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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/x86-64/kernel/process.c | |
3 | * | |
4 | * Copyright (C) 1995 Linus Torvalds | |
5 | * | |
6 | * Pentium III FXSR, SSE support | |
7 | * Gareth Hughes <gareth@valinux.com>, May 2000 | |
8 | * | |
9 | * X86-64 port | |
10 | * Andi Kleen. | |
76e4f660 AR |
11 | * |
12 | * CPU hotplug support - ashok.raj@intel.com | |
1da177e4 LT |
13 | * $Id: process.c,v 1.38 2002/01/15 10:08:03 ak Exp $ |
14 | */ | |
15 | ||
16 | /* | |
17 | * This file handles the architecture-dependent parts of process handling.. | |
18 | */ | |
19 | ||
20 | #include <stdarg.h> | |
21 | ||
76e4f660 | 22 | #include <linux/cpu.h> |
1da177e4 LT |
23 | #include <linux/errno.h> |
24 | #include <linux/sched.h> | |
25 | #include <linux/kernel.h> | |
26 | #include <linux/mm.h> | |
27 | #include <linux/elfcore.h> | |
28 | #include <linux/smp.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/user.h> | |
31 | #include <linux/module.h> | |
32 | #include <linux/a.out.h> | |
33 | #include <linux/interrupt.h> | |
34 | #include <linux/delay.h> | |
1da177e4 LT |
35 | #include <linux/ptrace.h> |
36 | #include <linux/utsname.h> | |
37 | #include <linux/random.h> | |
73649dab | 38 | #include <linux/kprobes.h> |
95833c83 | 39 | #include <linux/notifier.h> |
1da177e4 LT |
40 | |
41 | #include <asm/uaccess.h> | |
42 | #include <asm/pgtable.h> | |
43 | #include <asm/system.h> | |
44 | #include <asm/io.h> | |
45 | #include <asm/processor.h> | |
46 | #include <asm/i387.h> | |
47 | #include <asm/mmu_context.h> | |
48 | #include <asm/pda.h> | |
49 | #include <asm/prctl.h> | |
50 | #include <asm/kdebug.h> | |
51 | #include <asm/desc.h> | |
52 | #include <asm/proto.h> | |
53 | #include <asm/ia32.h> | |
95833c83 | 54 | #include <asm/idle.h> |
1da177e4 LT |
55 | |
56 | asmlinkage extern void ret_from_fork(void); | |
57 | ||
58 | unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED; | |
59 | ||
1da177e4 LT |
60 | unsigned long boot_option_idle_override = 0; |
61 | EXPORT_SYMBOL(boot_option_idle_override); | |
62 | ||
63 | /* | |
64 | * Powermanagement idle function, if any.. | |
65 | */ | |
66 | void (*pm_idle)(void); | |
67 | static DEFINE_PER_CPU(unsigned int, cpu_idle_state); | |
68 | ||
95833c83 AK |
69 | static struct notifier_block *idle_notifier; |
70 | static DEFINE_SPINLOCK(idle_notifier_lock); | |
71 | ||
72 | void idle_notifier_register(struct notifier_block *n) | |
73 | { | |
74 | unsigned long flags; | |
75 | spin_lock_irqsave(&idle_notifier_lock, flags); | |
76 | notifier_chain_register(&idle_notifier, n); | |
77 | spin_unlock_irqrestore(&idle_notifier_lock, flags); | |
78 | } | |
79 | EXPORT_SYMBOL_GPL(idle_notifier_register); | |
80 | ||
81 | void idle_notifier_unregister(struct notifier_block *n) | |
82 | { | |
83 | unsigned long flags; | |
84 | spin_lock_irqsave(&idle_notifier_lock, flags); | |
85 | notifier_chain_unregister(&idle_notifier, n); | |
86 | spin_unlock_irqrestore(&idle_notifier_lock, flags); | |
87 | } | |
88 | EXPORT_SYMBOL(idle_notifier_unregister); | |
89 | ||
90 | enum idle_state { CPU_IDLE, CPU_NOT_IDLE }; | |
91 | static DEFINE_PER_CPU(enum idle_state, idle_state) = CPU_NOT_IDLE; | |
92 | ||
93 | void enter_idle(void) | |
94 | { | |
95 | __get_cpu_var(idle_state) = CPU_IDLE; | |
96 | notifier_call_chain(&idle_notifier, IDLE_START, NULL); | |
97 | } | |
98 | ||
99 | static void __exit_idle(void) | |
100 | { | |
