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Commit | Line | Data |
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995473ae | 1 | /* |
ba180fd4 | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
3 | * Copyright 2003 PathScale, Inc. |
4 | * Licensed under the GPL | |
5 | */ | |
6 | ||
c5d4bb17 JD |
7 | #include <linux/stddef.h> |
8 | #include <linux/err.h> | |
9 | #include <linux/hardirq.h> | |
c5d4bb17 | 10 | #include <linux/mm.h> |
6613c5e8 | 11 | #include <linux/module.h> |
c5d4bb17 JD |
12 | #include <linux/personality.h> |
13 | #include <linux/proc_fs.h> | |
14 | #include <linux/ptrace.h> | |
15 | #include <linux/random.h> | |
5a0e3ad6 | 16 | #include <linux/slab.h> |
c5d4bb17 | 17 | #include <linux/sched.h> |
6613c5e8 | 18 | #include <linux/seq_file.h> |
c5d4bb17 JD |
19 | #include <linux/tick.h> |
20 | #include <linux/threads.h> | |
d50349b0 | 21 | #include <linux/tracehook.h> |
c5d4bb17 JD |
22 | #include <asm/current.h> |
23 | #include <asm/pgtable.h> | |
445c5786 | 24 | #include <asm/mmu_context.h> |
c5d4bb17 | 25 | #include <asm/uaccess.h> |
37185b33 AV |
26 | #include <as-layout.h> |
27 | #include <kern_util.h> | |
28 | #include <os.h> | |
29 | #include <skas.h> | |
1da177e4 | 30 | |
ba180fd4 JD |
31 | /* |
32 | * This is a per-cpu array. A processor only modifies its entry and it only | |
1da177e4 LT |
33 | * cares about its entry, so it's OK if another processor is modifying its |
34 | * entry. | |
35 | */ | |
36 | struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } }; | |
37 | ||
2dc5802a | 38 | static inline int external_pid(void) |
1da177e4 | 39 | { |
77bf4400 | 40 | /* FIXME: Need to look up userspace_pid by cpu */ |
ba180fd4 | 41 | return userspace_pid[0]; |
1da177e4 LT |
42 | } |
43 | ||
44 | int pid_to_processor_id(int pid) | |
45 | { | |
46 | int i; | |
47 | ||
c5d4bb17 | 48 | for (i = 0; i < ncpus; i++) { |
ba180fd4 | 49 | if (cpu_tasks[i].pid == pid) |
6e21aec3 | 50 | return i; |
1da177e4 | 51 | } |
6e21aec3 | 52 | return -1; |
1da177e4 LT |
53 | } |
54 | ||
55 | void free_stack(unsigned long stack, int order) | |
56 | { | |
57 | free_pages(stack, order); | |
58 | } | |
59 | ||
60 | unsigned long alloc_stack(int order, int atomic) | |
61 | { | |
62 | unsigned long page; | |
53f9fc93 | 63 | gfp_t flags = GFP_KERNEL; |
1da177e4 | 64 | |
46db4a42 PBG |
65 | if (atomic) |
66 | flags = GFP_ATOMIC; | |
1da177e4 | 67 | page = __get_free_pages(flags, order); |
5c8aacea | 68 | |
6e21aec3 | 69 | return page; |
1da177e4 LT |
70 | } |
71 | ||
6e21aec3 | 72 | static inline void set_current(struct task_struct *task) |
1da177e4 | 73 | { |
ca9bc0bb | 74 | cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task) |
2dc5802a | 75 | { external_pid(), task }); |
1da177e4 LT |
76 | } |
77 | ||
291248fd | 78 | extern void arch_switch_to(struct task_struct *to); |
77bf4400 | 79 | |
76b278ed | 80 | void *__switch_to(struct task_struct *from, struct task_struct *to) |
1da177e4 | 81 | { |
995473ae JD |
82 | to->thread.prev_sched = from; |
83 | set_current(to); | |
