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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 <asm/current.h>
22#include <asm/pgtable.h>
23#include <asm/uaccess.h>
24#include "as-layout.h"
25#include "kern_util.h"
26#include "os.h"
27#include "skas.h"
28#include "tlb.h"
29
30/*
31 * This is a per-cpu array. A processor only modifies its entry and it only
32 * cares about its entry, so it's OK if another processor is modifying its
33 * entry.
34 */
35struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
36
37static inline int external_pid(void)
38{
39 /* FIXME: Need to look up userspace_pid by cpu */
40 return userspace_pid[0];
41}
42
43int pid_to_processor_id(int pid)
44{
45 int i;
46
47 for (i = 0; i < ncpus; i++) {
48 if (cpu_tasks[i].pid == pid)
49 return i;
50 }
51 return -1;
52}
53
54void free_stack(unsigned long stack, int order)
55{
56 free_pages(stack, order);
57}
58
59unsigned long alloc_stack(int order, int atomic)
60{
61 unsigned long page;
62 gfp_t flags = GFP_KERNEL;
63
64 if (atomic)
65 flags = GFP_ATOMIC;
66 page = __get_free_pages(flags, order);
67
68 return page;
69}
70
71int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
72{
73 int pid;
74
75 current->thread.request.u.thread.proc = fn;
76 current->thread.request.u.thread.arg = arg;
77 pid = do_fork(CLONE_VM | CLONE_UNTRACED | flags, 0,
78 ¤t->thread.regs, 0, NULL, NULL);
79 return pid;
80}
81
82static inline void set_current(struct task_struct *task)
83{
84 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
85 { external_pid(), task });
86}
87
88extern void arch_switch_to(struct task_struct *to);
89
90void *_switch_to(void *prev, void *next, void *last)
91{
92 struct task_struct *from = prev;
93 struct task_struct *to = next;
94
95 to->thread.prev_sched = from;
96 set_current(to);
97
98 do {
99 current->thread.saved_task = NULL;
100
101 switch_threads(&from->thread.switch_buf,
102 &to->thread.switch_buf);
103
104 arch_switch_to(current);
105
106 if (current->thread.saved_task)
107 show_regs(&(current->thread.regs));
108 to = current->thread.saved_task;
109 from = current;
110 } while (current->thread.saved_task);
111
112 return current->thread.prev_sched;
113
114}
115
116void interrupt_end(void)
117{
118 if (need_resched())
119 schedule();
120 if (test_tsk_thread_flag(current, TIF_SIGPENDING))
121 do_signal();
122}
123
124void exit_thread(void)
125{
126}
127
128void *get_current(void)
129{
130 return 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 REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.gp, 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_stop_sched_tick(1);
249 nsecs = disable_timer();
250 idle_sleep(nsecs);
251 tick_nohz_restart_sched_tick();
252 }
253}
254
255void cpu_idle(void)
256{
257 cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
258 default_idle();
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}
289
290int copy_to_user_proc(void __user *to, void *from, int size)
291{
292 return copy_to_user(to, from, size);
293}
294
295int copy_from_user_proc(void *to, void __user *from, int size)
296{
297 return copy_from_user(to, from, size);
298}
299
300int clear_user_proc(void __user *buf, int size)
301{
302 return clear_user(buf, size);
303}
304
305int strlen_user_proc(char __user *str)
306{
307 return strlen_user(str);
308}
309
310int smp_sigio_handler(void)
311{
312#ifdef CONFIG_SMP
313 int cpu = current_thread_info()->cpu;
314 IPI_handler(cpu);
315 if (cpu != 0)
316 return 1;
317#endif
318 return 0;
319}
320
321int cpu(void)
322{
323 return current_thread_info()->cpu;
324}
325
326static atomic_t using_sysemu = ATOMIC_INIT(0);
327int sysemu_supported;
328
329void set_using_sysemu(int value)
330{
331 if (value > sysemu_supported)
332 return;
333 atomic_set(&using_sysemu, value);
334}
335
336int get_using_sysemu(void)
337{
338 return atomic_read(&using_sysemu);
339}
340
341static int sysemu_proc_show(struct seq_file *m, void *v)
342{
343 seq_printf(m, "%d\n", get_using_sysemu());
344 return 0;
345}
346
347static int sysemu_proc_open(struct inode *inode, struct file *file)
348{
349 return single_open(file, sysemu_proc_show, NULL);
350}
351
352static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
353 size_t count, loff_t *pos)
354{
355 char tmp[2];
356
357 if (copy_from_user(tmp, buf, 1))
358 return -EFAULT;
359
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 */
363 return count;
364}
365
366static const struct file_operations sysemu_proc_fops = {
367 .owner = THIS_MODULE,
368 .open = sysemu_proc_open,
369 .read = seq_read,
370 .llseek = seq_lseek,
371 .release = single_release,
372 .write = sysemu_proc_write,
373};
374
375int __init make_proc_sysemu(void)
376{
377 struct proc_dir_entry *ent;
378 if (!sysemu_supported)
379 return 0;
380
381 ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops);
382
383 if (ent == NULL)
384 {
385 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
386 return 0;
387 }
388
389 return 0;
390}
391
392late_initcall(make_proc_sysemu);
393
394int singlestepping(void * t)
395{
396 struct task_struct *task = t ? t : current;
397
398 if (!(task->ptrace & PT_DTRACE))
399 return 0;
400
401 if (task->thread.singlestep_syscall)
402 return 1;
403
404 return 2;
405}
406
407/*
408 * Only x86 and x86_64 have an arch_align_stack().
