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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
4 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
5 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
6 * Copyright 2003 PathScale, Inc.
7 */
8
9#include <linux/stddef.h>
10#include <linux/err.h>
11#include <linux/hardirq.h>
12#include <linux/mm.h>
13#include <linux/module.h>
14#include <linux/personality.h>
15#include <linux/proc_fs.h>
16#include <linux/ptrace.h>
17#include <linux/random.h>
18#include <linux/slab.h>
19#include <linux/sched.h>
20#include <linux/sched/debug.h>
21#include <linux/sched/task.h>
22#include <linux/sched/task_stack.h>
23#include <linux/seq_file.h>
24#include <linux/tick.h>
25#include <linux/threads.h>
26#include <linux/tracehook.h>
27#include <asm/current.h>
28#include <asm/pgtable.h>
29#include <asm/mmu_context.h>
30#include <linux/uaccess.h>
31#include <as-layout.h>
32#include <kern_util.h>
33#include <os.h>
34#include <skas.h>
35#include <timer-internal.h>
36
37/*
38 * This is a per-cpu array. A processor only modifies its entry and it only
39 * cares about its entry, so it's OK if another processor is modifying its
40 * entry.
41 */
42struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
43
44static inline int external_pid(void)
45{
46 /* FIXME: Need to look up userspace_pid by cpu */
47 return userspace_pid[0];
48}
49
50int pid_to_processor_id(int pid)
51{
52 int i;
53
54 for (i = 0; i < ncpus; i++) {
55 if (cpu_tasks[i].pid == pid)
56 return i;
57 }
58 return -1;
59}
60
61void free_stack(unsigned long stack, int order)
62{
63 free_pages(stack, order);
64}
65
66unsigned long alloc_stack(int order, int atomic)
67{
68 unsigned long page;
69 gfp_t flags = GFP_KERNEL;
70
71 if (atomic)
72 flags = GFP_ATOMIC;
73 page = __get_free_pages(flags, order);
74
75 return page;
76}
77
78static inline void set_current(struct task_struct *task)
79{
80 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
81 { external_pid(), task });
82}
83
84extern void arch_switch_to(struct task_struct *to);
85
86void *__switch_to(struct task_struct *from, struct task_struct *to)
87{
88 to->thread.prev_sched = from;
89 set_current(to);
90
91 switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
92 arch_switch_to(current);
93
94 return current->thread.prev_sched;
95}
96
97void interrupt_end(void)
98{
99 struct pt_regs *regs = ¤t->thread.regs;
100
101 if (need_resched())
102 schedule();
103 if (test_thread_flag(TIF_SIGPENDING))
104 do_signal(regs);
105 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
106 tracehook_notify_resume(regs);
107}
108
109int get_current_pid(void)
110{
111 return task_pid_nr(current);
112}
113
114/*
115 * This is called magically, by its address being stuffed in a jmp_buf
116 * and being longjmp-d to.
117 */
118void new_thread_handler(void)
119{
120 int (*fn)(void *), n;
121 void *arg;
122
123 if (current->thread.prev_sched != NULL)
124 schedule_tail(current->thread.prev_sched);
125 current->thread.prev_sched = NULL;
126
127 fn = current->thread.request.u.thread.proc;
128 arg = current->thread.request.u.thread.arg;
129
130 /*
131 * callback returns only if the kernel thread execs a process
132 */
133 n = fn(arg);
134 userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs);
135}
136
137/* Called magically, see new_thread_handler above */
138void fork_handler(void)
139{
140 force_flush_all();
141
142 schedule_tail(current->thread.prev_sched);
143
144 /*
145 * XXX: if interrupt_end() calls schedule, this call to
146 * arch_switch_to isn't needed. We could want to apply this to
147 * improve performance. -bb
148 */
149 arch_switch_to(current);
150
151 current->thread.prev_sched = NULL;
152
153 userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs);
154}
155
156int copy_thread(unsigned long clone_flags, unsigned long sp,
157 unsigned long arg, struct task_struct * p)
158{
159 void (*handler)(void);
160 int kthread = current->flags & PF_KTHREAD;
161 int ret = 0;
162
163 p->thread = (struct thread_struct) INIT_THREAD;
164
165 if (!kthread) {
166 memcpy(&p->thread.regs.regs, current_pt_regs(),
167 sizeof(p->thread.regs.regs));
168 PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0);
169 if (sp != 0)
170 REGS_SP(p->thread.regs.regs.gp) = sp;
171
172 handler = fork_handler;
173
174 arch_copy_thread(¤t->thread.arch, &p->thread.arch);
175 } else {
176 get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp);
177 p->thread.request.u.thread.proc = (int (*)(void *))sp;
178 p->thread.request.u.thread.arg = (void *)arg;
179 handler = new_thread_handler;
180 }
181
182 new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
183
184 if (!kthread) {
185 clear_flushed_tls(p);
186
187 /*
188 * Set a new TLS for the child thread?
