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1/*
2 * Copyright (C) 1995 Linus Torvalds
3 *
4 * Pentium III FXSR, SSE support
5 * Gareth Hughes <gareth@valinux.com>, May 2000
6 *
7 * X86-64 port
8 * Andi Kleen.
9 *
10 * CPU hotplug support - ashok.raj@intel.com
11 */
12
13/*
14 * This file handles the architecture-dependent parts of process handling..
15 */
16
17#include <linux/stackprotector.h>
18#include <linux/cpu.h>
19#include <linux/errno.h>
20#include <linux/sched.h>
21#include <linux/fs.h>
22#include <linux/kernel.h>
23#include <linux/mm.h>
24#include <linux/elfcore.h>
25#include <linux/smp.h>
26#include <linux/slab.h>
27#include <linux/user.h>
28#include <linux/interrupt.h>
29#include <linux/delay.h>
30#include <linux/module.h>
31#include <linux/ptrace.h>
32#include <linux/notifier.h>
33#include <linux/kprobes.h>
34#include <linux/kdebug.h>
35#include <linux/tick.h>
36#include <linux/prctl.h>
37#include <linux/uaccess.h>
38#include <linux/io.h>
39#include <linux/ftrace.h>
40#include <linux/cpuidle.h>
41
42#include <asm/pgtable.h>
43#include <asm/system.h>
44#include <asm/processor.h>
45#include <asm/i387.h>
46#include <asm/mmu_context.h>
47#include <asm/prctl.h>
48#include <asm/desc.h>
49#include <asm/proto.h>
50#include <asm/ia32.h>
51#include <asm/idle.h>
52#include <asm/syscalls.h>
53#include <asm/debugreg.h>
54
55asmlinkage extern void ret_from_fork(void);
56
57DEFINE_PER_CPU(unsigned long, old_rsp);
58static DEFINE_PER_CPU(unsigned char, is_idle);
59
60static ATOMIC_NOTIFIER_HEAD(idle_notifier);
61
62void idle_notifier_register(struct notifier_block *n)
63{
64 atomic_notifier_chain_register(&idle_notifier, n);
65}
66EXPORT_SYMBOL_GPL(idle_notifier_register);
67
68void idle_notifier_unregister(struct notifier_block *n)
69{
70 atomic_notifier_chain_unregister(&idle_notifier, n);
71}
72EXPORT_SYMBOL_GPL(idle_notifier_unregister);
73
74void enter_idle(void)
75{
76 percpu_write(is_idle, 1);
77 atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
78}
79
80static void __exit_idle(void)
81{
82 if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
83 return;
84 atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
85}
86
87/* Called from interrupts to signify idle end */
88void exit_idle(void)
89{
90 /* idle loop has pid 0 */
91 if (current->pid)
92 return;
93 __exit_idle();
94}
95
96#ifndef CONFIG_SMP
97static inline void play_dead(void)
98{
99 BUG();
100}
101#endif
102
103/*
104 * The idle thread. There's no useful work to be
105 * done, so just try to conserve power and have a
106 * low exit latency (ie sit in a loop waiting for
107 * somebody to say that they'd like to reschedule)
108 */
109void cpu_idle(void)
110{
111 current_thread_info()->status |= TS_POLLING;
112
113 /*
114 * If we're the non-boot CPU, nothing set the stack canary up
115 * for us. CPU0 already has it initialized but no harm in
116 * doing it again. This is a good place for updating it, as
117 * we wont ever return from this function (so the invalid
118 * canaries already on the stack wont ever trigger).
119 */
120 boot_init_stack_canary();
121
122 /* endless idle loop with no priority at all */
123 while (1) {
124 tick_nohz_stop_sched_tick(1);
125 while (!need_resched()) {
126
127 rmb();
128
129 if (cpu_is_offline(smp_processor_id()))
130 play_dead();
131 /*
132 * Idle routines should keep interrupts disabled
133 * from here on, until they go to idle.
134 * Otherwise, idle callbacks can misfire.
