2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Copyright 2003 PathScale, Inc.
4 * Licensed under the GPL
7 #include <linux/stddef.h>
9 #include <linux/hardirq.h>
10 #include <linux/gfp.h>
12 #include <linux/personality.h>
13 #include <linux/proc_fs.h>
14 #include <linux/ptrace.h>
15 #include <linux/random.h>
16 #include <linux/sched.h>
17 #include <linux/tick.h>
18 #include <linux/threads.h>
19 #include <asm/current.h>
20 #include <asm/pgtable.h>
21 #include <asm/uaccess.h>
22 #include "as-layout.h"
23 #include "kern_util.h"
29 * This is a per-cpu array. A processor only modifies its entry and it only
30 * cares about its entry, so it's OK if another processor is modifying its
33 struct cpu_task cpu_tasks
[NR_CPUS
] = { [0 ... NR_CPUS
- 1] = { -1, NULL
} };
35 static inline int external_pid(void)
37 /* FIXME: Need to look up userspace_pid by cpu */
38 return userspace_pid
[0];
41 int pid_to_processor_id(int pid
)
45 for (i
= 0; i
< ncpus
; i
++) {
46 if (cpu_tasks
[i
].pid
== pid
)
52 void free_stack(unsigned long stack
, int order
)
54 free_pages(stack
, order
);
57 unsigned long alloc_stack(int order
, int atomic
)
60 gfp_t flags
= GFP_KERNEL
;
64 page
= __get_free_pages(flags
, order
);
69 int kernel_thread(int (*fn
)(void *), void * arg
, unsigned long flags
)
73 current
->thread
.request
.u
.thread
.proc
= fn
;
74 current
->thread
.request
.u
.thread
.arg
= arg
;
75 pid
= do_fork(CLONE_VM
| CLONE_UNTRACED
| flags
, 0,
76 ¤t
->thread
.regs
, 0, NULL
, NULL
);
80 static inline void set_current(struct task_struct
*task
)
82 cpu_tasks
[task_thread_info(task
)->cpu
] = ((struct cpu_task
)
83 { external_pid(), task
});
86 extern void arch_switch_to(struct task_struct
*to
);
88 void *_switch_to(void *prev
, void *next
, void *last
)
90 struct task_struct
*from
= prev
;
91 struct task_struct
*to
= next
;
93 to
->thread
.prev_sched
= from
;
97 current
->thread
.saved_task
= NULL
;
99 switch_threads(&from
->thread
.switch_buf
,
100 &to
->thread
.switch_buf
);
102 arch_switch_to(current
);
104 if (current
->thread
.saved_task
)
105 show_regs(&(current
->thread
.regs
));
106 to
= current
->thread
.saved_task
;
108 } while (current
->thread
.saved_task
);
110 return current
->thread
.prev_sched
;
114 void interrupt_end(void)
118 if (test_tsk_thread_flag(current
, TIF_SIGPENDING
))
122 void exit_thread(void)
126 void *get_current(void)
131 <<<<<<< HEAD
:arch
/um
/kernel
/process
.c
132 extern void schedule_tail(struct task_struct
*prev
);
135 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a
:arch
/um
/kernel
/process
.c
137 * This is called magically, by its address being stuffed in a jmp_buf
138 * and being longjmp-d to.
140 void new_thread_handler(void)
142 int (*fn
)(void *), n
;
145 if (current
->thread
.prev_sched
!= NULL
)
146 schedule_tail(current
->thread
.prev_sched
);
147 current
->thread
.prev_sched
= NULL
;
149 fn
= current
->thread
.request
.u
.thread
.proc
;
150 arg
= current
->thread
.request
.u
.thread
.arg
;
153 * The return value is 1 if the kernel thread execs a process,
156 n
= run_kernel_thread(fn
, arg
, ¤t
->thread
.exec_buf
);
158 /* Handle any immediate reschedules or signals */
160 userspace(¤t
->thread
.regs
.regs
);
165 /* Called magically, see new_thread_handler above */
166 void fork_handler(void)
170 schedule_tail(current
->thread
.prev_sched
);
173 * XXX: if interrupt_end() calls schedule, this call to
174 * arch_switch_to isn't needed. We could want to apply this to
175 * improve performance. -bb
177 arch_switch_to(current
);
179 current
->thread
.prev_sched
= NULL
;
181 /* Handle any immediate reschedules or signals */
184 userspace(¤t
->thread
.regs
.regs
);
187 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long sp
,
188 unsigned long stack_top
, struct task_struct
* p
,
189 struct pt_regs
*regs
)
191 void (*handler
)(void);
194 p
->thread
= (struct thread_struct
) INIT_THREAD
;
196 if (current
->thread
.forking
) {
197 memcpy(&p
->thread
.regs
.regs
, ®s
->regs
,
198 sizeof(p
->thread
.regs
.regs
));
199 REGS_SET_SYSCALL_RETURN(p
->thread
.regs
.regs
.gp
, 0);
201 REGS_SP(p
->thread
.regs
.regs
.gp
) = sp
;
203 handler
= fork_handler
;
205 arch_copy_thread(¤t
->thread
.arch
, &p
->thread
.arch
);
208 get_safe_registers(p
->thread
.regs
.regs
.gp
);
209 p
->thread
.request
.u
.thread
= current
->thread
.request
.u
.thread
;
210 handler
= new_thread_handler
;
213 new_thread(task_stack_page(p
), &p
->thread
.switch_buf
, handler
);
215 if (current
->thread
.forking
) {
216 clear_flushed_tls(p
);
219 * Set a new TLS for the child thread?
