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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/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
55DEFINE_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 show_regs_common();
66 printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
67 printk_address(regs->ip, 1);
68 printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss,
69 regs->sp, regs->flags);
70 printk(KERN_DEFAULT "RAX: %016lx RBX: %016lx RCX: %016lx\n",
71 regs->ax, regs->bx, regs->cx);
72 printk(KERN_DEFAULT "RDX: %016lx RSI: %016lx RDI: %016lx\n",
73 regs->dx, regs->si, regs->di);
74 printk(KERN_DEFAULT "RBP: %016lx R08: %016lx R09: %016lx\n",
75 regs->bp, regs->r8, regs->r9);
76 printk(KERN_DEFAULT "R10: %016lx R11: %016lx R12: %016lx\n",
77 regs->r10, regs->r11, regs->r12);
78 printk(KERN_DEFAULT "R13: %016lx R14: %016lx R15: %016lx\n",
79 regs->r13, regs->r14, regs->r15);
80
81 asm("movl %%ds,%0" : "=r" (ds));
82 asm("movl %%cs,%0" : "=r" (cs));
83 asm("movl %%es,%0" : "=r" (es));
84 asm("movl %%fs,%0" : "=r" (fsindex));
85 asm("movl %%gs,%0" : "=r" (gsindex));
86
87 rdmsrl(MSR_FS_BASE, fs);
88 rdmsrl(MSR_GS_BASE, gs);
89 rdmsrl(MSR_KERNEL_GS_BASE, shadowgs);
90
91 if (!all)
92 return;
93
94 cr0 = read_cr0();
95 cr2 = read_cr2();
96 cr3 = read_cr3();
97 cr4 = read_cr4();
98
99 printk(KERN_DEFAULT "FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
100 fs, fsindex, gs, gsindex, shadowgs);
101 printk(KERN_DEFAULT "CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds,
102 es, cr0);
103 printk(KERN_DEFAULT "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3,
104 cr4);
105
106 get_debugreg(d0, 0);
107 get_debugreg(d1, 1);
108 get_debugreg(d2, 2);
109 printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
110 get_debugreg(d3, 3);
111 get_debugreg(d6, 6);
112 get_debugreg(d7, 7);
113 printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);
114}
115
116void release_thread(struct task_struct *dead_task)
117{
118 if (dead_task->mm) {
119 if (dead_task->mm->context.size) {
120 printk("WARNING: dead process %8s still has LDT? <%p/%d>\n",
121 dead_task->comm,
122 dead_task->mm->context.ldt,
123 dead_task->mm->context.size);
124 BUG();
125 }
126 }
127}
128
129static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr)
130{
131 struct user_desc ud = {
132 .base_addr = addr,
133 .limit = 0xfffff,
134 .seg_32bit = 1,
135 .limit_in_pages = 1,
136 .useable = 1,
137 };
138 struct desc_struct *desc = t->thread.tls_array;
139 desc += tls;
140 fill_ldt(desc, &ud);
141}
142
143static inline u32 read_32bit_tls(struct task_struct *t, int tls)
144{
145 return get_desc_base(&t->thread.tls_array[tls]);
146}
147
148int copy_thread(unsigned long clone_flags, unsigned long sp,
149 unsigned long unused,
150 struct task_struct *p, struct pt_regs *regs)
151{
152 int err;
153 struct pt_regs *childregs;
154 struct task_struct *me = current;
155
156 childregs = ((struct pt_regs *)
157 (THREAD_SIZE + task_stack_page(p))) - 1;
158 *childregs = *regs;
159
160 childregs->ax = 0;
161 if (user_mode(regs))
162 childregs->sp = sp;
163 else
164 childregs->sp = (unsigned long)childregs;
165
166 p->thread.sp = (unsigned long) childregs;
167 p->thread.sp0 = (unsigned long) (childregs+1);
168 p->thread.usersp = me->thread.usersp;
169
170 set_tsk_thread_flag(p, TIF_FORK);
171
172 p->fpu_counter = 0;
173 p->thread.io_bitmap_ptr = NULL;
174
175 savesegment(gs, p->thread.gsindex);
176 p->thread.gs = p->thread.gsindex ? 0 : me->thread.gs;
177 savesegment(fs, p->thread.fsindex);
178 p->thread.fs = p->thread.fsindex ? 0 : me->thread.fs;
179 savesegment(es, p->thread.es);
180 savesegment(ds, p->thread.ds);
181
182 err = -ENOMEM;
183 memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
184
185 if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) {
186 p->thread.io_bitmap_ptr = kmemdup(me->thread.io_bitmap_ptr,
187 IO_BITMAP_BYTES, GFP_KERNEL);
188 if (!p->thread.io_bitmap_ptr) {
189 p->thread.io_bitmap_max = 0;
190 return -ENOMEM;
191 }
192 set_tsk_thread_flag(p, TIF_IO_BITMAP);
193 }
194
195 /*
196 * Set a new TLS for the child thread?