135 */
136 local_irq_disable();
137 enter_idle();
138 /* Don't trace irqs off for idle */
139 stop_critical_timings();
140 if (cpuidle_idle_call())
141 pm_idle();
142 start_critical_timings();
143
144 /* In many cases the interrupt that ended idle
145 has already called exit_idle. But some idle
146 loops can be woken up without interrupt. */
147 __exit_idle();
148 }
149
150 tick_nohz_restart_sched_tick();
151 preempt_enable_no_resched();
152 schedule();
153 preempt_disable();
154 }
155}
156
157/* Prints also some state that isn't saved in the pt_regs */
158void __show_regs(struct pt_regs *regs, int all)
159{
160 unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs;
161 unsigned long d0, d1, d2, d3, d6, d7;
162 unsigned int fsindex, gsindex;
163 unsigned int ds, cs, es;
164
165 show_regs_common();
166 printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
167 printk_address(regs->ip, 1);
168 printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss,
169 regs->sp, regs->flags);
170 printk(KERN_DEFAULT "RAX: %016lx RBX: %016lx RCX: %016lx\n",
171 regs->ax, regs->bx, regs->cx);
172 printk(KERN_DEFAULT "RDX: %016lx RSI: %016lx RDI: %016lx\n",
173 regs->dx, regs->si, regs->di);
174 printk(KERN_DEFAULT "RBP: %016lx R08: %016lx R09: %016lx\n",
175 regs->bp, regs->r8, regs->r9);
176 printk(KERN_DEFAULT "R10: %016lx R11: %016lx R12: %016lx\n",
177 regs->r10, regs->r11, regs->r12);
178 printk(KERN_DEFAULT "R13: %016lx R14: %016lx R15: %016lx\n",
179 regs->r13, regs->r14, regs->r15);
180
181 asm("movl %%ds,%0" : "=r" (ds));
182 asm("movl %%cs,%0" : "=r" (cs));
183 asm("movl %%es,%0" : "=r" (es));
184 asm("movl %%fs,%0" : "=r" (fsindex));
185 asm("movl %%gs,%0" : "=r" (gsindex));
186
187 rdmsrl(MSR_FS_BASE, fs);
188 rdmsrl(MSR_GS_BASE, gs);
189 rdmsrl(MSR_KERNEL_GS_BASE, shadowgs);
190
191 if (!all)
192 return;
193
194 cr0 = read_cr0();
195 cr2 = read_cr2();
196 cr3 = read_cr3();
197 cr4 = read_cr4();
198
199 printk(KERN_DEFAULT "FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
200 fs, fsindex, gs, gsindex, shadowgs);
201 printk(KERN_DEFAULT "CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds,
202 es, cr0);
203 printk(KERN_DEFAULT "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3,
204 cr4);
205
206 get_debugreg(d0, 0);
207 get_debugreg(d1, 1);
208 get_debugreg(d2, 2);
209 printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
210 get_debugreg(d3, 3);
211 get_debugreg(d6, 6);
212 get_debugreg(d7, 7);
213 printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);
214}
215
216void release_thread(struct task_struct *dead_task)
217{
218 if (dead_task->mm) {
219 if (dead_task->mm->context.size) {
220 printk("WARNING: dead process %8s still has LDT? <%p/%d>\n",
221 dead_task->comm,
222 dead_task->mm->context.ldt,
223 dead_task->mm->context.size);
224 BUG();
225 }
226 }
227}
228
229static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr)
230{
231 struct user_desc ud = {
232 .base_addr = addr,
233 .limit = 0xfffff,
234 .seg_32bit = 1,
235 .limit_in_pages = 1,
236 .useable = 1,
237 };
238 struct desc_struct *desc = t->thread.tls_array;
239 desc += tls;
240 fill_ldt(desc, &ud);
241}
242
243static inline u32 read_32bit_tls(struct task_struct *t, int tls)
244{
245 return get_desc_base(&t->thread.tls_array[tls]);
246}
247
248/*
249 * This gets called before we allocate a new thread and copy
250 * the current task into it.
251 */
252void prepare_to_copy(struct task_struct *tsk)
253{
254 unlazy_fpu(tsk);
255}
256
257int copy_thread(unsigned long clone_flags, unsigned long sp,
258 unsigned long unused,
259 struct task_struct *p, struct pt_regs *regs)
260{
261 int err;
262 struct pt_regs *childregs;
263 struct task_struct *me = current;
264
265 childregs = ((struct pt_regs *)
266 (THREAD_SIZE + task_stack_page(p))) - 1;
267 *childregs = *regs;
268
269 childregs->ax = 0;
270 if (user_mode(regs))
271 childregs->sp = sp;
272 else
273 childregs->sp = (unsigned long)childregs;
274
275 p->thread.sp = (unsigned long) childregs;
276 p->thread.sp0 = (unsigned long) (childregs+1);
277 p->thread.usersp = me->thread.usersp;
278
279 set_tsk_thread_flag(p, TIF_FORK);
280
281 p->thread.io_bitmap_ptr = NULL;
282
283 savesegment(gs, p->thread.gsindex);
284 p->thread.gs = p->thread.gsindex ? 0 : me->thread.gs;
285 savesegment(fs, p->thread.fsindex);
286 p->thread.fs = p->thread.fsindex ? 0 : me->thread.fs;
287 savesegment(es, p->thread.es);
288 savesegment(ds, p->thread.ds);
289
290 err = -ENOMEM;
291 memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
292
293 if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) {
294 p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL);
295 if (!p->thread.io_bitmap_ptr) {
296 p->thread.io_bitmap_max = 0;
297 return -ENOMEM;
298 }
299 memcpy(p->thread.io_bitmap_ptr, me->thread.io_bitmap_ptr,
300 IO_BITMAP_BYTES);
301 set_tsk_thread_flag(p, TIF_IO_BITMAP);
302 }
303
304 /*
305 * Set a new TLS for the child thread?
306 */
307 if (clone_flags & CLONE_SETTLS) {
308#ifdef CONFIG_IA32_EMULATION
309 if (test_thread_flag(TIF_IA32))
310 err = do_set_thread_area(p, -1,
311 (struct user_desc __user *)childregs->si, 0);
312 else
313#endif
314 err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8);
315 if (err)
316 goto out;
317 }
318 err = 0;
319out:
320 if (err && p->thread.io_bitmap_ptr) {
321 kfree(p->thread.io_bitmap_ptr);
322 p->thread.io_bitmap_max = 0;
323 }
324
325 return err;
326}
327
328static void
329start_thread_common(struct pt_regs *regs, unsigned long new_ip,
330 unsigned long new_sp,
331 unsigned int _cs, unsigned int _ss, unsigned int _ds)
332{
333 loadsegment(fs, 0);
334 loadsegment(es, _ds);
335 loadsegment(ds, _ds);
336 load_gs_index(0);
337 regs->ip = new_ip;
338 regs->sp = new_sp;
339 percpu_write(old_rsp, new_sp);
340 regs->cs = _cs;
341 regs->ss = _ss;
342 regs->flags = X86_EFLAGS_IF;
343 /*
344 * Free the old FP and other extended state
345 */
346 free_thread_xstate(current);
347}
348
349void
350start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
351{
352 start_thread_common(regs, new_ip, new_sp,
353 __USER_CS, __USER_DS, 0);
354}
355
356#ifdef CONFIG_IA32_EMULATION
357void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp)
358{
359 start_thread_common(regs, new_ip, new_sp,
360 __USER32_CS, __USER32_DS, __USER32_DS);
361}
362#endif
363
364/*
365 * switch_to(x,y) should switch tasks from x to y.
366 *
367 * This could still be optimized:
368 * - fold all the options into a flag word and test it with a single test.
369 * - could test fs/gs bitsliced
370 *
371 * Kprobes not supported here. Set the probe on schedule instead.
372 * Function graph tracer not supported too.
373 */
374__notrace_funcgraph struct task_struct *
375__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
376{
377 struct thread_struct *prev = &prev_p->thread;
378 struct thread_struct *next = &next_p->thread;
379 int cpu = smp_processor_id();
380 struct tss_struct *tss = &per_cpu(init_tss, cpu);
381 unsigned fsindex, gsindex;
382 bool preload_fpu;
383
384 /*
385 * If the task has used fpu the last 5 timeslices, just do a full
386 * restore of the math state immediately to avoid the trap; the
387 * chances of needing FPU soon are obviously high now
388 */
389 preload_fpu = tsk_used_math(next_p) && next_p->fpu_counter > 5;
390
391 /* we're going to use this soon, after a few expensive things */
392 if (preload_fpu)
393 prefetch(next->fpu.state);
394
395 /*
396 * Reload esp0, LDT and the page table pointer:
397 */
398 load_sp0(tss, next);
399
400 /*
401 * Switch DS and ES.
402 * This won't pick up thread selector changes, but I guess that is ok.
403 */
404 savesegment(es, prev->es);
405 if (unlikely(next->es | prev->es))
406 loadsegment(es, next->es);
407
408 savesegment(ds, prev->ds);
409 if (unlikely(next->ds | prev->ds))
410 loadsegment(ds, next->ds);
411
412
413 /* We must save %fs and %gs before load_TLS() because
414 * %fs and %gs may be cleared by load_TLS().
415 *
416 * (e.g. xen_load_tls())
417 */
418 savesegment(fs, fsindex);
419 savesegment(gs, gsindex);
420
421 load_TLS(next, cpu);
422
423 /* Must be after DS reload */
424 __unlazy_fpu(prev_p);
425
426 /* Make sure cpu is ready for new context */
427 if (preload_fpu)
428 clts();
429
430 /*
431 * Leave lazy mode, flushing any hypercalls made here.
432 * This must be done before restoring TLS segments so
433 * the GDT and LDT are properly updated, and must be
434 * done before math_state_restore, so the TS bit is up
435 * to date.
436 */
437 arch_end_context_switch(next_p);
438
439 /*
440 * Switch FS and GS.
441 *
442 * Segment register != 0 always requires a reload. Also
443 * reload when it has changed. When prev process used 64bit
444 * base always reload to avoid an information leak.
445 */
446 if (unlikely(fsindex | next->fsindex | prev->fs)) {
447 loadsegment(fs, next->fsindex);
448 /*
449 * Check if the user used a selector != 0; if yes
450 * clear 64bit base, since overloaded base is always
451 * mapped to the Null selector
452 */
453 if (fsindex)
454 prev->fs = 0;
455 }
456 /* when next process has a 64bit base use it */
457 if (next->fs)
458 wrmsrl(MSR_FS_BASE, next->fs);
459 prev->fsindex = fsindex;
460
461 if (unlikely(gsindex | next->gsindex | prev->gs)) {
462 load_gs_index(next->gsindex);
463 if (gsindex)
464 prev->gs = 0;
465 }
466 if (next->gs)
467 wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
468 prev->gsindex = gsindex;
469
470 /*
471 * Switch the PDA and FPU contexts.