221 if (clone_flags
& CLONE_SETTLS
)
222 ret
= arch_copy_tls(p
);
228 void initial_thread_cb(void (*proc
)(void *), void *arg
)
230 int save_kmalloc_ok
= kmalloc_ok
;
233 initial_thread_cb_skas(proc
, arg
);
234 kmalloc_ok
= save_kmalloc_ok
;
237 void default_idle(void)
239 unsigned long long nsecs
;
242 /* endless idle loop with no priority at all */
245 * although we are an idle CPU, we do not want to
246 * get into the scheduler unnecessarily.
251 tick_nohz_stop_sched_tick();
252 nsecs
= disable_timer();
254 tick_nohz_restart_sched_tick();
260 cpu_tasks
[current_thread_info()->cpu
].pid
= os_getpid();
264 int __cant_sleep(void) {
265 return in_atomic() || irqs_disabled() || in_interrupt();
266 /* Is in_interrupt() really needed? */
269 int user_context(unsigned long sp
)
273 stack
= sp
& (PAGE_MASK
<< CONFIG_KERNEL_STACK_ORDER
);
274 return stack
!= (unsigned long) current_thread_info();
277 extern exitcall_t __uml_exitcall_begin
, __uml_exitcall_end
;
279 void do_uml_exitcalls(void)
283 call
= &__uml_exitcall_end
;
284 while (--call
>= &__uml_exitcall_begin
)
288 char *uml_strdup(const char *string
)
290 return kstrdup(string
, GFP_KERNEL
);
293 int copy_to_user_proc(void __user
*to
, void *from
, int size
)
295 return copy_to_user(to
, from
, size
);
298 int copy_from_user_proc(void *to
, void __user
*from
, int size
)
300 return copy_from_user(to
, from
, size
);
303 int clear_user_proc(void __user
*buf
, int size
)
305 return clear_user(buf
, size
);
308 int strlen_user_proc(char __user
*str
)
310 return strlen_user(str
);
313 int smp_sigio_handler(void)
316 int cpu
= current_thread_info()->cpu
;
326 return current_thread_info()->cpu
;
329 static atomic_t using_sysemu
= ATOMIC_INIT(0);
330 int sysemu_supported
;
332 void set_using_sysemu(int value
)
334 if (value
> sysemu_supported
)
336 atomic_set(&using_sysemu
, value
);
339 int get_using_sysemu(void)
341 return atomic_read(&using_sysemu
);
344 static int proc_read_sysemu(char *buf
, char **start
, off_t offset
, int size
,int *eof
, void *data
)
346 if (snprintf(buf
, size
, "%d\n", get_using_sysemu()) < size
)
353 static int proc_write_sysemu(struct file
*file
,const char __user
*buf
, unsigned long count
,void *data
)
357 if (copy_from_user(tmp
, buf
, 1))
360 if (tmp
[0] >= '0' && tmp
[0] <= '2')
361 set_using_sysemu(tmp
[0] - '0');
362 /* We use the first char, but pretend to write everything */
366 int __init
make_proc_sysemu(void)
368 struct proc_dir_entry
*ent
;
369 if (!sysemu_supported
)
372 ent
= create_proc_entry("sysemu", 0600, &proc_root
);
376 printk(KERN_WARNING
"Failed to register /proc/sysemu\n");
380 ent
->read_proc
= proc_read_sysemu
;
381 ent
->write_proc
= proc_write_sysemu
;
386 late_initcall(make_proc_sysemu
);
388 int singlestepping(void * t
)
390 struct task_struct
*task
= t
? t
: current
;
392 if (!(task
->ptrace
& PT_DTRACE
))
395 if (task
->thread
.singlestep_syscall
)
402 * Only x86 and x86_64 have an arch_align_stack().
403 * All other arches have "#define arch_align_stack(x) (x)"
404 * in their asm/system.h
405 * As this is included in UML from asm-um/system-generic.h,
406 * we can use it to behave as the subarch does.
408 #ifndef arch_align_stack
409 unsigned long arch_align_stack(unsigned long sp
)
411 if (!(current
->personality
& ADDR_NO_RANDOMIZE
) && randomize_va_space
)
412 sp
-= get_random_int() % 8192;
417 unsigned long get_wchan(struct task_struct
*p
)
419 unsigned long stack_page
, sp
, ip
;
422 if ((p
== NULL
) || (p
== current
) || (p
->state
== TASK_RUNNING
))
425 stack_page
= (unsigned long) task_stack_page(p
);
426 /* Bail if the process has no kernel stack for some reason */
430 sp
= p
->thread
.switch_buf
->JB_SP
;
432 * Bail if the stack pointer is below the bottom of the kernel
433 * stack for some reason
438 while (sp
< stack_page
+ THREAD_SIZE
) {
439 ip
= *((unsigned long *) sp
);
440 if (in_sched_functions(ip
))
441 /* Ignore everything until we're above the scheduler */
443 else if (kernel_text_address(ip
) && seen_sched
)
446 sp
+= sizeof(unsigned long);
452 int elf_core_copy_fpregs(struct task_struct
*t
, elf_fpregset_t
*fpu
)
454 int cpu
= current_thread_info()->cpu
;
456 return save_fp_registers(userspace_pid
[cpu
], (unsigned long *) fpu
);