197 */
198 if (clone_flags & CLONE_SETTLS) {
199#ifdef CONFIG_IA32_EMULATION
200 if (test_thread_flag(TIF_IA32))
201 err = do_set_thread_area(p, -1,
202 (struct user_desc __user *)childregs->si, 0);
203 else
204#endif
205 err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8);
206 if (err)
207 goto out;
208 }
209 err = 0;
210out:
211 if (err && p->thread.io_bitmap_ptr) {
212 kfree(p->thread.io_bitmap_ptr);
213 p->thread.io_bitmap_max = 0;
214 }
215
216 return err;
217}
218
219static void
220start_thread_common(struct pt_regs *regs, unsigned long new_ip,
221 unsigned long new_sp,
222 unsigned int _cs, unsigned int _ss, unsigned int _ds)
223{
224 loadsegment(fs, 0);
225 loadsegment(es, _ds);
226 loadsegment(ds, _ds);
227 load_gs_index(0);
228 current->thread.usersp = new_sp;
229 regs->ip = new_ip;
230 regs->sp = new_sp;
231 this_cpu_write(old_rsp, new_sp);
232 regs->cs = _cs;
233 regs->ss = _ss;
234 regs->flags = X86_EFLAGS_IF;
235 /*
236 * Free the old FP and other extended state
237 */
238 free_thread_xstate(current);
239}
240
241void
242start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
243{
244 start_thread_common(regs, new_ip, new_sp,
245 __USER_CS, __USER_DS, 0);
246}
247
248#ifdef CONFIG_IA32_EMULATION
249void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp)
250{
251 start_thread_common(regs, new_ip, new_sp,
252 test_thread_flag(TIF_X32)
253 ? __USER_CS : __USER32_CS,
254 __USER_DS, __USER_DS);
255}
256#endif
257
258/*
259 * switch_to(x,y) should switch tasks from x to y.
260 *
261 * This could still be optimized:
262 * - fold all the options into a flag word and test it with a single test.
263 * - could test fs/gs bitsliced
264 *
265 * Kprobes not supported here. Set the probe on schedule instead.
266 * Function graph tracer not supported too.
267 */
268__notrace_funcgraph struct task_struct *
269__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
270{
271 struct thread_struct *prev = &prev_p->thread;
272 struct thread_struct *next = &next_p->thread;
273 int cpu = smp_processor_id();
274 struct tss_struct *tss = &per_cpu(init_tss, cpu);
275 unsigned fsindex, gsindex;
276 fpu_switch_t fpu;
277
278 fpu = switch_fpu_prepare(prev_p, next_p, cpu);
279
280 /*
281 * Reload esp0, LDT and the page table pointer:
282 */
283 load_sp0(tss, next);
284
285 /*
286 * Switch DS and ES.
287 * This won't pick up thread selector changes, but I guess that is ok.
288 */
289 savesegment(es, prev->es);
290 if (unlikely(next->es | prev->es))
291 loadsegment(es, next->es);
292
293 savesegment(ds, prev->ds);
294 if (unlikely(next->ds | prev->ds))
295 loadsegment(ds, next->ds);
296
297
298 /* We must save %fs and %gs before load_TLS() because
299 * %fs and %gs may be cleared by load_TLS().
300 *
301 * (e.g. xen_load_tls())
302 */
303 savesegment(fs, fsindex);
304 savesegment(gs, gsindex);
305
306 load_TLS(next, cpu);
307
308 /*
309 * Leave lazy mode, flushing any hypercalls made here.
310 * This must be done before restoring TLS segments so
311 * the GDT and LDT are properly updated, and must be
312 * done before math_state_restore, so the TS bit is up
313 * to date.
314 */
315 arch_end_context_switch(next_p);
316
317 /*
318 * Switch FS and GS.
319 *
320 * Segment register != 0 always requires a reload. Also
321 * reload when it has changed. When prev process used 64bit
322 * base always reload to avoid an information leak.
323 */
324 if (unlikely(fsindex | next->fsindex | prev->fs)) {
325 loadsegment(fs, next->fsindex);
326 /*
327 * Check if the user used a selector != 0; if yes
328 * clear 64bit base, since overloaded base is always
329 * mapped to the Null selector
330 */
331 if (fsindex)
332 prev->fs = 0;
333 }
334 /* when next process has a 64bit base use it */
335 if (next->fs)
336 wrmsrl(MSR_FS_BASE, next->fs);
337 prev->fsindex = fsindex;
338
339 if (unlikely(gsindex | next->gsindex | prev->gs)) {
340 load_gs_index(next->gsindex);
341 if (gsindex)
342 prev->gs = 0;
343 }
344 if (next->gs)
345 wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
346 prev->gsindex = gsindex;
347
348 switch_fpu_finish(next_p, fpu);
349
350 /*
351 * Switch the PDA and FPU contexts.
352 */
353 prev->usersp = this_cpu_read(old_rsp);
354 this_cpu_write(old_rsp, next->usersp);
355 this_cpu_write(current_task, next_p);
356
357 this_cpu_write(kernel_stack,
358 (unsigned long)task_stack_page(next_p) +
359 THREAD_SIZE - KERNEL_STACK_OFFSET);
360
361 /*
362 * Now maybe reload the debug registers and handle I/O bitmaps
363 */
364 if (unlikely(task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT ||
365 task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV))
366 __switch_to_xtra(prev_p, next_p, tss);
367
368 return prev_p;
369}
370
371void set_personality_64bit(void)
372{
373 /* inherit personality from parent */
374
375 /* Make sure to be in 64bit mode */
376 clear_thread_flag(TIF_IA32);
377 clear_thread_flag(TIF_ADDR32);
378 clear_thread_flag(TIF_X32);
379
380 /* Ensure the corresponding mm is not marked. */
381 if (current->mm)
382 current->mm->context.ia32_compat = 0;
383
384 /* TBD: overwrites user setup. Should have two bits.
385 But 64bit processes have always behaved this way,
386 so it's not too bad. The main problem is just that
387 32bit childs are affected again. */
388 current->personality &= ~READ_IMPLIES_EXEC;
389}
390
391void set_personality_ia32(bool x32)
392{
393 /* inherit personality from parent */
394
395 /* Make sure to be in 32bit mode */
396 set_thread_flag(TIF_ADDR32);
397
398 /* Mark the associated mm as containing 32-bit tasks. */
399 if (current->mm)
400 current->mm->context.ia32_compat = 1;
401
402 if (x32) {
403 clear_thread_flag(TIF_IA32);
404 set_thread_flag(TIF_X32);
405 current->personality &= ~READ_IMPLIES_EXEC;
406 /* is_compat_task() uses the presence of the x32
407 syscall bit flag to determine compat status */
408 current_thread_info()->status &= ~TS_COMPAT;
409 } else {
410 set_thread_flag(TIF_IA32);
411 clear_thread_flag(TIF_X32);
412 current->personality |= force_personality32;
413 /* Prepare the first "return" to user space */
414 current_thread_info()->status |= TS_COMPAT;
415 }
416}
417EXPORT_SYMBOL_GPL(set_personality_ia32);
418
419unsigned long get_wchan(struct task_struct *p)
420{
421 unsigned long stack;
422 u64 fp, ip;
423 int count = 0;
424
425 if (!p || p == current || p->state == TASK_RUNNING)
426 return 0;
427 stack = (unsigned long)task_stack_page(p);
428 if (p->thread.sp < stack || p->thread.sp >= stack+THREAD_SIZE)
429 return 0;
430 fp = *(u64 *)(p->thread.sp);
431 do {
432 if (fp < (unsigned long)stack ||
433 fp >= (unsigned long)stack+THREAD_SIZE)
434 return 0;
435 ip = *(u64 *)(fp+8);
436 if (!in_sched_functions(ip))
437 return ip;
438 fp = *(u64 *)fp;
439 } while (count++ < 16);
440 return 0;
441}
442
443long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
444{
445 int ret = 0;
446 int doit = task == current;
447 int cpu;
448
449 switch (code) {
450 case ARCH_SET_GS:
451 if (addr >= TASK_SIZE_OF(task))
452 return -EPERM;
453 cpu = get_cpu();
454 /* handle small bases via the GDT because that's faster to
455 switch. */
456 if (addr <= 0xffffffff) {
457 set_32bit_tls(task, GS_TLS, addr);
458 if (doit) {
459 load_TLS(&task->thread, cpu);
460 load_gs_index(GS_TLS_SEL);
461 }
462 task->thread.gsindex = GS_TLS_SEL;
463 task->thread.gs = 0;
464 } else {
465 task->thread.gsindex = 0;
466 task->thread.gs = addr;
467 if (doit) {
468 load_gs_index(0);
469 ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr);
470 }
471 }
472 put_cpu();
473 break;
474 case ARCH_SET_FS:
475 /* Not strictly needed for fs, but do it for symmetry
476 with gs */
477 if (addr >= TASK_SIZE_OF(task))
478 return -EPERM;
479 cpu = get_cpu();
480 /* handle small bases via the GDT because that's faster to
481 switch. */
482 if (addr <= 0xffffffff) {
483 set_32bit_tls(task, FS_TLS, addr);
484 if (doit) {
485 load_TLS(&task->thread, cpu);
486 loadsegment(fs, FS_TLS_SEL);
487 }
488 task->thread.fsindex = FS_TLS_SEL;
489 task->thread.fs = 0;
490 } else {
491 task->thread.fsindex = 0;
492 task->thread.fs = addr;
493 if (doit) {
494 /* set the selector to 0 to not confuse
495 __switch_to */
496 loadsegment(fs, 0);
497 ret = checking_wrmsrl(MSR_FS_BASE, addr);
498 }
499 }
500 put_cpu();
501 break;
502 case ARCH_GET_FS: {
503 unsigned long base;
504 if (task->thread.fsindex == FS_TLS_SEL)
505 base = read_32bit_tls(task, FS_TLS);
506 else if (doit)
507 rdmsrl(MSR_FS_BASE, base);
508 else
509 base = task->thread.fs;
510 ret = put_user(base, (unsigned long __user *)addr);
511 break;
512 }
513 case ARCH_GET_GS: {
514 unsigned long base;
515 unsigned gsindex;
516 if (task->thread.gsindex == GS_TLS_SEL)
517 base = read_32bit_tls(task, GS_TLS);
518 else if (doit) {
519 savesegment(gs, gsindex);
520 if (gsindex)
521 rdmsrl(MSR_KERNEL_GS_BASE, base);
522 else
523 base = task->thread.gs;
524 } else
525 base = task->thread.gs;
526 ret = put_user(base, (unsigned long __user *)addr);
527 break;
528 }
529
530 default:
531 ret = -EINVAL;
532 break;
533 }
534
535 return ret;
536}
537
538long sys_arch_prctl(int code, unsigned long addr)
539{
540 return do_arch_prctl(current, code, addr);
541}
542
543unsigned long KSTK_ESP(struct task_struct *task)
544{
545 return (test_tsk_thread_flag(task, TIF_IA32)) ?
546 (task_pt_regs(task)->sp) : ((task)->thread.usersp);
547}
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}