472 */
473 prev->usersp = percpu_read(old_rsp);
474 percpu_write(old_rsp, next->usersp);
475 percpu_write(current_task, next_p);
476
477 percpu_write(kernel_stack,
478 (unsigned long)task_stack_page(next_p) +
479 THREAD_SIZE - KERNEL_STACK_OFFSET);
480
481 /*
482 * Now maybe reload the debug registers and handle I/O bitmaps
483 */
484 if (unlikely(task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT ||
485 task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV))
486 __switch_to_xtra(prev_p, next_p, tss);
487
488 /*
489 * Preload the FPU context, now that we've determined that the
490 * task is likely to be using it.
491 */
492 if (preload_fpu)
493 __math_state_restore();
494
495 return prev_p;
496}
497
498void set_personality_64bit(void)
499{
500 /* inherit personality from parent */
501
502 /* Make sure to be in 64bit mode */
503 clear_thread_flag(TIF_IA32);
504
505 /* Ensure the corresponding mm is not marked. */
506 if (current->mm)
507 current->mm->context.ia32_compat = 0;
508
509 /* TBD: overwrites user setup. Should have two bits.
510 But 64bit processes have always behaved this way,
511 so it's not too bad. The main problem is just that
512 32bit childs are affected again. */
513 current->personality &= ~READ_IMPLIES_EXEC;
514}
515
516void set_personality_ia32(void)
517{
518 /* inherit personality from parent */
519
520 /* Make sure to be in 32bit mode */
521 set_thread_flag(TIF_IA32);
522 current->personality |= force_personality32;
523
524 /* Mark the associated mm as containing 32-bit tasks. */
525 if (current->mm)
526 current->mm->context.ia32_compat = 1;
527
528 /* Prepare the first "return" to user space */
529 current_thread_info()->status |= TS_COMPAT;
530}
531
532unsigned long get_wchan(struct task_struct *p)
533{
534 unsigned long stack;
535 u64 fp, ip;
536 int count = 0;
537
538 if (!p || p == current || p->state == TASK_RUNNING)
539 return 0;
540 stack = (unsigned long)task_stack_page(p);
541 if (p->thread.sp < stack || p->thread.sp >= stack+THREAD_SIZE)
542 return 0;
543 fp = *(u64 *)(p->thread.sp);
544 do {
545 if (fp < (unsigned long)stack ||
546 fp >= (unsigned long)stack+THREAD_SIZE)
547 return 0;
548 ip = *(u64 *)(fp+8);
549 if (!in_sched_functions(ip))
550 return ip;
551 fp = *(u64 *)fp;
552 } while (count++ < 16);
553 return 0;
554}
555
556long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
557{
558 int ret = 0;
559 int doit = task == current;
560 int cpu;
561
562 switch (code) {
563 case ARCH_SET_GS:
564 if (addr >= TASK_SIZE_OF(task))
565 return -EPERM;
566 cpu = get_cpu();
567 /* handle small bases via the GDT because that's faster to
568 switch. */
569 if (addr <= 0xffffffff) {
570 set_32bit_tls(task, GS_TLS, addr);
571 if (doit) {
572 load_TLS(&task->thread, cpu);
573 load_gs_index(GS_TLS_SEL);
574 }
575 task->thread.gsindex = GS_TLS_SEL;
576 task->thread.gs = 0;
577 } else {
578 task->thread.gsindex = 0;
579 task->thread.gs = addr;
580 if (doit) {
581 load_gs_index(0);
582 ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr);
583 }
584 }
585 put_cpu();
586 break;
587 case ARCH_SET_FS:
588 /* Not strictly needed for fs, but do it for symmetry
589 with gs */
590 if (addr >= TASK_SIZE_OF(task))
591 return -EPERM;
592 cpu = get_cpu();
593 /* handle small bases via the GDT because that's faster to
594 switch. */
595 if (addr <= 0xffffffff) {
596 set_32bit_tls(task, FS_TLS, addr);
597 if (doit) {
598 load_TLS(&task->thread, cpu);
599 loadsegment(fs, FS_TLS_SEL);
600 }
601 task->thread.fsindex = FS_TLS_SEL;
602 task->thread.fs = 0;
603 } else {
604 task->thread.fsindex = 0;
605 task->thread.fs = addr;
606 if (doit) {
607 /* set the selector to 0 to not confuse
608 __switch_to */
609 loadsegment(fs, 0);
610 ret = checking_wrmsrl(MSR_FS_BASE, addr);
611 }
612 }
613 put_cpu();
614 break;
615 case ARCH_GET_FS: {
616 unsigned long base;
617 if (task->thread.fsindex == FS_TLS_SEL)
618 base = read_32bit_tls(task, FS_TLS);
619 else if (doit)
620 rdmsrl(MSR_FS_BASE, base);
621 else
622 base = task->thread.fs;
623 ret = put_user(base, (unsigned long __user *)addr);
624 break;
625 }
626 case ARCH_GET_GS: {
627 unsigned long base;
628 unsigned gsindex;
629 if (task->thread.gsindex == GS_TLS_SEL)
630 base = read_32bit_tls(task, GS_TLS);
631 else if (doit) {
632 savesegment(gs, gsindex);
633 if (gsindex)
634 rdmsrl(MSR_KERNEL_GS_BASE, base);
635 else
636 base = task->thread.gs;
637 } else
638 base = task->thread.gs;
639 ret = put_user(base, (unsigned long __user *)addr);
640 break;
641 }
642
643 default:
644 ret = -EINVAL;
645 break;
646 }
647
648 return ret;
649}
650
651long sys_arch_prctl(int code, unsigned long addr)
652{
653 return do_arch_prctl(current, code, addr);
654}
655
656unsigned long KSTK_ESP(struct task_struct *task)
657{
658 return (test_tsk_thread_flag(task, TIF_IA32)) ?