409 * All other arches have "#define arch_align_stack(x) (x)"
410 * in their asm/system.h
411 * As this is included in UML from asm-um/system-generic.h,
412 * we can use it to behave as the subarch does.
413 */
414#ifndef arch_align_stack
415unsigned long arch_align_stack(unsigned long sp)
416{
417 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
418 sp -= get_random_int() % 8192;
419 return sp & ~0xf;
420}
421#endif
422
423unsigned long get_wchan(struct task_struct *p)
424{
425 unsigned long stack_page, sp, ip;
426 bool seen_sched = 0;
427
428 if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING))
429 return 0;
430
431 stack_page = (unsigned long) task_stack_page(p);
432 /* Bail if the process has no kernel stack for some reason */
433 if (stack_page == 0)
434 return 0;
435
436 sp = p->thread.switch_buf->JB_SP;
437 /*
438 * Bail if the stack pointer is below the bottom of the kernel
439 * stack for some reason
440 */
441 if (sp < stack_page)
442 return 0;
443
444 while (sp < stack_page + THREAD_SIZE) {
445 ip = *((unsigned long *) sp);
446 if (in_sched_functions(ip))
447 /* Ignore everything until we're above the scheduler */
448 seen_sched = 1;
449 else if (kernel_text_address(ip) && seen_sched)
450 return ip;
451
452 sp += sizeof(unsigned long);
453 }
454
455 return 0;
456}
457
458int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
459{
460 int cpu = current_thread_info()->cpu;
461
462 return save_fp_registers(userspace_pid[cpu], (unsigned long *) fpu);
463}
464
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/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 <linux/time-internal.h>
35
36/*
37 * This is a per-cpu array. A processor only modifies its entry and it only
38 * cares about its entry, so it's OK if another processor is modifying its
39 * entry.
40 */
41struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
42
43static inline int external_pid(void)
44{
45 /* FIXME: Need to look up userspace_pid by cpu */
46 return userspace_pid[0];
47}
48
49int pid_to_processor_id(int pid)
50{
51 int i;
52
53 for (i = 0; i < ncpus; i++) {
54 if (cpu_tasks[i].pid == pid)
55 return i;
56 }
57 return -1;
58}
59
60void free_stack(unsigned long stack, int order)
61{
62 free_pages(stack, order);
63}
64
65unsigned long alloc_stack(int order, int atomic)
66{
67 unsigned long page;
68 gfp_t flags = GFP_KERNEL;
69
70 if (atomic)
71 flags = GFP_ATOMIC;
72 page = __get_free_pages(flags, order);
73
74 return page;
75}
76
77static inline void set_current(struct task_struct *task)
78{
79 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
80 { external_pid(), task });
81}
82
83extern void arch_switch_to(struct task_struct *to);
84
85void *__switch_to(struct task_struct *from, struct task_struct *to)
86{
87 to->thread.prev_sched = from;
88 set_current(to);
89
90 switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
91 arch_switch_to(current);
92
93 return current->thread.prev_sched;
94}
95
96void interrupt_end(void)
97{
98 struct pt_regs *regs = ¤t->thread.regs;
99
100 if (need_resched())
101 schedule();
102 if (test_thread_flag(TIF_SIGPENDING) ||
103 test_thread_flag(TIF_NOTIFY_SIGNAL))
104 do_signal(regs);
105 if (test_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, unsigned long tls)
158{
159 void (*handler)(void);
160 int kthread = current->flags & (PF_KTHREAD | PF_IO_WORKER);
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_set_tls(p, tls);
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
206void um_idle_sleep(void)
207{
208 if (time_travel_mode != TT_MODE_OFF)
209 time_travel_sleep();
210 else
211 os_idle_sleep();
212}
213
214void arch_cpu_idle(void)
215{
216 cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
217 um_idle_sleep();
218 raw_local_irq_enable();
219}
220
221int __cant_sleep(void) {
222 return in_atomic() || irqs_disabled() || in_interrupt();
223 /* Is in_interrupt() really needed? */
224}
225
226int user_context(unsigned long sp)
227{
228 unsigned long stack;
229
230 stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
231 return stack != (unsigned long) current_thread_info();
232}
233
234extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
235
236void do_uml_exitcalls(void)
237{
238 exitcall_t *call;
239
240 call = &__uml_exitcall_end;
241 while (--call >= &__uml_exitcall_begin)
242 (*call)();
243}
244
245char *uml_strdup(const char *string)
246{
247 return kstrdup(string, GFP_KERNEL);
248}
249EXPORT_SYMBOL(uml_strdup);
250
251int copy_to_user_proc(void __user *to, void *from, int size)
252{
253 return copy_to_user(to, from, size);
254}
255
256int copy_from_user_proc(void *to, void __user *from, int size)
257{
258 return copy_from_user(to, from, size);
259}
260
261int clear_user_proc(void __user *buf, int size)
262{
263 return clear_user(buf, size);
264}
265
266int cpu(void)
267{
268 return current_thread_info()->cpu;
269}
270
271static atomic_t using_sysemu = ATOMIC_INIT(0);
272int sysemu_supported;
273
274void set_using_sysemu(int value)
275{
276 if (value > sysemu_supported)
277 return;
278 atomic_set(&using_sysemu, value);
279}
280
281int get_using_sysemu(void)
282{
283 return atomic_read(&using_sysemu);
284}
285
286static int sysemu_proc_show(struct seq_file *m, void *v)
287{
288 seq_printf(m, "%d\n", get_using_sysemu());
289 return 0;
290}
291
292static int sysemu_proc_open(struct inode *inode, struct file *file)
293{
294 return single_open(file, sysemu_proc_show, NULL);
295}
296
297static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
298 size_t count, loff_t *pos)
299{
300 char tmp[2];
301
302 if (copy_from_user(tmp, buf, 1))
303 return -EFAULT;
304
305 if (tmp[0] >= '0' && tmp[0] <= '2')
306 set_using_sysemu(tmp[0] - '0');
307 /* We use the first char, but pretend to write everything */
308 return count;
309}
310
311static const struct proc_ops sysemu_proc_ops = {
312 .proc_open = sysemu_proc_open,
313 .proc_read = seq_read,
314 .proc_lseek = seq_lseek,
315 .proc_release = single_release,
316 .proc_write = sysemu_proc_write,
317};
318
319int __init make_proc_sysemu(void)
320{
321 struct proc_dir_entry *ent;
322 if (!sysemu_supported)
323 return 0;
324
325 ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_ops);
326
327 if (ent == NULL)
328 {
329 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
330 return 0;
331 }
332
333 return 0;
334}
335
336late_initcall(make_proc_sysemu);
337
338int singlestepping(void * t)
339{
340 struct task_struct *task = t ? t : current;
341
342 if (!(task->ptrace & PT_DTRACE))
343 return 0;
344
345 if (task->thread.singlestep_syscall)
346 return 1;
347
348 return 2;
349}
350
351/*
352 * Only x86 and x86_64 have an arch_align_stack().
353 * All other arches have "#define arch_align_stack(x) (x)"
354 * in their asm/exec.h
355 * As this is included in UML from asm-um/system-generic.h,
356 * we can use it to behave as the subarch does.
357 */
358#ifndef arch_align_stack
359unsigned long arch_align_stack(unsigned long sp)
360{
361 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
362 sp -= get_random_int() % 8192;
363 return sp & ~0xf;
364}
365#endif
366
367unsigned long get_wchan(struct task_struct *p)
368{
369 unsigned long stack_page, sp, ip;
370 bool seen_sched = 0;
371
372 if ((p == NULL) || (p == current) || task_is_running(p))
373 return 0;
374
375 stack_page = (unsigned long) task_stack_page(p);
376 /* Bail if the process has no kernel stack for some reason */
377 if (stack_page == 0)
378 return 0;
379
380 sp = p->thread.switch_buf->JB_SP;
381 /*
382 * Bail if the stack pointer is below the bottom of the kernel
383 * stack for some reason
384 */
385 if (sp < stack_page)
386 return 0;
387
388 while (sp < stack_page + THREAD_SIZE) {
389 ip = *((unsigned long *) sp);
390 if (in_sched_functions(ip))
391 /* Ignore everything until we're above the scheduler */
392 seen_sched = 1;
393 else if (kernel_text_address(ip) && seen_sched)
394 return ip;
395
396 sp += sizeof(unsigned long);
397 }
398
399 return 0;
400}
401
402int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
403{
404 int cpu = current_thread_info()->cpu;
405
406 return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu);
407}
408