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/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Copyright 2003 PathScale, Inc.
* Licensed under the GPL
*/
#include <linux/stddef.h>
#include <linux/err.h>
#include <linux/hardirq.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/personality.h>
#include <linux/proc_fs.h>
#include <linux/ptrace.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/tick.h>
#include <linux/threads.h>
#include <linux/tracehook.h>
#include <asm/current.h>
#include <asm/pgtable.h>
#include <asm/mmu_context.h>
#include <asm/uaccess.h>
#include "as-layout.h"
#include "kern_util.h"
#include "os.h"
#include "skas.h"
/*
* This is a per-cpu array. A processor only modifies its entry and it only
* cares about its entry, so it's OK if another processor is modifying its
* entry.
*/
struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
static inline int external_pid(void)
{
/* FIXME: Need to look up userspace_pid by cpu */
return userspace_pid[0];
}
int pid_to_processor_id(int pid)
{
int i;
for (i = 0; i < ncpus; i++) {
if (cpu_tasks[i].pid == pid)
return i;
}
return -1;
}
void free_stack(unsigned long stack, int order)
{
free_pages(stack, order);
}
unsigned long alloc_stack(int order, int atomic)
{
unsigned long page;
gfp_t flags = GFP_KERNEL;
if (atomic)
flags = GFP_ATOMIC;
page = __get_free_pages(flags, order);
return page;
}
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
int pid;
current->thread.request.u.thread.proc = fn;
current->thread.request.u.thread.arg = arg;
pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
¤t->thread.regs, 0, NULL, NULL);
return pid;
}
EXPORT_SYMBOL(kernel_thread);
static inline void set_current(struct task_struct *task)
{
cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
{ external_pid(), task });
}
extern void arch_switch_to(struct task_struct *to);
void *__switch_to(struct task_struct *from, struct task_struct *to)
{
to->thread.prev_sched = from;
set_current(to);
do {
current->thread.saved_task = NULL;
switch_threads(&from->thread.switch_buf,
&to->thread.switch_buf);
arch_switch_to(current);
if (current->thread.saved_task)
show_regs(&(current->thread.regs));
to = current->thread.saved_task;
from = current;
} while (current->thread.saved_task);
return current->thread.prev_sched;
}
void interrupt_end(void)
{
if (need_resched())
schedule();
if (test_thread_flag(TIF_SIGPENDING))
do_signal();
if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
tracehook_notify_resume(¤t->thread.regs);
}
void exit_thread(void)
{
}
int get_current_pid(void)
{
return task_pid_nr(current);
}
/*
* This is called magically, by its address being stuffed in a jmp_buf
* and being longjmp-d to.
*/
void new_thread_handler(void)
{
int (*fn)(void *), n;
void *arg;
if (current->thread.prev_sched != NULL)
schedule_tail(current->thread.prev_sched);
current->thread.prev_sched = NULL;
fn = current->thread.request.u.thread.proc;
arg = current->thread.request.u.thread.arg;
/*
* The return value is 1 if the kernel thread execs a process,
* 0 if it just exits
*/
n = run_kernel_thread(fn, arg, ¤t->thread.exec_buf);
if (n == 1) {
/* Handle any immediate reschedules or signals */
interrupt_end();
userspace(¤t->thread.regs.regs);
}
else do_exit(0);
}
/* Called magically, see new_thread_handler above */
void fork_handler(void)
{
force_flush_all();
schedule_tail(current->thread.prev_sched);
/*
* XXX: if interrupt_end() calls schedule, this call to
* arch_switch_to isn't needed. We could want to apply this to
* improve performance. -bb
*/
arch_switch_to(current);
current->thread.prev_sched = NULL;
/* Handle any immediate reschedules or signals */
interrupt_end();
userspace(¤t->thread.regs.regs);
}
int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long stack_top, struct task_struct * p,
struct pt_regs *regs)
{
void (*handler)(void);
int ret = 0;
p->thread = (struct thread_struct) INIT_THREAD;
if (current->thread.forking) {
memcpy(&p->thread.regs.regs, ®s->regs,
sizeof(p->thread.regs.regs));
UPT_SET_SYSCALL_RETURN(&p->thread.regs.regs, 0);
if (sp != 0)
REGS_SP(p->thread.regs.regs.gp) = sp;
handler = fork_handler;
arch_copy_thread(¤t->thread.arch, &p->thread.arch);
}
else {
get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp);
p->thread.request.u.thread = current->thread.request.u.thread;
handler = new_thread_handler;
}
new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
if (current->thread.forking) {
clear_flushed_tls(p);
/*
* Set a new TLS for the child thread?
*/
if (clone_flags & CLONE_SETTLS)
ret = arch_copy_tls(p);
}
return ret;
}
void initial_thread_cb(void (*proc)(void *), void *arg)
{
int save_kmalloc_ok = kmalloc_ok;
kmalloc_ok = 0;
initial_thread_cb_skas(proc, arg);
kmalloc_ok = save_kmalloc_ok;
}
void default_idle(void)
{
unsigned long long nsecs;
while (1) {
/* endless idle loop with no priority at all */
/*
* although we are an idle CPU, we do not want to
* get into the scheduler unnecessarily.
*/
if (need_resched())
schedule();
tick_nohz_idle_enter();
rcu_idle_enter();
nsecs = disable_timer();
idle_sleep(nsecs);
rcu_idle_exit();
tick_nohz_idle_exit();
}
}
void cpu_idle(void)
{
cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
default_idle();
}
int __cant_sleep(void) {
return in_atomic() || irqs_disabled() || in_interrupt();
/* Is in_interrupt() really needed? */
}
int user_context(unsigned long sp)
{
unsigned long stack;
stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
return stack != (unsigned long) current_thread_info();
}
extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
void do_uml_exitcalls(void)
{
exitcall_t *call;
call = &__uml_exitcall_end;
while (--call >= &__uml_exitcall_begin)
(*call)();
}
char *uml_strdup(const char *string)
{
return kstrdup(string
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