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Commit | Line | Data |
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995473ae | 1 | /* |
2eb5f31b AI |
2 | * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk}) |
3 | * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de) | |
ba180fd4 | 4 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
5 | * Copyright 2003 PathScale, Inc. |
6 | * Licensed under the GPL | |
7 | */ | |
8 | ||
c5d4bb17 JD |
9 | #include <linux/stddef.h> |
10 | #include <linux/err.h> | |
11 | #include <linux/hardirq.h> | |
c5d4bb17 | 12 | #include <linux/mm.h> |
6613c5e8 | 13 | #include <linux/module.h> |
c5d4bb17 JD |
14 | #include <linux/personality.h> |
15 | #include <linux/proc_fs.h> | |
16 | #include <linux/ptrace.h> | |
17 | #include <linux/random.h> | |
5a0e3ad6 | 18 | #include <linux/slab.h> |
c5d4bb17 | 19 | #include <linux/sched.h> |
b17b0153 | 20 | #include <linux/sched/debug.h> |
6613c5e8 | 21 | #include <linux/seq_file.h> |
c5d4bb17 JD |
22 | #include <linux/tick.h> |
23 | #include <linux/threads.h> | |
d50349b0 | 24 | #include <linux/tracehook.h> |
c5d4bb17 JD |
25 | #include <asm/current.h> |
26 | #include <asm/pgtable.h> | |
445c5786 | 27 | #include <asm/mmu_context.h> |
7c0f6ba6 | 28 | #include <linux/uaccess.h> |
37185b33 AV |
29 | #include <as-layout.h> |
30 | #include <kern_util.h> | |
31 | #include <os.h> | |
32 | #include <skas.h> | |
2eb5f31b | 33 | #include <timer-internal.h> |
1da177e4 | 34 | |
ba180fd4 JD |
35 | /* |
36 | * This is a per-cpu array. A processor only modifies its entry and it only | |
1da177e4 LT |
37 | * cares about its entry, so it's OK if another processor is modifying its |
38 | * entry. | |
39 | */ | |
40 | struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } }; | |
41 | ||
2dc5802a | 42 | static inline int external_pid(void) |
1da177e4 | 43 | { |
77bf4400 | 44 | /* FIXME: Need to look up userspace_pid by cpu */ |
ba180fd4 | 45 | return userspace_pid[0]; |
1da177e4 LT |
46 | } |
47 | ||
48 | int pid_to_processor_id(int pid) | |
49 | { | |
50 | int i; | |
51 | ||
c5d4bb17 | 52 | for (i = 0; i < ncpus; i++) { |
ba180fd4 | 53 | if (cpu_tasks[i].pid == pid) |
6e21aec3 | 54 | return i; |
1da177e4 | 55 | } |
6e21aec3 | 56 | return -1; |
1da177e4 LT |
57 | } |
58 | ||
59 | void free_stack(unsigned long stack, int order) | |
60 | { | |
61 | free_pages(stack, order); | |
62 | } | |
63 | ||
64 | unsigned long alloc_stack(int order, int atomic) | |
65 | { | |
66 | unsigned long page; | |
53f9fc93 | 67 | gfp_t flags = GFP_KERNEL; |
1da177e4 | 68 | |
46db4a42 PBG |
69 | if (atomic) |
70 | flags = GFP_ATOMIC; | |
1da177e4 | 71 | page = __get_free_pages(flags, order); |
5c8aacea | 72 | |
6e21aec3 | 73 | return page; |
1da177e4 LT |
74 | } |
75 | ||
6e21aec3 | 76 | static inline void set_current(struct task_struct *task) |
1da177e4 | 77 | { |
ca9bc0bb | 78 | cpu_tasks[task_thread_info(task)->cpu] = ((struct cpu_task) |
2dc5802a | 79 | { external_pid(), task }); |
1da177e4 LT |
80 | } |
81 | ||
291248fd | 82 | extern void arch_switch_to(struct task_struct *to); |
77bf4400 | 83 | |
76b278ed | 84 | void *__switch_to(struct task_struct *from, struct task_struct *to) |
1da177e4 | 85 | { |
995473ae JD |
86 | to->thread.prev_sched = from; |
87 | set_current(to); | |
f6e34c6a | 88 | |
a1850e9c RW |
89 | switch_threads(&from->thread.switch_buf, &to->thread.switch_buf); |
90 | arch_switch_to(current); | |
f6e34c6a | 91 | |
6e21aec3 | 92 | return current->thread.prev_sched; |
1da177e4 LT |
93 | } |
94 | ||
95 | void interrupt_end(void) | |
96 | { | |
ccaee5f8 IM |
97 | struct pt_regs *regs = ¤t->thread.regs; |
98 | ||
ba180fd4 | 99 | if (need_resched()) |
6e21aec3 | 100 | schedule(); |
d50349b0 | 101 | if (test_thread_flag(TIF_SIGPENDING)) |
ccaee5f8 | 102 | do_signal(regs); |
a42c6ded | 103 | if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) |
ccaee5f8 | 104 | tracehook_notify_resume(regs); |
1da177e4 LT |
105 | } |
106 | ||
c2220b2a | 107 | int get_current_pid(void) |
1da177e4 | 108 | { |
c2220b2a | 109 | return task_pid_nr(current); |
1da177e4 LT |
110 | } |
111 | ||
ba180fd4 JD |
112 | /* |
113 | * This is called magically, by its address being stuffed in a jmp_buf | |
77bf4400 JD |
114 | * and being longjmp-d to. |
115 | */ | |
116 | void new_thread_handler(void) | |
117 | { | |
118 | int (*fn)(void *), n; | |
119 | void *arg; | |
120 | ||
ba180fd4 | 121 | if (current->thread.prev_sched != NULL) |
77bf4400 JD |
122 | schedule_tail(current->thread.prev_sched); |
123 | current->thread.prev_sched = NULL; | |
124 | ||
125 | fn = current->thread.request.u.thread.proc; | |
126 | arg = current->thread.request.u.thread.arg; | |
127 | ||
ba180fd4 | 128 | /* |
22e2430d | 129 | * callback returns only if the kernel thread execs a process |
77bf4400 | 130 | */ |
22e2430d AV |
131 | n = fn(arg); |
132 | userspace(¤t->thread.regs.regs); | |
77bf4400 JD |
133 | } |
134 | ||
135 | /* Called magically, see new_thread_handler above */ | |
136 | void fork_handler(void) | |
137 | { | |
138 | force_flush_all(); | |
77bf4400 JD |
139 | |
140 | schedule_tail(current->thread.prev_sched); | |
141 | ||
ba180fd4 JD |
142 | /* |
143 | * XXX: if interrupt_end() calls schedule, this call to | |
77bf4400 | 144 | * arch_switch_to isn't needed. We could want to apply this to |
ba180fd4 JD |
145 | * improve performance. -bb |
146 | */ | |
291248fd | 147 | arch_switch_to(current); |
77bf4400 JD |
148 | |
149 | current->thread.prev_sched = NULL; | |
150 | ||
77bf4400 JD |
151 | userspace(¤t->thread.regs.regs); |
152 | } | |
153 | ||
6f2c55b8 | 154 | int copy_thread(unsigned long clone_flags, unsigned long sp, |
afa86fc4 | 155 | unsigned long arg, struct task_struct * p) |
1da177e4 | 156 | { |
77bf4400 | 157 | void (*handler)(void); |
d2ce4e92 | 158 | int kthread = current->flags & PF_KTHREAD; |
77bf4400 | 159 | int ret = 0; |
aa6758d4 | 160 | |
1da177e4 | 161 | p->thread = (struct thread_struct) INIT_THREAD; |
aa6758d4 | 162 | |
d2ce4e92 | 163 | if (!kthread) { |
2b067fc9 | 164 | memcpy(&p->thread.regs.regs, current_pt_regs(), |
77bf4400 | 165 | sizeof(p->thread.regs.regs)); |
a3170d2e | 166 | PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0); |
ba180fd4 | 167 | if (sp != 0) |
18baddda | 168 | REGS_SP(p->thread.regs.regs.gp) = sp; |
aa6758d4 | 169 | |
77bf4400 | 170 | handler = fork_handler; |
aa6758d4 | 171 | |
77bf4400 | 172 | arch_copy_thread(¤t->thread.arch, &p->thread.arch); |
d2ce4e92 | 173 | } else { |
fbfe9c84 | 174 | get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp); |
1f02ab4a AV |
175 | p->thread.request.u.thread.proc = (int (*)(void *))sp; |
176 | p->thread.request.u.thread.arg = (void *)arg; | |
77bf4400 JD |
177 | handler = new_thread_handler; |
178 | } | |
179 | ||
180 | new_thread(task_stack_page(p), &p->thread.switch_buf, handler); | |
181 | ||
d2ce4e92 | 182 | if (!kthread) { |
77bf4400 JD |
183 | clear_flushed_tls(p); |
184 | ||
185 | /* | |
186 | * Set a new TLS for the child thread? | |
187 | */ | |
188 | if (clone_flags & CLONE_SETTLS) | |
189 | ret = arch_copy_tls(p); | |
190 | } | |
aa6758d4 | 191 | |
aa6758d4 | 192 | return ret; |
1da177e4 LT |
193 | } |
194 | ||
195 | void initial_thread_cb(void (*proc)(void *), void *arg) | |
196 | { | |
197 | int save_kmalloc_ok = kmalloc_ok; | |
198 | ||
199 | kmalloc_ok = 0; | |
6aa802ce | 200 | initial_thread_cb_skas(proc, arg); |
1da177e4 LT |
201 | kmalloc_ok = save_kmalloc_ok; |
202 | } | |
995473ae | 203 | |
8198c169 | 204 | void arch_cpu_idle(void) |
1da177e4 | 205 | { |
a5a678c8 | 206 | cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); |
2eb5f31b | 207 | os_idle_sleep(UM_NSEC_PER_SEC); |
8198c169 | 208 | local_irq_enable(); |
1da177e4 LT |
209 | } |
210 | ||
b6316293 PBG |
211 | int __cant_sleep(void) { |
212 | return in_atomic() || irqs_disabled() || in_interrupt(); | |
213 | /* Is in_interrupt() really needed? */ | |
1da177e4 LT |
214 | } |
215 | ||
1da177e4 LT |
216 | int user_context(unsigned long sp) |
217 | { | |
218 | unsigned long stack; | |
219 | ||
220 | stack = sp & (PAGE_MASK << CONFIG_KERNEL_STACK_ORDER); | |
a5a678c8 | 221 | return stack != (unsigned long) current_thread_info(); |
1da177e4 LT |
222 | } |
223 | ||
1da177e4 LT |
224 | extern exitcall_t __uml_exitcall_begin, __uml_exitcall_end; |
225 | ||
226 | void do_uml_exitcalls(void) | |
227 | { | |
228 | exitcall_t *call; | |
229 | ||
230 | call = &__uml_exitcall_end; | |
231 | while (--call >= &__uml_exitcall_begin) | |
232 | (*call)(); | |
233 | } | |
234 | ||
c0a9290e | 235 | char *uml_strdup(const char *string) |
1da177e4 | 236 | { |
dfe52244 | 237 | return kstrdup(string, GFP_KERNEL); |
1da177e4 | 238 | } |
73395a00 | 239 | EXPORT_SYMBOL(uml_strdup); |
1da177e4 | 240 | |
1da177e4 LT |
241 | int copy_to_user_proc(void __user *to, void *from, int size) |
242 | { | |
6e21aec3 | 243 | return copy_to_user(to, from, size); |
1da177e4 LT |
244 | } |
245 | ||
246 | int copy_from_user_proc(void *to, void __user *from, int size) | |
247 | { | |
6e21aec3 | 248 | return copy_from_user(to, from, size); |
1da177e4 LT |
249 | } |
250 | ||
251 | int clear_user_proc(void __user *buf, int size) | |
252 | { | |
6e21aec3 | 253 | return clear_user(buf, size); |
1da177e4 LT |
254 | } |
255 | ||
256 | int strlen_user_proc(char __user *str) | |
257 | { | |
6e21aec3 | 258 | return strlen_user(str); |
1da177e4 LT |
259 | } |
260 | ||
1da177e4 LT |
261 | int cpu(void) |
262 | { | |
a5a678c8 | 263 | return current_thread_info()->cpu; |
1da177e4 LT |
264 | } |
265 | ||
266 | static atomic_t using_sysemu = ATOMIC_INIT(0); | |
267 | int sysemu_supported; | |
268 | ||
269 | void set_using_sysemu(int value) | |
270 | { | |
271 | if (value > sysemu_supported) | |
272 | return; | |
273 | atomic_set(&using_sysemu, value); | |
274 | } | |
275 | ||
276 | int get_using_sysemu(void) | |
277 | { | |
278 | return atomic_read(&using_sysemu); | |
279 | } | |
280 | ||
6613c5e8 | 281 | static int sysemu_proc_show(struct seq_file *m, void *v) |
1da177e4 | 282 | { |
6613c5e8 AD |
283 | seq_printf(m, "%d\n", get_using_sysemu()); |
284 | return 0; | |
285 | } | |
1da177e4 | 286 | |
6613c5e8 AD |
287 | static int sysemu_proc_open(struct inode *inode, struct file *file) |
288 | { | |
289 | return single_open(file, sysemu_proc_show, NULL); | |
1da177e4 LT |
290 | } |
291 | ||
6613c5e8 AD |
292 | static ssize_t sysemu_proc_write(struct file *file, const char __user *buf, |
293 | size_t count, loff_t *pos) | |
1da177e4 LT |
294 | { |
295 | char tmp[2]; | |
296 | ||
297 | if (copy_from_user(tmp, buf, 1)) | |
298 | return -EFAULT; | |
299 | ||
300 | if (tmp[0] >= '0' && tmp[0] <= '2') | |
301 | set_using_sysemu(tmp[0] - '0'); | |
ba180fd4 JD |
302 | /* We use the first char, but pretend to write everything */ |
303 | return count; | |
1da177e4 LT |
304 | } |
305 | ||
6613c5e8 AD |
306 | static const struct file_operations sysemu_proc_fops = { |
307 | .owner = THIS_MODULE, | |
308 | .open = sysemu_proc_open, | |
309 | .read = seq_read, | |
310 | .llseek = seq_lseek, | |
311 | .release = single_release, | |
312 | .write = sysemu_proc_write, | |
313 | }; | |
314 | ||
1da177e4 LT |
315 | int __init make_proc_sysemu(void) |
316 | { | |
317 | struct proc_dir_entry *ent; | |
318 | if (!sysemu_supported) | |
319 | return 0; | |
320 | ||
6613c5e8 | 321 | ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops); |
1da177e4 LT |
322 | |
323 | if (ent == NULL) | |
324 | { | |
30f417c6 | 325 | printk(KERN_WARNING "Failed to register /proc/sysemu\n"); |
6e21aec3 | 326 | return 0; |
1da177e4 LT |
327 | } |
328 | ||
1da177e4 LT |
329 | return 0; |
330 | } | |
331 | ||
332 | late_initcall(make_proc_sysemu); | |
333 | ||
334 | int singlestepping(void * t) | |
335 | { | |
336 | struct task_struct *task = t ? t : current; | |
337 | ||
c5d4bb17 | 338 | if (!(task->ptrace & PT_DTRACE)) |
ba180fd4 | 339 | return 0; |
1da177e4 LT |
340 | |
341 | if (task->thread.singlestep_syscall) | |
ba180fd4 | 342 | return 1; |
1da177e4 LT |
343 | |
344 | return 2; | |
345 | } | |
346 | ||
b8bd0220 BS |
347 | /* |
348 | * Only x86 and x86_64 have an arch_align_stack(). | |
349 | * All other arches have "#define arch_align_stack(x) (x)" | |
cf7bc58f | 350 | * in their asm/exec.h |
b8bd0220 BS |
351 | * As this is included in UML from asm-um/system-generic.h, |
352 | * we can use it to behave as the subarch does. | |
353 | */ | |
354 | #ifndef arch_align_stack | |
1da177e4 LT |
355 | unsigned long arch_align_stack(unsigned long sp) |
356 | { | |
8f80e946 | 357 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) |
1da177e4 LT |
358 | sp -= get_random_int() % 8192; |
359 | return sp & ~0xf; | |
360 | } | |
b8bd0220 | 361 | #endif |
c1127465 JD |
362 | |
363 | unsigned long get_wchan(struct task_struct *p) | |
364 | { | |
365 | unsigned long stack_page, sp, ip; | |
366 | bool seen_sched = 0; | |
367 | ||
368 | if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING)) | |
369 | return 0; | |
370 | ||
371 | stack_page = (unsigned long) task_stack_page(p); | |
372 | /* Bail if the process has no kernel stack for some reason */ | |
373 | if (stack_page == 0) | |
374 | return 0; | |
375 | ||
376 | sp = p->thread.switch_buf->JB_SP; | |
377 | /* | |
378 | * Bail if the stack pointer is below the bottom of the kernel | |
379 | * stack for some reason | |
380 | */ | |
381 | if (sp < stack_page) | |
382 | return 0; | |
383 | ||
384 | while (sp < stack_page + THREAD_SIZE) { | |
385 | ip = *((unsigned long *) sp); | |
386 | if (in_sched_functions(ip)) | |
387 | /* Ignore everything until we're above the scheduler */ | |
388 | seen_sched = 1; | |
389 | else if (kernel_text_address(ip) && seen_sched) | |
390 | return ip; | |
391 | ||
392 | sp += sizeof(unsigned long); | |
393 | } | |
394 | ||
395 | return 0; | |
396 | } | |
8192ab42 JD |
397 | |
398 | int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu) | |
399 | { | |
400 | int cpu = current_thread_info()->cpu; | |
401 | ||
a78ff111 | 402 | return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu); |
8192ab42 JD |
403 | } |
404 |