659 (task_pt_regs(task)->sp) : ((task)->thread.usersp);
660}
1/*
2 * Copyright (C) 1995 Linus Torvalds
3 *
4 * Pentium III FXSR, SSE support
5 * Gareth Hughes <gareth@valinux.com>, May 2000
6 *
7 * X86-64 port
8 * Andi Kleen.
9 *
10 * CPU hotplug support - ashok.raj@intel.com
11 */
12
13/*
14 * This file handles the architecture-dependent parts of process handling..
15 */
16
17#include <linux/cpu.h>
18#include <linux/errno.h>
19#include <linux/sched.h>
20#include <linux/fs.h>
21#include <linux/kernel.h>
22#include <linux/mm.h>
23#include <linux/elfcore.h>
24#include <linux/smp.h>
25#include <linux/slab.h>
26#include <linux/user.h>
27#include <linux/interrupt.h>
28#include <linux/delay.h>
29#include <linux/module.h>
30#include <linux/ptrace.h>
31#include <linux/notifier.h>
32#include <linux/kprobes.h>
33#include <linux/kdebug.h>
34#include <linux/prctl.h>
35#include <linux/uaccess.h>
36#include <linux/io.h>
37#include <linux/ftrace.h>
38
39#include <asm/pgtable.h>
40#include <asm/processor.h>
41#include <asm/i387.h>
42#include <asm/fpu-internal.h>
43#include <asm/mmu_context.h>
44#include <asm/prctl.h>
45#include <asm/desc.h>
46#include <asm/proto.h>
47#include <asm/ia32.h>
48#include <asm/idle.h>
49#include <asm/syscalls.h>
50#include <asm/debugreg.h>
51#include <asm/switch_to.h>
52
53asmlinkage extern void ret_from_fork(void);
54
55__visible DEFINE_PER_CPU(unsigned long, old_rsp);
56
57/* Prints also some state that isn't saved in the pt_regs */
58void __show_regs(struct pt_regs *regs, int all)
59{
60 unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs;
61 unsigned long d0, d1, d2, d3, d6, d7;
62 unsigned int fsindex, gsindex;
63 unsigned int ds, cs, es;
64
65 printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
66 printk_address(regs->ip);
67 printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss,
68 regs->sp, regs->flags);
69 printk(KERN_DEFAULT "RAX: %016lx RBX: %016lx RCX: %016lx\n",
70 regs->ax, regs->bx, regs->cx);
71 printk(KERN_DEFAULT "RDX: %016lx RSI: %016lx RDI: %016lx\n",
72 regs->dx, regs->si, regs->di);
73 printk(KERN_DEFAULT "RBP: %016lx R08: %016lx R09: %016lx\n",
74 regs->bp, regs->r8, regs->r9);
75 printk(KERN_DEFAULT "R10: %016lx R11: %016lx R12: %016lx\n",
76 regs->r10, regs->r11, regs->r12);
77 printk(KERN_DEFAULT "R13: %016lx R14: %016lx R15: %016lx\n",
78 regs->r13, regs->r14, regs->r15);
79
80 asm("movl %%ds,%0" : "=r" (ds));
81 asm("movl %%cs,%0" : "=r" (cs));
82 asm("movl %%es,%0" : "=r" (es));
83 asm("movl %%fs,%0" : "=r" (fsindex));
84 asm("movl %%gs,%0" : "=r" (gsindex));
85
86 rdmsrl(MSR_FS_BASE, fs);
87 rdmsrl(MSR_GS_BASE, gs);
88 rdmsrl(MSR_KERNEL_GS_BASE, shadowgs);
89
90 if (!all)
91 return;
92
93 cr0 = read_cr0();
94 cr2 = read_cr2();
95 cr3 = read_cr3();
96 cr4 = read_cr4();
97
98 printk(KERN_DEFAULT "FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
99 fs, fsindex, gs, gsindex, shadowgs);
100 printk(KERN_DEFAULT "CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds,
101 es, cr0);
102 printk(KERN_DEFAULT "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3,
103 cr4);
104
105 get_debugreg(d0, 0);
106 get_debugreg(d1, 1);
107 get_debugreg(d2, 2);
108 get_debugreg(d3, 3);
109 get_debugreg(d6, 6);
110 get_debugreg(d7, 7);
111
112 /* Only print out debug registers if they are in their non-default state. */
113 if ((d0 == 0) && (d1 == 0) && (d2 == 0) && (d3 == 0) &&
114 (d6 == DR6_RESERVED) && (d7 == 0x400))
115 return;
116
117 printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
118 printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);
119
120}
121
122void release_thread(struct task_struct *dead_task)
123{
124 if (dead_task->mm) {
125 if (dead_task->mm->context.size) {
126 pr_warn("WARNING: dead process %s still has LDT? <%p/%d>\n",
127 dead_task->comm,