189 */
190 if (clone_flags & CLONE_SETTLS)
191 ret = arch_copy_tls(p);
192 }
193
194 return ret;
195}
196
197void initial_thread_cb(void (*proc)(void *), void *arg)
198{
199 int save_kmalloc_ok = kmalloc_ok;
200
201 kmalloc_ok = 0;
202 initial_thread_cb_skas(proc, arg);
203 kmalloc_ok = save_kmalloc_ok;
204}
205
206static void time_travel_sleep(unsigned long long duration)
207{
208 unsigned long long next = time_travel_time + duration;
209
210 if (time_travel_mode != TT_MODE_INFCPU)
211 os_timer_disable();
212
213 while (time_travel_timer_mode == TT_TMR_PERIODIC &&
214 time_travel_timer_expiry < time_travel_time)
215 time_travel_set_timer_expiry(time_travel_timer_expiry +
216 time_travel_timer_interval);
217
218 if (time_travel_timer_mode != TT_TMR_DISABLED &&
219 time_travel_timer_expiry < next) {
220 if (time_travel_timer_mode == TT_TMR_ONESHOT)
221 time_travel_set_timer_mode(TT_TMR_DISABLED);
222 /*
223 * In basic mode, time_travel_time will be adjusted in
224 * the timer IRQ handler so it works even when the signal
225 * comes from the OS timer, see there.
226 */
227 if (time_travel_mode != TT_MODE_BASIC)
228 time_travel_set_time(time_travel_timer_expiry);
229
230 deliver_alarm();
231 } else {
232 time_travel_set_time(next);
233 }
234
235 if (time_travel_mode != TT_MODE_INFCPU) {
236 if (time_travel_timer_mode == TT_TMR_PERIODIC)
237 os_timer_set_interval(time_travel_timer_interval);
238 else if (time_travel_timer_mode == TT_TMR_ONESHOT)
239 os_timer_one_shot(time_travel_timer_expiry - next);
240 }
241}
242
243static void um_idle_sleep(void)
244{
245 unsigned long long duration = UM_NSEC_PER_SEC;
246
247 if (time_travel_mode != TT_MODE_OFF) {
248 time_travel_sleep(duration);
249 } else {
250 os_idle_sleep(duration);
251 }
252}
253
254void arch_cpu_idle(void)
255{
256 cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
257 um_idle_sleep();
258 local_irq_enable();
259}
260
261int __cant_sleep(void) {
262 return in_atomic() || irqs_disabled() || in_interrupt();
263 /* Is in_interrupt() really needed? */
264}
265
266int user_context(unsigned long sp)
267{
268 unsigned long stack;
269
270 stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
271 return stack != (unsigned long) current_thread_info();
272}
273
274extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
275
276void do_uml_exitcalls(void)
277{
278 exitcall_t *call;
279
280 call = &__uml_exitcall_end;
281 while (--call >= &__uml_exitcall_begin)
282 (*call)();
283}
284
285char *uml_strdup(const char *string)
286{
287 return kstrdup(string, GFP_KERNEL);
288}
289EXPORT_SYMBOL(uml_strdup);
290
291int copy_to_user_proc(void __user *to, void *from, int size)
292{
293 return copy_to_user(to, from, size);
294}
295
296int copy_from_user_proc(void *to, void __user *from, int size)
297{
298 return copy_from_user(to, from, size);
299}
300
301int clear_user_proc(void __user *buf, int size)
302{
303 return clear_user(buf, size);
304}
305
306int cpu(void)
307{
308 return current_thread_info()->cpu;
309}
310
311static atomic_t using_sysemu = ATOMIC_INIT(0);
312int sysemu_supported;
313
314void set_using_sysemu(int value)
315{
316 if (value > sysemu_supported)
317 return;
318 atomic_set(&using_sysemu, value);
319}
320
321int get_using_sysemu(void)
322{
323 return atomic_read(&using_sysemu);
324}
325
326static int sysemu_proc_show(struct seq_file *m, void *v)
327{
328 seq_printf(m, "%d\n", get_using_sysemu());
329 return 0;
330}
331
332static int sysemu_proc_open(struct inode *inode, struct file *file)
333{
334 return single_open(file, sysemu_proc_show, NULL);
335}
336
337static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
338 size_t count, loff_t *pos)
339{
340 char tmp[2];
341
342 if (copy_from_user(tmp, buf, 1))
