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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> |
1da177e4 LT |
39 | |
40 | #include <asm/uaccess.h> | |
41 | #include <asm/pgtable.h> | |
42 | #include <asm/system.h> | |
43 | #include <asm/io.h> | |
44 | #include <asm/processor.h> | |
45 | #include <asm/i387.h> | |
46 | #include <asm/mmu_context.h> | |
47 | #include <asm/pda.h> | |
48 | #include <asm/prctl.h> | |
49 | #include <asm/kdebug.h> | |
50 | #include <asm/desc.h> | |
51 | #include <asm/proto.h> | |
52 | #include <asm/ia32.h> | |
53 | ||
54 | asmlinkage extern void ret_from_fork(void); | |
55 | ||
56 | unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED; | |
57 | ||
58 | static atomic_t hlt_counter = ATOMIC_INIT(0); | |
59 | ||
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 | ||
69 | void disable_hlt(void) | |
70 | { | |
71 | atomic_inc(&hlt_counter); | |
72 | } | |
73 | ||
74 | EXPORT_SYMBOL(disable_hlt); | |
75 | ||
76 | void enable_hlt(void) | |
77 | { | |
78 | atomic_dec(&hlt_counter); | |
79 | } | |
80 | ||
81 | EXPORT_SYMBOL(enable_hlt); | |
82 | ||
83 | /* | |
84 | * We use this if we don't have any better | |
85 | * idle routine.. | |
86 | */ | |
87 | void default_idle(void) | |
88 | { | |
89 | if (!atomic_read(&hlt_counter)) { | |
90 | local_irq_disable(); | |
91 | if (!need_resched()) | |
92 | safe_halt(); | |
93 | else | |
94 | local_irq_enable(); | |
95 | } | |
96 | } | |
97 | ||
98 | /* | |
99 | * On SMP it's slightly faster (but much more power-consuming!) | |
100 | * to poll the ->need_resched flag instead of waiting for the | |
101 | * cross-CPU IPI to arrive. Use this option with caution. | |
102 | */ | |
103 | static void poll_idle (void) | |
104 | { | |
105 | int oldval; | |
106 | ||
107 | local_irq_enable(); | |
108 | ||
109 | /* | |
110 | * Deal with another CPU just having chosen a thread to | |
111 | * run here: | |
112 | */ | |
113 | oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED); | |
114 | ||
115 | if (!oldval) { | |
116 | set_thread_flag(TIF_POLLING_NRFLAG); | |
117 | asm volatile( | |
118 | "2:" | |
119 | "testl %0,%1;" | |
120 | "rep; nop;" | |
121 | "je 2b;" | |
122 | : : | |
123 | "i" (_TIF_NEED_RESCHED), | |
124 | "m" (current_thread_info()->flags)); | |
b8f68e9f | 125 | clear_thread_flag(TIF_POLLING_NRFLAG); |
1da177e4 LT |
126 | } else { |
127 | set_need_resched(); | |
128 | } | |
129 | } | |
130 | ||
131 | void cpu_idle_wait(void) | |
132 | { | |
133 | unsigned int cpu, this_cpu = get_cpu(); | |
134 | cpumask_t map; | |
135 | ||
136 | set_cpus_allowed(current, cpumask_of_cpu(this_cpu)); | |
137 | put_cpu(); | |
138 | ||
139 | cpus_clear(map); | |
140 | for_each_online_cpu(cpu) { | |
141 | per_cpu(cpu_idle_state, cpu) = 1; | |
142 | cpu_set(cpu, map); | |
143 | } | |
144 | ||
145 | __get_cpu_var(cpu_idle_state) = 0; | |
146 | ||
147 | wmb(); | |
148 | do { | |
149 | ssleep(1); | |
150 | for_each_online_cpu(cpu) { | |
151 | if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu)) | |
152 | cpu_clear(cpu, map); | |
153 | } | |
154 | cpus_and(map, map, cpu_online_map); | |
