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/seq_file.h>
23 #include <linux/tick.h>
24 #include <linux/threads.h>
25 #include <linux/tracehook.h>
26 #include <asm/current.h>
27 #include <asm/pgtable.h>
28 #include <asm/mmu_context.h>
29 #include <linux/uaccess.h>
30 #include <as-layout.h>
31 #include <kern_util.h>
34 #include <timer-internal.h>
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
41 struct cpu_task cpu_tasks
[NR_CPUS
] = { [0 ... NR_CPUS
- 1] = { -1, NULL
} };
43 static inline int external_pid(void)
45 /* FIXME: Need to look up userspace_pid by cpu */
46 return userspace_pid
[0];
49 int pid_to_processor_id(int pid
)
53 for (i
= 0; i
< ncpus
; i
++) {
54 if (cpu_tasks
[i
].pid
== pid
)
60 void free_stack(unsigned long stack
, int order
)
62 free_pages(stack
, order
);
65 unsigned long alloc_stack(int order
, int atomic
)
68 gfp_t flags
= GFP_KERNEL
;
72 page
= __get_free_pages(flags
, order
);
77 static inline void set_current(struct task_struct
*task
)
79 cpu_tasks
[task_thread_info(task
)->cpu
] = ((struct cpu_task
)
80 { external_pid(), task
});
83 extern void arch_switch_to(struct task_struct
*to
);
85 void *__switch_to(struct task_struct
*from
, struct task_struct
*to
)
87 to
->thread
.prev_sched
= from
;
90 switch_threads(&from
->thread
.switch_buf
, &to
->thread
.switch_buf
);
91 arch_switch_to(current
);
93 return current
->thread
.prev_sched
;
96 void interrupt_end(void)
98 struct pt_regs
*regs
= ¤t
->thread
.regs
;
102 if (test_thread_flag(TIF_SIGPENDING
))
104 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME
))
105 tracehook_notify_resume(regs
);
108 int get_current_pid(void)
110 return task_pid_nr(current
);
114 * This is called magically, by its address being stuffed in a jmp_buf
115 * and being longjmp-d to.
117 void new_thread_handler(void)
119 int (*fn
)(void *), n
;
122 if (current
->thread
.prev_sched
!= NULL
)
123 schedule_tail(current
->thread
.prev_sched
);
124 current
->thread
.prev_sched
= NULL
;
126 fn
= current
->thread
.request
.u
.thread
.proc
;
127 arg
= current
->thread
.request
.u
.thread
.arg
;
130 * callback returns only if the kernel thread execs a process
133 userspace(¤t
->thread
.regs
.regs
);
136 /* Called magically, see new_thread_handler above */
137 void fork_handler(void)
141 schedule_tail(current
->thread
.prev_sched
);
144 * XXX: if interrupt_end() calls schedule, this call to
145 * arch_switch_to isn't needed. We could want to apply this to
146 * improve performance. -bb
148 arch_switch_to(current
);
150 current
->thread
.prev_sched
= NULL
;
152 userspace(¤t
->thread
.regs
.regs
);
155 int copy_thread(unsigned long clone_flags
, unsigned long sp
,
156 unsigned long arg
, struct task_struct
* p
)
158 void (*handler
)(void);
159 int kthread
= current
->flags
& PF_KTHREAD
;
162 p
->thread
= (struct thread_struct
) INIT_THREAD
;
165 memcpy(&p
->thread
.regs
.regs
, current_pt_regs(),
166 sizeof(p
->thread
.regs
.regs
));
167 PT_REGS_SET_SYSCALL_RETURN(&p
->thread
.regs
, 0);
169 REGS_SP(p
->thread
.regs
.regs
.gp
) = sp
;
171 handler
= fork_handler
;
173 arch_copy_thread(¤t
->thread
.arch
, &p
->thread
.arch
);
175 get_safe_registers(p
->thread
.regs
.regs
.gp
, p
->thread
.regs
.regs
.fp
);
176 p
->thread
.request
.u
.thread
.proc
= (int (*)(void *))sp
;
177 p
->thread
.request
.u
.thread
.arg
= (void *)arg
;
178 handler
= new_thread_handler
;
181 new_thread(task_stack_page(p
), &p
->thread
.switch_buf
, handler
);
184 clear_flushed_tls(p
);
187 * Set a new TLS for the child thread?
189 if (clone_flags
& CLONE_SETTLS
)
190 ret
= arch_copy_tls(p
);
196 void initial_thread_cb(void (*proc
)(void *), void *arg
)
198 int save_kmalloc_ok
= kmalloc_ok
;
201 initial_thread_cb_skas(proc
, arg
);
202 kmalloc_ok
= save_kmalloc_ok
;
205 void arch_cpu_idle(void)
207 cpu_tasks
[current_thread_info()->cpu
].pid
= os_getpid();
208 os_idle_sleep(UM_NSEC_PER_SEC
);
212 int __cant_sleep(void) {
213 return in_atomic() || irqs_disabled() || in_interrupt();
214 /* Is in_interrupt() really needed? */
217 int user_context(unsigned long sp
)
221 stack
= sp
& (PAGE_MASK
<< CONFIG_KERNEL_STACK_ORDER
);
222 return stack
!= (unsigned long) current_thread_info();
225 extern exitcall_t __uml_exitcall_begin
, __uml_exitcall_end
;
227 void do_uml_exitcalls(void)
231 call
= &__uml_exitcall_end
;
232 while (--call
>= &__uml_exitcall_begin
)
236 char *uml_strdup(const char *string
)
238 return kstrdup(string
, GFP_KERNEL
);
240 EXPORT_SYMBOL(uml_strdup
);
242 int copy_to_user_proc(void __user
*to
, void *from
, int size
)
244 return copy_to_user(to
, from
, size
);
247 int copy_from_user_proc(void *to
, void __user
*from
, int size
)
249 return copy_from_user(to
, from
, size
);
252 int clear_user_proc(void __user
*buf
, int size
)
254 return clear_user(buf
, size
);
257 int strlen_user_proc(char __user
*str
)
259 return strlen_user(str
);
264 return current_thread_info()->cpu
;
267 static atomic_t using_sysemu
= ATOMIC_INIT(0);
268 int sysemu_supported
;
270 void set_using_sysemu(int value
)
272 if (value
> sysemu_supported
)
274 atomic_set(&using_sysemu
, value
);
277 int get_using_sysemu(void)
279 return atomic_read(&using_sysemu
);
282 static int sysemu_proc_show(struct seq_file
*m
, void *v
)
284 seq_printf(m
, "%d\n", get_using_sysemu());
288 static int sysemu_proc_open(struct inode
*inode
, struct file
*file
)
290 return single_open(file
, sysemu_proc_show
, NULL
);
293 static ssize_t
sysemu_proc_write(struct file
*file
, const char __user
*buf
,
294 size_t count
, loff_t
*pos
)
298 if (copy_from_user(tmp
, buf
, 1))
301 if (tmp
[0] >= '0' && tmp
[0] <= '2')
302 set_using_sysemu(tmp
[0] - '0');
303 /* We use the first char, but pretend to write everything */
307 static const struct file_operations sysemu_proc_fops
= {
308 .owner
= THIS_MODULE
,
309 .open
= sysemu_proc_open
,
312 .release
= single_release
,
313 .write
= sysemu_proc_write
,
316 int __init
make_proc_sysemu(void)
318 struct proc_dir_entry
*ent
;
319 if (!sysemu_supported
)
322 ent
= proc_create("sysemu", 0600, NULL
, &sysemu_proc_fops
);
326 printk(KERN_WARNING
"Failed to register /proc/sysemu\n");
333 late_initcall(make_proc_sysemu
);
335 int singlestepping(void * t
)
337 struct task_struct
*task
= t
? t
: current
;
339 if (!(task
->ptrace
& PT_DTRACE
))
342 if (task
->thread
.singlestep_syscall
)
349 * Only x86 and x86_64 have an arch_align_stack().
350 * All other arches have "#define arch_align_stack(x) (x)"
351 * in their asm/exec.h
352 * As this is included in UML from asm-um/system-generic.h,
353 * we can use it to behave as the subarch does.
355 #ifndef arch_align_stack
356 unsigned long arch_align_stack(unsigned long sp
)
358 if (!(current
->personality
& ADDR_NO_RANDOMIZE
) && randomize_va_space
)
359 sp
-= get_random_int() % 8192;
364 unsigned long get_wchan(struct task_struct
*p
)
366 unsigned long stack_page
, sp
, ip
;
369 if ((p
== NULL
) || (p
== current
) || (p
->state
== TASK_RUNNING
))
372 stack_page
= (unsigned long) task_stack_page(p
);
373 /* Bail if the process has no kernel stack for some reason */
377 sp
= p
->thread
.switch_buf
->JB_SP
;
379 * Bail if the stack pointer is below the bottom of the kernel
380 * stack for some reason
385 while (sp
< stack_page
+ THREAD_SIZE
) {
386 ip
= *((unsigned long *) sp
);
387 if (in_sched_functions(ip
))
388 /* Ignore everything until we're above the scheduler */
390 else if (kernel_text_address(ip
) && seen_sched
)
393 sp
+= sizeof(unsigned long);
399 int elf_core_copy_fpregs(struct task_struct
*t
, elf_fpregset_t
*fpu
)
401 int cpu
= current_thread_info()->cpu
;
403 return save_i387_registers(userspace_pid
[cpu
], (unsigned long *) fpu
);