f6e34c6a | 84 | |
3eddddcf | 85 | do { |
6aa802ce | 86 | current->thread.saved_task = NULL; |
77bf4400 | 87 | |
c5d4bb17 JD |
88 | switch_threads(&from->thread.switch_buf, |
89 | &to->thread.switch_buf); | |
77bf4400 | 90 | |
291248fd | 91 | arch_switch_to(current); |
77bf4400 | 92 | |
ba180fd4 | 93 | if (current->thread.saved_task) |
3eddddcf | 94 | show_regs(&(current->thread.regs)); |
c5d4bb17 JD |
95 | to = current->thread.saved_task; |
96 | from = current; | |
291248fd | 97 | } while (current->thread.saved_task); |
f6e34c6a | 98 | |
6e21aec3 | 99 | return current->thread.prev_sched; |
1da177e4 LT |
100 | } |
101 | ||
102 | void interrupt_end(void) | |
103 | { | |
ba180fd4 | 104 | if (need_resched()) |
6e21aec3 | 105 | schedule(); |
d50349b0 | 106 | if (test_thread_flag(TIF_SIGPENDING)) |
6e21aec3 | 107 | do_signal(); |
a42c6ded | 108 | if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) |
d50349b0 | 109 | tracehook_notify_resume(¤t->thread.regs); |
1da177e4 LT |
110 | } |
111 | ||
1da177e4 LT |
112 | void exit_thread(void) |
113 | { | |
1da177e4 | 114 | } |
995473ae | 115 | |
c2220b2a | 116 | int get_current_pid(void) |
1da177e4 | 117 | { |
c2220b2a | 118 | return task_pid_nr(current); |
1da177e4 LT |
119 | } |
120 | ||
ba180fd4 JD |
121 | /* |
122 | * This is called magically, by its address being stuffed in a jmp_buf | |
77bf4400 JD |
123 | * and being longjmp-d to. |
124 | */ | |
125 | void new_thread_handler(void) | |
126 | { | |
127 | int (*fn)(void *), n; | |
128 | void *arg; | |
129 | ||
ba180fd4 | 130 | if (current->thread.prev_sched != NULL) |
77bf4400 JD |
131 | schedule_tail(current->thread.prev_sched); |
132 | current->thread.prev_sched = NULL; | |
133 | ||
134 | fn = current->thread.request.u.thread.proc; | |
135 | arg = current->thread.request.u.thread.arg; | |
136 | ||
ba180fd4 | 137 | /* |
22e2430d | 138 | * callback returns only if the kernel thread execs a process |
77bf4400 | 139 | */ |
22e2430d AV |
140 | n = fn(arg); |
141 | userspace(¤t->thread.regs.regs); | |
77bf4400 JD |
142 | } |
143 | ||
144 | /* Called magically, see new_thread_handler above */ | |
145 | void fork_handler(void) | |
146 | { | |
147 | force_flush_all(); | |
77bf4400 JD |
148 | |
149 | schedule_tail(current->thread.prev_sched); | |
150 | ||
ba180fd4 JD |
151 | /* |
152 | * XXX: if interrupt_end() calls schedule, this call to | |
77bf4400 | 153 | * arch_switch_to isn't needed. We could want to apply this to |
ba180fd4 JD |
154 | * improve performance. -bb |
155 | */ | |
291248fd | 156 | arch_switch_to(current); |
77bf4400 JD |
157 | |
158 | current->thread.prev_sched = NULL; | |
159 | ||
77bf4400 JD |
160 | userspace(¤t->thread.regs.regs); |
161 | } | |
162 | ||
6f2c55b8 | 163 | int copy_thread(unsigned long clone_flags, unsigned long sp, |
1f02ab4a | 164 | unsigned long arg, struct task_struct * p, |
1da177e4 LT |
165 | struct pt_regs *regs) |
166 | { | |
77bf4400 | 167 | void (*handler)(void); |
d2ce4e92 | 168 | int kthread = current->flags & PF_KTHREAD; |
77bf4400 | 169 | int ret = 0; |
