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/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 <asm/uaccess.h>
28 #include <as-layout.h>
29 #include <kern_util.h>
32 #include <timer-internal.h>
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
39 struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
41 static inline int external_pid(void)
43 /* FIXME: Need to look up userspace_pid by cpu */
44 return userspace_pid[0];
47 int pid_to_processor_id(int pid)
51 for (i = 0; i < ncpus; i++) {
52 if (cpu_tasks[i].pid == pid)
58 void free_stack(unsigned long stack, int order)
60 free_pages(stack, order);
63 unsigned long alloc_stack(int order, int atomic)
66 gfp_t flags = GFP_KERNEL;
70 page = __get_free_pages(flags, order);
75 static inline void set_current(struct task_struct *task)
77 cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task)
78 { external_pid(), task });
81 extern void arch_switch_to(struct task_struct *to);
83 void *__switch_to(struct task_struct *from, struct task_struct *to)
85 to->thread.prev_sched = from;
88 switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
89 arch_switch_to(current);
91 return current->thread.prev_sched;
94 void interrupt_end(void)
96 struct pt_regs *regs = ¤t->thread.regs;
100 if (test_thread_flag(TIF_SIGPENDING))
102 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
103 tracehook_notify_resume(regs);
106 int get_current_pid(void)
108 return task_pid_nr(current);
112 * This is called magically, by its address being stuffed in a jmp_buf
113 * and being longjmp-d to.
115 void new_thread_handler(void)
117 int (*fn)(void *), n;
120 if (current->thread.prev_sched != NULL)
121 schedule_tail(current->thread.prev_sched);
122 current->thread.prev_sched = NULL;
124 fn = current->thread.request.u.thread.proc;
125 arg = current->thread.request.u.thread.arg;
128 * callback returns only if the kernel thread execs a process
131 userspace(¤t->thread.regs.regs);
134 /* Called magically, see new_thread_handler above */
135 void fork_handler(void)
139 schedule_tail(current->thread.prev_sched);
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
146 arch_switch_to(current);
148 current->thread.prev_sched = NULL;
150 userspace(¤t->thread.regs.regs);
153 int copy_thread(unsigned long clone_flags, unsigned long sp,
154 unsigned long arg, struct task_struct * p)
156 void (*handler)(void);
157 int kthread = current->flags & PF_KTHREAD;
160 p->thread = (struct thread_struct) INIT_THREAD;
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);
167 REGS_SP(p->thread.regs.regs.gp) = sp;
169 handler = fork_handler;
171 arch_copy_thread(¤t->thread.arch, &p->thread.arch);
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;
179 new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
182 clear_flushed_tls(p);
185 * Set a new TLS for the child thread?
187 if (clone_flags & CLONE_SETTLS)
188 ret = arch_copy_tls(p);
194 void initial_thread_cb(void (*proc)(void *), void *arg)
196 int save_kmalloc_ok = kmalloc_ok;
199 initial_thread_cb_skas(proc, arg);
200 kmalloc_ok = save_kmalloc_ok;
203 void arch_cpu_idle(void)
205 cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
206 os_idle_sleep(UM_NSEC_PER_SEC);
210 int __cant_sleep(void) {
211 return in_atomic() || irqs_disabled() || in_interrupt();
212 /* Is in_interrupt() really needed? */
215 int user_context(unsigned long sp)
219 stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER);
220 return stack != (unsigned long) current_thread_info();
223 extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end;
225 void do_uml_exitcalls(void)
229 call = &__uml_exitcall_end;
230 while (--call >= &__uml_exitcall_begin)
234 char *uml_strdup(const char *string)
236 return kstrdup(string, GFP_KERNEL);
238 EXPORT_SYMBOL(uml_strdup);
240 int copy_to_user_proc(void __user *to, void *from, int size)
242 return copy_to_user(to, from, size);
245 int copy_from_user_proc(void *to, void __user *from, int size)
247 return copy_from_user(to, from, size);
250 int clear_user_proc(void __user *buf, int size)
252 return clear_user(buf, size);
255 int strlen_user_proc(char __user *str)
257 return strlen_user(str);
262 return current_thread_info()->cpu;
265 static atomic_t using_sysemu = ATOMIC_INIT(0);
266 int sysemu_supported;
268 void set_using_sysemu(int value)
270 if (value > sysemu_supported)
272 atomic_set(&using_sysemu, value);
275 int get_using_sysemu(void)
277 return atomic_read(&using_sysemu);
280 static int sysemu_proc_show(struct seq_file *m, void *v)
282 seq_printf(m, "%d\n", get_using_sysemu());
286 static int sysemu_proc_open(struct inode *inode, struct file *file)
288 return single_open(file, sysemu_proc_show, NULL);
291 static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
292 size_t count, loff_t *pos)
296 if (copy_from_user(tmp, buf, 1))
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 */
305 static const struct file_operations sysemu_proc_fops = {
306 .owner = THIS_MODULE,
307 .open = sysemu_proc_open,
310 .release = single_release,
311 .write = sysemu_proc_write,
314 int __init make_proc_sysemu(void)
316 struct proc_dir_entry *ent;
317 if (!sysemu_supported)
320 ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops);
324 printk(KERN_WARNING "Failed to register /proc/sysemu\n");
331 late_initcall(make_proc_sysemu);
333 int singlestepping(void * t)
335 struct task_struct *task = t ? t : current;
337 if (!(task->ptrace & PT_DTRACE))
340 if (task->thread.singlestep_syscall)
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.
353 #ifndef arch_align_stack
354 unsigned long arch_align_stack(unsigned long sp)
356 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
357 sp -= get_random_int() % 8192;
362 unsigned long get_wchan(struct task_struct *p)
364 unsigned long stack_page, sp, ip;
367 if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING))
370 stack_page = (unsigned long) task_stack_page(p);
371 /* Bail if the process has no kernel stack for some reason */
375 sp = p->thread.switch_buf->JB_SP;
377 * Bail if the stack pointer is below the bottom of the kernel
378 * stack for some reason
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 */
388 else if (kernel_text_address(ip) && seen_sched)
391 sp += sizeof(unsigned long);
397 int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
399 int cpu = current_thread_info()->cpu;
401 return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu);