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
9 #include <linux/stddef.h>
10 #include <linux/err.h>
11 #include <linux/hardirq.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>
35 #include <timer-internal.h>
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
42 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
44 static inline int external_pid(void)
46 /* FIXME: Need to look up userspace_pid by cpu */
47 return userspace_pid[0];
50 int pid_to_processor_id(int pid)
54 for (i = 0; i < ncpus; i++) {
55 if (cpu_tasks[i].pid == pid)
61 void free_stack(unsigned long stack, int order)
63 free_pages(stack, order);
66 unsigned long alloc_stack(int order, int atomic)
69 gfp_t flags = GFP_KERNEL;
73 page = __get_free_pages(flags, order);
78 static inline void set_current(struct task_struct *task)
80 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
81 { external_pid(), task });
84 extern void arch_switch_to(struct task_struct *to);
86 void *__switch_to(struct task_struct *from, struct task_struct *to)
88 to->thread.prev_sched = from;
91 switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
92 arch_switch_to(current);
94 return current->thread.prev_sched;
97 void interrupt_end(void)
99 struct pt_regs *regs = ¤t->thread.regs;
103 if (test_thread_flag(TIF_SIGPENDING))
105 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
106 tracehook_notify_resume(regs);
109 int get_current_pid(void)
111 return task_pid_nr(current);
115 * This is called magically, by its address being stuffed in a jmp_buf
116 * and being longjmp-d to.
118 void new_thread_handler(void)
120 int (*fn)(void *), n;
123 if (current->thread.prev_sched != NULL)
124 schedule_tail(current->thread.prev_sched);
125 current->thread.prev_sched = NULL;
127 fn = current->thread.request.u.thread.proc;
128 arg = current->thread.request.u.thread.arg;
131 * callback returns only if the kernel thread execs a process
134 userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs);
137 /* Called magically, see new_thread_handler above */
138 void fork_handler(void)
142 schedule_tail(current->thread.prev_sched);
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
149 arch_switch_to(current);
151 current->thread.prev_sched = NULL;
153 userspace(¤t->thread.regs.regs, current_thread_info()->aux_fp_regs);
156 int copy_thread(unsigned long clone_flags, unsigned long sp,
157 unsigned long arg, struct task_struct * p)
159 void (*handler)(void);
160 int kthread = current->flags & PF_KTHREAD;
163 p->thread = (struct thread_struct) INIT_THREAD;
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);
170 REGS_SP(p->thread.regs.regs.gp) = sp;
172 handler = fork_handler;
174 arch_copy_thread(¤t->thread.arch, &p->thread.arch);
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;
182 new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
185 clear_flushed_tls(p);
188 * Set a new TLS for the child thread?
190 if (clone_flags & CLONE_SETTLS)
191 ret = arch_copy_tls(p);
197 void initial_thread_cb(void (*proc)(void *), void *arg)
199 int save_kmalloc_ok = kmalloc_ok;
202 initial_thread_cb_skas(proc, arg);
203 kmalloc_ok = save_kmalloc_ok;
206 static void time_travel_sleep(unsigned long long duration)
208 unsigned long long next = time_travel_time + duration;
210 if (time_travel_mode != TT_MODE_INFCPU)
213 if (time_travel_timer_mode != TT_TMR_DISABLED ||
214 time_travel_timer_expiry < next) {
215 if (time_travel_timer_mode == TT_TMR_ONESHOT)
216 time_travel_set_timer(TT_TMR_DISABLED, 0);
218 * time_travel_time will be adjusted in the timer
219 * IRQ handler so it works even when the signal
220 * comes from the OS timer
224 time_travel_set_time(next);
227 if (time_travel_mode != TT_MODE_INFCPU) {
228 if (time_travel_timer_mode == TT_TMR_PERIODIC)
229 os_timer_set_interval(time_travel_timer_interval);
230 else if (time_travel_timer_mode == TT_TMR_ONESHOT)
