = new_thread_handler;
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}
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new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
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if (!kthread) {
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clear_flushed_tls(p);
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/*
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* Set a new TLS for the child thread?
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*/
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if (clone_flags & CLONE_SETTLS)
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ret = arch_copy_tls(p);
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}
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return ret;
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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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initial_thread_cb_skas(proc, arg);
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kmalloc_ok = save_kmalloc_ok;
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}
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void arch_cpu_idle(void)
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{
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cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
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os_idle_sleep(UM_NSEC_PER_SEC);
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local_irq_enable();
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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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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_info();
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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(const char *string)
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{
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return kstrdup(string, GFP_KERNEL);
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}
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EXPORT_SYMBOL(uml_strdup);
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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 cpu(void)
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{
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return current_thread_info()->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 sysemu_proc_show(struct seq_file *m, void *v)
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{
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seq_printf(m, "%d\n", get_using_sysemu());
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return 0;
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}
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static int sysemu_proc_open(struct inode *inode, struct file *file)
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{
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return single_open(file, sysemu_proc_show, NULL);
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}
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static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
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size_t count, loff_t *pos)
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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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/* We use the first char, but pretend to write everything */
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return count;
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}
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static const struct file_operations sysemu_proc_fops = {
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.owner = THIS_MODULE,
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.open = sysemu_proc_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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.write = sysemu_proc_write,
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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 = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops);
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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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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/exec.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 (!(current->personality & ADDR_NO_RANDOMIZE) && 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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unsigned long get_wchan(struct task_struct *p)
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{
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unsigned long stack_page, sp, ip;
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bool seen_sched = 0;
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if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING))
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return 0;
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stack_page = (unsigned long) task_stack_page(p);
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/* Bail if the process has no kernel stack for some reason */
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if (stack_page == 0)
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return 0;
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sp = p->thread.switch_buf->JB_SP;
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/*
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* Bail if the stack pointer is below the bottom of the kernel
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* stack for some reason
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*/
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if (sp < stack_page)
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return 0;
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while (sp < stack_page + THREAD_SIZE) {
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ip = *((unsigned long *) sp);
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if (in_sched_functions(ip))
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/* Ignore everything until we're above the scheduler */
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seen_sched = 1;
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else if (kernel_text_address(ip) && seen_sched)
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return ip;
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sp += sizeof(unsigned long);
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}
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return 0;
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}
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int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
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{
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int cpu = current_thread_info()->cpu;
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return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu);
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}
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