2 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3 * Copyright 2003 PathScale, Inc.
4 * Licensed under the GPL
7 #include "linux/kernel.h"
8 #include "linux/sched.h"
9 #include "linux/interrupt.h"
10 #include "linux/string.h"
12 #include "linux/slab.h"
13 #include "linux/utsname.h"
15 #include "linux/utime.h"
16 #include "linux/smp_lock.h"
17 #include "linux/module.h"
18 #include "linux/init.h"
19 #include "linux/capability.h"
20 #include "linux/vmalloc.h"
21 #include "linux/spinlock.h"
22 #include "linux/proc_fs.h"
23 #include "linux/ptrace.h"
24 #include "linux/random.h"
25 #include "linux/personality.h"
26 #include "asm/unistd.h"
28 #include "asm/segment.h"
30 #include "asm/pgtable.h"
31 #include "asm/processor.h"
32 #include "asm/tlbflush.h"
33 #include "asm/uaccess.h"
35 #include "kern_util.h"
36 #include "as-layout.h"
38 #include "signal_kern.h"
43 #include "frame_kern.h"
44 #include "sigcontext.h"
48 /* This is a per-cpu array. A processor only modifies its entry and it only
49 * cares about its entry, so it's OK if another processor is modifying its
52 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
54 static inline int external_pid(struct task_struct *task)
56 /* FIXME: Need to look up userspace_pid by cpu */
57 return(userspace_pid[0]);
60 int pid_to_processor_id(int pid)
64 for(i = 0; i < ncpus; i++){
65 if(cpu_tasks[i].pid == pid)
71 void free_stack(unsigned long stack, int order)
73 free_pages(stack, order);
76 unsigned long alloc_stack(int order, int atomic)
79 gfp_t flags = GFP_KERNEL;
83 page = __get_free_pages(flags, order);
90 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
94 current->thread.request.u.thread.proc = fn;
95 current->thread.request.u.thread.arg = arg;
96 pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
97 ¤t->thread.regs, 0, NULL, NULL);
101 static inline void set_current(struct task_struct *task)
103 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
104 { external_pid(task), task });
107 extern void arch_switch_to(struct task_struct *from, struct task_struct *to);
109 void *_switch_to(void *prev, void *next, void *last)
111 struct task_struct *from = prev;
112 struct task_struct *to= next;
114 to->thread.prev_sched = from;
118 current->thread.saved_task = NULL;
120 /* XXX need to check runqueues[cpu].idle */
121 if(current->pid == 0)
124 switch_threads(&from->thread.switch_buf,
125 &to->thread.switch_buf);
127 arch_switch_to(current->thread.prev_sched, current);
129 if(current->pid == 0)
132 if(current->thread.saved_task)
133 show_regs(&(current->thread.regs));
134 next= current->thread.saved_task;
136 } while(current->thread.saved_task);
138 return current->thread.prev_sched;
142 void interrupt_end(void)
146 if(test_tsk_thread_flag(current, TIF_SIGPENDING))
150 void exit_thread(void)
154 void *get_current(void)
159 extern void schedule_tail(struct task_struct *prev);
161 /* This is called magically, by its address being stuffed in a jmp_buf
162 * and being longjmp-d to.
164 void new_thread_handler(void)
166 int (*fn)(void *), n;
169 if(current->thread.prev_sched != NULL)
170 schedule_tail(current->thread.prev_sched);
171 current->thread.prev_sched = NULL;
173 fn = current->thread.request.u.thread.proc;
174 arg = current->thread.request.u.thread.arg;
176 /* The return value is 1 if the kernel thread execs a process,
179 n = run_kernel_thread(fn, arg, ¤t->thread.exec_buf);
181 /* Handle any immediate reschedules or signals */
183 userspace(¤t->thread.regs.regs);
188 /* Called magically, see new_thread_handler above */
189 void fork_handler(void)
192 if(current->thread.prev_sched == NULL)
195 schedule_tail(current->thread.prev_sched);
197 /* XXX: if interrupt_end() calls schedule, this call to
198 * arch_switch_to isn't needed. We could want to apply this to
199 * improve performance. -bb */
200 arch_switch_to(current->thread.prev_sched, current);
202 current->thread.prev_sched = NULL;
204 /* Handle any immediate reschedules or signals */
207 userspace(¤t->thread.regs.regs);
210 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
211 unsigned long stack_top, struct task_struct * p,
212 struct pt_regs *regs)
214 void (*handler)(void);
217 p->thread = (struct thread_struct) INIT_THREAD;
219 if(current->thread.forking){
220 memcpy(&p->thread.regs.regs, ®s->regs,
221 sizeof(p->thread.regs.regs));
222 REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.regs, 0);
224 REGS_SP(p->thread.regs.regs.regs) = sp;
226 handler = fork_handler;
228 arch_copy_thread(¤t->thread.arch, &p->thread.arch);
231 init_thread_registers(&p->thread.regs.regs);
232 p->thread.request.u.thread = current->thread.request.u.thread;
233 handler = new_thread_handler;
236 new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
238 if (current->thread.forking) {
239 clear_flushed_tls(p);
242 * Set a new TLS for the child thread?