155 | } while (!cpus_empty(map)); | |
156 | } | |
157 | EXPORT_SYMBOL_GPL(cpu_idle_wait); | |
158 | ||
76e4f660 AR |
159 | #ifdef CONFIG_HOTPLUG_CPU |
160 | DECLARE_PER_CPU(int, cpu_state); | |
161 | ||
162 | #include <asm/nmi.h> | |
163 | /* We don't actually take CPU down, just spin without interrupts. */ | |
164 | static inline void play_dead(void) | |
165 | { | |
166 | idle_task_exit(); | |
167 | wbinvd(); | |
168 | mb(); | |
169 | /* Ack it */ | |
170 | __get_cpu_var(cpu_state) = CPU_DEAD; | |
171 | ||
172 | while (1) | |
173 | safe_halt(); | |
174 | } | |
175 | #else | |
176 | static inline void play_dead(void) | |
177 | { | |
178 | BUG(); | |
179 | } | |
180 | #endif /* CONFIG_HOTPLUG_CPU */ | |
181 | ||
1da177e4 LT |
182 | /* |
183 | * The idle thread. There's no useful work to be | |
184 | * done, so just try to conserve power and have a | |
185 | * low exit latency (ie sit in a loop waiting for | |
186 | * somebody to say that they'd like to reschedule) | |
187 | */ | |
188 | void cpu_idle (void) | |
189 | { | |
190 | /* endless idle loop with no priority at all */ | |
191 | while (1) { | |
192 | while (!need_resched()) { | |
193 | void (*idle)(void); | |
194 | ||
195 | if (__get_cpu_var(cpu_idle_state)) | |
196 | __get_cpu_var(cpu_idle_state) = 0; | |
197 | ||
198 | rmb(); | |
199 | idle = pm_idle; | |
200 | if (!idle) | |
201 | idle = default_idle; | |
76e4f660 AR |
202 | if (cpu_is_offline(smp_processor_id())) |
203 | play_dead(); | |
1da177e4 LT |
204 | idle(); |
205 | } | |
206 | ||
207 | schedule(); | |
208 | } | |
209 | } | |
210 | ||
211 | /* | |
212 | * This uses new MONITOR/MWAIT instructions on P4 processors with PNI, | |
213 | * which can obviate IPI to trigger checking of need_resched. | |
214 | * We execute MONITOR against need_resched and enter optimized wait state | |
215 | * through MWAIT. Whenever someone changes need_resched, we would be woken | |
216 | * up from MWAIT (without an IPI). | |
217 | */ | |
218 | static void mwait_idle(void) | |
219 | { | |
220 | local_irq_enable(); | |
221 | ||
222 | if (!need_resched()) { | |
223 | set_thread_flag(TIF_POLLING_NRFLAG); | |
224 | do { | |
225 | __monitor((void *)¤t_thread_info()->flags, 0, 0); | |
226 | if (need_resched()) | |
227 | break; | |
228 | __mwait(0, 0); | |
229 | } while (!need_resched()); | |
230 | clear_thread_flag(TIF_POLLING_NRFLAG); | |
231 | } | |
232 | } | |
233 | ||
e6982c67 | 234 | void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) |
1da177e4 LT |
235 | { |
236 | static int printed; | |
237 | if (cpu_has(c, X86_FEATURE_MWAIT)) { | |
238 | /* | |
239 | * Skip, if setup has overridden idle. | |
240 | * One CPU supports mwait => All CPUs supports mwait | |
241 | */ | |
242 | if (!pm_idle) { | |
243 | if (!printed) { | |
244 | printk("using mwait in idle threads.\n"); | |
245 | printed = 1; | |
246 | } | |
247 | pm_idle = mwait_idle; | |
248 | } | |
249 | } | |
250 | } | |
251 | ||
252 | static int __init idle_setup (char *str) | |
253 | { | |
254 | if (!strncmp(str, "poll", 4)) { | |
255 | printk("using polling idle threads.\n"); | |
256 | pm_idle = poll_idle; | |
257 | } | |