aa6758d4 | 170 | |
1da177e4 | 171 | p->thread = (struct thread_struct) INIT_THREAD; |
aa6758d4 | 172 | |
d2ce4e92 | 173 | if (!kthread) { |
77bf4400 JD |
174 | memcpy(&p->thread.regs.regs, ®s->regs, |
175 | sizeof(p->thread.regs.regs)); | |
a3170d2e | 176 | PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0); |
ba180fd4 | 177 | if (sp != 0) |
18baddda | 178 | REGS_SP(p->thread.regs.regs.gp) = sp; |
aa6758d4 | 179 | |
77bf4400 | 180 | handler = fork_handler; |
aa6758d4 | 181 | |
77bf4400 | 182 | arch_copy_thread(¤t->thread.arch, &p->thread.arch); |
d2ce4e92 | 183 | } else { |
fbfe9c84 | 184 | get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp); |
1f02ab4a AV |
185 | p->thread.request.u.thread.proc = (int (*)(void *))sp; |
186 | p->thread.request.u.thread.arg = (void *)arg; | |
77bf4400 JD |
187 | handler = new_thread_handler; |
188 | } | |
189 | ||
190 | new_thread(task_stack_page(p), &p->thread.switch_buf, handler); | |
191 | ||
d2ce4e92 | 192 | if (!kthread) { |
77bf4400 JD |
193 | clear_flushed_tls(p); |
194 | ||
195 | /* | |
196 | * Set a new TLS for the child thread? | |
197 | */ | |
198 | if (clone_flags & CLONE_SETTLS) | |
199 | ret = arch_copy_tls(p); | |
200 | } | |
aa6758d4 | 201 | |
aa6758d4 | 202 | return ret; |
1da177e4 LT |
203 | } |
204 | ||
205 | void initial_thread_cb(void (*proc)(void *), void *arg) | |
206 | { | |
207 | int save_kmalloc_ok = kmalloc_ok; | |
208 | ||
209 | kmalloc_ok = 0; | |
6aa802ce | 210 | initial_thread_cb_skas(proc, arg); |
1da177e4 LT |
211 | kmalloc_ok = save_kmalloc_ok; |
212 | } | |
995473ae | 213 | |
1da177e4 LT |
214 | void default_idle(void) |
215 | { | |
b160fb63 JD |
216 | unsigned long long nsecs; |
217 | ||
c5d4bb17 | 218 | while (1) { |
1da177e4 | 219 | /* endless idle loop with no priority at all */ |
1da177e4 LT |
220 | |
221 | /* | |
222 | * although we are an idle CPU, we do not want to | |
223 | * get into the scheduler unnecessarily. | |
224 | */ | |
ba180fd4 | 225 | if (need_resched()) |
1da177e4 | 226 | schedule(); |
995473ae | 227 | |
1268fbc7 FW |
228 | tick_nohz_idle_enter(); |
229 | rcu_idle_enter(); | |
b160fb63 JD |
230 | nsecs = disable_timer(); |
231 | idle_sleep(nsecs); | |
1268fbc7 FW |
232 | rcu_idle_exit(); |
233 | tick_nohz_idle_exit(); | |
1da177e4 LT |
234 | } |
235 | } | |
236 | ||
237 | void cpu_idle(void) | |
238 | { | |
a5a678c8 | 239 | cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); |
77bf4400 | 240 | default_idle(); |
1da177e4 LT |
241 | } |
242 | ||
b6316293 PBG |
243 | int __cant_sleep(void) { |
244 | return in_atomic() || irqs_disabled() || in_interrupt(); | |
245 | /* Is in_interrupt() really needed? */ | |
1da177e4 LT |
246 | } |
247 | ||
1da177e4 LT |
248 | int user_context(unsigned long sp) |
249 | { | |
250 | unsigned long stack; | |
251 | ||
252 | stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER); | |
a5a678c8 | 253 | return stack != (unsigned long) current_thread_info(); |
1da177e4 LT |
254 | } |
255 | ||
1da177e4 LT |
256 | extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end; |
257 | ||
258 | void do_uml_exitcalls(void) | |
259 | { | |
260 | exitcall_t *call; | |
261 | ||
262 | call = &__uml_exitcall_end; | |
263 | while (--call >= &__uml_exitcall_begin) | |
264 | (*call)(); | |
265 | } | |
266 | ||
c0a9290e | 267 | char *uml_strdup(const char *string) |
1da177e4 | 268 | { |
dfe52244 | 269 | return kstrdup(string, GFP_KERNEL); |
1da177e4 | 270 | } |
73395a00 | 271 | EXPORT_SYMBOL(uml_strdup); |
1da177e4 | 272 | |
1da177e4 LT |
273 | int copy_to_user_proc(void __user *to, void *from, int size) |
274 | { | |
6e21aec3 | 275 | return copy_to_user(to, from, size); |
1da177e4 LT |
276 | } |
277 | ||
278 | int copy_from_user_proc(void *to, void __user *from, int size) | |
279 | { | |
6e21aec3 | 280 | return copy_from_user(to, from, size); |
1da177e4 LT |
281 | } |
282 | ||
283 | int clear_user_proc(void __user *buf, int size) | |
284 | { | |
6e21aec3 | 285 | return clear_user(buf, size); |
1da177e4 LT |
286 | } |
287 | ||
288 | int strlen_user_proc(char __user *str) | |
289 | { | |
6e21aec3 | 290 | return strlen_user(str); |
1da177e4 LT |
291 | } |
292 | ||
293 | int smp_sigio_handler(void) | |
294 | { | |
295 | #ifdef CONFIG_SMP | |
a5a678c8 | 296 | int cpu = current_thread_info()->cpu; |
1da177e4 | 297 | IPI_handler(cpu); |
ba180fd4 | 298 | if (cpu != 0) |
6e21aec3 | 299 | return 1; |
1da177e4 | 300 | #endif |
6e21aec3 | 301 | return 0; |
1da177e4 LT |
302 | } |
303 | ||
1da177e4 LT |
304 | int cpu(void) |
305 | { | |
a5a678c8 | 306 | return current_thread_info()->cpu; |
1da177e4 LT |
307 | } |
308 | ||
309 | static atomic_t using_sysemu = ATOMIC_INIT(0); | |
310 | int sysemu_supported; | |
311 | ||
312 | void set_using_sysemu(int value) | |
313 | { | |
314 | if (value > sysemu_supported) | |
315 | return; | |
316 | atomic_set(&using_sysemu, value); | |
317 | } | |
318 | ||
319 | int get_using_sysemu(void) | |
320 | { | |
321 | return atomic_read(&using_sysemu); | |
322 | } | |
323 | ||
6613c5e8 | 324 | static int sysemu_proc_show(struct seq_file *m, void *v) |
1da177e4 | 325 | { |
6613c5e8 AD |
326 | seq_printf(m, "%d\n", get_using_sysemu()); |
327 | return 0; | |
328 | } | |
1da177e4 | 329 | |
6613c5e8 AD |
330 | static int sysemu_proc_open(struct inode *inode, struct file *file) |
331 | { | |
332 | return single_open(file, sysemu_proc_show, NULL); | |
1da177e4 LT |
333 | } |
334 | ||
6613c5e8 AD |
335 | static ssize_t sysemu_proc_write(struct file *file, const char __user *buf, |
336 | size_t count, loff_t *pos) | |
1da177e4 LT |
337 | { |
338 | char tmp[2]; | |
339 | ||
340 | if (copy_from_user(tmp, buf, 1)) | |
341 | return -EFAULT; | |
342 | ||
343 | if (tmp[0] >= '0' && tmp[0] <= '2') | |
344 | set_using_sysemu(tmp[0] - '0'); | |
ba180fd4 JD |
345 | /* We use the first char, but pretend to write everything */ |
346 | return count; | |
1da177e4 LT |
347 | } |
348 | ||
6613c5e8 AD |
349 | static const struct file_operations sysemu_proc_fops = { |
350 | .owner = THIS_MODULE, | |
351 | .open = sysemu_proc_open, | |
352 | .read = seq_read, | |