101 | __get_cpu_var(idle_state) = CPU_NOT_IDLE; | |
102 | notifier_call_chain(&idle_notifier, IDLE_END, NULL); | |
103 | } | |
104 | ||
105 | /* Called from interrupts to signify idle end */ | |
106 | void exit_idle(void) | |
107 | { | |
108 | if (current->pid | read_pda(irqcount)) | |
109 | return; | |
110 | __exit_idle(); | |
111 | } | |
112 | ||
1da177e4 LT |
113 | /* |
114 | * We use this if we don't have any better | |
115 | * idle routine.. | |
116 | */ | |
117 | void default_idle(void) | |
118 | { | |
64c7c8f8 NP |
119 | local_irq_enable(); |
120 | ||
2d52ede9 AK |
121 | clear_thread_flag(TIF_POLLING_NRFLAG); |
122 | smp_mb__after_clear_bit(); | |
123 | while (!need_resched()) { | |
124 | local_irq_disable(); | |
125 | if (!need_resched()) | |
126 | safe_halt(); | |
127 | else | |
128 | local_irq_enable(); | |
1da177e4 | 129 | } |
2d52ede9 | 130 | set_thread_flag(TIF_POLLING_NRFLAG); |
1da177e4 LT |
131 | } |
132 | ||
133 | /* | |
134 | * On SMP it's slightly faster (but much more power-consuming!) | |
135 | * to poll the ->need_resched flag instead of waiting for the | |
136 | * cross-CPU IPI to arrive. Use this option with caution. | |
137 | */ | |
138 | static void poll_idle (void) | |
139 | { | |
1da177e4 LT |
140 | local_irq_enable(); |
141 | ||
64c7c8f8 NP |
142 | asm volatile( |
143 | "2:" | |
144 | "testl %0,%1;" | |
145 | "rep; nop;" | |
146 | "je 2b;" | |
147 | : : | |
148 | "i" (_TIF_NEED_RESCHED), | |
149 | "m" (current_thread_info()->flags)); | |
1da177e4 LT |
150 | } |
151 | ||
152 | void cpu_idle_wait(void) | |
153 | { | |
154 | unsigned int cpu, this_cpu = get_cpu(); | |
155 | cpumask_t map; | |
156 | ||
157 | set_cpus_allowed(current, cpumask_of_cpu(this_cpu)); | |
158 | put_cpu(); | |
159 | ||
160 | cpus_clear(map); | |
161 | for_each_online_cpu(cpu) { | |
162 | per_cpu(cpu_idle_state, cpu) = 1; | |
163 | cpu_set(cpu, map); | |
164 | } | |
165 | ||
166 | __get_cpu_var(cpu_idle_state) = 0; | |
167 | ||
168 | wmb(); | |
169 | do { | |
170 | ssleep(1); | |
171 | for_each_online_cpu(cpu) { | |
a88cde13 AK |
172 | if (cpu_isset(cpu, map) && |
173 | !per_cpu(cpu_idle_state, cpu)) | |
1da177e4 LT |
174 | cpu_clear(cpu, map); |
175 | } | |
176 | cpus_and(map, map, cpu_online_map); | |
177 | } while (!cpus_empty(map)); | |
178 | } | |
179 | EXPORT_SYMBOL_GPL(cpu_idle_wait); | |
180 | ||
76e4f660 AR |
181 | #ifdef CONFIG_HOTPLUG_CPU |
182 | DECLARE_PER_CPU(int, cpu_state); | |
183 | ||
184 | #include <asm/nmi.h> | |
1fa744e6 | 185 | /* We halt the CPU with physical CPU hotplug */ |
76e4f660 AR |
186 | static inline void play_dead(void) |
187 | { | |
188 | idle_task_exit(); | |
189 | wbinvd(); | |
190 | mb(); | |
191 | /* Ack it */ | |
192 | __get_cpu_var(cpu_state) = CPU_DEAD; | |
193 | ||
1fa744e6 | 194 | local_irq_disable(); |
76e4f660 | 195 | while (1) |
1fa744e6 | 196 | halt(); |
76e4f660 AR |
197 | } |
198 | #else | |
199 | static inline void play_dead(void) | |
200 | { | |
201 | BUG(); | |
202 | } | |
203 | #endif /* CONFIG_HOTPLUG_CPU */ | |
204 | ||
1da177e4 LT |
205 | /* |
206 | * The idle thread. There's no useful work to be | |
207 | * done, so just try to conserve power and have a | |
208 | * low exit latency (ie sit in a loop waiting for | |
209 | * somebody to say that they'd like to reschedule) | |
210 | */ | |
211 | void cpu_idle (void) | |
212 | { | |
64c7c8f8 NP |
213 | set_thread_flag(TIF_POLLING_NRFLAG); |
214 | ||
1da177e4 LT |
215 | /* endless idle loop with no priority at all */ |
216 | while (1) { | |