258 | ||
259 | boot_option_idle_override = 1; | |
260 | return 1; | |
261 | } | |
262 | ||
263 | __setup("idle=", idle_setup); | |
264 | ||
265 | /* Prints also some state that isn't saved in the pt_regs */ | |
266 | void __show_regs(struct pt_regs * regs) | |
267 | { | |
268 | unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs; | |
269 | unsigned int fsindex,gsindex; | |
270 | unsigned int ds,cs,es; | |
271 | ||
272 | printk("\n"); | |
273 | print_modules(); | |
9acf23c4 AK |
274 | printk("Pid: %d, comm: %.20s %s %s %.*s\n", |
275 | current->pid, current->comm, print_tainted(), | |
276 | system_utsname.release, | |
277 | (int)strcspn(system_utsname.version, " "), | |
278 | system_utsname.version); | |
1da177e4 LT |
279 | printk("RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->rip); |
280 | printk_address(regs->rip); | |
281 | printk("\nRSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->rsp, regs->eflags); | |
282 | printk("RAX: %016lx RBX: %016lx RCX: %016lx\n", | |
283 | regs->rax, regs->rbx, regs->rcx); | |
284 | printk("RDX: %016lx RSI: %016lx RDI: %016lx\n", | |
285 | regs->rdx, regs->rsi, regs->rdi); | |
286 | printk("RBP: %016lx R08: %016lx R09: %016lx\n", | |
287 | regs->rbp, regs->r8, regs->r9); | |
288 | printk("R10: %016lx R11: %016lx R12: %016lx\n", | |
289 | regs->r10, regs->r11, regs->r12); | |
290 | printk("R13: %016lx R14: %016lx R15: %016lx\n", | |
291 | regs->r13, regs->r14, regs->r15); | |
292 | ||
293 | asm("movl %%ds,%0" : "=r" (ds)); | |
294 | asm("movl %%cs,%0" : "=r" (cs)); | |
295 | asm("movl %%es,%0" : "=r" (es)); | |
296 | asm("movl %%fs,%0" : "=r" (fsindex)); | |
297 | asm("movl %%gs,%0" : "=r" (gsindex)); | |
298 | ||
299 | rdmsrl(MSR_FS_BASE, fs); | |
300 | rdmsrl(MSR_GS_BASE, gs); | |
301 | rdmsrl(MSR_KERNEL_GS_BASE, shadowgs); | |
302 | ||
303 | asm("movq %%cr0, %0": "=r" (cr0)); | |
304 | asm("movq %%cr2, %0": "=r" (cr2)); | |
305 | asm("movq %%cr3, %0": "=r" (cr3)); | |
306 | asm("movq %%cr4, %0": "=r" (cr4)); | |
307 | ||
308 | printk("FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n", | |
309 | fs,fsindex,gs,gsindex,shadowgs); | |
310 | printk("CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds, es, cr0); | |
311 | printk("CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3, cr4); | |
312 | } | |
313 | ||
314 | void show_regs(struct pt_regs *regs) | |
315 | { | |
c078d326 | 316 | printk("CPU %d:", smp_processor_id()); |
1da177e4 LT |
317 | __show_regs(regs); |
318 | show_trace(®s->rsp); | |
319 | } | |
320 | ||
321 | /* | |
322 | * Free current thread data structures etc.. | |
323 | */ | |
324 | void exit_thread(void) | |
325 | { | |
326 | struct task_struct *me = current; | |
327 | struct thread_struct *t = &me->thread; | |
73649dab RL |
328 | |
329 | /* | |
330 | * Remove function-return probe instances associated with this task | |
331 | * and put them back on the free list. Do not insert an exit probe for | |
332 | * this function, it will be disabled by kprobe_flush_task if you do. | |
333 | */ | |
334 | kprobe_flush_task(me); | |
335 | ||
1da177e4 LT |
336 | if (me->thread.io_bitmap_ptr) { |
337 | struct tss_struct *tss = &per_cpu(init_tss, get_cpu()); | |
338 | ||
339 | kfree(t->io_bitmap_ptr); | |
340 | t->io_bitmap_ptr = NULL; | |
341 | /* | |
342 | * Careful, clear this in the TSS too: | |
343 | */ | |
344 | memset(tss->io_bitmap, 0xff, t->io_bitmap_max); | |
345 | t->io_bitmap_max = 0; | |
346 | put_cpu(); | |
347 | } | |
348 | } | |
349 | ||
350 | void flush_thread(void) | |
351 | { | |
352 | struct task_struct *tsk = current; | |
353 | struct thread_info *t = current_thread_info(); | |
354 | ||
73649dab RL |
355 | /* |
356 | * Remove function-return probe instances associated with this task | |
357 | * and put them back on the free list. Do not insert an exit probe for | |
358 | * this function, it will be disabled by kprobe_flush_task if you do. | |
359 | */ | |
360 | kprobe_flush_task(tsk); | |
361 | ||
1da177e4 LT |
362 | if (t->flags & _TIF_ABI_PENDING) |
363 | t->flags ^= (_TIF_ABI_PENDING | _TIF_IA32); | |
364 | ||
365 | tsk->thread.debugreg0 = 0; | |
366 | tsk->thread.debugreg1 = 0; | |
367 | tsk->thread.debugreg2 = 0; | |
368 | tsk->thread.debugreg3 = 0; | |
369 | tsk->thread.debugreg6 = 0; | |
370 | tsk->thread.debugreg7 = 0; | |
371 | memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); | |
372 | /* | |
373 | * Forget coprocessor state.. | |
374 | */ | |
375 | clear_fpu(tsk); | |
376 | clear_used_math(); | |
377 | } | |
378 | ||
379 | void release_thread(struct task_struct *dead_task) | |
380 | { | |
381 | if (dead_task->mm) { | |
382 | if (dead_task->mm->context.size) { | |
383 | printk("WARNING: dead process %8s still has LDT? <%p/%d>\n", | |
384 | dead_task->comm, | |
385 | dead_task->mm->context.ldt, | |
386 | dead_task->mm->context.size); | |
387 | BUG(); | |
388 | } | |
389 | } | |
390 | } | |
391 | ||
392 | static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr) | |
393 | { | |
394 | struct user_desc ud = { | |
395 | .base_addr = addr, | |
396 | .limit = 0xfffff, | |
397 | .seg_32bit = 1, | |
398 | .limit_in_pages = 1, | |
399 | .useable = 1, | |
400 | }; | |
401 | struct n_desc_struct *desc = (void *)t->thread.tls_array; | |
402 | desc += tls; | |
403 | desc->a = LDT_entry_a(&ud); | |
404 | desc->b = LDT_entry_b(&ud); | |
405 | } | |
406 | ||
407 | static inline u32 read_32bit_tls(struct task_struct *t, int tls) | |
408 | { | |
409 | struct desc_struct *desc = (void *)t->thread.tls_array; | |
410 | desc += tls; | |
411 | return desc->base0 | | |
412 | (((u32)desc->base1) << 16) | | |
413 | (((u32)desc->base2) << 24); | |
414 | } | |
415 | ||
416 | /* | |
417 | * This gets called before we allocate a new thread and copy | |
418 | * the current task into it. | |
419 | */ | |
420 | void prepare_to_copy(struct task_struct *tsk) | |
421 | { | |
422 | unlazy_fpu(tsk); | |
423 | } | |
424 | ||
425 | int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp, | |
426 | unsigned long unused, | |
427 | struct task_struct * p, struct pt_regs * regs) | |
428 | { | |
429 | int err; | |
430 | struct pt_regs * childregs; | |
431 | struct task_struct *me = current; | |
432 | ||