353 | .llseek = seq_lseek, | |
354 | .release = single_release, | |
355 | .write = sysemu_proc_write, | |
356 | }; | |
357 | ||
1da177e4 LT |
358 | int __init make_proc_sysemu(void) |
359 | { | |
360 | struct proc_dir_entry *ent; | |
361 | if (!sysemu_supported) | |
362 | return 0; | |
363 | ||
6613c5e8 | 364 | ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops); |
1da177e4 LT |
365 | |
366 | if (ent == NULL) | |
367 | { | |
30f417c6 | 368 | printk(KERN_WARNING "Failed to register /proc/sysemu\n"); |
6e21aec3 | 369 | return 0; |
1da177e4 LT |
370 | } |
371 | ||
1da177e4 LT |
372 | return 0; |
373 | } | |
374 | ||
375 | late_initcall(make_proc_sysemu); | |
376 | ||
377 | int singlestepping(void * t) | |
378 | { | |
379 | struct task_struct *task = t ? t : current; | |
380 | ||
c5d4bb17 | 381 | if (!(task->ptrace & PT_DTRACE)) |
ba180fd4 | 382 | return 0; |
1da177e4 LT |
383 | |
384 | if (task->thread.singlestep_syscall) | |
ba180fd4 | 385 | return 1; |
1da177e4 LT |
386 | |
387 | return 2; | |
388 | } | |
389 | ||
b8bd0220 BS |
390 | /* |
391 | * Only x86 and x86_64 have an arch_align_stack(). | |
392 | * All other arches have "#define arch_align_stack(x) (x)" | |
393 | * in their asm/system.h | |
394 | * As this is included in UML from asm-um/system-generic.h, | |
395 | * we can use it to behave as the subarch does. | |
396 | */ | |
397 | #ifndef arch_align_stack | |
1da177e4 LT |
398 | unsigned long arch_align_stack(unsigned long sp) |
399 | { | |
8f80e946 | 400 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) |
1da177e4 LT |
401 | sp -= get_random_int() % 8192; |
402 | return sp & ~0xf; | |
403 | } | |
b8bd0220 | 404 | #endif |
c1127465 JD |
405 | |
406 | unsigned long get_wchan(struct task_struct *p) | |
407 | { | |
408 | unsigned long stack_page, sp, ip; | |
409 | bool seen_sched = 0; | |
410 | ||
411 | if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING)) | |
412 | return 0; | |
413 | ||
414 | stack_page = (unsigned long) task_stack_page(p); | |
415 | /* Bail if the process has no kernel stack for some reason */ | |
416 | if (stack_page == 0) | |
417 | return 0; | |
418 | ||
419 | sp = p->thread.switch_buf->JB_SP; | |
420 | /* | |
421 | * Bail if the stack pointer is below the bottom of the kernel | |
422 | * stack for some reason | |
423 | */ | |
424 | if (sp < stack_page) | |
425 | return 0; | |
426 | ||
427 | while (sp < stack_page + THREAD_SIZE) { | |
428 | ip = *((unsigned long *) sp); | |
429 | if (in_sched_functions(ip)) | |
430 | /* Ignore everything until we're above the scheduler */ | |
431 | seen_sched = 1; | |
432 | else if (kernel_text_address(ip) && seen_sched) | |
433 | return ip; | |
434 | ||
435 | sp += sizeof(unsigned long); | |
436 | } | |
437 | ||
438 | return 0; | |
439 | } | |
8192ab42 JD |
440 | |
441 | int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu) | |
442 | { | |
443 | int cpu = current_thread_info()->cpu; | |
444 | ||
445 | return save_fp_registers(userspace_pid[cpu], (unsigned long *) fpu); | |
446 | } | |
447 |