217 | while (!need_resched()) { | |
218 | void (*idle)(void); | |
219 | ||
220 | if (__get_cpu_var(cpu_idle_state)) | |
221 | __get_cpu_var(cpu_idle_state) = 0; | |
222 | ||
223 | rmb(); | |
224 | idle = pm_idle; | |
225 | if (!idle) | |
226 | idle = default_idle; | |
76e4f660 AR |
227 | if (cpu_is_offline(smp_processor_id())) |
228 | play_dead(); | |
95833c83 | 229 | enter_idle(); |
1da177e4 | 230 | idle(); |
95833c83 | 231 | __exit_idle(); |
1da177e4 LT |
232 | } |
233 | ||
5bfb5d69 | 234 | preempt_enable_no_resched(); |
1da177e4 | 235 | schedule(); |
5bfb5d69 | 236 | preempt_disable(); |
1da177e4 LT |
237 | } |
238 | } | |
239 | ||
240 | /* | |
241 | * This uses new MONITOR/MWAIT instructions on P4 processors with PNI, | |
242 | * which can obviate IPI to trigger checking of need_resched. | |
243 | * We execute MONITOR against need_resched and enter optimized wait state | |
244 | * through MWAIT. Whenever someone changes need_resched, we would be woken | |
245 | * up from MWAIT (without an IPI). | |
246 | */ | |
247 | static void mwait_idle(void) | |
248 | { | |
249 | local_irq_enable(); | |
250 | ||
64c7c8f8 NP |
251 | while (!need_resched()) { |
252 | __monitor((void *)¤t_thread_info()->flags, 0, 0); | |
253 | smp_mb(); | |
254 | if (need_resched()) | |
255 | break; | |
256 | __mwait(0, 0); | |
1da177e4 LT |
257 | } |
258 | } | |
259 | ||
e6982c67 | 260 | void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) |
1da177e4 LT |
261 | { |
262 | static int printed; | |
263 | if (cpu_has(c, X86_FEATURE_MWAIT)) { | |
264 | /* | |
265 | * Skip, if setup has overridden idle. | |
266 | * One CPU supports mwait => All CPUs supports mwait | |
267 | */ | |
268 | if (!pm_idle) { | |
269 | if (!printed) { | |
270 | printk("using mwait in idle threads.\n"); | |
271 | printed = 1; | |
272 | } | |
273 | pm_idle = mwait_idle; | |
274 | } | |
275 | } | |
276 | } | |
277 | ||
278 | static int __init idle_setup (char *str) | |
279 | { | |
280 | if (!strncmp(str, "poll", 4)) { | |
281 | printk("using polling idle threads.\n"); | |
282 | pm_idle = poll_idle; | |
283 | } | |
284 | ||
285 | boot_option_idle_override = 1; | |
286 | return 1; | |
287 | } | |
288 | ||
289 | __setup("idle=", idle_setup); | |
290 | ||
291 | /* Prints also some state that isn't saved in the pt_regs */ | |
292 | void __show_regs(struct pt_regs * regs) | |
293 | { | |
294 | unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs; | |
295 | unsigned int fsindex,gsindex; | |
296 | unsigned int ds,cs,es; | |
297 | ||
298 | printk("\n"); | |
299 | print_modules(); | |
9acf23c4 AK |
300 | printk("Pid: %d, comm: %.20s %s %s %.*s\n", |
301 | current->pid, current->comm, print_tainted(), | |
302 | system_utsname.release, | |
303 | (int)strcspn(system_utsname.version, " "), | |
304 | system_utsname.version); | |
1da177e4 LT |
305 | printk("RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->rip); |
306 | printk_address(regs->rip); | |
a88cde13 AK |
307 | printk("\nRSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->rsp, |
308 | regs->eflags); | |
1da177e4 LT |
309 | printk("RAX: %016lx RBX: %016lx RCX: %016lx\n", |
310 | regs->rax, regs->rbx, regs->rcx); | |
311 | printk("RDX: %016lx RSI: %016lx RDI: %016lx\n", | |
312 | regs->rdx, regs->rsi, regs->rdi); | |
313 | printk("RBP: %016lx R08: %016lx R09: %016lx\n", | |
314 | regs->rbp, regs->r8, regs->r9); | |
315 | printk("R10: %016lx R11: %016lx R12: %016lx\n", | |
316 | regs->r10, regs->r11, regs->r12); | |
317 | printk("R13: %016lx R14: %016lx R15: %016lx\n", | |
318 | regs->r13, regs->r14, regs->r15); | |
319 | ||
320 | asm("movl %%ds,%0" : "=r" (ds)); | |
321 | asm("movl %%cs,%0" : "=r" (cs)); | |
322 | asm("movl %%es,%0" : "=r" (es)); | |
323 | asm("movl %%fs,%0" : "=r" (fsindex)); | |
324 | asm("movl %%gs,%0" : "=r" (gsindex)); | |
325 | ||
326 | rdmsrl(MSR_FS_BASE, fs); | |
327 | rdmsrl(MSR_GS_BASE, gs); | |
328 | rdmsrl(MSR_KERNEL_GS_BASE, shadowgs); | |
329 | ||
330 | asm("movq %%cr0, %0": "=r" (cr0)); | |
331 | asm("movq %%cr2, %0": "=r" (cr2)); | |
332 | asm("movq %%cr3, %0": "=r" (cr3)); | |
333 | asm("movq %%cr4, %0": "=r" (cr4)); | |
334 | ||
335 | printk("FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n", | |
336 | fs,fsindex,gs,gsindex,shadowgs); | |
337 | printk("CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds, es, cr0); | |
338 | printk("CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3, cr4); | |
339 | } | |
340 | ||
341 | void show_regs(struct pt_regs *regs) | |
342 | { | |
c078d326 | 343 | printk("CPU %d:", smp_processor_id()); |
1da177e4 LT |
344 | __show_regs(regs); |
345 | show_trace(®s->rsp); | |
346 | } | |
347 | ||
348 | /* | |
349 | * Free current thread data structures etc.. | |
350 | */ | |
351 | void exit_thread(void) | |
352 | { | |
353 | struct task_struct *me = current; | |
354 | struct thread_struct *t = &me->thread; | |
73649dab RL |
355 | |
356 | /* | |
357 | * Remove function-return probe instances associated with this task | |
358 | * and put them back on the free list. Do not insert an exit probe for | |
359 | * this function, it will be disabled by kprobe_flush_task if you do. | |
360 | */ | |
361 | kprobe_flush_task(me); | |
362 | ||
1da177e4 LT |
363 | if (me->thread.io_bitmap_ptr) { |
364 | struct tss_struct *tss = &per_cpu(init_tss, get_cpu()); | |
365 | ||
366 | kfree(t->io_bitmap_ptr); | |
367 | t->io_bitmap_ptr = NULL; | |
368 | /* | |
369 | * Careful, clear this in the TSS too: | |
370 | */ | |
371 | memset(tss->io_bitmap, 0xff, t->io_bitmap_max); | |
372 | t->io_bitmap_max = 0; | |
373 | put_cpu(); | |
374 | } | |
375 | } | |
376 | ||
377 | void flush_thread(void) | |
378 | { | |
379 | struct task_struct *tsk = current; | |
380 | struct thread_info *t = current_thread_info(); | |
381 | ||
382 | if (t->flags & _TIF_ABI_PENDING) | |
383 | t->flags ^= (_TIF_ABI_PENDING | _TIF_IA32); | |
384 | ||
385 | tsk->thread.debugreg0 = 0; | |
386 | tsk->thread.debugreg1 = 0; | |
387 | tsk->thread.debugreg2 = 0; | |
388 | tsk->thread.debugreg3 = 0; | |
389 | tsk->thread.debugreg6 = 0; | |
390 | tsk->thread.debugreg7 = 0; | |
391 | memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); | |
392 | /* | |
393 | * Forget coprocessor state.. | |
394 | */ | |
395 | clear_fpu(tsk); | |
396 | clear_used_math(); | |
397 | } | |
398 | ||
399 | void release_thread(struct task_struct *dead_task) | |
400 | { | |
401 | if (dead_task->mm) { | |
402 | if (dead_task->mm->context.size) { | |
403 | printk("WARNING: dead process %8s still has LDT? <%p/%d>\n", | |
404 | dead_task->comm, | |
405 | dead_task->mm->context.ldt, | |
406 | dead_task->mm->context.size); | |
407 | BUG(); | |
408 | } | |
409 | } | |
410 | } | |
411 | ||
412 | static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr) | |
413 | { | |
414 | struct user_desc ud = { | |
415 | .base_addr = addr, | |
416 | .limit = 0xfffff, | |
417 | .seg_32bit = 1, | |
418 | .limit_in_pages = 1, | |
419 | .useable = 1, | |
420 | }; | |
421 | struct n_desc_struct *desc = (void *)t->thread.tls_array; | |
422 | desc += tls; | |
423 | desc->a = LDT_entry_a(&ud); | |
424 | desc->b = LDT_entry_b(&ud); | |
425 | } | |
426 | ||
427 | static inline u32 read_32bit_tls(struct task_struct *t, int tls) | |
428 | { | |
429 | struct desc_struct *desc = (void *)t->thread.tls_array; | |
430 | desc += tls; | |
431 | return desc->base0 | | |
432 | (((u32)desc->base1) << 16) | | |
433 | (((u32)desc->base2) << 24); | |
434 | } | |
435 | ||
436 | /* | |
437 | * This gets called before we allocate a new thread and copy | |
438 | * the current task into it. | |
439 | */ | |
440 | void prepare_to_copy(struct task_struct *tsk) | |
441 | { | |
442 | unlazy_fpu(tsk); | |
443 | } | |
444 | ||
445 | int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp, | |
446 | unsigned long unused, | |
447 | struct task_struct * p, struct pt_regs * regs) | |
448 | { | |
449 | int err; | |
450 | struct pt_regs * childregs; | |
451 | struct task_struct *me = current; | |
452 | ||
a88cde13 | 453 | childregs = ((struct pt_regs *) |
57eafdc2 | 454 | (THREAD_SIZE + task_stack_page(p))) - 1; |
1da177e4 LT |
455 | *childregs = *regs; |
456 | ||
457 | childregs->rax = 0; | |
458 | childregs->rsp = rsp; | |
a88cde13 | 459 | if (rsp == ~0UL) |
1da177e4 | 460 | childregs->rsp = (unsigned long)childregs; |
1da177e4 LT |
461 | |
462 | p->thread.rsp = (unsigned long) childregs; | |
463 | p->thread.rsp0 = (unsigned long) (childregs+1); | |
464 | p->thread.userrsp = me->thread.userrsp; | |
465 | ||
e4f17c43 | 466 | set_tsk_thread_flag(p, TIF_FORK); |
1da177e4 LT |
467 | |
468 | p->thread.fs = me->thread.fs; | |
469 | p->thread.gs = me->thread.gs; | |
470 | ||
fd51f666 L |
471 | asm("mov %%gs,%0" : "=m" (p->thread.gsindex)); |
472 | asm("mov %%fs,%0" : "=m" (p->thread.fsindex)); | |
473 | asm("mov %%es,%0" : "=m" (p->thread.es)); | |
474 | asm("mov %%ds,%0" : "=m" (p->thread.ds)); | |
1da177e4 LT |
475 | |
476 | if (unlikely(me->thread.io_bitmap_ptr != NULL)) { | |
477 | p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); | |
478 | if (!p->thread.io_bitmap_ptr) { | |
479 | p->thread.io_bitmap_max = 0; | |
480 | return -ENOMEM; | |
481 | } | |
a88cde13 AK |
482 | memcpy(p->thread.io_bitmap_ptr, me->thread.io_bitmap_ptr, |
483 | IO_BITMAP_BYTES); | |
1da177e4 LT |
484 | } |
485 | ||
486 | /* | |
487 | * Set a new TLS for the child thread? | |
488 | */ | |
489 | if (clone_flags & CLONE_SETTLS) { | |
490 | #ifdef CONFIG_IA32_EMULATION | |
491 | if (test_thread_flag(TIF_IA32)) | |
492 | err = ia32_child_tls(p, childregs); | |
493 | else | |
494 | #endif | |
495 | err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8); | |
496 | if (err) | |
497 | goto out; | |
498 | } | |
499 | err = 0; | |
500 | out: | |
501 | if (err && p->thread.io_bitmap_ptr) { | |
502 | kfree(p->thread.io_bitmap_ptr); | |
503 | p->thread.io_bitmap_max = 0; | |
504 | } | |
505 | return err; | |
506 | } | |
507 | ||
508 | /* | |
509 | * This special macro can be used to load a debugging register | |
510 | */ | |
511 | #define loaddebug(thread,r) set_debug(thread->debugreg ## r, r) | |
512 | ||
513 | /* | |
514 | * switch_to(x,y) should switch tasks from x to y. | |
515 | * | |
516 | * This could still be optimized: | |
517 | * - fold all the options into a flag word and test it with a single test. | |
518 | * - could test fs/gs bitsliced | |
519 | */ | |
a88cde13 AK |
520 | struct task_struct * |
521 | __switch_to(struct task_struct *prev_p, struct task_struct *next_p) | |
1da177e4 LT |
522 | { |
523 | struct thread_struct *prev = &prev_p->thread, | |
524 | *next = &next_p->thread; | |
525 | int cpu = smp_processor_id(); | |
526 | struct tss_struct *tss = &per_cpu(init_tss, cpu); | |
527 | ||
528 | unlazy_fpu(prev_p); | |
529 | ||
530 | /* | |
531 | * Reload esp0, LDT and the page table pointer: | |
532 | */ | |
533 | tss->rsp0 = next->rsp0; | |
534 | ||
535 | /* | |
536 | * Switch DS and ES. | |
537 | * This won't pick up thread selector changes, but I guess that is ok. | |
538 | */ | |
fd51f666 | 539 | asm volatile("mov %%es,%0" : "=m" (prev->es)); |
1da177e4 LT |
540 | if (unlikely(next->es | prev->es)) |
541 | loadsegment(es, next->es); | |
542 | ||
fd51f666 | 543 | asm volatile ("mov %%ds,%0" : "=m" (prev->ds)); |
1da177e4 LT |
544 | if (unlikely(next->ds | prev->ds)) |
545 | loadsegment(ds, next->ds); | |
546 | ||
547 | load_TLS(next, cpu); | |
548 | ||
549 | /* | |
550 | * Switch FS and GS. | |
551 | */ | |
552 | { | |
553 | unsigned fsindex; | |
554 | asm volatile("movl %%fs,%0" : "=r" (fsindex)); | |
555 | /* segment register != 0 always requires a reload. | |
556 | also reload when it has changed. | |
557 | when prev process used 64bit base always reload | |
558 | to avoid an information leak. */ | |
559 | if (unlikely(fsindex | next->fsindex | prev->fs)) { | |
560 | loadsegment(fs, next->fsindex); | |
561 | /* check if the user used a selector != 0 | |
562 | * if yes clear 64bit base, since overloaded base | |
563 | * is always mapped to the Null selector | |
564 | */ | |
565 | if (fsindex) | |
566 | prev->fs = 0; | |
567 | } | |
568 | /* when next process has a 64bit base use it */ | |
569 | if (next->fs) | |
570 | wrmsrl(MSR_FS_BASE, next->fs); | |
571 | prev->fsindex = fsindex; | |
572 | } | |
573 | { | |
574 | unsigned gsindex; | |
575 | asm volatile("movl %%gs,%0" : "=r" (gsindex)); | |
576 | if (unlikely(gsindex | next->gsindex | prev->gs)) { | |
577 | load_gs_index(next->gsindex); | |
578 | if (gsindex) | |
579 | prev->gs = 0; | |
580 | } | |
581 | if (next->gs) | |
582 | wrmsrl(MSR_KERNEL_GS_BASE, next->gs); | |
583 | prev->gsindex = gsindex; | |
584 | } | |
585 | ||
586 | /* | |
587 | * Switch the PDA context. | |
588 | */ | |
589 | prev->userrsp = read_pda(oldrsp); | |
590 | write_pda(oldrsp, next->userrsp); | |
591 | write_pda(pcurrent, next_p); | |
a88cde13 | 592 | write_pda(kernelstack, |
57eafdc2 | 593 | task_stack_page(next_p) + THREAD_SIZE - PDA_STACKOFFSET); |
1da177e4 LT |
594 | |
595 | /* | |
596 | * Now maybe reload the debug registers | |
597 | */ | |
598 | if (unlikely(next->debugreg7)) { | |
599 | loaddebug(next, 0); | |
600 | loaddebug(next, 1); | |
601 | loaddebug(next, 2); | |
602 | loaddebug(next, 3); | |
603 | /* no 4 and 5 */ | |
604 | loaddebug(next, 6); | |
605 | loaddebug(next, 7); | |
606 | } | |
607 | ||
608 | ||
609 | /* | |
610 | * Handle the IO bitmap | |
611 | */ | |
612 | if (unlikely(prev->io_bitmap_ptr || next->io_bitmap_ptr)) { | |
613 | if (next->io_bitmap_ptr) | |
614 | /* | |
615 | * Copy the relevant range of the IO bitmap. | |
616 | * Normally this is 128 bytes or less: | |
617 | */ | |
618 | memcpy(tss->io_bitmap, next->io_bitmap_ptr, | |
619 | max(prev->io_bitmap_max, next->io_bitmap_max)); | |
620 | else { | |
621 | /* | |
622 | * Clear any possible leftover bits: | |
623 | */ | |
624 | memset(tss->io_bitmap, 0xff, prev->io_bitmap_max); | |
625 | } | |
626 | } | |
627 | ||
628 | return prev_p; | |
629 | } | |
630 | ||
631 | /* | |
632 | * sys_execve() executes a new program. | |
633 | */ | |
634 | asmlinkage | |
635 | long sys_execve(char __user *name, char __user * __user *argv, | |
636 | char __user * __user *envp, struct pt_regs regs) | |
637 | { | |
638 | long error; | |
639 | char * filename; | |
640 | ||
641 | filename = getname(name); | |
642 | error = PTR_ERR(filename); | |
643 | if (IS_ERR(filename)) | |
644 | return error; | |
645 | error = do_execve(filename, argv, envp, ®s); | |
646 | if (error == 0) { | |
647 | task_lock(current); | |
648 | current->ptrace &= ~PT_DTRACE; | |
649 | task_unlock(current); | |
650 | } | |
651 | putname(filename); | |
652 | return error; | |
653 | } | |
654 | ||
655 | void set_personality_64bit(void) | |
656 | { | |
657 | /* inherit personality from parent */ | |
658 | ||
659 | /* Make sure to be in 64bit mode */ | |
660 | clear_thread_flag(TIF_IA32); | |
661 | ||
662 | /* TBD: overwrites user setup. Should have two bits. | |
663 | But 64bit processes have always behaved this way, | |
664 | so it's not too bad. The main problem is just that | |
665 | 32bit childs are affected again. */ | |
666 | current->personality &= ~READ_IMPLIES_EXEC; | |
667 | } | |
668 | ||
669 | asmlinkage long sys_fork(struct pt_regs *regs) | |
670 | { | |
671 | return do_fork(SIGCHLD, regs->rsp, regs, 0, NULL, NULL); | |
672 | } | |
673 | ||
a88cde13 AK |
674 | asmlinkage long |
675 | sys_clone(unsigned long clone_flags, unsigned long newsp, | |
676 | void __user *parent_tid, void __user *child_tid, struct pt_regs *regs) | |
1da177e4 LT |
677 | { |
678 | if (!newsp) | |
679 | newsp = regs->rsp; | |
680 | return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid); | |
681 | } | |
682 | ||
683 | /* | |
684 | * This is trivial, and on the face of it looks like it | |
685 | * could equally well be done in user mode. | |
686 | * | |
687 | * Not so, for quite unobvious reasons - register pressure. | |
688 | * In user mode vfork() cannot have a stack frame, and if | |
689 | * done by calling the "clone()" system call directly, you | |
690 | * do not have enough call-clobbered registers to hold all | |
691 | * the information you need. | |
692 | */ | |
693 | asmlinkage long sys_vfork(struct pt_regs *regs) | |
694 | { | |
695 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->rsp, regs, 0, | |
696 | NULL, NULL); | |
697 | } | |
698 | ||
699 | unsigned long get_wchan(struct task_struct *p) | |
700 | { | |
701 | unsigned long stack; | |
702 | u64 fp,rip; | |
703 | int count = 0; | |
704 | ||
705 | if (!p || p == current || p->state==TASK_RUNNING) | |
706 | return 0; | |
57eafdc2 | 707 | stack = (unsigned long)task_stack_page(p); |
1da177e4 LT |
708 | if (p->thread.rsp < stack || p->thread.rsp > stack+THREAD_SIZE) |
709 | return 0; | |
710 | fp = *(u64 *)(p->thread.rsp); | |
711 | do { | |
a88cde13 AK |
712 | if (fp < (unsigned long)stack || |
713 | fp > (unsigned long)stack+THREAD_SIZE) | |
1da177e4 LT |
714 | return 0; |
715 | rip = *(u64 *)(fp+8); | |
716 | if (!in_sched_functions(rip)) | |
717 | return rip; | |
718 | fp = *(u64 *)fp; | |
719 | } while (count++ < 16); | |
720 | return 0; | |
721 | } | |
722 | ||
723 | long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) | |
724 | { | |
725 | int ret = 0; | |
726 | int doit = task == current; | |
727 | int cpu; | |
728 | ||
729 | switch (code) { | |
730 | case ARCH_SET_GS: | |
84929801 | 731 | if (addr >= TASK_SIZE_OF(task)) |
