linux/arch/um/kernel/process.c

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/*
* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
* Copyright 2003 PathScale, Inc.
* Licensed under the GPL
*/
#include "linux/kernel.h"
#include "linux/sched.h"
#include "linux/interrupt.h"
#include "linux/string.h"
#include "linux/mm.h"
#include "linux/slab.h"
#include "linux/utsname.h"
#include "linux/fs.h"
#include "linux/utime.h"
#include "linux/smp_lock.h"
#include "linux/module.h"
#include "linux/init.h"
#include "linux/capability.h"
#include "linux/vmalloc.h"
#include "linux/spinlock.h"
#include "linux/proc_fs.h"
#include "linux/ptrace.h"
#include "linux/random.h"
#include "linux/personality.h"
#include "asm/unistd.h"
#include "asm/mman.h"
#include "asm/segment.h"
#include "asm/stat.h"
#include "asm/pgtable.h"
#include "asm/processor.h"
#include "asm/tlbflush.h"
#include "asm/uaccess.h"
#include "asm/user.h"
#include "kern_util.h"
#include "as-layout.h"
#include "kern.h"
#include "signal_kern.h"
#include "init.h"
#include "irq_user.h"
#include "mem_user.h"
#include "tlb.h"
#include "frame_kern.h"
#include "sigcontext.h"
#include "os.h"
#include "mode.h"
#include "mode_kern.h"
#include "choose-mode.h"
#include "um_malloc.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(struct task_struct *task)
{
return CHOOSE_MODE_PROC(external_pid_tt, external_pid_skas, task);
}
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);
if(page == 0)
return 0;
stack_protections(page);
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,
&current->thread.regs, 0, NULL, NULL);
return pid;
}
static inline void set_current(struct task_struct *task)
{
cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
{ external_pid(task), task });
}
void *_switch_to(void *prev, void *next, void *last)
{
struct task_struct *from = prev;
struct task_struct *to= next;
to->thread.prev_sched = from;
set_current(to);
do {
current->thread.saved_task = NULL ;
CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
if(current->thread.saved_task)
show_regs(&(current->thread.regs));
next= current->thread.saved_task;
prev= current;
} while(current->thread.saved_task);
return current->thread.prev_sched;
}
void interrupt_end(void)
{
if(need_resched())
schedule();
if(test_tsk_thread_flag(current, TIF_SIGPENDING))
do_signal();
}
void release_thread(struct task_struct *task)
{
CHOOSE_MODE(release_thread_tt(task), release_thread_skas(task));
}
void exit_thread(void)
{
unprotect_stack((unsigned long) current_thread);
}
void *get_current(void)
{
return current;
}
int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
unsigned long stack_top, struct task_struct * p,
struct pt_regs *regs)
{
int ret;
p->thread = (struct thread_struct) INIT_THREAD;
ret = CHOOSE_MODE_PROC(copy_thread_tt, copy_thread_skas, nr,
clone_flags, sp, stack_top, p, regs);
if (ret || !current->thread.forking)
goto out;
clear_flushed_tls(p);
/*
* Set a new TLS for the child thread?
*/
if (clone_flags & CLONE_SETTLS)
ret = arch_copy_tls(p);
out:
return ret;
}
void initial_thread_cb(void (*proc)(void *), void *arg)
{
int save_kmalloc_ok = kmalloc_ok;
kmalloc_ok = 0;
CHOOSE_MODE_PROC(initial_thread_cb_tt, initial_thread_cb_skas, proc,
arg);
kmalloc_ok = save_kmalloc_ok;
}
#ifdef CONFIG_MODE_TT
unsigned long stack_sp(unsigned long page)
{
return page + PAGE_SIZE - sizeof(void *);
}
#endif
void default_idle(void)
{
CHOOSE_MODE(uml_idle_timer(), (void) 0);
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();
idle_sleep(10);
}
}
void cpu_idle(void)
{
CHOOSE_MODE(init_idle_tt(), init_idle_skas());
}
void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
pte_t *pte_out)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pte_t ptent;
if(task->mm == NULL)
return ERR_PTR(-EINVAL);
pgd = pgd_offset(task->mm, addr);
if(!pgd_present(*pgd))
return ERR_PTR(-EINVAL);
pud = pud_offset(pgd, addr);
if(!pud_present(*pud))
return ERR_PTR(-EINVAL);
pmd = pmd_offset(pud, addr);
if(!pmd_present(*pmd))
return ERR_PTR(-EINVAL);
pte = pte_offset_kernel(pmd, addr);
ptent = *pte;
if(!pte_present(ptent))
return ERR_PTR(-EINVAL);
if(pte_out != NULL)
*pte_out = ptent;
return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
}
char *current_cmd(void)
{
#if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
return "(Unknown)";
#else
void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
#endif
}
void dump_thread(struct pt_regs *regs, struct user *u)
{
}
void *um_kmalloc(int size)
{
return kmalloc(size, GFP_KERNEL);
}
void *um_kmalloc_atomic(int size)
{
return kmalloc(size, GFP_ATOMIC);
}
void *um_vmalloc(int size)
{
return vmalloc(size);
}
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;
}
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(char *string)
{
return kstrdup(string, GFP_KERNEL);
}
int copy_to_user_proc(void __user *to, void *from, int size)
{
return copy_to_user(to, from, size);
}
int copy_from_user_proc(void *to, void __user *from, int size)
{
return copy_from_user(to, from, size);
}
int clear_user_proc(void __user *buf, int size)
{
return clear_user(buf, size);
}
int strlen_user_proc(char __user *str)
{
return strlen_user(str);
}
int smp_sigio_handler(void)
{
#ifdef CONFIG_SMP
int cpu = current_thread->cpu;
IPI_handler(cpu);
if(cpu != 0)
return 1;
#endif
return 0;
}
int cpu(void)
{
return current_thread->cpu;
}
static atomic_t using_sysemu = ATOMIC_INIT(0);
int sysemu_supported;
void set_using_sysemu(int value)
{
if (value > sysemu_supported)
return;
atomic_set(&using_sysemu, value);
}
int get_using_sysemu(void)
{
return atomic_read(&using_sysemu);
}
static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
{
if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
*eof = 1;
return strlen(buf);
}
static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
{
char tmp[2];
if (copy_from_user(tmp, buf, 1))
return -EFAULT;
if (tmp[0] >= '0' && tmp[0] <= '2')
set_using_sysemu(tmp[0] - '0');
return count; /*We use the first char, but pretend to write everything*/
}
int __init make_proc_sysemu(void)
{
struct proc_dir_entry *ent;
if (!sysemu_supported)
return 0;
ent = create_proc_entry("sysemu", 0600, &proc_root);
if (ent == NULL)
{
printk(KERN_WARNING "Failed to register /proc/sysemu\n");
return 0;
}
ent->read_proc = proc_read_sysemu;
ent->write_proc = proc_write_sysemu;
return 0;
}
late_initcall(make_proc_sysemu);
int singlestepping(void * t)
{
struct task_struct *task = t ? t : current;
if ( ! (task->ptrace & PT_DTRACE) )
return(0);
if (task->thread.singlestep_syscall)
return(1);
return 2;
}
/*
* Only x86 and x86_64 have an arch_align_stack().
* All other arches have "#define arch_align_stack(x) (x)"
* in their asm/system.h
* As this is included in UML from asm-um/system-generic.h,
* we can use it to behave as the subarch does.
*/
#ifndef arch_align_stack
unsigned long arch_align_stack(unsigned long sp)
{
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
sp -= get_random_int() % 8192;
return sp & ~0xf;
}
#endif