343 return -EFAULT;
344
345 if (tmp[0] >= '0' && tmp[0] <= '2')
346 set_using_sysemu(tmp[0] - '0');
347 /* We use the first char, but pretend to write everything */
348 return count;
349}
350
351static const struct file_operations sysemu_proc_fops = {
352 .owner = THIS_MODULE,
353 .open = sysemu_proc_open,
354 .read = seq_read,
355 .llseek = seq_lseek,
356 .release = single_release,
357 .write = sysemu_proc_write,
358};
359
360int __init make_proc_sysemu(void)
361{
362 struct proc_dir_entry *ent;
363 if (!sysemu_supported)
364 return 0;
365
366 ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops);
367
368 if (ent == NULL)
369 {
370 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
371 return 0;
372 }
373
374 return 0;
375}
376
377late_initcall(make_proc_sysemu);
378
379int singlestepping(void * t)
380{
381 struct task_struct *task = t ? t : current;
382
383 if (!(task->ptrace & PT_DTRACE))
384 return 0;
385
386 if (task->thread.singlestep_syscall)
387 return 1;
388
389 return 2;
390}
391
392/*
393 * Only x86 and x86_64 have an arch_align_stack().
394 * All other arches have "#define arch_align_stack(x) (x)"
395 * in their asm/exec.h
396 * As this is included in UML from asm-um/system-generic.h,
397 * we can use it to behave as the subarch does.
398 */
399#ifndef arch_align_stack
400unsigned long arch_align_stack(unsigned long sp)
401{
402 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
403 sp -= get_random_int() % 8192;
404 return sp & ~0xf;
405}
406#endif
407
408unsigned long get_wchan(struct task_struct *p)
409{
410 unsigned long stack_page, sp, ip;
411 bool seen_sched = 0;
412
413 if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING))
414 return 0;
415
416 stack_page = (unsigned long) task_stack_page(p);
417 /* Bail if the process has no kernel stack for some reason */
418 if (stack_page == 0)
419 return 0;
420
421 sp = p->thread.switch_buf->JB_SP;
422 /*
423 * Bail if the stack pointer is below the bottom of the kernel
424 * stack for some reason
425 */
426 if (sp < stack_page)
427 return 0;
428
429 while (sp < stack_page + THREAD_SIZE) {
430 ip = *((unsigned long *) sp);
431 if (in_sched_functions(ip))
432 /* Ignore everything until we're above the scheduler */
433 seen_sched = 1;
434 else if (kernel_text_address(ip) && seen_sched)
435 return ip;
436
437 sp += sizeof(unsigned long);
438 }
439
440 return 0;
441}
442
443int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
444{
445 int cpu = current_thread_info()->cpu;
446
447 return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu);
448}
449
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
4 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
5 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
6 * Copyright 2003 PathScale, Inc.
7 */
8
9#include <linux/stddef.h>
10#include <linux/err.h>
11#include <linux/hardirq.h>
12#include <linux/mm.h>
13#include <linux/module.h>
14#include <linux/personality.h>
15#include <linux/proc_fs.h>
16#include <linux/ptrace.h>
17#include <linux/random.h>
18#include <linux/slab.h>
19#include <linux/sched.h>
20#include <linux/sched/debug.h>
21#include <linux/sched/task.h>
22#include <linux/sched/task_stack.h>
23#include <linux/seq_file.h>
24#include <linux/tick.h>
25#include <linux/threads.h>
26#include <linux/resume_user_mode.h>
27#include <asm/current.h>
28#include <asm/mmu_context.h>
29#include <linux/uaccess.h>
30#include <as-layout.h>
31#include <kern_util.h>
32#include <os.h>
33#include <skas.h>
34#include <registers.h>
35#include <linux/time-internal.h>
36#include <linux/elfcore.h>
37
38/*
39 * This is a per-cpu array. A processor only modifies its entry and it only
40 * cares about its entry, so it's OK if another processor is modifying its
41 * entry.