1da177e4 LT |
732 | return -EPERM; |
733 | cpu = get_cpu(); | |
734 | /* handle small bases via the GDT because that's faster to | |
735 | switch. */ | |
736 | if (addr <= 0xffffffff) { | |
737 | set_32bit_tls(task, GS_TLS, addr); | |
738 | if (doit) { | |
739 | load_TLS(&task->thread, cpu); | |
740 | load_gs_index(GS_TLS_SEL); | |
741 | } | |
742 | task->thread.gsindex = GS_TLS_SEL; | |
743 | task->thread.gs = 0; | |
744 | } else { | |
745 | task->thread.gsindex = 0; | |
746 | task->thread.gs = addr; | |
747 | if (doit) { | |
a88cde13 AK |
748 | load_gs_index(0); |
749 | ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr); | |
1da177e4 LT |
750 | } |
751 | } | |
752 | put_cpu(); | |
753 | break; | |
754 | case ARCH_SET_FS: | |
755 | /* Not strictly needed for fs, but do it for symmetry | |
756 | with gs */ | |
84929801 | 757 | if (addr >= TASK_SIZE_OF(task)) |
1da177e4 LT |
758 | return -EPERM; |
759 | cpu = get_cpu(); | |
760 | /* handle small bases via the GDT because that's faster to | |
761 | switch. */ | |
762 | if (addr <= 0xffffffff) { | |
763 | set_32bit_tls(task, FS_TLS, addr); | |
764 | if (doit) { | |
765 | load_TLS(&task->thread, cpu); | |
a88cde13 | 766 | asm volatile("movl %0,%%fs" :: "r"(FS_TLS_SEL)); |
1da177e4 LT |
767 | } |
768 | task->thread.fsindex = FS_TLS_SEL; | |
769 | task->thread.fs = 0; | |
770 | } else { | |
771 | task->thread.fsindex = 0; | |
772 | task->thread.fs = addr; | |
773 | if (doit) { | |
774 | /* set the selector to 0 to not confuse | |
775 | __switch_to */ | |
a88cde13 AK |
776 | asm volatile("movl %0,%%fs" :: "r" (0)); |
777 | ret = checking_wrmsrl(MSR_FS_BASE, addr); | |
1da177e4 LT |
778 | } |
779 | } | |
780 | put_cpu(); | |
781 | break; | |
782 | case ARCH_GET_FS: { | |
783 | unsigned long base; | |
784 | if (task->thread.fsindex == FS_TLS_SEL) | |
785 | base = read_32bit_tls(task, FS_TLS); | |
a88cde13 | 786 | else if (doit) |
1da177e4 | 787 | rdmsrl(MSR_FS_BASE, base); |
a88cde13 | 788 | else |
1da177e4 LT |
789 | base = task->thread.fs; |
790 | ret = put_user(base, (unsigned long __user *)addr); | |
791 | break; | |
792 | } | |
793 | case ARCH_GET_GS: { | |
794 | unsigned long base; | |
795 | if (task->thread.gsindex == GS_TLS_SEL) | |
796 | base = read_32bit_tls(task, GS_TLS); | |
a88cde13 | 797 | else if (doit) |
1da177e4 | 798 | rdmsrl(MSR_KERNEL_GS_BASE, base); |
a88cde13 | 799 | else |
1da177e4 LT |
800 | base = task->thread.gs; |
801 | ret = put_user(base, (unsigned long __user *)addr); | |
802 | break; | |
803 | } | |
804 | ||
805 | default: | |
806 | ret = -EINVAL; | |
807 | break; | |
808 | } | |
809 | ||
810 | return ret; | |
811 | } | |
812 | ||
813 | long sys_arch_prctl(int code, unsigned long addr) | |
814 | { | |
815 | return do_arch_prctl(current, code, addr); | |
816 | } | |
817 | ||
818 | /* | |
819 | * Capture the user space registers if the task is not running (in user space) | |
820 | */ | |
821 | int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) | |
822 | { | |
823 | struct pt_regs *pp, ptregs; | |
824 | ||
bb049232 | 825 | pp = task_pt_regs(tsk); |
1da177e4 LT |
826 | |
827 | ptregs = *pp; | |
828 | ptregs.cs &= 0xffff; | |
829 | ptregs.ss &= 0xffff; | |
830 | ||
831 | elf_core_copy_regs(regs, &ptregs); | |
832 | ||
833 | return 1; | |
834 | } | |
835 | ||
836 | unsigned long arch_align_stack(unsigned long sp) | |
837 | { | |
838 | if (randomize_va_space) | |
839 | sp -= get_random_int() % 8192; | |
840 | return sp & ~0xf; | |
841 | } |