231 os_timer_one_shot(time_travel_timer_expiry - next);
235 static void um_idle_sleep(void)
237 unsigned long long duration = UM_NSEC_PER_SEC;
239 if (time_travel_mode != TT_MODE_OFF) {
240 time_travel_sleep(duration);
242 os_idle_sleep(duration);
246 void arch_cpu_idle(void)
248 cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
253 int __cant_sleep(void) {
254 return in_atomic() || irqs_disabled() || in_interrupt();
255 /* Is in_interrupt() really needed? */
258 int user_context(unsigned long sp)
262 stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
263 return stack != (unsigned long) current_thread_info();
266 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
268 void do_uml_exitcalls(void)
272 call = &__uml_exitcall_end;
273 while (--call >= &__uml_exitcall_begin)
277 char *uml_strdup(const char *string)
279 return kstrdup(string, GFP_KERNEL);
281 EXPORT_SYMBOL(uml_strdup);
283 int copy_to_user_proc(void __user *to, void *from, int size)
285 return copy_to_user(to, from, size);
288 int copy_from_user_proc(void *to, void __user *from, int size)
290 return copy_from_user(to, from, size);
293 int clear_user_proc(void __user *buf, int size)
295 return clear_user(buf, size);
300 return current_thread_info()->cpu;
303 static atomic_t using_sysemu = ATOMIC_INIT(0);
304 int sysemu_supported;
306 void set_using_sysemu(int value)
308 if (value > sysemu_supported)
310 atomic_set(&using_sysemu, value);
313 int get_using_sysemu(void)
315 return atomic_read(&using_sysemu);
318 static int sysemu_proc_show(struct seq_file *m, void *v)
320 seq_printf(m, "%d\n", get_using_sysemu());
324 static int sysemu_proc_open(struct inode *inode, struct file *file)
326 return single_open(file, sysemu_proc_show, NULL);
329 static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
330 size_t count, loff_t *pos)
334 if (copy_from_user(tmp, buf, 1))
337 if (tmp[0] >= '0' && tmp[0] <= '2')
338 set_using_sysemu(tmp[0] - '0');
339 /* We use the first char, but pretend to write everything */
343 static const struct file_operations sysemu_proc_fops = {
344 .owner = THIS_MODULE,
345 .open = sysemu_proc_open,
348 .release = single_release,
349 .write = sysemu_proc_write,
352 int __init make_proc_sysemu(void)
354 struct proc_dir_entry *ent;
355 if (!sysemu_supported)
358 ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops);
362 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
369 late_initcall(make_proc_sysemu);
371 int singlestepping(void * t)
373 struct task_struct *task = t ? t : current;
375 if (!(task->ptrace & PT_DTRACE))
378 if (task->thread.singlestep_syscall)
385 * Only x86 and x86_64 have an arch_align_stack().
386 * All other arches have "#define arch_align_stack(x) (x)"
387 * in their asm/exec.h
388 * As this is included in UML from asm-um/system-generic.h,
389 * we can use it to behave as the subarch does.
391 #ifndef arch_align_stack
392 unsigned long arch_align_stack(unsigned long sp)
394 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
395 sp -= get_random_int() % 8192;
400 unsigned long get_wchan(struct task_struct *p)
402 unsigned long stack_page, sp, ip;
405 if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING))
408 stack_page = (unsigned long) task_stack_page(p);
409 /* Bail if the process has no kernel stack for some reason */
413 sp = p->thread.switch_buf->JB_SP;
415 * Bail if the stack pointer is below the bottom of the kernel
416 * stack for some reason
421 while (sp < stack_page + THREAD_SIZE) {
422 ip = *((unsigned long *) sp);
423 if (in_sched_functions(ip))
424 /* Ignore everything until we're above the scheduler */
426 else if (kernel_text_address(ip) && seen_sched)
429 sp += sizeof(unsigned long);
435 int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
437 int cpu = current_thread_info()->cpu;
439 return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu);