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1/*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Copyright 2003 PathScale, Inc.
4 * Licensed under the GPL
5 */
6
7#include <linux/stddef.h>
8#include <linux/err.h>
9#include <linux/hardirq.h>
10#include <linux/mm.h>
11#include <linux/module.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/slab.h>
17#include <linux/sched.h>
18#include <linux/seq_file.h>
19#include <linux/tick.h>
20#include <linux/threads.h>
21#include <linux/tracehook.h>
22#include <asm/current.h>
23#include <asm/pgtable.h>
24#include <asm/mmu_context.h>
25#include <asm/uaccess.h>
26#include "as-layout.h"
27#include "kern_util.h"
28#include "os.h"
29#include "skas.h"
30
31/*
32 * This is a per-cpu array. A processor only modifies its entry and it only
33 * cares about its entry, so it's OK if another processor is modifying its
34 * entry.
35 */
36struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
37
38static inline int external_pid(void)
39{
40 /* FIXME: Need to look up userspace_pid by cpu */
41 return userspace_pid[0];
42}
43
44int pid_to_processor_id(int pid)
45{
46 int i;
47
48 for (i = 0; i < ncpus; i++) {
49 if (cpu_tasks[i].pid == pid)
50 return i;
51 }
52 return -1;
53}
54
55void free_stack(unsigned long stack, int order)
56{
57 free_pages(stack, order);
58}
59
60unsigned long alloc_stack(int order, int atomic)
61{
62 unsigned long page;
63 gfp_t flags = GFP_KERNEL;
64
65 if (atomic)
66 flags = GFP_ATOMIC;
67 page = __get_free_pages(flags, order);
68
69 return page;
70}
71
72int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
73{
74 int pid;
75
76 current->thread.request.u.thread.proc = fn;
77 current->thread.request.u.thread.arg = arg;
78 pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
79 ¤t->thread.regs, 0, NULL, NULL);
80 return pid;
81}
82EXPORT_SYMBOL(kernel_thread);
83
84static inline void set_current(struct task_struct *task)
85{
86 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
87 { external_pid(), task });
88}
89
90extern void arch_switch_to(struct task_struct *to);
91
92void *__switch_to(struct task_struct *from, struct task_struct *to)
93{
94 to->thread.prev_sched = from;
95 set_current(to);
96
97 do {
98 current->thread.saved_task = NULL;
99
100 switch_threads(&from->thread.switch_buf,
101 &to->thread.switch_buf);
102
103 arch_switch_to(current);
104
105 if (current->thread.saved_task)
106 show_regs(&(current->thread.regs));
107 to = current->thread.saved_task;
108 from = current;
109 } while (current->thread.saved_task);
110
111 return current->thread.prev_sched;
112}
113
114void interrupt_end(void)
115{
116 if (need_resched())
117 schedule();
118 if (test_thread_flag(TIF_SIGPENDING))
119 do_signal();
120 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
121 tracehook_notify_resume(¤t->thread.regs);
122}
123
124void exit_thread(void)
125{
126}
127
128int get_current_pid(void)
129{
130 return task_pid_nr(current);
131}
132
133/*
134 * This is called magically, by its address being stuffed in a jmp_buf
135 * and being longjmp-d to.
136 */
137void new_thread_handler(void)
138{
139 int (*fn)(void *), n;
140 void *arg;
141
142 if (current->thread.prev_sched != NULL)
143 schedule_tail(current->thread.prev_sched);
144 current->thread.prev_sched = NULL;
145
146 fn = current->thread.request.u.thread.proc;
147 arg = current->thread.request.u.thread.arg;
148
149 /*
150 * The return value is 1 if the kernel thread execs a process,
151 * 0 if it just exits
152 */
153 n = run_kernel_thread(fn, arg, ¤t->thread.exec_buf);
154 if (n == 1) {
155 /* Handle any immediate reschedules or signals */
156 interrupt_end();
157 userspace(¤t->thread.regs.regs);
158 }
159 else do_exit(0);
160}
161
162/* Called magically, see new_thread_handler above */
163void fork_handler(void)
164{
165 force_flush_all();
166
167 schedule_tail(current->thread.prev_sched);
168
169 /*
170 * XXX: if interrupt_end() calls schedule, this call to
171 * arch_switch_to isn't needed. We could want to apply this to
172 * improve performance. -bb
173 */
174 arch_switch_to(current);
175
176 current->thread.prev_sched = NULL;
177
178 /* Handle any immediate reschedules or signals */
179 interrupt_end();
180
181 userspace(¤t->thread.regs.regs);
182}
183
184int copy_thread(unsigned long clone_flags, unsigned long sp,
185 unsigned long stack_top, struct task_struct * p,
186 struct pt_regs *regs)
187{
188 void (*handler)(void);
189 int ret = 0;
190
191 p->thread = (struct thread_struct) INIT_THREAD;
192
193 if (current->thread.forking) {
194 memcpy(&p->thread.regs.regs, ®s->regs,
195 sizeof(p->thread.regs.regs));
196 UPT_SET_SYSCALL_RETURN(&p->thread.regs.regs, 0);
197 if (sp != 0)
198 REGS_SP(p->thread.regs.regs.gp) = sp;
199
200 handler = fork_handler;
201
202 arch_copy_thread(¤t->thread.arch, &p->thread.arch);
203 }
204 else {
205 get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp);
206 p->thread.request.u.thread = current->thread.request.u.thread;
207 handler = new_thread_handler;
208 }
209
210 new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
211
212 if (current->thread.forking) {
213 clear_flushed_tls(p);
214
215 /*
216 * Set a new TLS for the child thread?
217 */
218 if (clone_flags & CLONE_SETTLS)
219 ret = arch_copy_tls(p);
220 }
221
222 return ret;
223}
224
225void initial_thread_cb(void (*proc)(void *), void *arg)
226{
227 int save_kmalloc_ok = kmalloc_ok;
228
229 kmalloc_ok = 0;
230 initial_thread_cb_skas(proc, arg);
231 kmalloc_ok = save_kmalloc_ok;
232}
233
234void default_idle(void)
235{
236 unsigned long long nsecs;
237
238 while (1) {
239 /* endless idle loop with no priority at all */
240
241 /*
242 * although we are an idle CPU, we do not want to
243 * get into the scheduler unnecessarily.
244 */
245 if (need_resched())
246 schedule();
247
248 tick_nohz_idle_enter();
249 rcu_idle_enter();
250 nsecs = disable_timer();
251 idle_sleep(nsecs);
252 rcu_idle_exit();
253 tick_nohz_idle_exit();
254 }
255}
256
257void cpu_idle(void)
258{
259 cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
260 default_idle();
261}
262
263int __cant_sleep(void) {
264 return in_atomic() || irqs_disabled() || in_interrupt();
265 /* Is in_interrupt() really needed? */
266}
267
268int user_context(unsigned long sp)
269{
270 unsigned long stack;
271
272 stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
273 return stack != (unsigned long) current_thread_info();
274}
275
276extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
277
278void do_uml_exitcalls(void)
279{
280 exitcall_t *call;
281
282 call = &__uml_exitcall_end;
283 while (--call >= &__uml_exitcall_begin)
284 (*call)();
285}
286
287char *uml_strdup(const char *string)
288{
289 return kstrdup(string, GFP_KERNEL);
290}
291EXPORT_SYMBOL(uml_strdup);
292
293int copy_to_user_proc(void __user *to, void *from, int size)
294{
295 return copy_to_user(to, from, size);
296}
297
298int copy_from_user_proc(void *to, void __user *from, int size)
299{
300 return copy_from_user(to, from, size);
301}
302
303int clear_user_proc(void __user *buf, int size)
304{
305 return clear_user(buf, size);
306}
307
308int strlen_user_proc(char __user *str)
309{
310 return strlen_user(str);
311}
312
313int smp_sigio_handler(void)
314{
315#ifdef CONFIG_SMP
316 int cpu = current_thread_info()->cpu;
317 IPI_handler(cpu);
