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