42 */
43struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
44
45static inline int external_pid(void)
46{
47 /* FIXME: Need to look up userspace_pid by cpu */
48 return userspace_pid[0];
49}
50
51int pid_to_processor_id(int pid)
52{
53 int i;
54
55 for (i = 0; i < ncpus; i++) {
56 if (cpu_tasks[i].pid == pid)
57 return i;
58 }
59 return -1;
60}
61
62void free_stack(unsigned long stack, int order)
63{
64 free_pages(stack, order);
65}
66
67unsigned long alloc_stack(int order, int atomic)
68{
69 unsigned long page;
70 gfp_t flags = GFP_KERNEL;
71
72 if (atomic)
73 flags = GFP_ATOMIC;
74 page = __get_free_pages(flags, order);
75
76 return page;
77}
78
79static inline void set_current(struct task_struct *task)
80{
81 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
82 { external_pid(), task });
83}
84
85extern void arch_switch_to(struct task_struct *to);
86
87void *__switch_to(struct task_struct *from, struct task_struct *to)
88{
89 to->thread.prev_sched = from;
90 set_current(to);
91
92 switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
93 arch_switch_to(current);
94
95 return current->thread.prev_sched;
96}
97
98void interrupt_end(void)
99{
100 struct pt_regs *regs = ¤t->thread.regs;
101
102 if (need_resched())
103 schedule();
104 if (test_thread_flag(TIF_SIGPENDING) ||
105 test_thread_flag(TIF_NOTIFY_SIGNAL))
106 do_signal(regs);
107 if (test_thread_flag(TIF_NOTIFY_RESUME))
108 resume_user_mode_work(regs);
109}
110
111int get_current_pid(void)
112{
113 return task_pid_nr(current);
114}
115
116/*
117 * This is called magically, by its address being stuffed in a jmp_buf
118 * and being longjmp-d to.
119 */
120void new_thread_handler(void)
121{
122 int (*fn)(void *), n;
123 void *arg;
124
125 if (current->thread.prev_sched != NULL)
126 schedule_tail(current->thread.prev_sched);
127 current->thread.prev_sched = NULL;
128
129 fn = current->thread.request.u.thread.proc;
130 arg = current->thread.request.u.thread.arg;
131
132 /*
133 * callback returns only if the kernel thread execs a process
134 */
135 n = fn(arg);
136 userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs);
137}
138
139/* Called magically, see new_thread_handler above */
140void fork_handler(void)
141{
142 force_flush_all();
143
144 schedule_tail(current->thread.prev_sched);
145
146 /*
147 * XXX: if interrupt_end() calls schedule, this call to
148 * arch_switch_to isn't needed. We could want to apply this to
149 * improve performance. -bb
150 */
151 arch_switch_to(current);
152
153 current->thread.prev_sched = NULL;
154
155 userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs);
156}
157
158int copy_thread(struct task_struct * p, const struct kernel_clone_args *args)
159{
160 unsigned long clone_flags = args->flags;
161 unsigned long sp = args->stack;
162 unsigned long tls = args->tls;
163 void (*handler)(void);
164 int ret = 0;
165
166 p->thread = (struct thread_struct) INIT_THREAD;
167
168 if (!args->fn) {
169 memcpy(&p->thread.regs.regs, current_pt_regs(),
170 sizeof(p->thread.regs.regs));
171 PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0);
172 if (sp != 0)
173 REGS_SP(p->thread.regs.regs.gp) = sp;
174
175 handler = fork_handler;
176
177 arch_copy_thread(¤t->thread.arch, &p->thread.arch);
178 } else {
179 get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp);
180 p->thread.request.u.thread.proc = args->fn;
181 p->thread.request.u.thread.arg = args->fn_arg;
182 handler = new_thread_handler;
183 }
184
185 new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
186
187 if (!args->fn) {
188 clear_flushed_tls(p);
189
190 /*
191 * Set a new TLS for the child thread?