244 if (clone_flags & CLONE_SETTLS)
245 ret = arch_copy_tls(p);
251 void initial_thread_cb(void (*proc)(void *), void *arg)
253 int save_kmalloc_ok = kmalloc_ok;
256 initial_thread_cb_skas(proc, arg);
257 kmalloc_ok = save_kmalloc_ok;
260 void default_idle(void)
263 /* endless idle loop with no priority at all */
266 * although we are an idle CPU, we do not want to
267 * get into the scheduler unnecessarily.
278 cpu_tasks[current_thread->cpu].pid = os_getpid();
282 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
292 return ERR_PTR(-EINVAL);
293 pgd = pgd_offset(task->mm, addr);
294 if(!pgd_present(*pgd))
295 return ERR_PTR(-EINVAL);
297 pud = pud_offset(pgd, addr);
298 if(!pud_present(*pud))
299 return ERR_PTR(-EINVAL);
301 pmd = pmd_offset(pud, addr);
302 if(!pmd_present(*pmd))
303 return ERR_PTR(-EINVAL);
305 pte = pte_offset_kernel(pmd, addr);
307 if(!pte_present(ptent))
308 return ERR_PTR(-EINVAL);
312 return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);
315 char *current_cmd(void)
317 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
320 void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
321 return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
325 void dump_thread(struct pt_regs *regs, struct user *u)
329 int __cant_sleep(void) {
330 return in_atomic() || irqs_disabled() || in_interrupt();
331 /* Is in_interrupt() really needed? */
334 int user_context(unsigned long sp)
338 stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
339 return stack != (unsigned long) current_thread;
342 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
344 void do_uml_exitcalls(void)
348 call = &__uml_exitcall_end;
349 while (--call >= &__uml_exitcall_begin)
353 char *uml_strdup(char *string)
355 return kstrdup(string, GFP_KERNEL);
358 int copy_to_user_proc(void __user *to, void *from, int size)
360 return copy_to_user(to, from, size);
363 int copy_from_user_proc(void *to, void __user *from, int size)
365 return copy_from_user(to, from, size);
368 int clear_user_proc(void __user *buf, int size)
370 return clear_user(buf, size);
373 int strlen_user_proc(char __user *str)
375 return strlen_user(str);
378 int smp_sigio_handler(void)
381 int cpu = current_thread->cpu;
391 return current_thread->cpu;
394 static atomic_t using_sysemu = ATOMIC_INIT(0);
395 int sysemu_supported;
397 void set_using_sysemu(int value)
399 if (value > sysemu_supported)
401 atomic_set(&using_sysemu, value);
404 int get_using_sysemu(void)
406 return atomic_read(&using_sysemu);
409 static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
411 if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
417 static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data)
421 if (copy_from_user(tmp, buf, 1))
424 if (tmp[0] >= '0' && tmp[0] <= '2')
425 set_using_sysemu(tmp[0] - '0');
426 return count; /*We use the first char, but pretend to write everything*/
429 int __init make_proc_sysemu(void)
431 struct proc_dir_entry *ent;
432 if (!sysemu_supported)
435 ent = create_proc_entry("sysemu", 0600, &proc_root);
439 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
443 ent->read_proc = proc_read_sysemu;
444 ent->write_proc = proc_write_sysemu;
449 late_initcall(make_proc_sysemu);
451 int singlestepping(void * t)
453 struct task_struct *task = t ? t : current;
455 if ( ! (task->ptrace & PT_DTRACE) )
458 if (task->thread.singlestep_syscall)
465 * Only x86 and x86_64 have an arch_align_stack().
466 * All other arches have "#define arch_align_stack(x) (x)"
467 * in their asm/system.h
468 * As this is included in UML from asm-um/system-generic.h,
469 * we can use it to behave as the subarch does.
471 #ifndef arch_align_stack
472 unsigned long arch_align_stack(unsigned long sp)
474 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
475 sp -= get_random_int() % 8192;