433 | childregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) p->thread_info)) - 1; | |
434 | ||
435 | *childregs = *regs; | |
436 | ||
437 | childregs->rax = 0; | |
438 | childregs->rsp = rsp; | |
439 | if (rsp == ~0UL) { | |
440 | childregs->rsp = (unsigned long)childregs; | |
441 | } | |
442 | ||
443 | p->thread.rsp = (unsigned long) childregs; | |
444 | p->thread.rsp0 = (unsigned long) (childregs+1); | |
445 | p->thread.userrsp = me->thread.userrsp; | |
446 | ||
447 | set_ti_thread_flag(p->thread_info, TIF_FORK); | |
448 | ||
449 | p->thread.fs = me->thread.fs; | |
450 | p->thread.gs = me->thread.gs; | |
451 | ||
fd51f666 L |
452 | asm("mov %%gs,%0" : "=m" (p->thread.gsindex)); |
453 | asm("mov %%fs,%0" : "=m" (p->thread.fsindex)); | |
454 | asm("mov %%es,%0" : "=m" (p->thread.es)); | |
455 | asm("mov %%ds,%0" : "=m" (p->thread.ds)); | |
1da177e4 LT |
456 | |
457 | if (unlikely(me->thread.io_bitmap_ptr != NULL)) { | |
458 | p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); | |
459 | if (!p->thread.io_bitmap_ptr) { | |
460 | p->thread.io_bitmap_max = 0; | |
461 | return -ENOMEM; | |
462 | } | |
463 | memcpy(p->thread.io_bitmap_ptr, me->thread.io_bitmap_ptr, IO_BITMAP_BYTES); | |
464 | } | |
465 | ||
466 | /* | |
467 | * Set a new TLS for the child thread? | |
468 | */ | |
469 | if (clone_flags & CLONE_SETTLS) { | |
470 | #ifdef CONFIG_IA32_EMULATION | |
471 | if (test_thread_flag(TIF_IA32)) | |
472 | err = ia32_child_tls(p, childregs); | |
473 | else | |
474 | #endif | |
475 | err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8); | |
476 | if (err) | |
477 | goto out; | |
478 | } | |
479 | err = 0; | |
480 | out: | |
481 | if (err && p->thread.io_bitmap_ptr) { | |
482 | kfree(p->thread.io_bitmap_ptr); | |
483 | p->thread.io_bitmap_max = 0; | |
484 | } | |
485 | return err; | |
486 | } | |
487 | ||
488 | /* | |
489 | * This special macro can be used to load a debugging register | |
490 | */ | |
491 | #define loaddebug(thread,r) set_debug(thread->debugreg ## r, r) | |
492 | ||
493 | /* | |
494 | * switch_to(x,y) should switch tasks from x to y. | |
495 | * | |
496 | * This could still be optimized: | |
497 | * - fold all the options into a flag word and test it with a single test. | |
498 | * - could test fs/gs bitsliced | |
499 | */ | |
500 | struct task_struct *__switch_to(struct task_struct *prev_p, struct task_struct *next_p) | |
501 | { | |
502 | struct thread_struct *prev = &prev_p->thread, | |
503 | *next = &next_p->thread; | |
504 | int cpu = smp_processor_id(); | |
505 | struct tss_struct *tss = &per_cpu(init_tss, cpu); | |
506 | ||
507 | unlazy_fpu(prev_p); | |
508 | ||
509 | /* | |
510 | * Reload esp0, LDT and the page table pointer: | |
511 | */ | |
512 | tss->rsp0 = next->rsp0; | |
513 | ||
514 | /* | |
515 | * Switch DS and ES. | |
516 | * This won't pick up thread selector changes, but I guess that is ok. | |
517 | */ | |
fd51f666 | 518 | asm volatile("mov %%es,%0" : "=m" (prev->es)); |
1da177e4 LT |
519 | if (unlikely(next->es | prev->es)) |
520 | loadsegment(es, next->es); | |
521 | ||
fd51f666 | 522 | asm volatile ("mov %%ds,%0" : "=m" (prev->ds)); |
1da177e4 LT |