128 dead_task->mm->context.ldt,
129 dead_task->mm->context.size);
130 BUG();
131 }
132 }
133}
134
135static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr)
136{
137 struct user_desc ud = {
138 .base_addr = addr,
139 .limit = 0xfffff,
140 .seg_32bit = 1,
141 .limit_in_pages = 1,
142 .useable = 1,
143 };
144 struct desc_struct *desc = t->thread.tls_array;
145 desc += tls;
146 fill_ldt(desc, &ud);
147}
148
149static inline u32 read_32bit_tls(struct task_struct *t, int tls)
150{
151 return get_desc_base(&t->thread.tls_array[tls]);
152}
153
154int copy_thread(unsigned long clone_flags, unsigned long sp,
155 unsigned long arg, struct task_struct *p)
156{
157 int err;
158 struct pt_regs *childregs;
159 struct task_struct *me = current;
160
161 p->thread.sp0 = (unsigned long)task_stack_page(p) + THREAD_SIZE;
162 childregs = task_pt_regs(p);
163 p->thread.sp = (unsigned long) childregs;
164 p->thread.usersp = me->thread.usersp;
165 set_tsk_thread_flag(p, TIF_FORK);
166 p->thread.fpu_counter = 0;
167 p->thread.io_bitmap_ptr = NULL;
168
169 savesegment(gs, p->thread.gsindex);
170 p->thread.gs = p->thread.gsindex ? 0 : me->thread.gs;
171 savesegment(fs, p->thread.fsindex);
172 p->thread.fs = p->thread.fsindex ? 0 : me->thread.fs;
173 savesegment(es, p->thread.es);
174 savesegment(ds, p->thread.ds);
175 memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
176
177 if (unlikely(p->flags & PF_KTHREAD)) {
178 /* kernel thread */
179 memset(childregs, 0, sizeof(struct pt_regs));
180 childregs->sp = (unsigned long)childregs;
181 childregs->ss = __KERNEL_DS;
182 childregs->bx = sp; /* function */
183 childregs->bp = arg;
184 childregs->orig_ax = -1;
185 childregs->cs = __KERNEL_CS | get_kernel_rpl();
186 childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_FIXED;
187 return 0;
188 }
189 *childregs = *current_pt_regs();
190
191 childregs->ax = 0;
192 if (sp)
193 childregs->sp = sp;
194
195 err = -ENOMEM;
196 memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
197
198 if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) {
199 p->thread.io_bitmap_ptr = kmemdup(me->thread.io_bitmap_ptr,
200 IO_BITMAP_BYTES, GFP_KERNEL);
201 if (!p->thread.io_bitmap_ptr) {
202 p->thread.io_bitmap_max = 0;
203 return -ENOMEM;
204 }
205 set_tsk_thread_flag(p, TIF_IO_BITMAP);
206 }
207
208 /*
209 * Set a new TLS for the child thread?
210 */
211 if (clone_flags & CLONE_SETTLS) {
212#ifdef CONFIG_IA32_EMULATION
213 if (test_thread_flag(TIF_IA32))
214 err = do_set_thread_area(p, -1,
215 (struct user_desc __user *)childregs->si, 0);
216 else
217#endif
218 err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8);
219 if (err)
220 goto out;
221 }
222 err = 0;
223out:
224 if (err && p->thread.io_bitmap_ptr) {
225 kfree(p->thread.io_bitmap_ptr);
226 p->thread.io_bitmap_max = 0;
227 }
228
229 return err;
230}
231
232static void
233start_thread_common(struct pt_regs *regs, unsigned long new_ip,
234 unsigned long new_sp,
235 unsigned int _cs, unsigned int _ss, unsigned int _ds)
236{
237 loadsegment(fs, 0);
238 loadsegment(es, _ds);
239 loadsegment(ds, _ds);
240 load_gs_index(0);
241 current->thread.usersp = new_sp;
242 regs->ip = new_ip;
243 regs->sp = new_sp;
244 this_cpu_write(old_rsp, new_sp);
245 regs->cs = _cs;
246 regs->ss = _ss;
247 regs->flags = X86_EFLAGS_IF;
248}
249
250void
251start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
252{
253 start_thread_common(regs, new_ip, new_sp,
254 __USER_CS, __USER_DS, 0);
255}
256
257#ifdef CONFIG_IA32_EMULATION
258void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp)
259{
260 start_thread_common(regs, new_ip, new_sp,
261 test_thread_flag(TIF_X32)
262 ? __USER_CS : __USER32_CS,
263 __USER_DS, __USER_DS);
264}
265#endif
266
267/*
268 * switch_to(x,y) should switch tasks from x to y.