318 if (cpu != 0)
319 return 1;
320#endif
321 return 0;
322}
323
324int cpu(void)
325{
326 return current_thread_info()->cpu;
327}
328
329static atomic_t using_sysemu = ATOMIC_INIT(0);
330int sysemu_supported;
331
332void set_using_sysemu(int value)
333{
334 if (value > sysemu_supported)
335 return;
336 atomic_set(&using_sysemu, value);
337}
338
339int get_using_sysemu(void)
340{
341 return atomic_read(&using_sysemu);
342}
343
344static int sysemu_proc_show(struct seq_file *m, void *v)
345{
346 seq_printf(m, "%d\n", get_using_sysemu());
347 return 0;
348}
349
350static int sysemu_proc_open(struct inode *inode, struct file *file)
351{
352 return single_open(file, sysemu_proc_show, NULL);
353}
354
355static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
356 size_t count, loff_t *pos)
357{
358 char tmp[2];
359
360 if (copy_from_user(tmp, buf, 1))
361 return -EFAULT;
362
363 if (tmp[0] >= '0' && tmp[0] <= '2')
364 set_using_sysemu(tmp[0] - '0');
365 /* We use the first char, but pretend to write everything */
366 return count;
367}
368
369static const struct file_operations sysemu_proc_fops = {
370 .owner = THIS_MODULE,
371 .open = sysemu_proc_open,
372 .read = seq_read,
373 .llseek = seq_lseek,
374 .release = single_release,
375 .write = sysemu_proc_write,
376};
377
378int __init make_proc_sysemu(void)
379{
380 struct proc_dir_entry *ent;
381 if (!sysemu_supported)
382 return 0;
383
384 ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops);
385
386 if (ent == NULL)
387 {
388 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
389 return 0;
390 }
391
392 return 0;
393}
394
395late_initcall(make_proc_sysemu);
396
397int singlestepping(void * t)
398{
399 struct task_struct *task = t ? t : current;
400
401 if (!(task->ptrace & PT_DTRACE))
402 return 0;
403
404 if (task->thread.singlestep_syscall)
405 return 1;
406
407 return 2;
408}
409
410/*
411 * Only x86 and x86_64 have an arch_align_stack().
412 * All other arches have "#define arch_align_stack(x) (x)"
413 * in their asm/system.h
414 * As this is included in UML from asm-um/system-generic.h,
415 * we can use it to behave as the subarch does.
416 */
417#ifndef arch_align_stack
418unsigned long arch_align_stack(unsigned long sp)
419{
420 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
421 sp -= get_random_int() % 8192;
422 return sp & ~0xf;
423}
424#endif
425
426unsigned long get_wchan(struct task_struct *p)
427{
428 unsigned long stack_page, sp, ip;
429 bool seen_sched = 0;
430
431 if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING))
432 return 0;
433
434 stack_page = (unsigned long) task_stack_page(p);
435 /* Bail if the process has no kernel stack for some reason */
436 if (stack_page == 0)
437 return 0;
438
439 sp = p->thread.switch_buf->JB_SP;
440 /*
441 * Bail if the stack pointer is below the bottom of the kernel
442 * stack for some reason
443 */
444 if (sp < stack_page)
445 return 0;
446
447 while (sp < stack_page + THREAD_SIZE) {
448 ip = *((unsigned long *) sp);
449 if (in_sched_functions(ip))
450 /* Ignore everything until we're above the scheduler */
451 seen_sched = 1;
452 else if (kernel_text_address(ip) && seen_sched)
453 return ip;
454
455 sp += sizeof(unsigned long);
456 }
457
458 return 0;
459}
460
461int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
462{
463 int cpu = current_thread_info()->cpu;
464
465 return save_fp_registers(userspace_pid[cpu], (unsigned long *) fpu);
466}
467
1/*
2 * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
3 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
4 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
5 * Copyright 2003 PathScale, Inc.
6 * Licensed under the GPL
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/seq_file.h>
21#include <linux/tick.h>
22#include <linux/threads.h>
23#include <linux/tracehook.h>
24#include <asm/current.h>
25#include <asm/pgtable.h>
26#include <asm/mmu_context.h>
27#include <linux/uaccess.h>
28#include <as-layout.h>
29#include <kern_util.h>
30#include <os.h>
31#include <skas.h>
32#include <timer-internal.h>
33
34/*
35 * This is a per-cpu array. A processor only modifies its entry and it only
36 * cares about its entry, so it's OK if another processor is modifying its
37 * entry.