523 | if (unlikely(next->ds | prev->ds)) |
524 | loadsegment(ds, next->ds); | |
525 | ||
526 | load_TLS(next, cpu); | |
527 | ||
528 | /* | |
529 | * Switch FS and GS. | |
530 | */ | |
531 | { | |
532 | unsigned fsindex; | |
533 | asm volatile("movl %%fs,%0" : "=r" (fsindex)); | |
534 | /* segment register != 0 always requires a reload. | |
535 | also reload when it has changed. | |
536 | when prev process used 64bit base always reload | |
537 | to avoid an information leak. */ | |
538 | if (unlikely(fsindex | next->fsindex | prev->fs)) { | |
539 | loadsegment(fs, next->fsindex); | |
540 | /* check if the user used a selector != 0 | |
541 | * if yes clear 64bit base, since overloaded base | |
542 | * is always mapped to the Null selector | |
543 | */ | |
544 | if (fsindex) | |
545 | prev->fs = 0; | |
546 | } | |
547 | /* when next process has a 64bit base use it */ | |
548 | if (next->fs) | |
549 | wrmsrl(MSR_FS_BASE, next->fs); | |
550 | prev->fsindex = fsindex; | |
551 | } | |
552 | { | |
553 | unsigned gsindex; | |
554 | asm volatile("movl %%gs,%0" : "=r" (gsindex)); | |
555 | if (unlikely(gsindex | next->gsindex | prev->gs)) { | |
556 | load_gs_index(next->gsindex); | |
557 | if (gsindex) | |
558 | prev->gs = 0; | |
559 | } | |
560 | if (next->gs) | |
561 | wrmsrl(MSR_KERNEL_GS_BASE, next->gs); | |
562 | prev->gsindex = gsindex; | |
563 | } | |
564 | ||
565 | /* | |
566 | * Switch the PDA context. | |
567 | */ | |
568 | prev->userrsp = read_pda(oldrsp); | |
569 | write_pda(oldrsp, next->userrsp); | |
570 | write_pda(pcurrent, next_p); | |
571 | write_pda(kernelstack, (unsigned long)next_p->thread_info + THREAD_SIZE - PDA_STACKOFFSET); | |
572 | ||
573 | /* | |
574 | * Now maybe reload the debug registers | |
575 | */ | |
576 | if (unlikely(next->debugreg7)) { | |
577 | loaddebug(next, 0); | |
578 | loaddebug(next, 1); | |
579 | loaddebug(next, 2); | |
580 | loaddebug(next, 3); | |
581 | /* no 4 and 5 */ | |
582 | loaddebug(next, 6); | |
583 | loaddebug(next, 7); | |
584 | } | |
585 | ||
586 | ||
587 | /* | |
588 | * Handle the IO bitmap | |
589 | */ | |
590 | if (unlikely(prev->io_bitmap_ptr || next->io_bitmap_ptr)) { | |
591 | if (next->io_bitmap_ptr) | |
592 | /* | |
593 | * Copy the relevant range of the IO bitmap. | |
594 | * Normally this is 128 bytes or less: | |
595 | */ | |
596 | memcpy(tss->io_bitmap, next->io_bitmap_ptr, | |
597 | max(prev->io_bitmap_max, next->io_bitmap_max)); | |
598 | else { | |
599 | /* | |
600 | * Clear any possible leftover bits: | |
601 | */ | |
602 | memset(tss->io_bitmap, 0xff, prev->io_bitmap_max); | |
603 | } | |
604 | } | |
605 | ||
606 | return prev_p; | |
607 | } | |
608 | ||
609 | /* | |
610 | * sys_execve() executes a new program. | |
611 | */ | |
612 | asmlinkage | |
613 | long sys_execve(char __user *name, char __user * __user *argv, | |
614 | char __user * __user *envp, struct pt_regs regs) | |
615 | { | |
616 | long error; | |
617 | char * filename; | |
618 | ||
619 | filename = getname(name); | |
620 | error = PTR_ERR(filename); | |
621 | if (IS_ERR(filename)) | |
622 | return error; | |