269 *
270 * This could still be optimized:
271 * - fold all the options into a flag word and test it with a single test.
272 * - could test fs/gs bitsliced
273 *
274 * Kprobes not supported here. Set the probe on schedule instead.
275 * Function graph tracer not supported too.
276 */
277__visible __notrace_funcgraph struct task_struct *
278__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
279{
280 struct thread_struct *prev = &prev_p->thread;
281 struct thread_struct *next = &next_p->thread;
282 int cpu = smp_processor_id();
283 struct tss_struct *tss = &per_cpu(init_tss, cpu);
284 unsigned fsindex, gsindex;
285 fpu_switch_t fpu;
286
287 fpu = switch_fpu_prepare(prev_p, next_p, cpu);
288
289 /*
290 * Reload esp0, LDT and the page table pointer:
291 */
292 load_sp0(tss, next);
293
294 /*
295 * Switch DS and ES.
296 * This won't pick up thread selector changes, but I guess that is ok.
297 */
298 savesegment(es, prev->es);
299 if (unlikely(next->es | prev->es))
300 loadsegment(es, next->es);
301
302 savesegment(ds, prev->ds);
303 if (unlikely(next->ds | prev->ds))
304 loadsegment(ds, next->ds);
305
306
307 /* We must save %fs and %gs before load_TLS() because
308 * %fs and %gs may be cleared by load_TLS().
309 *
310 * (e.g. xen_load_tls())
311 */
312 savesegment(fs, fsindex);
313 savesegment(gs, gsindex);
314
315 load_TLS(next, cpu);
316
317 /*
318 * Leave lazy mode, flushing any hypercalls made here.
319 * This must be done before restoring TLS segments so
320 * the GDT and LDT are properly updated, and must be
321 * done before math_state_restore, so the TS bit is up
322 * to date.
323 */
324 arch_end_context_switch(next_p);
325
326 /*
327 * Switch FS and GS.
328 *
329 * Segment register != 0 always requires a reload. Also
330 * reload when it has changed. When prev process used 64bit
331 * base always reload to avoid an information leak.
332 */
333 if (unlikely(fsindex | next->fsindex | prev->fs)) {
334 loadsegment(fs, next->fsindex);
335 /*
336 * Check if the user used a selector != 0; if yes
337 * clear 64bit base, since overloaded base is always
338 * mapped to the Null selector
339 */
340 if (fsindex)
341 prev->fs = 0;
342 }
343 /* when next process has a 64bit base use it */
344 if (next->fs)
345 wrmsrl(MSR_FS_BASE, next->fs);
346 prev->fsindex = fsindex;
347
348 if (unlikely(gsindex | next->gsindex | prev->gs)) {
349 load_gs_index(next->gsindex);
350 if (gsindex)
351 prev->gs = 0;
352 }
353 if (next->gs)
354 wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
355 prev->gsindex = gsindex;
356
357 switch_fpu_finish(next_p, fpu);
358
359 /*
360 * Switch the PDA and FPU contexts.
361 */
362 prev->usersp = this_cpu_read(old_rsp);
363 this_cpu_write(old_rsp, next->usersp);
364 this_cpu_write(current_task, next_p);
365
366 /*
367 * If it were not for PREEMPT_ACTIVE we could guarantee that the
368 * preempt_count of all tasks was equal here and this would not be
369 * needed.
370 */
371 task_thread_info(prev_p)->saved_preempt_count = this_cpu_read(__preempt_count);
372 this_cpu_write(__preempt_count, task_thread_info(next_p)->saved_preempt_count);
373
374 this_cpu_write(kernel_stack,
375 (unsigned long)task_stack_page(next_p) +
376 THREAD_SIZE - KERNEL_STACK_OFFSET);
377
378 /*
379 * Now maybe reload the debug registers and handle I/O bitmaps
380 */
381 if (unlikely(task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT ||
382 task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV))
383 __switch_to_xtra(prev_p, next_p, tss);
384
385 return prev_p;
386}
387
388void set_personality_64bit(void)
389{
390 /* inherit personality from parent */
391
392 /* Make sure to be in 64bit mode */
393 clear_thread_flag(TIF_IA32);
394 clear_thread_flag(TIF_ADDR32);
395 clear_thread_flag(TIF_X32);
396
397 /* Ensure the corresponding mm is not marked. */
398 if (current->mm)
399 current->mm->context.ia32_compat = 0;
400
401 /* TBD: overwrites user setup. Should have two bits.