192 */
193 if (clone_flags & CLONE_SETTLS)
194 ret = arch_set_tls(p, tls);
195 }
196
197 return ret;
198}
199
200void initial_thread_cb(void (*proc)(void *), void *arg)
201{
202 int save_kmalloc_ok = kmalloc_ok;
203
204 kmalloc_ok = 0;
205 initial_thread_cb_skas(proc, arg);
206 kmalloc_ok = save_kmalloc_ok;
207}
208
209void um_idle_sleep(void)
210{
211 if (time_travel_mode != TT_MODE_OFF)
212 time_travel_sleep();
213 else
214 os_idle_sleep();
215}
216
217void arch_cpu_idle(void)
218{
219 cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
220 um_idle_sleep();
221}
222
223int __uml_cant_sleep(void) {
224 return in_atomic() || irqs_disabled() || in_interrupt();
225 /* Is in_interrupt() really needed? */
226}
227
228int user_context(unsigned long sp)
229{
230 unsigned long stack;
231
232 stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
233 return stack != (unsigned long) current_thread_info();
234}
235
236extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
237
238void do_uml_exitcalls(void)
239{
240 exitcall_t *call;
241
242 call = &__uml_exitcall_end;
243 while (--call >= &__uml_exitcall_begin)
244 (*call)();
245}
246
247char *uml_strdup(const char *string)
248{
249 return kstrdup(string, GFP_KERNEL);
250}
251EXPORT_SYMBOL(uml_strdup);
252
253int copy_to_user_proc(void __user *to, void *from, int size)
254{
255 return copy_to_user(to, from, size);
256}
257
258int copy_from_user_proc(void *to, void __user *from, int size)
259{
260 return copy_from_user(to, from, size);
261}
262
263int clear_user_proc(void __user *buf, int size)
264{
265 return clear_user(buf, size);
266}
267
268static atomic_t using_sysemu = ATOMIC_INIT(0);
269int sysemu_supported;
270
271void set_using_sysemu(int value)
272{
273 if (value > sysemu_supported)
274 return;
275 atomic_set(&using_sysemu, value);
276}
277
278int get_using_sysemu(void)
279{
280 return atomic_read(&using_sysemu);
281}
282
283static int sysemu_proc_show(struct seq_file *m, void *v)
284{
285 seq_printf(m, "%d\n", get_using_sysemu());
286 return 0;
287}
288
289static int sysemu_proc_open(struct inode *inode, struct file *file)
290{
291 return single_open(file, sysemu_proc_show, NULL);
292}
293
294static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
295 size_t count, loff_t *pos)
296{
297 char tmp[2];
298
299 if (copy_from_user(tmp, buf, 1))
300 return -EFAULT;
301
302 if (tmp[0] >= '0' && tmp[0] <= '2')
303 set_using_sysemu(tmp[0] - '0');
304 /* We use the first char, but pretend to write everything */
305 return count;
306}
307
308static const struct proc_ops sysemu_proc_ops = {
309 .proc_open = sysemu_proc_open,
310 .proc_read = seq_read,
311 .proc_lseek = seq_lseek,
312 .proc_release = single_release,
313 .proc_write = sysemu_proc_write,
314};
315
316int __init make_proc_sysemu(void)
317{
318 struct proc_dir_entry *ent;
319 if (!sysemu_supported)
320 return 0;
321
322 ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_ops);
323
324 if (ent == NULL)
325 {
326 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
327 return 0;
328 }
329
330 return 0;
331}
332
333late_initcall(make_proc_sysemu);
334
335int singlestepping(void)
336{
337 return test_thread_flag(TIF_SINGLESTEP);
338}
339
340/*
341 * Only x86 and x86_64 have an arch_align_stack().
342 * All other arches have "#define arch_align_stack(x) (x)"
343 * in their asm/exec.h
344 * As this is included in UML from asm-um/system-generic.h,
345 * we can use it to behave as the subarch does.
346 */
347#ifndef arch_align_stack
348unsigned long arch_align_stack(unsigned long sp)
349{
350 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
351 sp -= get_random_u32_below(8192);
352 return sp & ~0xf;
353}
354#endif
355
356unsigned long __get_wchan(struct task_struct *p)
357{
358 unsigned long stack_page, sp, ip;
359 bool seen_sched = 0;
360
361 stack_page = (unsigned long) task_stack_page(p);
362 /* Bail if the process has no kernel stack for some reason */
363 if (stack_page == 0)
364 return 0;
365
366 sp = p->thread.switch_buf->JB_SP;
367 /*
368 * Bail if the stack pointer is below the bottom of the kernel
369 * stack for some reason
370 */
371 if (sp < stack_page)
372 return 0;
373
374 while (sp < stack_page + THREAD_SIZE) {
375 ip = *((unsigned long *) sp);
376 if (in_sched_functions(ip))
377 /* Ignore everything until we're above the scheduler */
378 seen_sched = 1;
379 else if (kernel_text_address(ip) && seen_sched)
380 return ip;
381
382 sp += sizeof(unsigned long);
383 }
384
385 return 0;
386}
387
388int elf_core_copy_task_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
389{
390 int cpu = current_thread_info()->cpu;
391
392 return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu);
393}
394