623 | error = do_execve(filename, argv, envp, ®s); | |
624 | if (error == 0) { | |
625 | task_lock(current); | |
626 | current->ptrace &= ~PT_DTRACE; | |
627 | task_unlock(current); | |
628 | } | |
629 | putname(filename); | |
630 | return error; | |
631 | } | |
632 | ||
633 | void set_personality_64bit(void) | |
634 | { | |
635 | /* inherit personality from parent */ | |
636 | ||
637 | /* Make sure to be in 64bit mode */ | |
638 | clear_thread_flag(TIF_IA32); | |
639 | ||
640 | /* TBD: overwrites user setup. Should have two bits. | |
641 | But 64bit processes have always behaved this way, | |
642 | so it's not too bad. The main problem is just that | |
643 | 32bit childs are affected again. */ | |
644 | current->personality &= ~READ_IMPLIES_EXEC; | |
645 | } | |
646 | ||
647 | asmlinkage long sys_fork(struct pt_regs *regs) | |
648 | { | |
649 | return do_fork(SIGCHLD, regs->rsp, regs, 0, NULL, NULL); | |
650 | } | |
651 | ||
652 | asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp, void __user *parent_tid, void __user *child_tid, struct pt_regs *regs) | |
653 | { | |
654 | if (!newsp) | |
655 | newsp = regs->rsp; | |
656 | return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid); | |
657 | } | |
658 | ||
659 | /* | |
660 | * This is trivial, and on the face of it looks like it | |
661 | * could equally well be done in user mode. | |
662 | * | |
663 | * Not so, for quite unobvious reasons - register pressure. | |
664 | * In user mode vfork() cannot have a stack frame, and if | |
665 | * done by calling the "clone()" system call directly, you | |
666 | * do not have enough call-clobbered registers to hold all | |
667 | * the information you need. | |
668 | */ | |
669 | asmlinkage long sys_vfork(struct pt_regs *regs) | |
670 | { | |
671 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->rsp, regs, 0, | |
672 | NULL, NULL); | |
673 | } | |
674 | ||
675 | unsigned long get_wchan(struct task_struct *p) | |
676 | { | |
677 | unsigned long stack; | |
678 | u64 fp,rip; | |
679 | int count = 0; | |
680 | ||
681 | if (!p || p == current || p->state==TASK_RUNNING) | |
682 | return 0; | |
683 | stack = (unsigned long)p->thread_info; | |
684 | if (p->thread.rsp < stack || p->thread.rsp > stack+THREAD_SIZE) | |
685 | return 0; | |
686 | fp = *(u64 *)(p->thread.rsp); | |
687 | do { | |
688 | if (fp < (unsigned long)stack || fp > (unsigned long)stack+THREAD_SIZE) | |
689 | return 0; | |
690 | rip = *(u64 *)(fp+8); | |
691 | if (!in_sched_functions(rip)) | |
692 | return rip; | |
693 | fp = *(u64 *)fp; | |
694 | } while (count++ < 16); | |
695 | return 0; | |
696 | } | |
697 | ||
698 | long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) | |
699 | { | |
700 | int ret = 0; | |
701 | int doit = task == current; | |
702 | int cpu; | |
703 | ||
704 | switch (code) { | |
705 | case ARCH_SET_GS: | |
84929801 | 706 | if (addr >= TASK_SIZE_OF(task)) |
1da177e4 LT |
707 | return -EPERM; |
708 | cpu = get_cpu(); | |
709 | /* handle small bases via the GDT because that's faster to | |
710 | switch. */ | |
711 | if (addr <= 0xffffffff) { | |
712 | set_32bit_tls(task, GS_TLS, addr); | |