402 But 64bit processes have always behaved this way,
403 so it's not too bad. The main problem is just that
404 32bit childs are affected again. */
405 current->personality &= ~READ_IMPLIES_EXEC;
406}
407
408void set_personality_ia32(bool x32)
409{
410 /* inherit personality from parent */
411
412 /* Make sure to be in 32bit mode */
413 set_thread_flag(TIF_ADDR32);
414
415 /* Mark the associated mm as containing 32-bit tasks. */
416 if (current->mm)
417 current->mm->context.ia32_compat = 1;
418
419 if (x32) {
420 clear_thread_flag(TIF_IA32);
421 set_thread_flag(TIF_X32);
422 current->personality &= ~READ_IMPLIES_EXEC;
423 /* is_compat_task() uses the presence of the x32
424 syscall bit flag to determine compat status */
425 current_thread_info()->status &= ~TS_COMPAT;
426 } else {
427 set_thread_flag(TIF_IA32);
428 clear_thread_flag(TIF_X32);
429 current->personality |= force_personality32;
430 /* Prepare the first "return" to user space */
431 current_thread_info()->status |= TS_COMPAT;
432 }
433}
434EXPORT_SYMBOL_GPL(set_personality_ia32);
435
436unsigned long get_wchan(struct task_struct *p)
437{
438 unsigned long stack;
439 u64 fp, ip;
440 int count = 0;
441
442 if (!p || p == current || p->state == TASK_RUNNING)
443 return 0;
444 stack = (unsigned long)task_stack_page(p);
445 if (p->thread.sp < stack || p->thread.sp >= stack+THREAD_SIZE)
446 return 0;
447 fp = *(u64 *)(p->thread.sp);
448 do {
449 if (fp < (unsigned long)stack ||
450 fp >= (unsigned long)stack+THREAD_SIZE)
451 return 0;
452 ip = *(u64 *)(fp+8);
453 if (!in_sched_functions(ip))
454 return ip;
455 fp = *(u64 *)fp;
456 } while (count++ < 16);
457 return 0;
458}
459
460long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
461{
462 int ret = 0;
463 int doit = task == current;
464 int cpu;
465
466 switch (code) {
467 case ARCH_SET_GS:
468 if (addr >= TASK_SIZE_OF(task))
469 return -EPERM;
470 cpu = get_cpu();
471 /* handle small bases via the GDT because that's faster to
472 switch. */
473 if (addr <= 0xffffffff) {
474 set_32bit_tls(task, GS_TLS, addr);
475 if (doit) {
476 load_TLS(&task->thread, cpu);
477 load_gs_index(GS_TLS_SEL);
478 }
479 task->thread.gsindex = GS_TLS_SEL;
480 task->thread.gs = 0;
481 } else {
482 task->thread.gsindex = 0;
483 task->thread.gs = addr;
484 if (doit) {
485 load_gs_index(0);
486 ret = wrmsrl_safe(MSR_KERNEL_GS_BASE, addr);
487 }
488 }
489 put_cpu();
490 break;
491 case ARCH_SET_FS:
492 /* Not strictly needed for fs, but do it for symmetry
493 with gs */
494 if (addr >= TASK_SIZE_OF(task))
495 return -EPERM;
496 cpu = get_cpu();
497 /* handle small bases via the GDT because that's faster to
498 switch. */
499 if (addr <= 0xffffffff) {
500 set_32bit_tls(task, FS_TLS, addr);
501 if (doit) {
502 load_TLS(&task->thread, cpu);
503 loadsegment(fs, FS_TLS_SEL);
504 }
505 task->thread.fsindex = FS_TLS_SEL;
506 task->thread.fs = 0;
507 } else {
508 task->thread.fsindex = 0;
509 task->thread.fs = addr;
510 if (doit) {
511 /* set the selector to 0 to not confuse
512 __switch_to */
513 loadsegment(fs, 0);
514 ret = wrmsrl_safe(MSR_FS_BASE, addr);
515 }
516 }
517 put_cpu();
518 break;
519 case ARCH_GET_FS: {
520 unsigned long base;
521 if (task->thread.fsindex == FS_TLS_SEL)
522 base = read_32bit_tls(task, FS_TLS);
523 else if (doit)
524 rdmsrl(MSR_FS_BASE, base);
525 else
526 base = task->thread.fs;
527 ret = put_user(base, (unsigned long __user *)addr);
528 break;
529 }
530 case ARCH_GET_GS: {
531 unsigned long base;
532 unsigned gsindex;
533 if (task->thread.gsindex == GS_TLS_SEL)
534 base = read_32bit_tls(task, GS_TLS);
535 else if (doit) {
536 savesegment(gs, gsindex);
537 if (gsindex)
538 rdmsrl(MSR_KERNEL_GS_BASE, base);
539 else
540 base = task->thread.gs;
541 } else
542 base = task->thread.gs;
543 ret = put_user(base, (unsigned long __user *)addr);
544 break;
545 }
546
547 default:
548 ret = -EINVAL;
549 break;
550 }
551
552 return ret;
553}
554
555long sys_arch_prctl(int code, unsigned long addr)
556{
557 return do_arch_prctl(current, code, addr);
558}
559
560unsigned long KSTK_ESP(struct task_struct *task)
561{
562 return (test_tsk_thread_flag(task, TIF_IA32)) ?
563 (task_pt_regs(task)->sp) : ((task)->thread.usersp);
564}