38 */
39struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
40
41static inline int external_pid(void)
42{
43 /* FIXME: Need to look up userspace_pid by cpu */
44 return userspace_pid[0];
45}
46
47int pid_to_processor_id(int pid)
48{
49 int i;
50
51 for (i = 0; i < ncpus; i++) {
52 if (cpu_tasks[i].pid == pid)
53 return i;
54 }
55 return -1;
56}
57
58void free_stack(unsigned long stack, int order)
59{
60 free_pages(stack, order);
61}
62
63unsigned long alloc_stack(int order, int atomic)
64{
65 unsigned long page;
66 gfp_t flags = GFP_KERNEL;
67
68 if (atomic)
69 flags = GFP_ATOMIC;
70 page = __get_free_pages(flags, order);
71
72 return page;
73}
74
75static inline void set_current(struct task_struct *task)
76{
77 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
78 { external_pid(), task });
79}
80
81extern void arch_switch_to(struct task_struct *to);
82
83void *__switch_to(struct task_struct *from, struct task_struct *to)
84{
85 to->thread.prev_sched = from;
86 set_current(to);
87
88 switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
89 arch_switch_to(current);
90
91 return current->thread.prev_sched;
92}
93
94void interrupt_end(void)
95{
96 struct pt_regs *regs = ¤t->thread.regs;
97
98 if (need_resched())
99 schedule();
100 if (test_thread_flag(TIF_SIGPENDING))
101 do_signal(regs);
102 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
103 tracehook_notify_resume(regs);
104}
105
106int get_current_pid(void)
107{
108 return task_pid_nr(current);
109}
110
111/*
112 * This is called magically, by its address being stuffed in a jmp_buf
113 * and being longjmp-d to.
114 */
115void new_thread_handler(void)
116{
117 int (*fn)(void *), n;
118 void *arg;
119
120 if (current->thread.prev_sched != NULL)
121 schedule_tail(current->thread.prev_sched);
122 current->thread.prev_sched = NULL;
123
124 fn = current->thread.request.u.thread.proc;
125 arg = current->thread.request.u.thread.arg;
126
127 /*
128 * callback returns only if the kernel thread execs a process
129 */
130 n = fn(arg);
131 userspace(¤t->thread.regs.regs);
132}
133
134/* Called magically, see new_thread_handler above */
135void fork_handler(void)
136{
137 force_flush_all();
138
139 schedule_tail(current->thread.prev_sched);
140
141 /*
142 * XXX: if interrupt_end() calls schedule, this call to
143 * arch_switch_to isn't needed. We could want to apply this to
144 * improve performance. -bb
145 */
146 arch_switch_to(current);
147
148 current->thread.prev_sched = NULL;
149
150 userspace(¤t->thread.regs.regs);
151}
152
153int copy_thread(unsigned long clone_flags, unsigned long sp,
154 unsigned long arg, struct task_struct * p)
155{
156 void (*handler)(void);
157 int kthread = current->flags & PF_KTHREAD;
158 int ret = 0;
159
160 p->thread = (struct thread_struct) INIT_THREAD;
161
162 if (!kthread) {
163 memcpy(&p->thread.regs.regs, current_pt_regs(),
164 sizeof(p->thread.regs.regs));
165 PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0);
166 if (sp != 0)
167 REGS_SP(p->thread.regs.regs.gp) = sp;
168
169 handler = fork_handler;
170
171 arch_copy_thread(¤t->thread.arch, &p->thread.arch);
172 } else {
173 get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp);
174 p->thread.request.u.thread.proc = (int (*)(void *))sp;
175 p->thread.request.u.thread.arg = (void *)arg;
176 handler = new_thread_handler;
177 }
178
179 new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
180
181 if (!kthread) {
182 clear_flushed_tls(p);
183
184 /*
185 * Set a new TLS for the child thread?