713 | if (doit) { | |
714 | load_TLS(&task->thread, cpu); | |
715 | load_gs_index(GS_TLS_SEL); | |
716 | } | |
717 | task->thread.gsindex = GS_TLS_SEL; | |
718 | task->thread.gs = 0; | |
719 | } else { | |
720 | task->thread.gsindex = 0; | |
721 | task->thread.gs = addr; | |
722 | if (doit) { | |
723 | load_gs_index(0); | |
724 | ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr); | |
725 | } | |
726 | } | |
727 | put_cpu(); | |
728 | break; | |
729 | case ARCH_SET_FS: | |
730 | /* Not strictly needed for fs, but do it for symmetry | |
731 | with gs */ | |
84929801 | 732 | if (addr >= TASK_SIZE_OF(task)) |
1da177e4 LT |
733 | return -EPERM; |
734 | cpu = get_cpu(); | |
735 | /* handle small bases via the GDT because that's faster to | |
736 | switch. */ | |
737 | if (addr <= 0xffffffff) { | |
738 | set_32bit_tls(task, FS_TLS, addr); | |
739 | if (doit) { | |
740 | load_TLS(&task->thread, cpu); | |
741 | asm volatile("movl %0,%%fs" :: "r" (FS_TLS_SEL)); | |
742 | } | |
743 | task->thread.fsindex = FS_TLS_SEL; | |
744 | task->thread.fs = 0; | |
745 | } else { | |
746 | task->thread.fsindex = 0; | |
747 | task->thread.fs = addr; | |
748 | if (doit) { | |
749 | /* set the selector to 0 to not confuse | |
750 | __switch_to */ | |
751 | asm volatile("movl %0,%%fs" :: "r" (0)); | |
752 | ret = checking_wrmsrl(MSR_FS_BASE, addr); | |
753 | } | |
754 | } | |
755 | put_cpu(); | |
756 | break; | |
757 | case ARCH_GET_FS: { | |
758 | unsigned long base; | |
759 | if (task->thread.fsindex == FS_TLS_SEL) | |
760 | base = read_32bit_tls(task, FS_TLS); | |
761 | else if (doit) { | |
762 | rdmsrl(MSR_FS_BASE, base); | |
763 | } else | |
764 | base = task->thread.fs; | |
765 | ret = put_user(base, (unsigned long __user *)addr); | |
766 | break; | |
767 | } | |
768 | case ARCH_GET_GS: { | |
769 | unsigned long base; | |
770 | if (task->thread.gsindex == GS_TLS_SEL) | |
771 | base = read_32bit_tls(task, GS_TLS); | |
772 | else if (doit) { | |
773 | rdmsrl(MSR_KERNEL_GS_BASE, base); | |
774 | } else | |
775 | base = task->thread.gs; | |
776 | ret = put_user(base, (unsigned long __user *)addr); | |
777 | break; | |
778 | } | |
779 | ||
780 | default: | |
781 | ret = -EINVAL; | |
782 | break; | |
783 | } | |
784 | ||
785 | return ret; | |
786 | } | |
787 | ||
788 | long sys_arch_prctl(int code, unsigned long addr) | |
789 | { | |
790 | return do_arch_prctl(current, code, addr); | |
791 | } | |
792 | ||
793 | /* | |
794 | * Capture the user space registers if the task is not running (in user space) | |
795 | */ | |
796 | int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) | |
797 | { | |
798 | struct pt_regs *pp, ptregs; | |
799 | ||
800 | pp = (struct pt_regs *)(tsk->thread.rsp0); | |
801 | --pp; | |
802 | ||
803 | ptregs = *pp; | |
804 | ptregs.cs &= 0xffff; | |
805 | ptregs.ss &= 0xffff; | |
806 | ||
807 | elf_core_copy_regs(regs, &ptregs); | |
808 | ||
809 | return 1; | |
810 | } | |
811 | ||
812 | unsigned long arch_align_stack(unsigned long sp) | |
813 | { | |
814 | if (randomize_va_space) | |
815 | sp -= get_random_int() % 8192; | |
816 | return sp & ~0xf; | |
817 | } |