186 */
187 if (clone_flags & CLONE_SETTLS)
188 ret = arch_copy_tls(p);
189 }
190
191 return ret;
192}
193
194void initial_thread_cb(void (*proc)(void *), void *arg)
195{
196 int save_kmalloc_ok = kmalloc_ok;
197
198 kmalloc_ok = 0;
199 initial_thread_cb_skas(proc, arg);
200 kmalloc_ok = save_kmalloc_ok;
201}
202
203void arch_cpu_idle(void)
204{
205 cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
206 os_idle_sleep(UM_NSEC_PER_SEC);
207 local_irq_enable();
208}
209
210int __cant_sleep(void) {
211 return in_atomic() || irqs_disabled() || in_interrupt();
212 /* Is in_interrupt() really needed? */
213}
214
215int user_context(unsigned long sp)
216{
217 unsigned long stack;
218
219 stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
220 return stack != (unsigned long) current_thread_info();
221}
222
223extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
224
225void do_uml_exitcalls(void)
226{
227 exitcall_t *call;
228
229 call = &__uml_exitcall_end;
230 while (--call >= &__uml_exitcall_begin)
231 (*call)();
232}
233
234char *uml_strdup(const char *string)
235{
236 return kstrdup(string, GFP_KERNEL);
237}
238EXPORT_SYMBOL(uml_strdup);
239
240int copy_to_user_proc(void __user *to, void *from, int size)
241{
242 return copy_to_user(to, from, size);
243}
244
245int copy_from_user_proc(void *to, void __user *from, int size)
246{
247 return copy_from_user(to, from, size);
248}
249
250int clear_user_proc(void __user *buf, int size)
251{
252 return clear_user(buf, size);
253}
254
255int strlen_user_proc(char __user *str)
256{
257 return strlen_user(str);
258}
259
260int cpu(void)
261{
262 return current_thread_info()->cpu;
263}
264
265static atomic_t using_sysemu = ATOMIC_INIT(0);
266int sysemu_supported;
267
268void set_using_sysemu(int value)
269{
270 if (value > sysemu_supported)
271 return;
272 atomic_set(&using_sysemu, value);
273}
274
275int get_using_sysemu(void)
276{
277 return atomic_read(&using_sysemu);
278}
279
280static int sysemu_proc_show(struct seq_file *m, void *v)
281{
282 seq_printf(m, "%d\n", get_using_sysemu());
283 return 0;
284}
285
286static int sysemu_proc_open(struct inode *inode, struct file *file)
287{
288 return single_open(file, sysemu_proc_show, NULL);
289}
290
291static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
292 size_t count, loff_t *pos)
293{
294 char tmp[2];
295
296 if (copy_from_user(tmp, buf, 1))
297 return -EFAULT;
298
299 if (tmp[0] >= '0' && tmp[0] <= '2')
300 set_using_sysemu(tmp[0] - '0');
301 /* We use the first char, but pretend to write everything */
302 return count;
303}
304
305static const struct file_operations sysemu_proc_fops = {
306 .owner = THIS_MODULE,
307 .open = sysemu_proc_open,
308 .read = seq_read,
309 .llseek = seq_lseek,
310 .release = single_release,
311 .write = sysemu_proc_write,
312};
313
314int __init make_proc_sysemu(void)
315{
316 struct proc_dir_entry *ent;
317 if (!sysemu_supported)
318 return 0;
319
320 ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops);
321
322 if (ent == NULL)
323 {
324 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
325 return 0;
326 }
327
328 return 0;
329}
330
331late_initcall(make_proc_sysemu);
332
333int singlestepping(void * t)
334{
335 struct task_struct *task = t ? t : current;
336
337 if (!(task->ptrace & PT_DTRACE))
338 return 0;
339
340 if (task->thread.singlestep_syscall)
341 return 1;
342
343 return 2;
344}
345
346/*
347 * Only x86 and x86_64 have an arch_align_stack().
348 * All other arches have "#define arch_align_stack(x) (x)"
349 * in their asm/exec.h
350 * As this is included in UML from asm-um/system-generic.h,
351 * we can use it to behave as the subarch does.
352 */
353#ifndef arch_align_stack
354unsigned long arch_align_stack(unsigned long sp)
355{
356 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
357 sp -= get_random_int() % 8192;
358 return sp & ~0xf;
359}
360#endif
361
362unsigned long get_wchan(struct task_struct *p)
363{
364 unsigned long stack_page, sp, ip;
365 bool seen_sched = 0;
366
367 if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING))
368 return 0;
369
370 stack_page = (unsigned long) task_stack_page(p);
371 /* Bail if the process has no kernel stack for some reason */
372 if (stack_page == 0)
373 return 0;
374
375 sp = p->thread.switch_buf->JB_SP;
376 /*
377 * Bail if the stack pointer is below the bottom of the kernel
378 * stack for some reason
379 */
380 if (sp < stack_page)
381 return 0;
382
383 while (sp < stack_page + THREAD_SIZE) {
384 ip = *((unsigned long *) sp);
385 if (in_sched_functions(ip))
386 /* Ignore everything until we're above the scheduler */
387 seen_sched = 1;
388 else if (kernel_text_address(ip) && seen_sched)
389 return ip;
390
391 sp += sizeof(unsigned long);
392 }
393
394 return 0;
395}
396
397int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
398{
399 int cpu = current_thread_info()->cpu;
400
401 return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu);
402}
403